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Joël Greffier, Dabli D, Faby S, Pastor M, Croisille C, de Oliveira F, Erath J, Beregi JP. Abdominal image quality and dose reduction with energy-integrating or photon-counting detectors dual-source CT: A phantom study. Diagn Interv Imaging 2024:S2211-5684(24)00120-7. [PMID: 38760277 DOI: 10.1016/j.diii.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 05/02/2024] [Accepted: 05/03/2024] [Indexed: 05/19/2024]
Abstract
PURPOSE The purpose of this study was to assess image-quality and dose reduction potential using a photon-counting computed tomography (PCCT) system by comparison with two different dual-source CT (DSCT) systems using two phantoms. MATERIALS AND METHODS Acquisitions on phantoms were performed using two DSCT systems (DSCT1 [Somatom Force] and DSCT2 [Somatom Pro.Pulse]) and one PCCT system (Naeotom Alpha) at four dose levels (13/6/3.4/1.8 mGy). Noise power spectrum (NPS) and task-based transfer function (TTF) were computed to assess noise magnitude and noise texture and spatial resolution (f50), respectively. Detectability indexes (d') were computed to model the detection of abdominal lesions: one unenhanced high-contrast task, one contrast-enhanced high-contrast task and one unenhanced low-contrast task. Image quality was subjectively assessed on an anthropomorphic phantom by two radiologists. RESULTS For all dose levels, noise magnitude values were lower with PCCT than with DSCTs. For all CT systems, similar noise texture values were found at 13 and 6 mGy, but the greatest noise texture values were found for DSCT2 and the lowest for PCCT at 3.4 and 1.8 mGy. For high-contrast inserts, similar or lower f50 values were found with PCCT than with DSCT1 and the opposite pattern was found for the low-contrast insert. For the three simulated lesions, d' values were greater with PCCT than with DSCTs. Abdominal images were rated satisfactory for clinical use by the radiologists for all dose levels with PCCT and for 13 and 6 mGy with DSCTs. CONCLUSION By comparison with DSCTs, PCCT reduces image-noise and improves detectability of simulated abdominal lesions without altering the spatial resolution and image texture. Image-quality obtained with PCCT seem to indicate greater potential for dose optimization than those obtained with DSCTs.
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Affiliation(s)
- Joël Greffier
- IMAGINE UR UM 103, Montpellier University, Department of Medical Imaging, Nîmes University Hospital, 30900 Nîmes, France.
| | - Djamel Dabli
- IMAGINE UR UM 103, Montpellier University, Department of Medical Imaging, Nîmes University Hospital, 30900 Nîmes, France
| | - Sebastian Faby
- Department of Computed Tomography, Siemens Healthineers AG, 91301 Forchheim, Germany
| | - Maxime Pastor
- IMAGINE UR UM 103, Montpellier University, Department of Medical Imaging, Nîmes University Hospital, 30900 Nîmes, France
| | - Cédric Croisille
- Department of Computed Tomography, Siemens Healthineers AG, 91301 Forchheim, Germany
| | - Fabien de Oliveira
- IMAGINE UR UM 103, Montpellier University, Department of Medical Imaging, Nîmes University Hospital, 30900 Nîmes, France
| | - Julien Erath
- Department of Computed Tomography, Siemens Healthineers AG, 91301 Forchheim, Germany
| | - Jean Paul Beregi
- IMAGINE UR UM 103, Montpellier University, Department of Medical Imaging, Nîmes University Hospital, 30900 Nîmes, France
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Elbehairy AF, Marshall H, Naish JH, Wild JM, Parraga G, Horsley A, Vestbo J. Advances in COPD imaging using CT and MRI: linkage with lung physiology and clinical outcomes. Eur Respir J 2024; 63:2301010. [PMID: 38548292 DOI: 10.1183/13993003.01010-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 03/16/2024] [Indexed: 05/04/2024]
Abstract
Recent years have witnessed major advances in lung imaging in patients with COPD. These include significant refinements in images obtained by computed tomography (CT) scans together with the introduction of new techniques and software that aim for obtaining the best image whilst using the lowest possible radiation dose. Magnetic resonance imaging (MRI) has also emerged as a useful radiation-free tool in assessing structural and more importantly functional derangements in patients with well-established COPD and smokers without COPD, even before the existence of overt changes in resting physiological lung function tests. Together, CT and MRI now allow objective quantification and assessment of structural changes within the airways, lung parenchyma and pulmonary vessels. Furthermore, CT and MRI can now provide objective assessments of regional lung ventilation and perfusion, and multinuclear MRI provides further insight into gas exchange; this can help in structured decisions regarding treatment plans. These advances in chest imaging techniques have brought new insights into our understanding of disease pathophysiology and characterising different disease phenotypes. The present review discusses, in detail, the advances in lung imaging in patients with COPD and how structural and functional imaging are linked with common resting physiological tests and important clinical outcomes.
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Affiliation(s)
- Amany F Elbehairy
- Department of Chest Diseases, Faculty of Medicine, Alexandria University, Alexandria, Egypt
- Division of Infection, Immunity and Respiratory Medicine, The University of Manchester and Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Helen Marshall
- POLARIS, Imaging, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Josephine H Naish
- MCMR, Manchester University NHS Foundation Trust, Manchester, UK
- Bioxydyn Limited, Manchester, UK
| | - Jim M Wild
- POLARIS, Imaging, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
- Insigneo Institute for in silico Medicine, Sheffield, UK
| | - Grace Parraga
- Robarts Research Institute, Western University, London, ON, Canada
- Department of Medical Biophysics, Western University, London, ON, Canada
- Division of Respirology, Western University, London, ON, Canada
| | - Alexander Horsley
- Division of Infection, Immunity and Respiratory Medicine, The University of Manchester and Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Jørgen Vestbo
- Division of Infection, Immunity and Respiratory Medicine, The University of Manchester and Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
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Peters AA, Solomon JB, von Stackelberg O, Samei E, Alsaihati N, Valenzuela W, Debic M, Heidt C, Huber AT, Christe A, Heverhagen JT, Kauczor HU, Heussel CP, Ebner L, Wielpütz MO. Influence of CT dose reduction on AI-driven malignancy estimation of incidental pulmonary nodules. Eur Radiol 2024; 34:3444-3452. [PMID: 37870625 PMCID: PMC11126495 DOI: 10.1007/s00330-023-10348-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/10/2023] [Accepted: 09/03/2023] [Indexed: 10/24/2023]
Abstract
OBJECTIVES The purpose of this study was to determine the influence of dose reduction on a commercially available lung cancer prediction convolutional neuronal network (LCP-CNN). METHODS CT scans from a cohort provided by the local lung cancer center (n = 218) with confirmed pulmonary malignancies and their corresponding reduced dose simulations (25% and 5% dose) were subjected to the LCP-CNN. The resulting LCP scores (scale 1-10, increasing malignancy risk) and the proportion of correctly classified nodules were compared. The cohort was divided into a low-, medium-, and high-risk group based on the respective LCP scores; shifts between the groups were studied to evaluate the potential impact on nodule management. Two different malignancy risk score thresholds were analyzed: a higher threshold of ≥ 9 ("rule-in" approach) and a lower threshold of > 4 ("rule-out" approach). RESULTS In total, 169 patients with 196 nodules could be included (mean age ± SD, 64.5 ± 9.2 year; 49% females). Mean LCP scores for original, 25% and 5% dose levels were 8.5 ± 1.7, 8.4 ± 1.7 (p > 0.05 vs. original dose) and 8.2 ± 1.9 (p < 0.05 vs. original dose), respectively. The proportion of correctly classified nodules with the "rule-in" approach decreased with simulated dose reduction from 58.2 to 56.1% (p = 0.34) and to 52.0% for the respective dose levels (p = 0.01). For the "rule-out" approach the respective values were 95.9%, 96.4%, and 94.4% (p = 0.12). When reducing the original dose to 25%/5%, eight/twenty-two nodules shifted to a lower, five/seven nodules to a higher malignancy risk group. CONCLUSION CT dose reduction may affect the analyzed LCP-CNN regarding the classification of pulmonary malignancies and potentially alter pulmonary nodule management. CLINICAL RELEVANCE STATEMENT Utilization of a "rule-out" approach with a lower malignancy risk threshold prevents underestimation of the nodule malignancy risk for the analyzed software, especially in high-risk cohorts. KEY POINTS • LCP-CNN may be affected by CT image parameters such as noise resulting from low-dose CT acquisitions. • CT dose reduction can alter pulmonary nodule management recommendations by affecting the outcome of the LCP-CNN. • Utilization of a lower malignancy risk threshold prevents underestimation of pulmonary malignancies in high-risk cohorts.
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Affiliation(s)
- Alan A Peters
- Diagnostic and Interventional Radiology, Heidelberg University Hospital, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany.
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland.
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Im Neuenheimer Feld 156, 69120, Heidelberg, Germany.
- Department of Diagnostic and Interventional Radiology With Nuclear Medicine, Thoraxklinik at University of Heidelberg, Röntgenstraße 1, 69126, Heidelberg, Germany.
| | - Justin B Solomon
- Carl E. Ravin Advanced Imaging Laboratories, Medical Physics Graduate Program, Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Oyunbileg von Stackelberg
- Diagnostic and Interventional Radiology, Heidelberg University Hospital, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Im Neuenheimer Feld 156, 69120, Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology With Nuclear Medicine, Thoraxklinik at University of Heidelberg, Röntgenstraße 1, 69126, Heidelberg, Germany
| | - Ehsan Samei
- Carl E. Ravin Advanced Imaging Laboratories, Medical Physics Graduate Program, Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Njood Alsaihati
- Carl E. Ravin Advanced Imaging Laboratories, Medical Physics Graduate Program, Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Waldo Valenzuela
- University Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland
| | - Manuel Debic
- Diagnostic and Interventional Radiology, Heidelberg University Hospital, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Im Neuenheimer Feld 156, 69120, Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology With Nuclear Medicine, Thoraxklinik at University of Heidelberg, Röntgenstraße 1, 69126, Heidelberg, Germany
| | - Christian Heidt
- Diagnostic and Interventional Radiology, Heidelberg University Hospital, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Im Neuenheimer Feld 156, 69120, Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology With Nuclear Medicine, Thoraxklinik at University of Heidelberg, Röntgenstraße 1, 69126, Heidelberg, Germany
| | - Adrian T Huber
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland
| | - Andreas Christe
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland
| | - Johannes T Heverhagen
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland
- Department of BioMedical Research, Experimental Radiology, University of Bern, Bern, Switzerland
- Department of Radiology, The Ohio State University, Columbus, OH, USA
| | - Hans-Ulrich Kauczor
- Diagnostic and Interventional Radiology, Heidelberg University Hospital, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Im Neuenheimer Feld 156, 69120, Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology With Nuclear Medicine, Thoraxklinik at University of Heidelberg, Röntgenstraße 1, 69126, Heidelberg, Germany
| | - Claus P Heussel
- Diagnostic and Interventional Radiology, Heidelberg University Hospital, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Im Neuenheimer Feld 156, 69120, Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology With Nuclear Medicine, Thoraxklinik at University of Heidelberg, Röntgenstraße 1, 69126, Heidelberg, Germany
| | - Lukas Ebner
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland
| | - Mark O Wielpütz
- Diagnostic and Interventional Radiology, Heidelberg University Hospital, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Im Neuenheimer Feld 156, 69120, Heidelberg, Germany
- Department of Diagnostic and Interventional Radiology With Nuclear Medicine, Thoraxklinik at University of Heidelberg, Röntgenstraße 1, 69126, Heidelberg, Germany
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Rau S, Rau A, Stein T, Hagar MT, Faby S, Bamberg F, Weiss J. Value of virtual non-contrast images to identify uncomplicated cystic renal lesions: photon-counting detector CT vs. dual-energy integrating detector CT. LA RADIOLOGIA MEDICA 2024; 129:669-676. [PMID: 38512614 PMCID: PMC11088563 DOI: 10.1007/s11547-024-01801-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 02/14/2024] [Indexed: 03/23/2024]
Abstract
PURPOSE To investigate the value of photon-counting detector CT (PCD-CT) derived virtual non-contrast (VNC) reconstructions to identify renal cysts in comparison with conventional dual-energy integrating detector (DE EID) CT-derived VNC reconstructions. MATERIAL AND METHODS We prospectively enrolled consecutive patients with simple renal cysts (Bosniak classification-Version 2019, density ≤ 20 HU and/or enhancement ≤ 20 HU) who underwent multiphase (non-contrast, arterial, portal venous phase) PCD-CT and for whom non-contrast and portal venous phase DE EID-CT was available. Subsequently, VNC reconstructions were calculated for all contrast phases and density as well as contrast enhancement within the cysts were measured and compared. MRI and/or ultrasound served as reference standards for lesion classification. RESULTS 19 patients (1 cyst per patient; age 69.5 ± 10.7 years; 17 [89.5%] male) were included. Density measurements on PCD-CT non-contrast and VNC reconstructions (arterial and portal venous phase) revealed no significant effect on HU values (p = 0.301). In contrast, a significant difference between non-contrast vs. VNC images was found for DE EID-CT (p = 0.02). For PCD-CT, enhancement for VNC reconstructions was < 20 HU for all evaluated cysts. DE EID-CT measurements revealed an enhancement of > 20 HU in five lesions (26.3%) using the VNC reconstructions, which was not seen with the non-contrast images. CONCLUSION PCD-CT-derived VNC images allow for reliable and accurate characterization of simple cystic renal lesions similar to non-contrast scans whereas VNC images calculated from DE EID-CT resulted in substantial false characterization. Thus, PCD-CT-derived VNC images may substitute for non-contrast images and reduce radiation dose and follow-up imaging.
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Affiliation(s)
- Stephan Rau
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany.
| | - Alexander Rau
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany
| | - Thomas Stein
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany
| | - Muhammad Taha Hagar
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany
| | - Sebastian Faby
- Siemens Healthcare GmbH, Siemensstr. 3, 91301, Forchheim, Germany
| | - Fabian Bamberg
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany
| | - Jakob Weiss
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany
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Pallasch FB, Rau A, Reisert M, Rau S, Diallo T, Stein T, Faby S, Bamberg F, Weiss J. Photon-counting detector computed tomography for metal artifact reduction: a comparative study of different artifact reduction techniques in patients with orthopedic implants. LA RADIOLOGIA MEDICA 2024:10.1007/s11547-024-01822-x. [PMID: 38689182 DOI: 10.1007/s11547-024-01822-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 04/16/2024] [Indexed: 05/02/2024]
Abstract
PURPOSE Artifacts caused by metallic implants remain a challenge in computed tomography (CT). We investigated the impact of photon-counting detector computed tomography (PCD-CT) for artifact reduction in patients with orthopedic implants with respect to image quality and diagnostic confidence using different artifact reduction approaches. MATERIAL AND METHODS In this prospective study, consecutive patients with orthopedic implants underwent PCD-CT imaging of the implant area. Four series were reconstructed for each patient (clinical standard reconstruction [PCD-CTStd], monoenergetic images at 140 keV [PCD-CT140keV], iterative metal artifact reduction (iMAR) corrected [PCD-CTiMAR], combination of iMAR and 140 keV monoenergetic [PCD-CT140keV+iMAR]). Subsequently, three radiologists evaluated the reconstructions in a random and blinded manner for image quality, artifact severity, anatomy delineation (adjacent and distant), and diagnostic confidence using a 5-point Likert scale (5 = excellent). In addition, the coefficient of variation [CV] and the relative quantitative artifact reduction potential were obtained as objective measures. RESULTS We enrolled 39 patients with a mean age of 67.3 ± 13.2 years (51%; n = 20 male) and a mean BMI of 26.1 ± 4 kg/m2. All image quality measures and diagnostic confidence were significantly higher for the iMAR vs. non-iMAR reconstructions (all p < 0.001). No significant effect of the different artifact reduction approaches on CV was observed (p = 0.26). The quantitative analysis indicated the most effective artifact reduction for the iMAR reconstructions, which was higher than PCD-CT140keV (p < 0.001). CONCLUSION PCD-CT allows for effective metal artifact reduction in patients with orthopedic implants, resulting in superior image quality and diagnostic confidence with the potential to improve patient management and clinical decision making.
