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Meloni A, Maffei E, Clemente A, De Gori C, Occhipinti M, Positano V, Berti S, La Grutta L, Saba L, Cau R, Bossone E, Mantini C, Cavaliere C, Punzo B, Celi S, Cademartiri F. Spectral Photon-Counting Computed Tomography: Technical Principles and Applications in the Assessment of Cardiovascular Diseases. J Clin Med 2024; 13:2359. [PMID: 38673632 PMCID: PMC11051476 DOI: 10.3390/jcm13082359] [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: 03/16/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
Spectral Photon-Counting Computed Tomography (SPCCT) represents a groundbreaking advancement in X-ray imaging technology. The core innovation of SPCCT lies in its photon-counting detectors, which can count the exact number of incoming x-ray photons and individually measure their energy. The first part of this review summarizes the key elements of SPCCT technology, such as energy binning, energy weighting, and material decomposition. Its energy-discriminating ability represents the key to the increase in the contrast between different tissues, the elimination of the electronic noise, and the correction of beam-hardening artifacts. Material decomposition provides valuable insights into specific elements' composition, concentration, and distribution. The capability of SPCCT to operate in three or more energy regimes allows for the differentiation of several contrast agents, facilitating quantitative assessments of elements with specific energy thresholds within the diagnostic energy range. The second part of this review provides a brief overview of the applications of SPCCT in the assessment of various cardiovascular disease processes. SPCCT can support the study of myocardial blood perfusion and enable enhanced tissue characterization and the identification of contrast agents, in a manner that was previously unattainable.
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Affiliation(s)
- Antonella Meloni
- Bioengineering Unit, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.)
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Erica Maffei
- Department of Radiology, Istituto di Ricovero e Cura a Carattere Scientifico SYNLAB SDN, 80131 Naples, Italy; (E.M.); (C.C.); (B.P.)
| | - Alberto Clemente
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Carmelo De Gori
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Mariaelena Occhipinti
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Vicenzo Positano
- Bioengineering Unit, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.)
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Sergio Berti
- Diagnostic and Interventional Cardiology Department, Fondazione G. Monasterio CNR-Regione Toscana, 54100 Massa, Italy;
| | - Ludovico La Grutta
- Department of Radiology, University Hospital “P. Giaccone”, 90127 Palermo, Italy;
| | - Luca Saba
- Department of Radiology, University Hospital of Cagliari, 09042 Monserrato (CA), Italy; (L.S.); (R.C.)
| | - Riccardo Cau
- Department of Radiology, University Hospital of Cagliari, 09042 Monserrato (CA), Italy; (L.S.); (R.C.)
| | - Eduardo Bossone
- Department of Cardiology, Ospedale Cardarelli, 80131 Naples, Italy;
| | - Cesare Mantini
- Department of Radiology, “G. D’Annunzio” University, 66100 Chieti, Italy;
| | - Carlo Cavaliere
- Department of Radiology, Istituto di Ricovero e Cura a Carattere Scientifico SYNLAB SDN, 80131 Naples, Italy; (E.M.); (C.C.); (B.P.)
| | - Bruna Punzo
- Department of Radiology, Istituto di Ricovero e Cura a Carattere Scientifico SYNLAB SDN, 80131 Naples, Italy; (E.M.); (C.C.); (B.P.)
| | - Simona Celi
- BioCardioLab, Fondazione G. Monasterio CNR-Regione Toscana, 54100 Massa, Italy;
| | - Filippo Cademartiri
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
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Cundari G, Marchitelli L, Pambianchi G, Catapano F, Conia L, Stancanelli G, Catalano C, Galea N. Imaging biomarkers in cardiac CT: moving beyond simple coronary anatomical assessment. LA RADIOLOGIA MEDICA 2024; 129:380-400. [PMID: 38319493 PMCID: PMC10942914 DOI: 10.1007/s11547-024-01771-5] [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: 08/01/2023] [Accepted: 01/03/2024] [Indexed: 02/07/2024]
Abstract
Cardiac computed tomography angiography (CCTA) is considered the standard non-invasive tool to rule-out obstructive coronary artery disease (CAD). Moreover, several imaging biomarkers have been developed on cardiac-CT imaging to assess global CAD severity and atherosclerotic burden, including coronary calcium scoring, the segment involvement score, segment stenosis score and the Leaman-score. Myocardial perfusion imaging enables the diagnosis of myocardial ischemia and microvascular damage, and the CT-based fractional flow reserve quantification allows to evaluate non-invasively hemodynamic impact of the coronary stenosis. The texture and density of the epicardial and perivascular adipose tissue, the hypodense plaque burden, the radiomic phenotyping of coronary plaques or the fat radiomic profile are novel CT imaging features emerging as biomarkers of inflammation and plaque instability, which may implement the risk stratification strategies. The ability to perform myocardial tissue characterization by extracellular volume fraction and radiomic features appears promising in predicting arrhythmogenic risk and cardiovascular events. New imaging biomarkers are expanding the potential of cardiac CT for phenotyping the individual profile of CAD involvement and opening new frontiers for the practice of more personalized medicine.