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Affiliation(s)
- Fabian Bernhard Pallasch
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany.
| | - Alexander Rau
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Marco Reisert
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Stephan Rau
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Thierno Diallo
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Thomas Stein
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Sebastian Faby
- Siemens Healthcare GmbH, Siemensstr. 3, 91301, Forchheim, Germany
| | - Fabian Bamberg
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Jakob Weiss
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
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Rajagopal JR, Schwartz FR, McCabe C, Farhadi F, Zarei M, Ria F, Abadi E, Segars P, Ramirez-Giraldo JC, Jones EC, Henry T, Marin D, Samei E. Technology Characterization Through Diverse Evaluation Methodologies: Application to Thoracic Imaging in Photon-Counting Computed Tomography. J Comput Assist Tomogr 2024:00004728-990000000-00312. [PMID: 38626754 DOI: 10.1097/rct.0000000000001608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2024]
Abstract
OBJECTIVE Different methods can be used to condition imaging systems for clinical use. The purpose of this study was to assess how these methods complement one another in evaluating a system for clinical integration of an emerging technology, photon-counting computed tomography (PCCT), for thoracic imaging. METHODS Four methods were used to assess a clinical PCCT system (NAEOTOM Alpha; Siemens Healthineers, Forchheim, Germany) across 3 reconstruction kernels (Br40f, Br48f, and Br56f). First, a phantom evaluation was performed using a computed tomography quality control phantom to characterize noise magnitude, spatial resolution, and detectability. Second, clinical images acquired using conventional and PCCT systems were used for a multi-institutional reader study where readers from 2 institutions were asked to rank their preference of images. Third, the clinical images were assessed in terms of in vivo image quality characterization of global noise index and detectability. Fourth, a virtual imaging trial was conducted using a validated simulation platform (DukeSim) that models PCCT and a virtual patient model (XCAT) with embedded lung lesions imaged under differing conditions of respiratory phase and positional displacement. Using known ground truth of the patient model, images were evaluated for quantitative biomarkers of lung intensity histograms and lesion morphology metrics. RESULTS For the physical phantom study, the Br56f kernel was shown to have the highest resolution despite having the highest noise and lowest detectability. Readers across both institutions preferred the Br56f kernel (71% first rank) with a high interclass correlation (0.990). In vivo assessments found superior detectability for PCCT compared with conventional computed tomography but higher noise and reduced detectability with increased kernel sharpness. For the virtual imaging trial, Br40f was shown to have the best performance for histogram measures, whereas Br56f was shown to have the most precise and accurate morphology metrics. CONCLUSION The 4 evaluation methods each have their strengths and limitations and bring complementary insight to the evaluation of PCCT. Although no method offers a complete answer, concordant findings between methods offer affirmatory confidence in a decision, whereas discordant ones offer insight for added perspective. Aggregating our findings, we concluded the Br56f kernel best for high-resolution tasks and Br40f for contrast-dependent tasks.
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Affiliation(s)
| | - Fides R Schwartz
- Duke University Health System, Department of Radiology, Duke University Medical Center, Durham, NC
| | - Cindy McCabe
- From the Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC
| | | | - Mojtaba Zarei
- From the Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC
| | - Francesco Ria
- From the Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC
| | - Ehsan Abadi
- From the Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC
| | - Paul Segars
- From the Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC
| | | | - Elizabeth C Jones
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD
| | - Travis Henry
- Duke University Health System, Department of Radiology, Duke University Medical Center, Durham, NC
| | - Daniele Marin
- Duke University Health System, Department of Radiology, Duke University Medical Center, Durham, NC
| | - Ehsan Samei
- From the Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC
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Berthe D, Kolb A, Rabi A, Sellerer T, Somerkivi V, Feuerriegel GC, Sauter AP, Meurer F, Hämisch Y, Pantsar T, Lohman H, Pfeiffer D, Pfeiffer F. Evaluation of Spectral X-Ray Imaging for Panoramic Dental Images Based on a Simulation Framework. JOURNAL OF IMAGING INFORMATICS IN MEDICINE 2024; 37:892-898. [PMID: 38343244 PMCID: PMC11031517 DOI: 10.1007/s10278-023-00940-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/25/2023] [Accepted: 10/05/2023] [Indexed: 04/20/2024]
Abstract
Modern photon counting detectors allow the calculation of virtual monoenergetic or material decomposed X-ray images but are not yet used for dental panoramic radiography systems. To assess the diagnostic potential and image quality of photon counting detectors in dental panoramic radiography, ethics approval from the local ethics committee was obtained for this retrospective study. Conventional CT scans of the head and neck region were segmented into bone and soft tissue. The resulting datasets were used to calculate panoramic equivalent thickness bone and soft tissue images by forward projection, using a geometry like that of conventional panoramic radiographic systems. The panoramic equivalent thickness images were utilized to generate synthetic conventional panoramic radiographs and panoramic virtual monoenergetic radiographs at various energies. The conventional, two virtual monoenergetic images at 40 keV and 60 keV, and material-separated bone and soft tissue panoramic equivalent thickness X-ray images simulated from 17 head CTs were evaluated in a reader study involving three experienced radiologists regarding their diagnostic value and image quality. Compared to conventional panoramic radiographs, the material-separated bone panoramic equivalent thickness image exhibits a higher image quality and diagnostic value in assessing the bone structure p < . 001 and details such as teeth or root canals p < . 001 . Panoramic virtual monoenergetic radiographs do not show a significant advantage over conventional panoramic radiographs. The conducted reader study shows the potential of spectral X-ray imaging for dental panoramic imaging to improve the diagnostic value and image quality.
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Affiliation(s)
- Daniel Berthe
- Department of Physics, School of Natural Sciences, Technical University of Munich, 85748, Garching, Germany.
- Munich Institute of Biomedical Engineering, Technical University of Munich, Boltzmannstr. 11, 85748, Garching, Germany.
| | - Anna Kolb
- Department of Physics, School of Natural Sciences, Technical University of Munich, 85748, Garching, Germany
- Munich Institute of Biomedical Engineering, Technical University of Munich, Boltzmannstr. 11, 85748, Garching, Germany
| | - Abdulrahman Rabi
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675, Munich, Germany
| | - Thorsten Sellerer
- Department of Physics, School of Natural Sciences, Technical University of Munich, 85748, Garching, Germany
- Munich Institute of Biomedical Engineering, Technical University of Munich, Boltzmannstr. 11, 85748, Garching, Germany
| | - Villseveri Somerkivi
- Department of Physics, School of Natural Sciences, Technical University of Munich, 85748, Garching, Germany
- Munich Institute of Biomedical Engineering, Technical University of Munich, Boltzmannstr. 11, 85748, Garching, Germany
- Planmeca Oy, 00880, Helsinki, Finland
| | - Georg Constantin Feuerriegel
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675, Munich, Germany
| | - Andreas Philipp Sauter
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675, Munich, Germany
| | - Felix Meurer
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675, Munich, Germany
| | | | | | | | - Daniela Pfeiffer
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675, Munich, Germany
| | - Franz Pfeiffer
- Department of Physics, School of Natural Sciences, Technical University of Munich, 85748, Garching, Germany
- Munich Institute of Biomedical Engineering, Technical University of Munich, Boltzmannstr. 11, 85748, Garching, Germany
- Department of Diagnostic and Interventional Radiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675, Munich, Germany
- Institute for Advanced Study, Technical University of Munich, 85748, Garching, Germany
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Kämmerling N, Tesselaar E, Booij R, Fornander L, Persson A, Farnebo S. A comparative study of image quality and diagnostic confidence in diagnosis and follow-up of scaphoid fractures using photon-counting detector CT and energy-integrating detector CT. Eur J Radiol 2024; 173:111383. [PMID: 38377892 DOI: 10.1016/j.ejrad.2024.111383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/08/2024] [Accepted: 02/16/2024] [Indexed: 02/22/2024]
Abstract
PURPOSE Scaphoid fractures in patients and assessment of healing using PCD-CT have, as far as we know, not yet been studied. Therefore, the aim was to compare photon counting detector CT (PCD-CT) with energy integrating detector CT (EID-CT) in terms of fracture visibility and evaluation of fracture healing. METHOD Eight patients with scaphoid fracture were examined with EID-CT and PCD-CT within the first week post-trauma, and with additional scans at 4, 6 and 8 weeks. Our clinical protocol for wrist examination with EID-CT was used (CTDIvol 3.1 ± 0.1 mGy, UHR kernel Ur77). For PCD-CT matched radiation dose, reconstruction kernel Br89. Quantitative analyses of noise, CNR, trabecular and cortical sharpness, and bone volume fraction were conducted. Five radiologists evaluated the images for fracture visibility, fracture gap consolidation and image quality, and rated their confidence in the diagnosis. RESULTS The trabecular and cortical sharpness were superior in images obtained with PCD-CT compared with EID-CT. A successive reduction in trabecular bone volume fraction during the immobilized periods was found with both systems. Despite higher noise and lower CNR with PCD-CT, radiologists rated the image quality of PCD-CT as superior. The visibility of the fracture line within 1-week post-trauma was rated higher with PCD-CT as was diagnostic confidence, but the subsequent assessments of fracture gap consolidation during healing process and the confidence in diagnosis were found equivalent between both systems. CONCLUSION PCD-CT offers superior visibility of bone microstructure compared with EID-CT. The evaluation of fracture healing and confidence in diagnosis were rated equally with both systems, but the radiologists found primary fracture visibility and overall image quality superior with PCD-CT.
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Affiliation(s)
- Nina Kämmerling
- Department of Radiology, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
| | - Erik Tesselaar
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Department of Medical Radiation Physics, Linköping University, Linköping, Sweden
| | - Ronald Booij
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Department of Radiology & Nuclear Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Lotta Fornander
- Department of Orthopedic Surgery, Norrköping, and Department of Biomedical and Clinical Sciences, Linköping University, Norrköping, Sweden
| | - Anders Persson
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Simon Farnebo
- Department of Hand and Plastic Surgery, Linköping University, Linköping, Sweden
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9
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Dane B, Ruff A, O'Donnell T, El-Ali A, Ginocchio L, Prabhu V, Megibow A. Photon-Counting Computed Tomography Versus Energy-Integrating Dual-Energy Computed Tomography: Virtual Noncontrast Image Quality Comparison. J Comput Assist Tomogr 2024; 48:251-256. [PMID: 38013203 DOI: 10.1097/rct.0000000000001562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
PURPOSE This study aimed to compare the image quality of portal venous phase-derived virtual noncontrast (VNC) images from photon-counting computed tomography (PCCT) with energy-integrating dual-energy computed tomography (EI-DECT) in the same patient using quantitative and qualitative analyses. METHODS Consecutive patients retrospectively identified with available portal venous phase-derived VNC images from both PCCT and EI-DECT were included. Patients without available VNC in picture archiving and communication system in PCCT or prior EI-DECT and non-portal venous phase acquisitions were excluded. Three fellowship-trained radiologists blinded to VNC source qualitatively assessed VNC images on a 5-point scale for overall image quality, image noise, small structure delineation, noise texture, artifacts, and degree of iodine removal. Quantitative assessment used region-of-interest measurements within the aorta at 4 standard locations, both psoas muscles, both renal cortices, spleen, retroperitoneal fat, and inferior vena cava. Attenuation (Hounsfield unit), quantitative noise (Hounsfield unit SD), contrast-to-noise ratio (CNR) (CNR vascular , CNR kidney , CNR spleen , CNR fat ), signal-to-noise ratio (SNR) (SNR vascular , SNR kidney , SNR spleen , SNR fat ), and radiation dose were compared between PCCT and EI-DECT with the Wilcoxon signed rank test. A P < 0.05 indicated statistical significance. RESULTS A total of 74 patients (27 men; mean ± SD age, 63 ± 13 years) were included. Computed tomography dose index volumes for PCCT and EI-DECT were 9.2 ± 3.5 mGy and 9.4 ± 9.0 mGy, respectively ( P = 0.06). Qualitatively, PCCT VNC images had better overall image quality, image noise, small structure delineation, noise texture, and fewer artifacts (all P < 0.00001). Virtual noncontrast images from PCCT had lower attenuation (all P < 0.05), noise ( P = 0.006), and higher CNR ( P < 0.0001-0.04). Contrast-enhanced structures had lower SNR on PCCT ( P = 0.001, 0.002), reflecting greater contrast removal. The SNRfat (nonenhancing) was higher for PCCT than EI-DECT ( P < 0.00001). CONCLUSIONS Virtual noncontrast images from PCCT had improved image quality, lower noise, improved CNR and SNR compared with those derived from EI-DECT.
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Affiliation(s)
- Bari Dane
- From the Department of Radiology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY
| | - Andrew Ruff
- From the Department of Radiology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY
| | | | - Alexander El-Ali
- From the Department of Radiology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY
| | - Luke Ginocchio
- From the Department of Radiology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY
| | - Vinay Prabhu
- From the Department of Radiology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY
| | - Alec Megibow
- From the Department of Radiology, NYU Langone Health, NYU Grossman School of Medicine, New York, NY
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10
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McCollough CH, Winfree TN, Melka EF, Rajendran K, Carter RE, Leng S. Photon-Counting Detector Computed Tomography Versus Energy-Integrating Detector Computed Tomography for Coronary Artery Calcium Quantitation. J Comput Assist Tomogr 2024; 48:212-216. [PMID: 37801651 PMCID: PMC10939985 DOI: 10.1097/rct.0000000000001554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/08/2023]
Abstract
OBJECTIVES Photon-counting detector (PCD) computed tomography (CT) offers improved spatial and contrast resolution, which can impact quantitative measurements. This work aims to determine in human subjects the effect of dual-source PCD-CT on the quantitation of coronary artery calcification (CAC) compared with dual-source energy-integrating detector (EID) CT in both 1- and 3-mm images. METHODS This prospective study enrolled patients receiving a clinical EID-CT CAC examination to undergo a research PCD-CT CAC examination. Axial images were reconstructed with a 512 × 512 matrix, 200-mm field of view, 3-mm section thickness/1.5-mm interval using a quantitative kernel (Qr36). Sharper kernels (Qr56/QIR strength 4 for PCD and Qr49/ADMIRE strength 5 for EID) were used to reconstruct images with 1-mm section thickness/0.5-mm interval. Pooled analysis was performed for all calcifications with nonzero values, and volume and Agatston scores were compared between EID-CT and PCD-CT. A Wilcoxon signed-rank test was performed with P < 0.05 considered statistically significant. RESULTS In 21 subjects (median age, 58 years; range, 50-75 years; 13 male [62%]) with a total of 42 calcified arteries detected at 3 mm and 46 calcified arteries at 1-mm images, EID-CT CAC volume and Agatston scores were significantly lower than those of PCD-CT ( P ≤ 0.001). At 3-mm thickness, the mean (standard deviation) volume and Agatston score for EID-CT were 55.5 (63.4) mm 3 and 63.8 (76.9), respectively, and 61.5 (69.4) mm 3 and 70.4 (85.3) for PCD-CT ( P = 0.0001 and P = 0.0013). At 1-mm thickness, the mean (standard deviation) volume and score for EID-CT were 50.0 (56.3) mm 3 and 61.1 (69.3), respectively, and 59.5 (63.9) mm 3 and 72.5 (79.9) for PCD-CT ( P < 0.0001 for both). The applied radiation dose (volume CT dose index) for the PCD-CT scan was 2.1 ± 0.6 mGy, which was 13% lower than for the EID-CT scan (2.4 ± 0.7 mGy, P < 0.001). CONCLUSIONS Relative to EID-CT, PCD-CT demonstrated a small but significant increase in coronary artery calcium volume and Agatston score.
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Affiliation(s)
| | - Tim N Winfree
- From the Department of Radiology, Mayo Clinic, Rochester, MN
| | - Elnata F Melka
- From the Department of Radiology, Mayo Clinic, Rochester, MN
| | | | - Rickey E Carter
- Department of Health Science Research, Mayo Clinic, Jacksonville, FL
| | - Shuai Leng
- From the Department of Radiology, Mayo Clinic, Rochester, MN
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11
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Fletcher JG, Inoue A, Bratt A, Horst KK, Koo CW, Rajiah PS, Baffour FI, Ko JP, Remy-Jardin M, McCollough CH, Yu L. Photon-counting CT in Thoracic Imaging: Early Clinical Evidence and Incorporation Into Clinical Practice. Radiology 2024; 310:e231986. [PMID: 38501953 DOI: 10.1148/radiol.231986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
Photon-counting CT (PCCT) is an emerging advanced CT technology that differs from conventional CT in its ability to directly convert incident x-ray photon energies into electrical signals. The detector design also permits substantial improvements in spatial resolution and radiation dose efficiency and allows for concurrent high-pitch and high-temporal-resolution multienergy imaging. This review summarizes (a) key differences in PCCT image acquisition and image reconstruction compared with conventional CT; (b) early evidence for the clinical benefit of PCCT for high-spatial-resolution diagnostic tasks in thoracic imaging, such as assessment of airway and parenchymal diseases, as well as benefits of high-pitch and multienergy scanning; (c) anticipated radiation dose reduction, depending on the diagnostic task, and increased utility for routine low-dose thoracic CT imaging; (d) adaptations for thoracic imaging in children; (e) potential for further quantitation of thoracic diseases; and (f) limitations and trade-offs. Moreover, important points for conducting and interpreting clinical studies examining the benefit of PCCT relative to conventional CT and integration of PCCT systems into multivendor, multispecialty radiology practices are discussed.
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Affiliation(s)
- Joel G Fletcher
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Akitoshi Inoue
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Alex Bratt
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Kelly K Horst
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Chi Wan Koo
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Prabhakar Shantha Rajiah
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Francis I Baffour
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Jane P Ko
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Martine Remy-Jardin
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Cynthia H McCollough
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
| | - Lifeng Yu
- From the Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN, 55905 (J.G.F., A.I., A.B., K.K.H., C.W.K., P.S.R., F.I.B., C.H.M., L.Y.); Department of Radiology, Shiga University of Medical Science, Shiga, Japan (A.I.); Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York, NY (J.P.K.); and IMALLIANCE-Haut-de-France, Valenciennes, France (M.R.J.)
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12
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Sharma S, Pal D, Abadi E, Segars P, Hsieh J, Samei E. Deep silicon photon-counting CT: A first simulation-based study for assessing perceptual benefits across diverse anatomies. Eur J Radiol 2024; 171:111279. [PMID: 38194843 PMCID: PMC10922475 DOI: 10.1016/j.ejrad.2023.111279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/26/2023] [Accepted: 12/20/2023] [Indexed: 01/11/2024]
Abstract
OBJECTIVES To assess perceptual benefits provided by the improved spatial resolution and noise performance of deep silicon photon-counting CT (Si-PCCT) over conventional energy-integrating CT (ECT) using polychromatic images for various clinical tasks and anatomical regions. MATERIALS AND METHODS Anthropomorphic, computational models were developed for lungs, liver, inner ear, and head-and-neck (H&N) anatomies. These regions included specific abnormalities such as lesions in the lungs and liver, and calcified plaques in the carotid arteries. The anatomical models were imaged using a scanner-specific CT simulation platform (DukeSim) modeling a Si-PCCT prototype and a conventional ECT system at matched dose levels. The simulated polychromatic projections were reconstructed with matched in-plane resolutions using manufacturer-specific software. The reconstructed pairs of images were scored by radiologists to gauge the task-specific perceptual benefits provided by Si-PCCT compared to ECT based on visualization of anatomical and image quality features. The scores were standardized as z-scores for minimizing inter-observer variability and compared between the systems for evidence of statistically significant improvement (one-sided Wilcoxon rank-sum test with a significance level of 0.05) in perceptual performance for Si-PCCT. RESULTS Si-PCCT offered favorable image quality and improved visualization capabilities, leading to mean improvements in task-specific perceptual performance over ECT for most tasks. The improvements for Si-PCCT were statistically significant for the visualization of lung lesion (0.08 ± 0.89 vs. 0.90 ± 0.48), liver lesion (-0.64 ± 0.37 vs. 0.95 ± 0.55), and soft tissue structures (-0.47 ± 0.90 vs. 0.33 ± 1.24) and cochlea (-0.47 ± 0.80 vs. 0.38 ± 0.62) in inner ear. CONCLUSIONS Si-PCCT exhibited mean improvements in task-specific perceptual performance over ECT for most clinical tasks considered in this study, with statistically significant improvement for 6/20 tasks. The perceptual performance of Si-PCCT is expected to improve further with availability of spectral information and reconstruction kernels optimized for high resolution provided by smaller pixel size of Si-PCCT. The outcomes of this study indicate the positive potential of Si-PCCT for benefiting routine clinical practice through improved image quality and visualization capabilities.
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Affiliation(s)
- Shobhit Sharma
- Center for Virtual Imaging Trials and Carl E. Ravin Advanced Imaging Laboratories, 2424 Erwin Rd, Suite 302, Durham, NC 27705, USA; Department of Physics, Duke University, Science Drive, Durham, NC 27708, USA
| | - Debashish Pal
- GE Healthcare, 3000 N Grandview Blvd, Waukesha, WI 53188, USA
| | - Ehsan Abadi
- Center for Virtual Imaging Trials and Carl E. Ravin Advanced Imaging Laboratories, 2424 Erwin Rd, Suite 302, Durham, NC 27705, USA; Department of Radiology, Duke University, 2301 Erwin Rd, Durham, NC 27705, USA.
| | - Paul Segars
- Center for Virtual Imaging Trials and Carl E. Ravin Advanced Imaging Laboratories, 2424 Erwin Rd, Suite 302, Durham, NC 27705, USA; Department of Radiology, Duke University, 2301 Erwin Rd, Durham, NC 27705, USA
| | - Jiang Hsieh
- GE Healthcare, 3000 N Grandview Blvd, Waukesha, WI 53188, USA
| | - Ehsan Samei
- Center for Virtual Imaging Trials and Carl E. Ravin Advanced Imaging Laboratories, 2424 Erwin Rd, Suite 302, Durham, NC 27705, USA; Department of Physics, Duke University, Science Drive, Durham, NC 27708, USA; Department of Radiology, Duke University, 2301 Erwin Rd, Durham, NC 27705, USA
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13
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Bhattarai M, Bache S, Abadi E, Samei E. A systematic task-based image quality assessment of photon-counting and energy integrating CT as a function of reconstruction kernel and phantom size. Med Phys 2024; 51:1047-1060. [PMID: 37469179 PMCID: PMC10796834 DOI: 10.1002/mp.16619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 04/25/2023] [Accepted: 06/28/2023] [Indexed: 07/21/2023] Open
Abstract
BACKGROUND Image quality of photon-counting and energy integrating CT scanners changes with object size, dose to the object, and kernel selection. PURPOSE To comprehensively compare task-generic image quality of photon-counting CT (PCCT) and energy integrating CT (EICT) systems as a function of phantom size, dose, and reconstruction kernel. METHODS A size-variant phantom (Mercury Phantom 3.0) was used to characterize the image quality of PCCT and EICT systems as a function of object size. The phantom contained five cylinders attached by slanted tapered sections. Each cylinder contained two sections: one uniform for noise, and the other with inserts for spatial resolution and contrast measurements. The phantom was scanned on Siemens' SOMATOM Force and NAEOTOM Alpha at 1.18 and 7.51 mGy without tube current modulation. CTDIvol was matched across two systems by setting the required tube currents, else, all other acquisition settings were fixed. CT sinograms were reconstructed using FBP and iterative (ADMIRE2 - Force; QIR2 - Alpha) algorithms with Body regular (Br) kernels. Noise Power Spectrum (NPS), Task Transfer Function (TTF), contrast-to-noise ratio (CNR), and detectability index (d') for a task of identifying 2-mm disk were evaluated based on AAPM TG-233 metrology using imQuest, an open-source software package. Averaged noise frequency (fav ) and 50% cut-off frequency for TTF (f50 ) were used as scalar metrics to quantify noise texture and spatial resolution, respectively. The difference between image quality metrics' measurements was calculated as IQPCCT - IQEICT . RESULTS From Br40 (soft) to Br64 (sharp), f50 for air insert increased from 0.35 mm-1 ± 0.04 (standard deviation) to 0.76 mm-1 ± 0.17, 0.34 mm-1 ± 0.04 to 0.77 mm-1 ± 0.17, 0.37 mm-1 ± 0.02 to 0.95 mm-1 ± 0.17 for PCCT-T3D-QIR2, PCCT-70keV-QIR2, and EICT-ADMIRE2, respectively, when averaged over all sizes and dose levels. Similarly, from Br40 to Br64, noise magnitude increased from 10.86 HU ± 7.12 to 38.61 HU ± 18.84, 10.94 HU ± 7.08 to 38.82 HU ± 18.70, 13.74 HU ± 11.02 to 52.11 HU ± 26.22 for PCCT-T3D-QIR2, PCCT-70keV-QIR2, and EICT-ADMIRE2, respectively. The difference in fav was consistent across all sizes and dose levels. PCCT-70keV-VMI showed better consistency in contrast measurements for iodine and bone inserts than PCCT-T3D and EICT; however, PCCT-T3D had higher contrast for both inserts. From Br40 to Br64, considering all sizes and dose levels, CNR for iodine insert decreased from 52.30 ± 46.44 to 12.18 ± 10.07, 40.42 ± 33.42 to 9.48 ± 7.16, 39.94 ± 37.60 to 7.84 ± 6.67 for PCCT-T3D-QIR2, PCCT-70keV-QIR2, and EICT-ADMIRE2, respectively. CONCLUSIONS Both PCCT image types, T3D and 70-keV-VMI exhibited similar or better noise, contrast, CNR than EICT when comparing kernels with similar names. For 512 × 512 matrix, PCCT's sharp kernels had lower resolution than EICT's sharp kernels. For all image quality metrics, except extreme low, every dose condition had a similar set of IQ-matching kernels. It suggests that considering patient size and dose level to determine IQ-matching kernel pairs across PCCT and EICT systems may not be imperative while translating protocols, except when the signal to the detector is extremely low.
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Affiliation(s)
- Mridul Bhattarai
- Medical Physics Graduate Program, Duke University, Durham, North Carolina, 27705, USA
- Center for Virtual Imaging Trials (CVIT), Duke University, Durham, North Carolina, 27705, USA
- Department of Radiology – School of Medicine, Duke University, Durham, North Carolina, 27705, USA
| | - Steve Bache
- Clinical Imaging Physics Group – Duke University Health System, Durham, North Carolina, 27705, USA
| | - Ehsan Abadi
- Medical Physics Graduate Program, Duke University, Durham, North Carolina, 27705, USA
- Center for Virtual Imaging Trials (CVIT), Duke University, Durham, North Carolina, 27705, USA
- Department of Radiology – School of Medicine, Duke University, Durham, North Carolina, 27705, USA
| | - Ehsan Samei
- Medical Physics Graduate Program, Duke University, Durham, North Carolina, 27705, USA
- Center for Virtual Imaging Trials (CVIT), Duke University, Durham, North Carolina, 27705, USA
- Department of Radiology – School of Medicine, Duke University, Durham, North Carolina, 27705, USA
- Clinical Imaging Physics Group – Duke University Health System, Durham, North Carolina, 27705, USA
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Dettmer S, Werncke T, Mitkovska VN, Brod T, Joean O, Vogel-Claussen J, Wacker F, Welte T, Rademacher J. Photon Counting Computed Tomography with the Radiation Dose of a Chest X-Ray: Feasibility and Diagnostic Yield. Respiration 2024; 103:88-94. [PMID: 38272004 PMCID: PMC10871675 DOI: 10.1159/000536065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 12/23/2023] [Indexed: 01/27/2024] Open
Abstract
INTRODUCTION Photon counting (PC) detectors allow a reduction of the radiation dose in CT. Chest X-ray (CXR) is known to have a low sensitivity and specificity for detection of pneumonic infiltrates. The aims were to establish an ultra-low-dose CT (ULD-CT) protocol at a PC-CT with the radiation dose comparable to the dose of a CXR and to evaluate its clinical yield in patients with suspicion of pneumonia. METHODS A ULD-CT protocol was established with the aim to meet the radiation dose of a CXR. In this retrospective study, all adult patients who received a ULD-CT of the chest with suspected pneumonia were included. Radiation exposure of ULD-CT and CXR was calculated. The clinical significance (new diagnosis, change of therapy, additional findings) and limitations were evaluated by a radiologist and a pulmonologist considering previous CXR and clinical data. RESULTS Twenty-seven patients (70% male, mean age 68 years) were included. With our ULD-CT protocol, the radiation dose of a CXR could be reached (mean radiation exposure 0.11 mSv). With ULD-CT, the diagnosis changed in 11 patients (41%), there were relevant additional findings in 4 patients (15%), an infiltrate (particularly fungal infiltrate under immunosuppression) could be ruled out with certainty in 10 patients (37%), and the therapy changed in 10 patients (37%). Two patients required an additional CT with contrast medium to rule out a pulmonary embolism or pleural empyema. CONCLUSIONS With ULD-CT, the radiation dose of a CXR could be reached while the clinical impact is higher with change in diagnosis in 41%.
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Affiliation(s)
- Sabine Dettmer
- Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
| | - Thomas Werncke
- Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | | | - Torben Brod
- Emergency Department, Hannover Medical School, Hannover, Germany
| | - Oana Joean
- Department of Respiratory Medicine and Infectious Diseases, Hannover Medical School, Hannover, Germany
| | - Jens Vogel-Claussen
- Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
| | - Frank Wacker
- Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
| | - Tobias Welte
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
- Department of Respiratory Medicine and Infectious Diseases, Hannover Medical School, Hannover, Germany
| | - Jessica Rademacher
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
- Department of Respiratory Medicine and Infectious Diseases, Hannover Medical School, Hannover, Germany
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Skrodzki D, Molinaro M, Brown R, Moitra P, Pan D. Synthesis and Bioapplication of Emerging Nanomaterials of Hafnium. ACS NANO 2024; 18:1289-1324. [PMID: 38166377 DOI: 10.1021/acsnano.3c08917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
A significant amount of progress in nanotechnology has been made due to the development of engineered nanoparticles. The use of metallic nanoparticles for various biomedical applications has been extensively investigated. Biomedical research is highly focused on them because of their inert nature, nanoscale structure, and similar size to many biological molecules. The intrinsic characteristics of these particles, including electronic, optical, physicochemical, and surface plasmon resonance, that can be altered by altering their size, shape, environment, aspect ratio, ease of synthesis, and functionalization properties, have led to numerous biomedical applications. Targeted drug delivery, sensing, photothermal and photodynamic therapy, and imaging are some of these. The promising clinical results of NBTXR3, a high-Z radiosensitizing nanomaterial derived from hafnium, have demonstrated translational potential of this metal. This radiosensitization approach leverages the dependence of energy attenuation on atomic number to enhance energy-matter interactions conducive to radiation therapy. High-Z nanoparticle localization in tumor issue differentially increases the effect of ionizing radiation on cancer cells versus nearby healthy ones and mitigates adverse effects by reducing the overall radiation burden. This principle enables material multifunctionality as contrast agents in X-ray-based imaging. The physiochemical properties of hafnium (Z = 72) are particularly advantageous for these applications. A well-placed K-edge absorption energy and high mass attenuation coefficient compared to elements in human tissue across clinical energy ranges leads to significant attenuation. Chemical reactivity allows for variety in nanoparticle synthesis, composition, and functionalization. Nanoparticles such as hafnium oxide exhibit excellent biocompatibility due to physiochemical inertness prior to incidence with ionizing radiation. Additionally, the optical and electronic properties are applicable in biosensing, optical component coatings, and semiconductors. The wide interest has prompted extensive research in design and synthesis to facilitate property fine-tuning. This review summarizes synthetic methods for hafnium-based nanomaterials and applications in therapy, imaging, and biosensing with a mechanistic focus. A discussion and future perspective section highlights clinical progress and elaborates on current challenges. By focusing on factors impacting applicational effectiveness and examining limitations this review aims to support researchers and expedite clinical translation of future hafnium-based nanomedicine.
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Affiliation(s)
- David Skrodzki
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Matthew Molinaro
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Richard Brown
- Department of Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Parikshit Moitra
- Department of Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Dipanjan Pan
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Huck Institutes of the Life Sciences, 101 Huck Life Sciences Building, University Park, Pennsylvania 16802, United States
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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Lahoud E, Zaffrani Y, Yagil Y. Photon counting x-ray detectors as scatter probes. Med Phys 2024; 51:93-102. [PMID: 38043090 DOI: 10.1002/mp.16871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/16/2023] [Accepted: 11/17/2023] [Indexed: 12/05/2023] Open
Abstract
BACKGROUND Direct conversion x-ray Photon Counting Detectors (PCD) are posed to play a vital role in future medical imaging devices such as Computed Tomography (CT) scanners. PCD are expected to improve current CT technology on several fronts, such as resolution, dose utilization, and spectral performance. However, they are not readily expected to improve the handling of object scatter, one of the major sources of image artifacts in CT technology. PURPOSE We explore a potential method for obtaining in-situ object scatter estimation using the same PCD array used in the x-ray imaging system, such as in computed tomography. This unexpected benefit of using PCD has the potential to improve the image quality by providing better input into the scatter estimation and correction algorithms used in image reconstruction. METHODS In CT scanners the primary method for rejecting scatter signal originating from the scanned object relies on placing anti-scatter grids (ASG) close to the detector plane. This remains the case when transitioning to using PCD instead of energy integration detectors in CT. However, the combination of PCD and ASG opens a possibility to use some of the unique properties of PCD, namely, very low noise and coincidence counters to obtain, in addition to the attenuation data, a simultaneous and instantaneous estimate of the scatter signal reaching every detector element. When a small air gap is introduced between the ASG and the detector surface, the scatter radiation with large angular distribution has a greater probability of producing charge sharing events that can be detected by a coincidence counter. In this work we demonstrate the feasibility of such an approach in a tabletop experiment using PCD detector that lacks coincidence counting capability, instead we use the spectral signature of split charge events as proxy to coincidence counting. For this purpose, we first demonstrate the spectral impact of ASG misalignment using the same experimental setup. In addition, we perform a separate tabletop scattering experiment from a narrow column of water that demonstrates another potential use of the low noise capabilities of PCDs. RESULTS We measured and quantified the high sensitivity of the spectral response to ASG alignment on the PCD detector pixel array, we found that the probability of energy misregistration of 60 keV photons can increase by up to a factor of 3 when the ASG is poorly aligned. We then leveraged these results to obtain an estimate on the expected increase in coincidence counts for a wide range of scatter-to-primary (SPR) ratio and find a good match with expectations from a geometric modeling of the system, where the expected increase in coincidences was of the order of the SPR. Finally, the low noise detector also allowed us to measure the real space scatter signal associated with the coherent molecular form factor of water, revealing the ring-shaped scatter signal with an energy dependent distribution that was well captured by calculation. CONCLUSIONS The advent of PCD detectors and their imminent use in commercial CT scanners opens new and exciting possibilities for utilizing PCD detectors in unexpected ways. In this proof-of-concept study, we showed how charge sharing, a spectral information degrading effect, can instead be used to obtain in-situ scatter estimation. We also demonstrated the PCD ability to perform extremely sensitive measurements using affordable benchtop setup for investigations normally reserved for synchrotron facilities.
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Marcus RP, Nagy DA, Feuerriegel GC, Anhaus J, Nanz D, Sutter R. Photon-Counting Detector CT With Denoising for Imaging of the Osseous Pelvis at Low Radiation Doses: A Phantom Study. AJR Am J Roentgenol 2024; 222:e2329765. [PMID: 37646387 DOI: 10.2214/ajr.23.29765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
BACKGROUND. Photon-counting detector (PCD) CT may allow lower radiation doses than used for conventional energy-integrating detector (EID) CT, with preserved image quality. OBJECTIVE. The purpose of this study was to compare PCD CT and EID CT, reconstructed with and without a denoising tool, in terms of image quality of the osseous pelvis in a phantom, with attention to low radiation doses. METHODS. A pelvic phantom comprising human bones in acrylic material mimicking soft tissue underwent PCD CT and EID CT at various tube potentials and radiation doses ranging from 0.05 to 5.00 mGy. Additional denoised reconstructions were generated using a commercial tool. Noise was measured in the acrylic material. Two readers performed independent qualitative assessments that entailed determining the denoised EID CT reconstruction with the lowest acceptable dose and then comparing this reference reconstruction with PCD CT reconstructions without and with denoising, using subjective Likert scales. RESULTS. Noise was lower for PCD CT than for EID CT. For instance, at 0.05 mGy and 100 kV with tin filter, noise was 38.4 HU for PCD CT versus 48.8 HU for EID CT. Denoising further reduced noise; for example, for PCD CT at 100 kV with tin filter at 0.25 mGy, noise was 19.9 HU without denoising versus 9.7 HU with denoising. For both readers, lowest acceptable dose for EID CT was 0.10 mGy (total score, 11 of 15 for both readers). Both readers somewhat agreed that PCD CT without denoising at 0.10 mGy (reflecting reference reconstruction dose) was relatively better than the reference reconstruction in terms of osseous structures, artifacts, and image quality. Both readers also somewhat agreed that denoised PCD CT reconstructions at 0.10 mGy and 0.05 mGy (reflecting matched and lower doses, respectively, with respect to reference reconstruction dose) were relatively better than the reference reconstruction for the image quality measures. CONCLUSION. PCD CT showed better-quality images than EID CT when performed at the lowest acceptable radiation dose for EID CT. PCD CT with denoising yielded better-quality images at a dose lower than lowest acceptable dose for EID CT. CLINICAL IMPACT. PCD CT with denoising could facilitate lower radiation doses for pelvic imaging.
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Affiliation(s)
- Roy P Marcus
- Department of Radiology, Balgrist University Hospital Zurich, Forchstrasse 340, Zurich 8008, Switzerland
- Faculty of Medicine, University of Zurich, Zurich, Switzerland
| | - Daniel A Nagy
- Department of Radiology, Balgrist University Hospital Zurich, Forchstrasse 340, Zurich 8008, Switzerland
- Faculty of Medicine, University of Zurich, Zurich, Switzerland
| | - Georg C Feuerriegel
- Department of Radiology, Balgrist University Hospital Zurich, Forchstrasse 340, Zurich 8008, Switzerland
- Faculty of Medicine, University of Zurich, Zurich, Switzerland
| | | | - Daniel Nanz
- Faculty of Medicine, University of Zurich, Zurich, Switzerland
- Swiss Center for Musculoskeletal Imaging, Balgrist Campus, Zurich, Switzerland
| | - Reto Sutter
- Department of Radiology, Balgrist University Hospital Zurich, Forchstrasse 340, Zurich 8008, Switzerland
- Faculty of Medicine, University of Zurich, Zurich, Switzerland
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Horst KK, Yu L, McCollough CH, Esquivel A, Thorne JE, Rajiah PS, Baffour F, Hull NC, Weber NM, Thacker PG, Thomas KB, Binkovitz LA, Guerin JB, Fletcher JG. Potential benefits of photon counting detector computed tomography in pediatric imaging. Br J Radiol 2023; 96:20230189. [PMID: 37750939 PMCID: PMC10646626 DOI: 10.1259/bjr.20230189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 08/29/2023] [Accepted: 08/30/2023] [Indexed: 09/27/2023] Open
Abstract
Photon counting detector (PCD) CT represents the newest advance in CT technology, with improved radiation dose efficiency, increased spatial resolution, inherent spectral imaging capabilities, and the ability to eliminate electronic noise. Its design fundamentally differs from conventional energy integrating detector CT because photons are directly converted to electrical signal in a single step. Rather than converting X-rays to visible light and having an output signal that is a summation of energies, PCD directly counts each photon and records its individual energy information. The current commercially available PCD-CT utilizes a dual-source CT geometry, which allows 66 ms cardiac temporal resolution and high-pitch (up to 3.2) scanning. This can greatly benefit pediatric patients by facilitating high quality fast scanning to allow sedation-free imaging. The energy-resolving nature of the utilized PCDs allows "always-on" dual-energy imaging capabilities, such as the creation of virtual monoenergetic, virtual non-contrast, virtual non-calcium, and other material-specific images. These features may be combined with high-resolution imaging, made possible by the decreased size of individual detector elements and the absence of interelement septa. This work reviews the foundational concepts associated with PCD-CT and presents examples to highlight the benefits of PCD-CT in the pediatric population.
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Affiliation(s)
- Kelly K. Horst
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | - Lifeng Yu
- Department of Radiology, Mayo Clinic, Rochester, United States
| | | | - Andrea Esquivel
- Department of Radiology, Mayo Clinic, Rochester, United States
| | | | | | - Francis Baffour
- Department of Radiology, Mayo Clinic, Rochester, United States
| | - Nathan C. Hull
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | | | - Paul G. Thacker
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | - Kristen B. Thomas
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | - Larry A. Binkovitz
- Pediatric Radiology Division, Department of Radiology, Mayo Clinic, Rochester, United States
| | - Julie B. Guerin
- Department of Radiology, Mayo Clinic, Rochester, United States
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Pu X, Wang X, Ran L, Xie T, Li Z, Yang Z, Lin R, Zeng J. Comparison of predictive performance for cage subsidence between CT-based Hounsfield units and MRI-based vertebral bone quality score following oblique lumbar interbody fusion. Eur Radiol 2023; 33:8637-8644. [PMID: 37462819 DOI: 10.1007/s00330-023-09929-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 03/15/2023] [Accepted: 03/25/2023] [Indexed: 11/26/2023]
Abstract
OBJECTIVE To compare the predictive performance between CT-based Hounsfield units (HU) and MRI-based vertebral bone quality (VBQ) for cage subsidence (CS) following oblique lumbar interbody fusion combined with anterolateral single-rod screw fixation (OLIF-AF). METHODS A retrospective study was performed on consecutive patients who underwent OLIF-AF at our institution from 2018 to 2020. CS was determined by CT according to the change in the midpoint intervertebral space height. The VBQ score and HU value were measured from preoperative MRI and CT, respectively. Then, we evaluated the predictive performance of those two parameters by comparing the receiver operating characteristic (ROC) curves. RESULTS The mean global and segmental VBQ scores were significantly higher in the CS group, and the mean global and segmental HU values were significantly lower in the CS group. The area under the curve (AUC) of CS prediction was higher in the operative segments' VBQ score and HU value than the measurement in the global lumbar spine. Finally, the combined segmental VBQ score and segmental HU value demonstrated the highest AUC. CONCLUSION Both MRI-based VBQ score and CT-based HU value can achieve accurate CS prediction. Moreover, the combination of those two measurements indicated the best predictive performance. CLINICAL RELEVANCE STATEMENT Both MRI-based VBQ score and CT-based HU value can be used for cage subsidence prediction, in order to take preventive measures early enough. KEY POINTS • Osteoporosis is a risk factor for CS, both MRI-based VBQ score and CT-based HU value are important predictors during vertebral bone quality evaluation. • The VBQ score and HU value measured in the operative segments are better predictors of CS than the measurement in the global lumbar spine. • Combined segmental VBQ score and segmental HU value achieved the best predictive performance for CS.
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Affiliation(s)
- Xingxiao Pu
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue Road, Chengdu, 610041, People's Republic of China
- Department of Orthopedic Spine Surgery, Yan'an Hospital Affiliated to Kunming Medical University, Kunming, Yunnan, 650051, People's Republic of China
| | - Xiandi Wang
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue Road, Chengdu, 610041, People's Republic of China
| | - Liyu Ran
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue Road, Chengdu, 610041, People's Republic of China
| | - Tianhang Xie
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue Road, Chengdu, 610041, People's Republic of China
| | - Zhuhai Li
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue Road, Chengdu, 610041, People's Republic of China
- Department of Spine Surgery, The People's Hospital of Guangxi Zhuang Autonomous Region, No. 6 TaoYuan Rd, Nanning, 530021, Guangxi, China
| | - Zhiqiang Yang
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue Road, Chengdu, 610041, People's Republic of China
| | - Run Lin
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue Road, Chengdu, 610041, People's Republic of China
| | - Jiancheng Zeng
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue Road, Chengdu, 610041, People's Republic of China.
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Hamabuchi N, Ohno Y, Kimata H, Ito Y, Fujii K, Akino N, Takenaka D, Yoshikawa T, Oshima Y, Matsuyama T, Nagata H, Ueda T, Ikeda H, Ozawa Y, Toyama H. Effectiveness of deep learning reconstruction on standard to ultra-low-dose high-definition chest CT images. Jpn J Radiol 2023; 41:1373-1388. [PMID: 37498483 PMCID: PMC10687108 DOI: 10.1007/s11604-023-01470-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 07/09/2023] [Indexed: 07/28/2023]
Abstract
PURPOSE Deep learning reconstruction (DLR) has been introduced by major vendors, tested for CT examinations of a variety of organs, and compared with other reconstruction methods. The purpose of this study was to compare the capabilities of DLR for image quality improvement and lung texture evaluation with those of hybrid-type iterative reconstruction (IR) for standard-, reduced- and ultra-low-dose CTs (SDCT, RDCT and ULDCT) obtained with high-definition CT (HDCT) and reconstructed at 0.25-mm, 0.5-mm and 1-mm section thicknesses with 512 × 512 or 1024 × 1024 matrixes for patients with various pulmonary diseases. MATERIALS AND METHODS Forty age-, gender- and body mass index-matched patients with various pulmonary diseases underwent SDCT (CT dose index volume : mean ± standard deviation, 9.0 ± 1.8 mGy), RDCT (CTDIvol: 1.7 ± 0.2 mGy) and ULDCT (CTDIvol: 0.8 ± 0.1 mGy) at a HDCT. All CT data set were then reconstructed with 512 × 512 or 1024 × 1024 matrixes by means of hybrid-type IR and DLR. SNR of lung parenchyma and probabilities of all lung textures were assessed for each CT data set. SNR and detection performance of each lung texture reconstructed with DLR and hybrid-type IR were then compared by means of paired t tests and ROC analyses for all CT data at each section thickness. RESULTS Data for each radiation dose showed DLR attained significantly higher SNR than hybrid-type IR for each of the CT data (p < 0.0001). On assessments of all findings except consolidation and nodules or masses, areas under the curve (AUCs) for ULDCT with hybrid-type IR for each section thickness (0.91 ≤ AUC ≤ 0.97) were significantly smaller than those with DLR (0.97 ≤ AUC ≤ 1, p < 0.05) and the standard protocol (0.98 ≤ AUC ≤ 1, p < 0.05). CONCLUSION DLR is potentially more effective for image quality improvement and lung texture evaluation than hybrid-type IR on all radiation dose CTs obtained at HDCT and reconstructed with each section thickness with both matrixes for patients with a variety of pulmonary diseases.
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Affiliation(s)
- Nayu Hamabuchi
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Yoshiharu Ohno
- Department of Diagnostic Radiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
| | - Hirona Kimata
- Canon Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Yuya Ito
- Canon Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Kenji Fujii
- Canon Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Naruomi Akino
- Canon Medical Systems Corporation, Otawara, Tochigi, Japan
| | - Daisuke Takenaka
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
- Department of Diagnostic Radiology, Hyogo Cancer Center, Akashi, Hyogo, Japan
| | - Takeshi Yoshikawa
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
- Department of Diagnostic Radiology, Hyogo Cancer Center, Akashi, Hyogo, Japan
| | - Yuka Oshima
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Takahiro Matsuyama
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Hiroyuki Nagata
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Takahiro Ueda
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Hirotaka Ikeda
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Yoshiyuki Ozawa
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Hiroshi Toyama
- Department of Radiology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
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Donuru A, Araki T, Dako F, Dave JK, Perez RP, Xu D, Nachiappan A, Barbosa EM, Noel P, Litt H, Knollman F. Photon-counting detector CT allows significant reduction in radiation dose while maintaining image quality and noise on non-contrast chest CT. Eur J Radiol Open 2023; 11:100538. [PMID: 38028186 PMCID: PMC10665661 DOI: 10.1016/j.ejro.2023.100538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 10/25/2023] [Accepted: 11/03/2023] [Indexed: 12/01/2023] Open
Abstract
Purpose To investigate if clinical non-contrast chest CT studies obtained with PCD CT using much lower radiation exposure can achieve the same image quality as with the currently established EID protocol. Materials/methods A total of seventy-one patients were identified who had a non-contrast chest computed tomography (CT) done on PCD CT and EID CT scanners within a 4-month interval. Five fellowship trained chest radiologists, blinded to the scanner details were asked to review the cases side-by-side and record their preference for images from either the photon-counting-detector (PCD) CT or the energy-integrating detector (EID) CT scanner. Results The median CTDIvol for PCD-CT system was 4.710 mGy and EID system was 7.80 mGy (p < 0.001). The median DLP with the PCD-CT was 182.0 mGy.cm and EID system was 262.60 mGy.cm (p < 0.001). The contrast to noise ratio (CNR) was superior on the PCD-CT system 59.2 compared to the EID-CT 53.3; (p < 0.001). Kappa-statistic showed that there was poor agreement between the readers over the image quality from the PCD and EID scanners (κ = 0.19; 95 % CI: 0.12 - 0.27; p < 0.001). Chi-square analysis revealed that 3 out of 5 readers showed a significant preference for images from the PCDCT (p ≤ 0.012). There was no significant difference in the preferences of two readers between EID-CT and PCD-CT images. Conclusion The first clinical PCD-CT system allows a significant reduction in radiation exposure while maintaining image quality and image noise using a standardized non-contrast chest CT protocol.
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Affiliation(s)
- Achala Donuru
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tetsuro Araki
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Farouk Dako
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jaydev K. Dave
- Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA
| | - Raul Porto Perez
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Dongming Xu
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Arun Nachiappan
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eduardo Mortani Barbosa
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Peter Noel
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Harold Litt
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Friedrich Knollman
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
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Pallasch FB, Rau A, Reisert M, Rau S, Diallo T, Stein T, Faby S, Bamberg F, Weiss J. Impact of different metal artifact reduction techniques in photon-counting computed tomography head and neck scans in patients with dental hardware. Eur Radiol 2023:10.1007/s00330-023-10430-8. [PMID: 37968474 DOI: 10.1007/s00330-023-10430-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 09/18/2023] [Accepted: 10/02/2023] [Indexed: 11/17/2023]
Abstract
OBJECTIVES Metal artifacts remain a challenge in computed tomography. We investigated the potential of photon-counting computed tomography (PCD-CT) for metal artifact reduction using an iterative metal artifact reduction (iMAR) algorithm alone and in combination with high keV monoenergetic images (140 keV) in patients with dental hardware. MATERIAL AND METHODS Consecutive patients with dental implants were prospectively included in this study and received PCD-CT imaging of the craniofacial area. Four series were reconstructed (standard [PCD-CTstd], monoenergetic at 140 keV [PCD-CT140keV], iMAR corrected [PCD-CTiMAR], combination of iMAR and 140 keV monoenergetic [PCD-CTiMAR+140keV]). All reconstructions were assessed qualitatively by four radiologists (independent and blinded reading on a 5-point Likert scale [5 = excellent; no artifact]) regarding overall image quality, artifact severity, and delineation of adjacent and distant anatomy. To assess signal homogeneity and evaluate the magnitude of artifact reduction, we performed quantitative measures of coefficient of variation (CV) and a region of interest (ROI)-based relative change in artifact reduction [PCD-CT/PCD-CTstd]. RESULTS We enrolled 48 patients (mean age 66.5 ± 11.2 years, 50% (n = 24) males; mean BMI 25.2 ± 4.7 kg/m2; mean CTDIvol 6.2 ± 6 mGy). We found improved overall image quality, reduced artifacts and superior delineation of both adjacent and distant anatomy for the iMAR vs. non-iMAR reconstructions (all p < 0.001). No significant effect of the different artifact reduction approaches on CV was observed (p = 0.42). The ROI-based analysis indicated the most effective artifact reduction for the iMAR reconstructions, which was significantly higher compared to PCD-CT140keV (p < 0.001). CONCLUSION PCD-CT offers highly effective approaches for metal artifact reduction with the potential to overcome current diagnostic challenges in patients with dental implants. CLINICAL RELEVANCE STATEMENT Metallic artifacts pose a significant challenge in CT imaging, potentially leading to missed findings. Our study shows that PCD-CT with iMAR post-processing reduces artifacts, improves image quality, and can possibly reveal pathologies previously obscured by artifacts, without additional dose application. KEY POINTS • Photon-counting detector CT (PCD-CT) offers highly effective approaches for metal artifact reduction in patients with dental fillings/implants. • Iterative metal artifact reduction (iMAR) is superior to high keV monoenergetic reconstructions at 140 keV for artifact reduction and provides higher image quality. • Signal homogeneity of the reconstructed images is not affected by the different artifact reduction techniques.
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Affiliation(s)
- Fabian Bernhard Pallasch
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany.
| | - Alexander Rau
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Marco Reisert
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Stephan Rau
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Thierno Diallo
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Thomas Stein
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Sebastian Faby
- Siemens Healthcare GmbH, Siemensstr. 3, 91301, Forchheim, Germany
| | - Fabian Bamberg
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
| | - Jakob Weiss
- Department of Radiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg im Breisgau, Germany
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23
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Srinivas-Rao S, Cao J, Marin D, Kambadakone A. Dual-Energy Computed Tomography to Photon Counting Computed Tomography: Emerging Technological Innovations. Radiol Clin North Am 2023; 61:933-944. [PMID: 37758361 DOI: 10.1016/j.rcl.2023.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Computed tomography (CT) has seen remarkable developments in the past several decades, radically transforming the role of imaging in day-to-day clinical practice. Dual-energy CT (DECT), an exciting innovation introduced in the early part of this century, has widened the scope of CT, opening new opportunities due to its ability to provide superior tissue characterization. The introduction of photon-counting CT (PCCT) heralds a paradigm shift in CT scanner technology representing another significant milestone in CT innovation. PCCT offers several advantages over DECT, such as improved spectral resolution, enhanced tissue characterization, reduced image artifacts, and improved image quality.
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Affiliation(s)
- Shravya Srinivas-Rao
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, White 270, Boston, MA 02114-2696, USA
| | - Jinjin Cao
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, White 270, Boston, MA 02114-2696, USA
| | - Daniele Marin
- Department of Radiology, Duke University Medical Center, Box 3808 Erwin Road, Durham, NC 27710, USA
| | - Avinash Kambadakone
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, White 270, Boston, MA 02114-2696, USA.
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24
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Patzer TS, Kunz AS, Huflage H, Gruschwitz P, Pannenbecker P, Afat S, Herrmann J, Petritsch B, Bley TA, Grunz JP. Combining virtual monoenergetic imaging and iterative metal artifact reduction in first-generation photon-counting computed tomography of patients with dental implants. Eur Radiol 2023; 33:7818-7829. [PMID: 37284870 PMCID: PMC10598126 DOI: 10.1007/s00330-023-09790-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/04/2023] [Accepted: 04/27/2023] [Indexed: 06/08/2023]
Abstract
OBJECTIVES While established for energy-integrating detector computed tomography (CT), the effect of virtual monoenergetic imaging (VMI) and iterative metal artifact reduction (iMAR) in photon-counting detector (PCD) CT lacks thorough investigation. This study evaluates VMI, iMAR, and combinations thereof in PCD-CT of patients with dental implants. MATERIAL AND METHODS In 50 patients (25 women; mean age 62.0 ± 9.9 years), polychromatic 120 kVp imaging (T3D), VMI, T3DiMAR, and VMIiMAR were compared. VMIs were reconstructed at 40, 70, 110, 150, and 190 keV. Artifact reduction was assessed by attenuation and noise measurements in the most hyper- and hypodense artifacts, as well as in artifact-impaired soft tissue of the mouth floor. Three readers subjectively evaluated artifact extent and soft tissue interpretability. Furthermore, new artifacts through overcorrection were assessed. RESULTS iMAR reduced hyper-/hypodense artifacts (T3D 1305.0/-1418.4 versus T3DiMAR 103.2/-46.9 HU), soft tissue impairment (106.7 versus 39.7 HU), and image noise (16.9 versus 5.2 HU) compared to non-iMAR datasets (p ≤ 0.001). VMIiMAR ≥ 110 keV subjectively enhanced artifact reduction over T3DiMAR (p ≤ 0.023). Without iMAR, VMI displayed no measurable artifact reduction (p ≥ 0.186) and facilitated no significant denoising over T3D (p ≥ 0.366). However, VMI ≥ 110 keV reduced soft tissue impairment (p ≤ 0.009). VMIiMAR ≥ 110 keV resulted in less overcorrection than T3DiMAR (p ≤ 0.001). Inter-reader reliability was moderate/good for hyperdense (0.707), hypodense (0.802), and soft tissue artifacts (0.804). CONCLUSION While VMI alone holds minimal metal artifact reduction potential, iMAR post-processing enabled substantial reduction of hyperdense and hypodense artifacts. The combination of VMI ≥ 110 keV and iMAR resulted in the least extensive metal artifacts. CLINICAL RELEVANCE Combining iMAR with VMI represents a potent tool for maxillofacial PCD-CT with dental implants achieving substantial artifact reduction and high image quality. KEY POINTS • Post-processing of photon-counting CT scans with an iterative metal artifact reduction algorithm substantially reduces hyperdense and hypodense artifacts arising from dental implants. • Virtual monoenergetic images presented only minimal metal artifact reduction potential. • The combination of both provided a considerable benefit in subjective analysis compared to iterative metal artifact reduction alone.
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Affiliation(s)
- Theresa Sophie Patzer
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstraße 6, 97080, Würzburg, Germany.
| | - Andreas Steven Kunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstraße 6, 97080, Würzburg, Germany
| | - Henner Huflage
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstraße 6, 97080, Würzburg, Germany
| | - Philipp Gruschwitz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstraße 6, 97080, Würzburg, Germany
| | - Pauline Pannenbecker
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstraße 6, 97080, Würzburg, Germany
| | - Saif Afat
- Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Hoppe-Seyler-Str 3, 72076, Tübingen, Germany
| | - Judith Herrmann
- Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Hoppe-Seyler-Str 3, 72076, Tübingen, Germany
| | - Bernhard Petritsch
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstraße 6, 97080, Würzburg, Germany
| | - Thorsten Alexander Bley
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstraße 6, 97080, Würzburg, Germany
| | - Jan-Peter Grunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstraße 6, 97080, Würzburg, Germany
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25
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Farhadi F, Sahbaee P, Rajagopal JR, Nikpanah M, Saboury B, Gutjahr R, Biassou NM, Shah R, Flohr TG, Samei E, Pritchard WF, Malayeri AA, Bluemke DA, Jones EC. Virtual monoenergetic imaging in photon-counting CT of the head and neck. Clin Imaging 2023; 102:109-115. [PMID: 37672849 PMCID: PMC10838526 DOI: 10.1016/j.clinimag.2023.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 08/08/2023] [Indexed: 09/08/2023]
Abstract
PURPOSE Advantages of virtual monoenergetic images (VMI) have been reported for dual energy CT of the head and neck, and more recently VMIs derived from photon-counting (PCCT) angiography of the head and neck. We report image quality metrics of VMI in a PCCT angiography dataset, expanding the anatomical regions evaluated and extending observer-based qualitative methods further than previously reported. METHODS In a prospective study, asymptomatic subjects underwent contrast enhanced PCCT of the head and neck using an investigational scanner. Image sets of low, high, and full spectrum (Threshold-1) energies; linear mix of low and high energies (Mix); and 23 VMIs (40-150 keV, 5 keV increments) were generated. In 8 anatomical locations, SNR and radiologists' preferences for VMI energy levels were measured using a forced-choice rank method (4 observers) and ratings of image quality using visual grading characteristic (VGC) analysis (2 observers) comparing VMI to Mix and Threshold-1 images. RESULTS Fifteen subjects were included (7 men, 8 women, mean 57 years, range 46-75). Among all VMIs, SNRs varied by anatomic location. The highest SNRs were observed in VMIs. Radiologists preferred 50-60 keV VMIs for vascular structures and 75-85 keV for all other structures. Cumulative ratings of image quality averaged across all locations were higher for VMIs with areas under the curve of VMI vs Mix and VMI vs Threshold-1 of 0.67 and 0.68 for the first reader and 0.72 and 0.76 for the second, respectively. CONCLUSION Preferred keV level and quality ratings of VMI compared to mixed and Threshold-1 images varied by anatomical location.
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Affiliation(s)
- Faraz Farhadi
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | | | - Jayasai R Rajagopal
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA; Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Moozhan Nikpanah
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Babak Saboury
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | | | - Nadia M Biassou
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Ritu Shah
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | | | - Ehsan Samei
- Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - William F Pritchard
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA; Center for Interventional Oncology, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Ashkan A Malayeri
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - David A Bluemke
- Department of Radiology, University of Wisconsin, Madison, WI, USA
| | - Elizabeth C Jones
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA.
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26
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Wu Y, Ye Z, Chen J, Deng L, Song B. Photon Counting CT: Technical Principles, Clinical Applications, and Future Prospects. Acad Radiol 2023; 30:2362-2382. [PMID: 37369618 DOI: 10.1016/j.acra.2023.05.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 05/27/2023] [Accepted: 05/28/2023] [Indexed: 06/29/2023]
Abstract
Photon-counting computed tomography (PCCT) is a new technique that utilizes photon-counting detectors to convert individual X-ray photons directly into an electrical signal, which can achieve higher spatial resolution, improved iodine signal, radiation dose reduction, artifact reduction, and multienergy imaging. This review introduces the technical principles of PCCT, and summarizes its first-in-human experience and current applications in clinical settings, and discusses the future prospects of PCCT.
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Affiliation(s)
- Yingyi Wu
- Department of Radiology, West China Hospital, Sichuan University, No. 37 Guoxue Alley, Chengdu 610041, China (Y.Y.W., Z.Y., J.C., L.P.D., B.S.)
| | - Zheng Ye
- Department of Radiology, West China Hospital, Sichuan University, No. 37 Guoxue Alley, Chengdu 610041, China (Y.Y.W., Z.Y., J.C., L.P.D., B.S.)
| | - Jie Chen
- Department of Radiology, West China Hospital, Sichuan University, No. 37 Guoxue Alley, Chengdu 610041, China (Y.Y.W., Z.Y., J.C., L.P.D., B.S.)
| | - Liping Deng
- Department of Radiology, West China Hospital, Sichuan University, No. 37 Guoxue Alley, Chengdu 610041, China (Y.Y.W., Z.Y., J.C., L.P.D., B.S.)
| | - Bin Song
- Department of Radiology, West China Hospital, Sichuan University, No. 37 Guoxue Alley, Chengdu 610041, China (Y.Y.W., Z.Y., J.C., L.P.D., B.S.); Department of Radiology, Sanya People' s Hospital, Sanya, Hainan, China (B.S.).
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27
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Douek PC, Boccalini S, Oei EHG, Cormode DP, Pourmorteza A, Boussel L, Si-Mohamed SA, Budde RPJ. Clinical Applications of Photon-counting CT: A Review of Pioneer Studies and a Glimpse into the Future. Radiology 2023; 309:e222432. [PMID: 37787672 PMCID: PMC10623209 DOI: 10.1148/radiol.222432] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 03/24/2023] [Accepted: 04/11/2023] [Indexed: 10/04/2023]
Abstract
CT systems equipped with photon-counting detectors (PCDs), referred to as photon-counting CT (PCCT), are beginning to change imaging in several subspecialties, such as cardiac, vascular, thoracic, and musculoskeletal radiology. Evidence has been building in the literature underpinning the many advantages of PCCT for different clinical applications. These benefits derive from the distinct features of PCDs, which are made of semiconductor materials capable of converting photons directly into electric signal. PCCT advancements include, among the most important, improved spatial resolution, noise reduction, and spectral properties. PCCT spatial resolution on the order of 0.25 mm allows for the improved visualization of small structures (eg, small vessels, arterial walls, distal bronchi, and bone trabeculations) and their pathologies, as well as the identification of previously undetectable anomalies. In addition, blooming artifacts from calcifications, stents, and other dense structures are reduced. The benefits of the spectral capabilities of PCCT are broad and include reducing radiation and contrast material dose for patients. In addition, multiple types of information can be extracted from a single data set (ie, multiparametric imaging), including quantitative data often regarded as surrogates of functional information (eg, lung perfusion). PCCT also allows for a novel type of CT imaging, K-edge imaging. This technique, combined with new contrast materials specifically designed for this modality, opens the door to new applications for imaging in the future.
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Affiliation(s)
| | | | - Edwin H. G. Oei
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - David P. Cormode
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - Amir Pourmorteza
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - Loic Boussel
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - Salim A. Si-Mohamed
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - Ricardo P. J. Budde
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
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28
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McCollough CH, Rajiah PS. Milestones in CT: Past, Present, and Future. Radiology 2023; 309:e230803. [PMID: 37847140 PMCID: PMC10644676 DOI: 10.1148/radiol.230803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
In 1971, the first patient CT examination by Ambrose and Hounsfield paved the way for not only volumetric imaging of the brain but of the entire body. From the initial 5-minute scan for a 180° rotation to today's 0.24-second scan for a 360° rotation, CT technology continues to reinvent itself. This article describes key historical milestones in CT technology from the earliest days of CT to the present, with a look toward the future of this essential imaging modality. After a review of the beginnings of CT and its early adoption, the technical steps taken to decrease scan times-both per image and per examination-are reviewed. Novel geometries such as electron-beam CT and dual-source CT have also been developed in the quest for ever-faster scans and better in-plane temporal resolution. The focus of the past 2 decades on radiation dose optimization and management led to changes in how exposure parameters such as tube current and tube potential are prescribed such that today, examinations are more customized to the specific patient and diagnostic task than ever before. In the mid-2000s, CT expanded its reach from gray-scale to color with the clinical introduction of dual-energy CT. Today's most recent technical innovation-photon-counting CT-offers greater capabilities in multienergy CT as well as spatial resolution as good as 125 μm. Finally, artificial intelligence is poised to impact both the creation and processing of CT images, as well as automating many tasks to provide greater accuracy and reproducibility in quantitative applications.
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Affiliation(s)
- Cynthia H. McCollough
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
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29
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Schwartz FR, Ria F, McCabe C, Zarei M, Rajagopal J, Molvin L, Marin D, O'Sullivan-Murphy B, Kalisz KR, Tailor TD, Washington L, Henry T, Samei E. Image quality of photon counting and energy integrating chest CT - Prospective head-to-head comparison on same patients. Eur J Radiol 2023; 166:111014. [PMID: 37542816 DOI: 10.1016/j.ejrad.2023.111014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/11/2023] [Accepted: 07/25/2023] [Indexed: 08/07/2023]
Abstract
PURPOSE To prospectively compare the image quality of high-resolution, low-dose photon-counting detector CT (PCD-CT) with standard energy-integrating-detector CT (EID) on the same patients. METHOD IRB-approved, prospective study; patients received same-day non-contrast CT on EID and PCD-CT (NAEOTOM Alpha, blinded) with clinical protocols. Four blinded radiologists evaluated subsegmental bronchial wall definition, noise, and overall image quality in randomized order (0 = worst; 100 = best). Cases were quantitatively compared using the average Global-Noise-Index (GNI), Noise-Power-Spectrum average frequency (fav), NPS frequency-peak (fpeak), Task-Transfer-Function-10%-frequency (f10) an adjusted detectability index (d'adj), and applied output radiation doses (CTDIvol). RESULTS Sixty patients were prospectively imaged (27 men, mean age 67 ± 10 years, mean BMI 27.9 ± 6.5, 15.9-49.4 kg/m2). Subsegmental wall definition was rated significantly better for PCD-CT than EID (mean 71 [56-87] vs 60 [45-76]; P < 0.001), noise was rated higher for PCD-CT (48 [26-69] vs 34 [13-56]; P < 0.001). Overall image quality was rated significantly higher for PCD-CT than EID (66 [48-85] vs 61 [42-79], P = 0.008). Automated image quality measures showed similar differences for PCD-CT vs EID (mean GNI 70 ± 19 HU vs 26 ± 8 HU, fav 0.35 ± 0.02 vs 0.25 ± 0.02 mm-1, fpeak 0.07 ± 0.01 vs 0.09 ± 0.03 mm-1, f10 0.7 ± 0.08 vs 0.6 ± 0.1 mm-1, all p-values < 0.001). PCD-CT showed a 10% average d'adj increase (-49% min, 233% max). PCD-CT studies were acquired at significantly lower radiation doses than EID (mean CTDIvol 4.5 ± 2.1 vs 7.7 ± 3.2 mGy, P < 0.01). CONCLUSION Though PCD-CT had higher measured and perceived noise, it offered equivalent or better diagnostic quality compared to EID at lower radiation doses, due to its improved resolution.
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Affiliation(s)
- Fides R Schwartz
- Duke University Health System, Department of Radiology, 2301 Erwin Road Box 3808, Durham, NC 27110, United States.
| | - Francesco Ria
- Duke University Health System, Department of Radiology, 2301 Erwin Road Box 3808, Durham, NC 27110, United States.
| | - Cindy McCabe
- Duke University Health System, Department of Radiology, 2301 Erwin Road Box 3808, Durham, NC 27110, United States.
| | - Mojtaba Zarei
- Duke University Health System, Department of Radiology, 2301 Erwin Road Box 3808, Durham, NC 27110, United States.
| | - Jayasai Rajagopal
- Duke University Health System, Department of Radiology, 2301 Erwin Road Box 3808, Durham, NC 27110, United States.
| | - Lior Molvin
- Duke University Health System, Department of Radiology, 2301 Erwin Road Box 3808, Durham, NC 27110, United States.
| | - Daniele Marin
- Duke University Health System, Department of Radiology, 2301 Erwin Road Box 3808, Durham, NC 27110, United States.
| | - Bryan O'Sullivan-Murphy
- Duke University Health System, Department of Radiology, 2301 Erwin Road Box 3808, Durham, NC 27110, United States.
| | - Kevin R Kalisz
- Duke University Health System, Department of Radiology, 2301 Erwin Road Box 3808, Durham, NC 27110, United States.
| | - Tina D Tailor
- Duke University Health System, Department of Radiology, 2301 Erwin Road Box 3808, Durham, NC 27110, United States.
| | - Lacey Washington
- Duke University Health System, Department of Radiology, 2301 Erwin Road Box 3808, Durham, NC 27110, United States.
| | - Travis Henry
- Duke University Health System, Department of Radiology, 2301 Erwin Road Box 3808, Durham, NC 27110, United States.
| | - Ehsan Samei
- Duke University Health System, Department of Radiology, 2301 Erwin Road Box 3808, Durham, NC 27110, United States.
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30
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Graafen D, Müller L, Halfmann MC, Stoehr F, Foerster F, Düber C, Yang Y, Emrich T, Kloeckner R. Soft Reconstruction Kernels Improve HCC Imaging on a Photon-Counting Detector CT. Acad Radiol 2023; 30 Suppl 1:S143-S154. [PMID: 37095047 DOI: 10.1016/j.acra.2023.03.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 03/08/2023] [Accepted: 03/20/2023] [Indexed: 04/26/2023]
Abstract
RATIONALE AND OBJECTIVES Hepatocellular carcinoma (HCC) is the only tumor entity that allows non-invasive diagnosis based on imaging without further histological proof. Therefore, excellent image quality is of utmost importance for HCC diagnosis. Novel photon-counting detector (PCD) CT improves image quality via noise reduction and higher spatial resolution, inherently providing spectral information. The aim of this study was to investigate these improvements for HCC imaging with triple-phase liver PCD-CT in a phantom and patient population study focusing on identification of the optimal reconstruction kernel. MATERIALS AND METHODS Phantom experiments were performed to analyze objective quality characteristics of the regular body and quantitative reconstruction kernels, each with four sharpness levels (36-40-44-48). For 24 patients with viable HCC lesions on PCD-CT, virtual monoenergetic images at 50 keV were reconstructed using these kernels. Quantitative image analysis included contrast-to-noise ratio (CNR) and edge sharpness. Three raters performed qualitative analyses evaluating noise, contrast, lesion conspicuity, and overall image quality. RESULTS In all contrast phases, the CNR was highest using the kernels with a sharpness level of 36 (all p < 0.05), with no significant influence on lesion sharpness. Softer reconstruction kernels were also rated better regarding noise and image quality (all p < 0.05). No significant differences were found in image contrast and lesion conspicuity. Comparing body and quantitative kernels with equal sharpness levels, there was no difference in image quality criteria, neither regarding in vitro nor in vivo analysis. CONCLUSION Soft reconstruction kernels yield the best overall quality for the evaluation of HCC in PCD-CT. As the image quality of quantitative kernels with potential for spectral post-processing is not restricted compared to regular body kernels, they should be preferred.
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Affiliation(s)
- D Graafen
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.).
| | - L Müller
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.)
| | - M C Halfmann
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.); German Center for Cardiovascular Research (DZHK), Partner-Site Rhine-Main, Mainz, Germany (M.C.H., T.E.)
| | - F Stoehr
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.)
| | - F Foerster
- Department of Medicine I, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (F.F.)
| | - C Düber
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.)
| | - Y Yang
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.)
| | - T Emrich
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.); German Center for Cardiovascular Research (DZHK), Partner-Site Rhine-Main, Mainz, Germany (M.C.H., T.E.); Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (T.E.)
| | - R Kloeckner
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany (D.G., L.M., M.C.H., F.S., C.D., Y.Y., T.E., R.K.)
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31
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Gaillandre Y, Duhamel A, Flohr T, Faivre JB, Khung S, Hutt A, Felloni P, Remy J, Remy-Jardin M. Ultra-high resolution CT imaging of interstitial lung disease: impact of photon-counting CT in 112 patients. Eur Radiol 2023; 33:5528-5539. [PMID: 37071165 DOI: 10.1007/s00330-023-09616-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/17/2023] [Accepted: 02/23/2023] [Indexed: 04/19/2023]
Abstract
OBJECTIVES To compare lung parenchyma analysis on ultra-high resolution (UHR) images of a photon-counting CT (PCCT) scanner with that of high-resolution (HR) images of an energy-integrating detector CT (EID-CT). METHODS A total of 112 patients with stable interstitial lung disease (ILD) were investigated (a) at T0 with HRCT on a 3rd-generation dual-source CT scanner; (b) at T1 with UHR on a PCCT scanner; (c) with a comparison of 1-mm-thick lung images. RESULTS Despite a higher level of objective noise at T1 (74.1 ± 14.1 UH vs 38.1 ± 8.7 UH; p < 0.0001), higher qualitative scores were observed at T1 with (a) visualization of more distal bronchial divisions (median order; Q1-Q3) (T1: 10th division [9-10]; T0: 9th division [8-9]; p < 0.0001); (b) greater scores of sharpness of bronchial walls (p < 0.0001) and right major fissure (p < 0.0001). The scores of visualization of CT features of ILD were significantly superior at T1 (micronodules: p = 0.03; linear opacities, intralobular reticulation, bronchiectasis, bronchiolectasis, and honeycombing: p < 0.0001), leading to the reclassification of 4 patients with non-fibrotic ILD at T0, recognized with fibrotic ILD at T1. At T1, the mean (± SD) radiation dose (CTDI vol: 2.7 ± 0.5 mGy; DLP: 88.5 ± 21 mGy.cm) was significantly lower than that delivered at T0 (CTDI vol: 3.6 ± 0.9 mGy; DLP: 129.8 ± 31.7 mGy.cm) (p < 0.0001), corresponding to a mean reduction of 27% and 32% for the CTDIvol and DLP, respectively. CONCLUSIONS The UHR scanning mode of PCCT allowed a more precise depiction of CT features of ILDs and reclassification of ILD patterns with significant radiation dose reduction. CLINICAL RELEVANCE STATEMENT Evaluation of lung parenchymal structures with ultra-high-resolution makes subtle changes at the level of the secondary pulmonary lobules and lung microcirculation becoming visually accessible, opening new options for synergistic collaborations between highly-detailed morphology and artificial intelligence. KEY POINTS • Photon-counting CT (PCCT) provides a more precise analysis of lung parenchymal structures and CT features of interstitial lung diseases (ILDs). • The UHR mode ensures a more precise delineation of fine fibrotic abnormalities with the potential of modifying the categorization of ILD patterns. • Better image quality at a lower radiation dose with PCCT opens new horizons for further dose reduction in noncontrast UHR examinations.
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Affiliation(s)
- Yann Gaillandre
- ULR 2694 METRICS Evaluation des technologies de santé et des pratiques médicales, F-59000, Lille, France
| | - Alain Duhamel
- ULR 2694 METRICS Evaluation des technologies de santé et des pratiques médicales, F-59000, Lille, France
- Department of Biostatistics, ULR 2694 METRICS Evaluation des technologies de santé et des pratiques médicales, Univ. Lille, CHU Lille, F-59000, Lille, France
| | - Thomas Flohr
- Department of Computed Tomography Research & Development, Siemens Healthineers, 91301, Forchheim, Germany
| | - Jean-Baptiste Faivre
- ULR 2694 METRICS Evaluation des technologies de santé et des pratiques médicales, F-59000, Lille, France
| | - Suonita Khung
- ULR 2694 METRICS Evaluation des technologies de santé et des pratiques médicales, F-59000, Lille, France
| | - Antoine Hutt
- ULR 2694 METRICS Evaluation des technologies de santé et des pratiques médicales, F-59000, Lille, France
| | - Paul Felloni
- ULR 2694 METRICS Evaluation des technologies de santé et des pratiques médicales, F-59000, Lille, France
| | - Jacques Remy
- ULR 2694 METRICS Evaluation des technologies de santé et des pratiques médicales, F-59000, Lille, France
| | - Martine Remy-Jardin
- ULR 2694 METRICS Evaluation des technologies de santé et des pratiques médicales, F-59000, Lille, France.
- Department of Thoracic Imaging, Heart & Lung Institute, University Hospital Center of Lille, Blvd Jules Leclercq, 59000, Lille, France.
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McCollough CH, Rajendran K, Baffour FI, Diehn FE, Ferrero A, Glazebrook KN, Horst KK, Johnson TF, Leng S, Mileto A, Rajiah PS, Schmidt B, Yu L, Flohr TG, Fletcher JG. Clinical applications of photon counting detector CT. Eur Radiol 2023; 33:5309-5320. [PMID: 37020069 PMCID: PMC10330165 DOI: 10.1007/s00330-023-09596-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 12/13/2022] [Accepted: 02/03/2023] [Indexed: 04/07/2023]
Abstract
The X-ray detector is a fundamental component of a CT system that determines the image quality and dose efficiency. Until the approval of the first clinical photon-counting-detector (PCD) system in 2021, all clinical CT scanners used scintillating detectors, which do not capture information about individual photons in the two-step detection process. In contrast, PCDs use a one-step process whereby X-ray energy is converted directly into an electrical signal. This preserves information about individual photons such that the numbers of X-ray in different energy ranges can be counted. Primary advantages of PCDs include the absence of electronic noise, improved radiation dose efficiency, increased iodine signal and the ability to use lower doses of iodinated contrast material, and better spatial resolution. PCDs with more than one energy threshold can sort the detected photons into two or more energy bins, making energy-resolved information available for all acquisitions. This allows for material classification or quantitation tasks to be performed in conjunction with high spatial resolution, and in the case of dual-source CT, high pitch, or high temporal resolution acquisitions. Some of the most promising applications of PCD-CT involve imaging of anatomy where exquisite spatial resolution adds clinical value. These include imaging of the inner ear, bones, small blood vessels, heart, and lung. This review describes the clinical benefits observed to date and future directions for this technical advance in CT imaging. KEY POINTS: • Beneficial characteristics of photon-counting detectors include the absence of electronic noise, increased iodine signal-to-noise ratio, improved spatial resolution, and full-time multi-energy imaging. • Promising applications of PCD-CT involve imaging of anatomy where exquisite spatial resolution adds clinical value and applications requiring multi-energy data simultaneous with high spatial and/or temporal resolution. • Future applications of PCD-CT technology may include extremely high spatial resolution tasks, such as the detection of breast micro-calcifications, and quantitative imaging of native tissue types and novel contrast agents.
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Affiliation(s)
- Cynthia H McCollough
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
| | - Kishore Rajendran
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Francis I Baffour
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Felix E Diehn
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Andrea Ferrero
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Katrina N Glazebrook
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Kelly K Horst
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Tucker F Johnson
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Shuai Leng
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Achille Mileto
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | | | - Bernhard Schmidt
- Computed Tomography, Siemens Healthineers, Siemensstrasse 3, Forchheim, 91301, Germany
| | - Lifeng Yu
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Thomas G Flohr
- Computed Tomography, Siemens Healthineers, Siemensstrasse 3, Forchheim, 91301, Germany
| | - Joel G Fletcher
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
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33
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Bache ST, Samei E. A methodology for incorporating a photon-counting CT system into routine clinical use. J Appl Clin Med Phys 2023; 24:e14069. [PMID: 37389963 PMCID: PMC10402682 DOI: 10.1002/acm2.14069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 04/24/2023] [Accepted: 05/22/2023] [Indexed: 07/02/2023] Open
Abstract
Photon-counting computed tomography (PCCT) systems are increasingly available in the U.S. following Food and Drug Administration (FDA) approval of the first clinical PCCT system in Fall 2021. Consequently, there will be a need to incorporate PCCTs into existing fleets of traditional CT systems. The commissioning process of a PCCT was devised by evaluating the degree of agreement between the performance of the PCCT and that of established clinical CT systems. A PCCT system (Siemens NAEOTOM Alpha) was evaluated using the American College of Radiology(ACR) CT phantom (Gammex 464). The phantom was scanned on the system and on a 3rd Generation EID CT system (Siemens Force) at three clinical dose levels. Images were reconstructed across the range of available reconstruction kernels and Iterative Reconstruction (IR) strengths. Two image quality metrics-spatial resolution and noise texture-were calculated using AAPM TG233 software (imQuest), as well as a dose metric to achieve target image noise magnitude of 10 HU. For each pair of EID-PCCT kernel/IR strengths, the difference in metrics were calculated, weighted, and multiplied over all metrics to determine the concordance between systems. IR performance was characterized by comparing relative noise texture and reference dose as a function of IR strength for each system. In general, as kernel "sharpness" increased for each system, spatial resolution, noise spatial frequency, and reference dose increased. For a given kernel, EID reconstruction showed higher spatial resolution compared to PCCT in standard resolution mode. PCCT implementation of IR better preserved noise texture across all strengths compared to the EID, demonstrated by respective 20 and 7% shifts in noise texture from IR "Off" to IR "Max." Overall, the closest match for a given EID reconstruction kernel/IR strength was identified as a PCCT kernel with "sharpness" increased by 1 step and IR strength increased by 1-2 steps. Substantial dose reduction potential of up to 70% was found when targeting a constant noise magnitude.
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Affiliation(s)
- Steven T. Bache
- Department of Radiology Clinical Imaging Physics GroupDuke University Medical CenterDurhamNorth CarolinaUSA
| | - Ehsan Samei
- Carl E. Ravin Advanced Imaging LaboratoriesDuke University Medical CenterDurhamNorth CarolinaUSA
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34
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Graafen D, Stoehr F, Halfmann MC, Emrich T, Foerster F, Yang Y, Düber C, Müller L, Kloeckner R. Quantum iterative reconstruction on a photon-counting detector CT improves the quality of hepatocellular carcinoma imaging. Cancer Imaging 2023; 23:69. [PMID: 37480062 PMCID: PMC10362630 DOI: 10.1186/s40644-023-00592-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 07/08/2023] [Indexed: 07/23/2023] Open
Abstract
BACKGROUND Excellent image quality is crucial for workup of hepatocellular carcinoma (HCC) in patients with liver cirrhosis because a signature tumor signal allows for non-invasive diagnosis without histologic proof. Photon-counting detector computed tomography (PCD-CT) can enhance abdominal image quality, especially in combination with a novel iterative reconstruction algorithm, quantum iterative reconstruction (QIR). The purpose of this study was to analyze the impact of different QIR levels on PCD-CT imaging of HCC in both phantom and patient scans. METHODS Virtual monoenergetic images at 50 keV were reconstructed using filtered back projection and all available QIR levels (QIR 1-4). Objective image quality properties were investigated in phantom experiments. The study also included 44 patients with triple-phase liver PCD-CT scans of viable HCC lesions. Quantitative image analysis involved assessing the noise, contrast, and contrast-to-noise ratio of the lesions. Qualitative image analysis was performed by three raters evaluating noise, artifacts, lesion conspicuity, and overall image quality using a 5-point Likert scale. RESULTS Noise power spectra in the phantom experiments showed increasing noise suppression with higher QIR levels without affecting the modulation transfer function. This pattern was confirmed in the in vivo scans, in which the lowest noise levels were found in QIR-4 reconstructions, with around a 50% reduction in median noise level compared with the filtered back projection images. As contrast does not change with QIR, QIR-4 also yielded the highest contrast-to-noise ratios. With increasing QIR levels, rater scores were significantly better for all qualitative image criteria (all p < .05). CONCLUSIONS Without compromising image sharpness, the best image quality of iodine contrast optimized low-keV virtual monoenergetic images can be achieved using the highest QIR level to suppress noise. Using these settings as standard reconstruction for HCC in PCD-CT imaging might improve diagnostic accuracy and confidence.
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Affiliation(s)
- Dirk Graafen
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.
| | - Fabian Stoehr
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Moritz C Halfmann
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- German Center for Cardiovascular Research (DZHK), Partner-Site Rhine-Main, Mainz, Germany
| | - Tilman Emrich
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- German Center for Cardiovascular Research (DZHK), Partner-Site Rhine-Main, Mainz, Germany
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Friedrich Foerster
- Department of Medicine I, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Yang Yang
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Christoph Düber
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Lukas Müller
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Roman Kloeckner
- Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- Present Address: Institute of Interventional Radiology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
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35
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Garcelon C, Abascal J, Olivier C, Uk S, Si-Mohamed S, Ea HK, Douek P, Peyrin F, Chappard C. Quantification of cartilage and subchondral bone cysts on knee specimens based on a spectral photon-counting computed tomography. Sci Rep 2023; 13:11080. [PMID: 37422514 PMCID: PMC10329701 DOI: 10.1038/s41598-023-38238-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 07/05/2023] [Indexed: 07/10/2023] Open
Abstract
Spectral photon-counting computed tomography (SPCCT) is a new technique with the capability to provide mono-energetic (monoE) images with high signal to noise ratio. We demonstrate the feasibility of SPCCT to characterize at the same time cartilage and subchondral bone cysts (SBCs) without contrast agent in osteoarthritis (OA). To achieve this goal, 10 human knee specimens (6 normal and 4 with OA) were imaged with a clinical prototype SPCCT. The monoE images at 60 keV with isotropic voxels of 250 × 250 × 250 µm3 were compared with monoE synchrotron radiation CT (SR micro-CT) images at 55 keV with isotropic voxels of 45 × 45 × 45 µm3 used as benchmark for cartilage segmentation. In the two OA knees with SBCs, the volume and density of SBCs were evaluated in SPCCT images. In 25 compartments (lateral tibial (LT), medial tibial, (MT), lateral femoral (LF), medial femoral and patella), the mean bias between SPCCT and SR micro-CT analyses were 101 ± 272 mm3 for cartilage volume and 0.33 mm ± 0.18 for mean cartilage thickness. Between normal and OA knees, mean cartilage thicknesses were found statistically different (0.005 < p < 0.04) for LT, MT and LF compartments. The 2 OA knees displayed different SBCs profiles in terms of volume, density, and distribution according to size and location. SPCCT with fast acquisitions is able to characterize cartilage morphology and SBCs. SPCCT can be used potentially as a new tool in clinical studies in OA.
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Affiliation(s)
- Célestin Garcelon
- Paris Cité University, CNRS, INSERM, B3OA UMR 7052 U1273, Paris, France
| | - Juan Abascal
- University of Lyon, INSA-Lyon, CNRS, INSERM, CREATIS UMR 5220, U1206, Lyon, France
| | - Cecile Olivier
- University of Lyon, INSA-Lyon, CNRS, INSERM, CREATIS UMR 5220, U1206, Lyon, France
| | - Stéphanie Uk
- Paris Cité University, CNRS, INSERM, B3OA UMR 7052 U1273, Paris, France
| | - Salim Si-Mohamed
- University of Lyon, INSA-Lyon, CNRS, INSERM, CREATIS UMR 5220, U1206, Lyon, France
| | - Hang-Korng Ea
- Rheumatology Department, University Paris Cité, Paris, France
| | - Philippe Douek
- University of Lyon, INSA-Lyon, CNRS, INSERM, CREATIS UMR 5220, U1206, Lyon, France
| | - Francoise Peyrin
- University of Lyon, INSA-Lyon, CNRS, INSERM, CREATIS UMR 5220, U1206, Lyon, France
| | - Christine Chappard
- Paris Cité University, CNRS, INSERM, B3OA UMR 7052 U1273, Paris, France.
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Flohr T, Schmidt B. Technical Basics and Clinical Benefits of Photon-Counting CT. Invest Radiol 2023; 58:441-450. [PMID: 37185302 PMCID: PMC10259209 DOI: 10.1097/rli.0000000000000980] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 03/05/2023] [Indexed: 05/17/2023]
Abstract
ABSTRACT Novel photon-counting detector CT (PCD-CT) has the potential to address the limitations of previous CT systems, such as insufficient spatial resolution, limited accuracy in detecting small low-contrast structures, or missing routine availability of spectral information. In this review article, we explain the basic principles and potential clinical benefits of PCD-CT, with a focus on recent literature that has grown rapidly since the commercial introduction of a clinically approved PCD-CT.
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37
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Si-Mohamed SA, Boccalini S, Villien M, Yagil Y, Erhard K, Boussel L, Douek PC. First Experience With a Whole-Body Spectral Photon-Counting CT Clinical Prototype. Invest Radiol 2023; 58:459-471. [PMID: 36822663 PMCID: PMC10259214 DOI: 10.1097/rli.0000000000000965] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 01/20/2023] [Indexed: 02/25/2023]
Abstract
ABSTRACT Spectral photon-counting computed tomography (SPCCT) technology holds great promise for becoming the next generation of computed tomography (CT) systems. Its technical characteristics have many advantages over conventional CT imaging. For example, SPCCT provides better spatial resolution, greater dose efficiency for ultra-low-dose and low-dose protocols, and tissue contrast superior to that of conventional CT. In addition, SPCCT takes advantage of several known approaches in the field of spectral CT imaging, such as virtual monochromatic imaging and material decomposition imaging. In addition, SPCCT takes advantage of a new approach in this field, known as K-edge imaging, which allows specific and quantitative imaging of a heavy atom-based contrast agent. Hence, the high potential of SPCCT systems supports their ongoing investigation in clinical research settings. In this review, we propose an overview of our clinical research experience of a whole-body SPCCT clinical prototype, to give an insight into the potential benefits for clinical human imaging on image quality, diagnostic confidence, and new approaches in spectral CT imaging.
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Affiliation(s)
- Salim A. Si-Mohamed
- From the University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France
- Department of Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France
| | - Sara Boccalini
- From the University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France
- Department of Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France
| | | | | | | | - Loic Boussel
- From the University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France
- Department of Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France
| | - Philippe C. Douek
- From the University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France
- Department of Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France
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Meloni A, Cademartiri F, Pistoia L, Degiorgi G, Clemente A, De Gori C, Positano V, Celi S, Berti S, Emdin M, Panetta D, Menichetti L, Punzo B, Cavaliere C, Bossone E, Saba L, Cau R, La Grutta L, Maffei E. Dual-Source Photon-Counting Computed Tomography-Part III: Clinical Overview of Vascular Applications beyond Cardiac and Neuro Imaging. J Clin Med 2023; 12:jcm12113798. [PMID: 37297994 DOI: 10.3390/jcm12113798] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/29/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023] Open
Abstract
Photon-counting computed tomography (PCCT) is an emerging technology that is expected to radically change clinical CT imaging. PCCT offers several advantages over conventional CT, which can be combined to improve and expand the diagnostic possibilities of CT angiography. After a brief description of the PCCT technology and its main advantages we will discuss the new opportunities brought about by PCCT in the field of vascular imaging, while addressing promising future clinical scenarios.
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Affiliation(s)
- Antonella Meloni
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
- Department of Bioengineering, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | | | - Laura Pistoia
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Giulia Degiorgi
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Alberto Clemente
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Carmelo De Gori
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Vincenzo Positano
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
- Department of Bioengineering, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Simona Celi
- BioCardioLab, Department of Bioengineering, Fondazione Monasterio/CNR, 54100 Massa, Italy
| | - Sergio Berti
- Cardiology Unit, Ospedale del Cuore, Fondazione Monasterio/CNR, 54100 Massa, Italy
| | - Michele Emdin
- Department of Cardiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Daniele Panetta
- Institute of Clinical Physiology, National Council of Research, 56124 Pisa, Italy
| | - Luca Menichetti
- Institute of Clinical Physiology, National Council of Research, 56124 Pisa, Italy
| | - Bruna Punzo
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy
| | - Carlo Cavaliere
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy
| | - Eduardo Bossone
- Department of Cardiology, Ospedale Cardarelli, 80131 Naples, Italy
| | - Luca Saba
- Department of Radiology, University Hospital, 09042 Monserrato, CA, Italy
| | - Riccardo Cau
- Department of Radiology, University Hospital, 09042 Monserrato, CA, Italy
| | - Ludovico La Grutta
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties-ProMISE, Department of Radiology, University Hospital "P. Giaccone", 90127 Palermo, Italy
| | - Erica Maffei
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
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Patzer TS, Kunz AS, Huflage H, Luetkens KS, Conrads N, Gruschwitz P, Pannenbecker P, Ergün S, Bley TA, Grunz JP. Quantitative and qualitative image quality assessment in shoulder examinations with a first-generation photon-counting detector CT. Sci Rep 2023; 13:8226. [PMID: 37217553 DOI: 10.1038/s41598-023-35367-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 05/17/2023] [Indexed: 05/24/2023] Open
Abstract
Photon-counting detector (PCD) CT allows for ultra-high-resolution (UHR) examinations of the shoulder without requiring an additional post-patient comb filter to narrow the detector aperture. This study was designed to compare the PCD performance with a high-end energy-integrating detector (EID) CT. Sixteen cadaveric shoulders were examined with both scanners using dose-matched 120 kVp acquisition protocols (low-dose/full-dose: CTDIvol = 5.0/10.0 mGy). Specimens were scanned in UHR mode with the PCD-CT, whereas EID-CT examinations were conducted in accordance with the clinical standard as "non-UHR". Reconstruction of EID data employed the sharpest kernel available for standard-resolution scans (ρ50 = 12.3 lp/cm), while PCD data were reconstructed with both a comparable kernel (11.8 lp/cm) and a sharper dedicated bone kernel (16.5 lp/cm). Six radiologists with 2-9 years of experience in musculoskeletal imaging rated image quality subjectively. Interrater agreement was analyzed by calculation of the intraclass correlation coefficient in a two-way random effects model. Quantitative analyses comprised noise recording and calculating signal-to-noise ratios based on attenuation measurements in bone and soft tissue. Subjective image quality was higher in UHR-PCD-CT than in EID-CT and non-UHR-PCD-CT datasets (all p < 0.001). While low-dose UHR-PCD-CT was considered superior to full-dose non-UHR studies on either scanner (all p < 0.001), ratings of low-dose non-UHR-PCD-CT and full-dose EID-CT examinations did not differ (p > 0.99). Interrater reliability was moderate, indicated by a single measures intraclass correlation coefficient of 0.66 (95% confidence interval: 0.58-0.73; p < 0.001). Image noise was lowest and signal-to-noise ratios were highest in non-UHR-PCD-CT reconstructions at either dose level (p < 0.001). This investigation demonstrates that superior depiction of trabecular microstructure and considerable denoising can be realized without additional radiation dose by employing a PCD for shoulder CT imaging. Allowing for UHR scans without dose penalty, PCD-CT appears as a promising alternative to EID-CT for shoulder trauma assessment in clinical routine.
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Affiliation(s)
- Theresa Sophie Patzer
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany
| | - Andreas Steven Kunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany
| | - Henner Huflage
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany
| | - Karsten Sebastian Luetkens
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany
| | - Nora Conrads
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany
| | - Philipp Gruschwitz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany
| | - Pauline Pannenbecker
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany
| | - Süleyman Ergün
- Institute of Anatomy and Cell Biology, University of Würzburg, Koellikerstr. 6, 97070, Würzburg, Germany
| | - Thorsten Alexander Bley
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany
| | - Jan-Peter Grunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Str. 6, 97080, Würzburg, Germany.
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Pickford Scienti OLP, Darambara DG. Demonstrating a Novel, Hidden Source of Spectral Distortion in X-ray Photon Counting Detectors and Assessing Novel Trigger Schemes Proposed to Avoid It. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23094445. [PMID: 37177647 PMCID: PMC10181505 DOI: 10.3390/s23094445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/22/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023]
Abstract
X-ray photon counting spectral imaging (x-CSI) determines a detected photon's energy by comparing the charge it induces with several thresholds, counting how many times each is crossed (the standard method, STD). This paper is the first to demonstrate that this approach can unexpectedly delete counts from the recorded energy spectrum under some clinically relevant conditions: a process we call negative counting. Four alternative counting schemes are proposed and simulated for a wide range of sensor geometries (pixel pitch 100-600 µm, sensor thickness 1-3 mm), number of thresholds (3, 5, 8, 24 and 130) and medically relevant X-ray fluxes (106-109 photons mm-2 s-1). Spectral efficiency and counting efficiency are calculated for each simulation. Performance gains are explained mechanistically and correlated well with the improved suppression of "negative counting". The best performing scheme (Shift Register, SR) entirely eliminates negative counting, remaining close to an ideal scheme at fluxes of up to 108 photons mm-2 s-1. At the highest fluxes considered, the deviation from ideal behaviour is reduced by 2/3 in SR compared with STD. The results have significant implications both for generally improving spectral fidelity and as a possible path toward the 109 photons mm-2 s-1 goal in photon-counting CT.
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Affiliation(s)
- Oliver L P Pickford Scienti
- Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, London SM2 5NG, UK
| | - Dimitra G Darambara
- Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, London SM2 5NG, UK
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Fink N, Zsarnoczay E, Schoepf UJ, O'Doherty J, Griffith JP, Pinos D, Tesche C, Ricke J, Willemink MJ, Varga-Szemes A, Emrich T. Radiation Dose Reduction for Coronary Artery Calcium Scoring Using a Virtual Noniodine Algorithm on Photon-Counting Detector Computed-Tomography Phantom Data. Diagnostics (Basel) 2023; 13:diagnostics13091540. [PMID: 37174932 PMCID: PMC10177425 DOI: 10.3390/diagnostics13091540] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/14/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
Background: On the basis of the hypothesis that virtual noniodine (VNI)-based coronary artery calcium scoring (CACS) is feasible at reduced radiation doses, this study assesses the impact of radiation dose reduction on the accuracy of this VNI algorithm on a photon-counting detector (PCD)-CT. Methods: In a systematic in vitro setting, a phantom for CACS simulating three chest sizes was scanned on a clinical PCD-CT. The standard radiation dose was chosen at volumetric CT dose indices (CTDIVol) of 1.5, 3.3, 7.0 mGy for small, medium-sized, and large phantoms, and was gradually reduced by adjusting the tube current resulting in 100, 75, 50, and 25%, respectively. VNI images were reconstructed at 55 keV, quantum iterative reconstruction (QIR)1, and at 60 keV/QIR4, and evaluated regarding image quality (image noise (IN), contrast-to-noise ratio (CNR)), and CACS. All VNI results were compared to true noncontrast (TNC)-based CACS at 70 keV and standard radiation dose (reference). Results: INTNC was significantly higher than INVNI, and INVNI at 55 keV/QIR1 higher than at 60 keV/QIR4 (100% dose: 16.7 ± 1.9 vs. 12.8 ± 1.7 vs. 7.7 ± 0.9; p < 0.001 for every radiation dose). CNRTNC was higher than CNRVNI, but it was better to use 60 keV/QIR4 (p < 0.001). CACSVNI showed strong correlation and agreement at every radiation dose (p < 0.001, r > 0.9, intraclass correlation coefficient > 0.9). The coefficients of the variation in root-mean squared error were less than 10% and thus clinically nonrelevant for the CACSVNI of every radiation dose. Conclusion: This phantom study suggests that CACSVNI is feasible on PCD-CT, even at reduced radiation dose while maintaining image quality and CACS accuracy.
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Affiliation(s)
- Nicola Fink
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Emese Zsarnoczay
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
- Medical Imaging Center, Semmelweis University, Korányi Sándor utca 2, 1083 Budapest, Hungary
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
| | - Jim O'Doherty
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
- Siemens Medical Solutions, 40 Liberty Boulevard, Malvern, PA 19355, USA
| | - Joseph P Griffith
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
| | - Daniel Pinos
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
| | - Christian Tesche
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
- Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany
| | - Jens Ricke
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Martin J Willemink
- Department of Radiology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, USA
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
| | - Tilman Emrich
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
- Department of Diagnostic and Interventional Radiology, University Medical Center of Johannes-Gutenberg-University, Langenbeckstr. 1, 55131 Mainz, Germany
- German Centre for Cardiovascular Research, Partner Site Rhine-Main, 55131 Mainz, Germany
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van der Bie J, van Straten M, Booij R, Bos D, Dijkshoorn ML, Hirsch A, Sharma SP, Oei EHG, Budde RPJ. Photon-counting CT: Review of initial clinical results. Eur J Radiol 2023; 163:110829. [PMID: 37080060 DOI: 10.1016/j.ejrad.2023.110829] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 04/05/2023] [Indexed: 04/22/2023]
Abstract
Photon-counting computed tomography (PCCT) is a new technology that enables higher spatial resolution compared to conventional CT techniques, energy resolved imaging and spectral post-processing. This leads to improved contrast-to-noise ratio, artifact and potential dose reduction as well as elimination of electronic noise. Since the introduction of clinical PCCT in 2021, a shift has been observed from solely pre-clinical studies to clinical research (i.e. use of PCCT imaging in humans). This review article is focused on the initial clinical results of PCCT by explaining the current PCCT systems, the applications themselves and, the challenges of PCCT.
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Affiliation(s)
- Judith van der Bie
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands.
| | - Marcel van Straten
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands.
| | - Ronald Booij
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands.
| | - Daniel Bos
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands; Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands.
| | - Marcel L Dijkshoorn
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands.
| | - Alexander Hirsch
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands; Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands.
| | - Simran P Sharma
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands; Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands.
| | - Edwin H G Oei
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands.
| | - Ricardo P J Budde
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands.
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43
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Cao J, Bache S, Schwartz FR, Frush D. Pediatric Applications of Photon-Counting Detector CT. AJR Am J Roentgenol 2023; 220:580-589. [PMID: 36287620 DOI: 10.2214/ajr.22.28391] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Photon-counting detector (PCD) CT represents the most recent generational advance in CT technology. PCD CT has the potential to reduce image noise, improve spatial resolution and contrast resolution, and provide multispectral capability, all of which may be achieved with an overall decrease in the radiation dose. These effects may be used to reduce the iodinated contrast media dose and potentially obtain multiphase images through a single-acquisition technique. The benefits of PCD CT have previously been shown primarily in phantoms and adult patients. This article describes the application of PCD CT in children, as illustrated by clinical examples from a commercially available PCD CT system.
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Affiliation(s)
- Joseph Cao
- Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, 2301 Erwin Rd, Durham, NC 27705
| | - Steve Bache
- Department of Radiology, Clinical Imaging Physics Group, Duke University Medical Center, Durham, NC
| | | | - Donald Frush
- Department of Radiology, Division of Pediatric Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, NC
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Marton N, Gyebnar J, Fritsch K, Majnik J, Nagy G, Simon J, Müller V, Tarnoki AD, Tarnoki DL, Maurovich-Horvat P. Photon-counting computed tomography in the assessment of rheumatoid arthritis-associated interstitial lung disease: an initial experience. Diagn Interv Radiol 2023; 29:291-299. [PMID: 36987949 PMCID: PMC10679703 DOI: 10.4274/dir.2023.221959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 01/22/2023] [Indexed: 03/30/2023]
Abstract
PURPOSE Interstitial lung disease (ILD) accounts for a significant proportion of mortality and morbidity in patients with rheumatoid arthritis (RA). The aim of this cross-sectional study is to evaluate the performance of novel photon-counting detector computed tomography (PCD-CT) in the detection of pulmonary parenchymal involvement. METHODS Sixty-one patients with RA without a previous definitive diagnosis of ILD underwent high-resolution (HR) (0.4 mm slice thickness) and ultra-high-resolution (UHR) (0.2 mm slice thickness) PCDCT examination. The extent of interstitial abnormalities [ground-glass opacity (GGO), reticulation, bronchiectasis, and honeycombing] were scored in each lobe using a Likert-type scale. Total ILD scores were calculated as the sum of scores from all lobes. RESULTS Reticulation and bronchiectasis scores were higher in the UHR measurements taken compared with the HR protocol [median (quartile 1, quartile 3): 2 (0, 3.5) vs. 0 (0, 3), P < 0.001 and 2 (0, 2) vs. 0 (0, 2), P < 0.001, respectively]; however, GGO and honeycombing scores did not differ [2 (2, 4) vs. 2 (2, 4), P = 0.944 and 0 (0, 0) vs. 0 (0, 0), P = 0.641, respectively]. Total ILD scores from both HR and UHR scans showed a mild negative correlation in diffusion capacity for carbon monoxide (HR: r = -0.297, P = 0.034; UHR: r = -0.294, P = 0.036). The pattern of lung parenchymal involvement did not differ significantly between the two protocols. The HR protocol had significantly lower volume CT dose index [0.67 (0.69, 1.06) mGy], total dose length product [29 (24.48, 33.2) mGy*cm] compared with UHR scans [8.18 (6.80, 9.23) mGy, P < 0.001 and 250 (218, 305) mGy*cm, P < 0.001]. CONCLUSION UHR PCD-CT provides more detailed information on ILD in patients with RA than low-dose HR PCDCT. HR PCD-CT image acquisition with a low effective radiation dose may serve as a valuable, low-radiation screening tool in the selection of patients for further, higher-dose UHR PCD-CT screening.
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Affiliation(s)
- Nikolett Marton
- Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
| | - Janos Gyebnar
- Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
| | - Kinga Fritsch
- Department of Rheumatology, Buda Hospital of the Hospitaller Order of Saint John of God, Budapest, Hungary
| | - Judit Majnik
- Department of Rheumatology, Buda Hospital of the Hospitaller Order of Saint John of God, Budapest, Hungary
- Department of Rheumatology and Clinical Immunology, Semmelweis University, Budapest, Hungary
| | - Gyorgy Nagy
- Department of Rheumatology, Buda Hospital of the Hospitaller Order of Saint John of God, Budapest, Hungary
- Department of Rheumatology and Clinical Immunology, Semmelweis University, Budapest, Hungary
| | - Judit Simon
- Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
- MTA-SE Cardiovascular Imaging Research Group, Semmelweis University, Budapest, Hungary
| | - Veronika Müller
- Department of Pulmonology, Semmelweis University, Budapest, Hungary
| | - Adam Domonkos Tarnoki
- Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
- Department of Oncologic Imaging and Invasive Diagnostic Radiology, National Institute of Oncology, Budapest, Hungary
| | - David Laszlo Tarnoki
- Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
- Department of Oncologic Imaging and Invasive Diagnostic Radiology, National Institute of Oncology, Budapest, Hungary
| | - Pal Maurovich-Horvat
- Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
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Ultrahigh-Resolution Photon-Counting Detector CT of the Lungs: Association of Reconstruction Kernel and Slice Thickness With Image Quality. AJR Am J Roentgenol 2023; 220:672-680. [PMID: 36475813 DOI: 10.2214/ajr.22.28515] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND. Prior work has shown improved image quality for photon-counting detector (PCD) CT of the lungs compared with energy-integrating detector CT. A paucity of the literature has compared PCD CT of the lungs using different reconstruction parameters. OBJECTIVE. The purpose of this study is to the compare the image quality of ultra-high-resolution (UHR) PCD CT image sets of the lungs that were reconstructed using different kernels and slice thicknesses. METHODS. This retrospective study included 29 patients (17 women and 12 men; median age, 56 years) who underwent noncontrast chest CT from February 15, 2022, to March 15, 2022, by use of a commercially available PCD CT scanner. All acquisitions used UHR mode (1024 × 1024 matrix). Nine image sets were reconstructed for all combinations of three sharp kernels (BI56, BI60, and BI64) and three slice thicknesses (0.2, 0.4, and 1.0 mm). Three radiologists independently reviewed reconstructions for measures of visualization of pulmonary anatomic structures and pathologies; reader assessments were pooled. Reconstructions were compared with the clinical reference reconstruction (obtained using the BI64 kernel and a 1.0-mm slice thickness [BI641.0-mm]). RESULTS. The median difference in the number of bronchial divisions identified versus the clinical reference reconstruction was higher for reconstructions with BI640.4-mm (0.5), BI600.4-mm (0.3), BI640.2-mm (0.5), and BI600.2-mm (0.2) (all p < .05). The median bronchial wall sharpness versus the clinical reference reconstruction was higher for reconstructions with BI640.4-mm (0.3) and BI640.2-mm (0.3) and was lower for BI561.0-mm (-0.7) and BI560.4-mm (-0.3) (all p < .05). Median pulmonary fissure sharpness versus the clinical reference reconstruction was higher for reconstructions with BI640.4-mm (0.3), BI600.4-mm (0.3), BI560.4-mm (0.5), BI640.2-mm (0.5), BI600.2-mm (0.5), and BI560.2-mm (0.3) (all p < .05). Median pulmonary vessel sharpness versus the clinical reference reconstruction was lower for reconstructions with BI561.0-mm (-0.3), BI60 0.4-mm (-0.3), BI560.4-mm (-0.7), BI640.2-mm (-0.7), BI600.2-mm (-0.7), and BI560.2-mm (-0.7). Median lung nodule conspicuity versus the clinical reference reconstruction was lower for reconstructions with BI561.0-mm (-0.3) and BI560.4-mm (-0.3) (both p < .05). Median conspicuity of all other pathologies versus the clinical reference reconstruction was lower for reconstructions with BI561.0 mm (-0.3), BI560.4-mm (-0.3), BI640.2-mm (-0.3), BI600.2-mm (-0.3), and BI560.2-mm (-0.3). Other comparisons among reconstructions were not significant (all p > .05). CONCLUSION. Only the reconstruction using BI640.4-mm yielded improved bronchial division identification and bronchial wall and pulmonary fissure sharpness without a loss in pulmonary vessel sharpness or conspicuity of nodules or other pathologies. CLINICAL IMPACT. The findings of this study may guide protocol optimization for UHR PCD CT of the lungs.
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Conrads N, Grunz JP, Huflage H, Luetkens KS, Feldle P, Pennig L, Ergün S, Alexander Bley T, Petritsch B, Kunz AS. Ultrahigh-resolution computed tomography of the cervical spine without dose penalty employing a cadmium-telluride photon-counting detector. Eur J Radiol 2023; 160:110718. [PMID: 36731400 DOI: 10.1016/j.ejrad.2023.110718] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 01/18/2023] [Accepted: 01/25/2023] [Indexed: 01/28/2023]
Abstract
PURPOSE This cadaveric study compared image quality between a third-generation dual-source CT scanner with energy-integrating detector technology (EID) and a first-generation CT system employing a photon-counting detector (PCD) for the cervical spine in ultrahigh-resolution mode. METHODS The cervical spine of eight formalin-fixed full-body cadaveric specimens was scanned with both CT systems using 140 kVp scan protocols matched for CTDIvol (full-dose; low-dose; ultralow-dose; 10 mGy; 3 mGy; 1 mGy). Images were reconstructed with 1 mm slice thickness and 0.5 mm increment. Three radiologists rated overall subjective image quality based on an equidistant five-point scale with the intraclass correlation coefficient (ICC) calculated for assessment of interobserver reliability. Contrast-to-noise ratios were calculated individually for bone (CNRbone) and muscle tissue (CNRmuscle) to provide objective criteria of image analysis. RESULTS Subjective image quality, as well as CNRbone, and CNRmuscle were each superior for PCD-CT compared to EID-CT among dose-matched scan protocol pairs (all p < 0.05). Between full-dose EID-CT and low-dose PCD-CT, subjective image quality was equal (p = 0.903), while superior quantitative results regarding the latter were ascertained (both p < 0.001). Similarly, objective analysis determined higher CNRbone, and CNRmuscle in ultralow-dose PCD-CT compared to low-dose EID-CT (both p < 0.001), while readers considered the image quality of the respective studies comparable (p > 0.99). Interobserver reliability was good, denoted by an ICC of 0.861 (95 % confidence interval: 0.788 - 0.914; p < 0.001). CONCLUSIONS In cervical spine examinations, both subjective and objective image quality of PCD-CT were superior to EID-CT in comparison of scan protocols with corresponding dose levels, suggesting potential for significantly reducing the radiation exposure without compromising image quality.
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Affiliation(s)
- Nora Conrads
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany.
| | - Jan-Peter Grunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Henner Huflage
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Karsten Sebastian Luetkens
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Philipp Feldle
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Lenhard Pennig
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937 Cologne, Germany
| | - Süleyman Ergün
- Institute of Anatomy and Cell Biology, University of Würzburg, Koellikerstraße 6, 97070 Würzburg, Germany
| | - Thorsten Alexander Bley
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Bernhard Petritsch
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
| | - Andreas Steven Kunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080 Würzburg, Germany
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Inoue A, Johnson TF, Walkoff LA, Levin DL, Hartman TE, Burke KA, Rajendran K, Yu L, McCollough CH, Fletcher JG. Lung Cancer Screening Using Clinical Photon-Counting Detector Computed Tomography and Energy-Integrating-Detector Computed Tomography: A Prospective Patient Study. J Comput Assist Tomogr 2023; 47:229-235. [PMID: 36573321 DOI: 10.1097/rct.0000000000001419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE To evaluate the diagnostic quality of photon-counting detector (PCD) computed tomography (CT) in patients undergoing lung cancer screening compared with conventional energy-integrating detector (EID) CT in a prospective multireader study. MATERIALS Patients undergoing lung cancer screening with conventional EID-CT were prospectively enrolled and scanned on a PCD-CT system using similar automatic exposure control settings and reconstruction kernels. Three thoracic radiologists blinded to CT system compared PCD-CT and EID-CT images and scored examinations using a 5-point Likert comparison score (-2 [left image is worse] to +2 [left image is better]) for artifacts, sharpness, image noise, diagnostic image quality, emphysema visualization, and lung nodule evaluation focusing on the border. Post hoc correction of Likert scores was performed such that they reflected PCD-CT performance in comparison to EID-CT. A nonreader radiologist measured objective image noise. RESULTS Thirty-three patients (mean, 66.9 ± 5.6 years; 11 female; body mass index; 30.1 ± 5.1 kg/m 2 ) were enrolled. Mean volume CT dose index for PCD-CT was lower (0.61 ± 0.21 vs 0.73 ± 0.22; P < 0.001). Pooled reader results showed significant differences between imaging modalities for all comparative rankings ( P < 0.001), with PCD-CT favored for sharpness, image noise, image quality, and emphysema visualization and lung nodule border, but not artifacts. Photon-counting detector CT had significantly lower image noise (74.4 ± 10.5 HU vs 80.1 ± 8.6 HU; P = 0.048). CONCLUSIONS Photon-counting detector CT with similar acquisition and reconstruction settings demonstrated improved image quality and less noise despite lower radiation dose, with improved ability to depict pulmonary emphysema and lung nodule borders compared with EID-CT at low-dose lung cancer CT screening.
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Affiliation(s)
- Akitoshi Inoue
- From the Department of Radiology, Mayo Clinic, Rochester, MN
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Sartoretti T, Wildberger JE, Flohr T, Alkadhi H. Photon-counting detector CT: early clinical experience review. Br J Radiol 2023:20220544. [PMID: 36744809 DOI: 10.1259/bjr.20220544] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Since its development in the 1970s, X-ray CT has emerged as a landmark diagnostic imaging modality of modern medicine. Technological advances have been crucial to the success of CT imaging, as they have increasingly enabled improvements in image quality and diagnostic value at increasing radiation dose efficiency. With recent advances in engineering and physics, a novel technology has emerged with the potential to surpass several shortcomings and limitations of current CT systems. Photon-counting detector (PCD)-CT might substantially improve and expand the applicability of CT imaging by offering intrinsic spectral capabilities, increased spatial resolution, reduced electronic noise and improved image contrast. In this review we sought to summarize the first clinical experience of PCD-CT. We focused on most recent prototype and first clinically approved PCD-CT systems thereby reviewing initial publications and presenting corresponding clinical cases.
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Affiliation(s)
- Thomas Sartoretti
- Diagnostic and Interventional Radiology, University Hospital Zürich, University of Zürich, Zürich, Switzerland.,Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.,Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Joachim E Wildberger
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.,Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Thomas Flohr
- Siemens Healthcare GmbH, Computed Tomography, Forchheim, Germany
| | - Hatem Alkadhi
- Diagnostic and Interventional Radiology, University Hospital Zürich, University of Zürich, Zürich, Switzerland
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Affiliation(s)
- Theresa C McLoud
- From the Department of Radiology, Harvard Medical School, Massachusetts General Hospital, 55 Fruit St, MZ-FND 216, Boston, MA 02114-2696 (T.C.M.); and Department of Radiology, Mayo Clinic College of Medicine and Science, Mayo Clinic Florida, Jacksonville, Fla (B.P.L.)
| | - Brent P Little
- From the Department of Radiology, Harvard Medical School, Massachusetts General Hospital, 55 Fruit St, MZ-FND 216, Boston, MA 02114-2696 (T.C.M.); and Department of Radiology, Mayo Clinic College of Medicine and Science, Mayo Clinic Florida, Jacksonville, Fla (B.P.L.)
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50
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Boccalini S, Si-Mohamed S. Spectral photon counting CT: Not just a pimped-up new version of dual-energy CT. Diagn Interv Imaging 2023; 104:51-52. [PMID: 36428159 DOI: 10.1016/j.diii.2022.10.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 11/23/2022]
Affiliation(s)
- Sara Boccalini
- Department of Cardiovascular and Thoracic Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, 69500 Bron, France; Université Claude Bernard Lyon 1, 69100 Villeurbanne, France.
| | - Salim Si-Mohamed
- Department of Cardiovascular and Thoracic Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, 69500 Bron, France; Université Lyon, INSA-Lyon, UJM-Saint Etienne, CREATIS, CNRS UMR 5220, Inserm U1206, 69100 Villeurbanne, France
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