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Affiliation(s)
- Giulia Cundari
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy
| | - Livia Marchitelli
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy
| | - Giacomo Pambianchi
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy
| | - Federica Catapano
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini, 4, Pieve Emanuele, 20090, Milano, Italy
- Humanitas Research Hospital IRCCS, Via Alessandro Manzoni, 56, Rozzano, 20089, Milano, Italy
| | - Luca Conia
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy
| | - Giuseppe Stancanelli
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy
| | - Carlo Catalano
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy
| | - Nicola Galea
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Viale Regina Elena 324, 00161, Rome, Italy.
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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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Boccalini S, Mayard C, Lacombe H, Villien M, Si-Mohamed S, Delahaye F, Boussel L, Budde RPJ, Pozzi M, Douek P. Ultra-High-Resolution and K-Edge Imaging of Prosthetic Heart Valves With Spectral Photon-Counting CT: A Phantom Study. Invest Radiol 2024:00004424-990000000-00201. [PMID: 38421666 DOI: 10.1097/rli.0000000000001068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
BACKGROUND AND PURPOSE The contribution of cardiac computed tomography (CT) for the detection and characterization of prosthetic heart valve (PHV) complications is still limited due mainly to artifacts. Computed tomography systems equipped with photon-counting detectors (PCDs) have the potential to overcome these limitations. Therefore, the aim of the study was to compare image quality of PHV with PCD-CT and dual-energy dual-layer CT (DEDL-CT). MATERIALS AND METHODS Two metallic and 3 biological PHVs were placed in a tube containing diluted iodinated contrast inside a thoracic phantom and scanned repeatedly at different angles on a DEDL-CT and PCD-CT. Two small lesions (~2 mm thickness; containing muscle and fat, respectively) were attached to the structure of 4 valves, placed inside the thoracic phantom, with and without an extension ring, and scanned again. Acquisition parameters were matched for the 2 CT systems and used for all scans. Metallic valves were scanned again with parameters adapted for tungsten K-edge imaging. For all valves, different metallic parts were measured on conventional images to assess their thickness and blooming artifacts. In addition, 6 parallelepipeds per metallic valve were drawn, and all voxels with density <3 times the standard deviation of the contrast media were recorded as an estimate of streak artifacts. For subjective analysis, 3 expert readers assessed conventional images of the valves, with and without lesions, and tungsten K-edge images. Conspicuity and sharpness of the different parts of the valve, the lesions, metallic, and blooming artifacts were scored on a 4-point scale. Measurements and scores were compared with the paired t test or Wilcoxon test. RESULTS The objective analysis showed that, with PCD-CT, valvular metallic structures were thinner and presented less blooming artifacts. Metallic artifacts were also reduced with PCD-CT (11 [interquartile (IQ) = 6] vs 40 [IQ = 13] % of voxels). Subjective analysis allowed noticing that some structures were visible or clearly visible only with PCD-CT. In addition, PCD-CT yielded better scores for the conspicuity and for the sharpness of all structures (all Ps < 0.006), except for the conspicuity of the leaflets of the mechanical valves, which were well visible with either technique (4 [IQ = 3] for both). Both blooming and streak artifacts were reduced with PCD-CT (P ≤ 0.01). Overall, the use of PCD-CT resulted in better conspicuity and sharpness of the lesions compared with DEDL-CT (both Ps < 0.02). In addition, only with PCD-CT some differences between the 2 lesions were detectable. Adding the extension ring resulted in reduced conspicuity and sharpness with DEDL-CT (P = 0.04 and P = 0.02, respectively) and only in reduced sharpness with PCD-CT (P = 0.04). Tungsten K-edge imaging allowed for the visualization of the only dense structure containing it, the leaflets, and it resulted in images judged having less blooming and metallic artifacts as compared with conventional PCD-CT images (P < 0.01). CONCLUSIONS With PCD-CT, objective and subjective image quality of metallic and biological PHVs is improved compared with DEDL-CT. Notwithstanding the improvements in image quality, millimetric lesions attached to the structure of the valves remain a challenge for PCD-CT. Tungsten K-edge imaging allows for even further reduction of artifacts.
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Affiliation(s)
- Sara Boccalini
- From the University of Lyon, INSA-Lyon, University Claude Bernard Lyon 1, Villeurbanne, France (S.B., F.D.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France (S.B., C.M., S.S.-M., L.B., P.D.); University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, Villeurbanne, France (H.L., S.S.-M., L.B., P.D.); Philips Healthcare, Suresnes, France (M.V.); Department of Cardiology, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France (F.D.); Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, the Netherlands (R.B.); and Department of Cardiac Surgery, Louis Pradel Hospital, Hospices Civils de Lyon, Bron, France (M.P.)
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Simon J, Hrenkó Á, Kerkovits NM, Nagy K, Vértes M, Balogh H, Nagy N, Munkácsi T, Emrich T, Varga-Szemes A, Boussoussou M, Vattay B, Vecsey-Nagy M, Kolossváry M, Szilveszter B, Merkely B, Maurovich-Horvat P. Photon-counting detector CT reduces the rate of referrals to invasive coronary angiography as compared to CT with whole heart coverage energy-integrating detector. J Cardiovasc Comput Tomogr 2024; 18:69-74. [PMID: 38097408 DOI: 10.1016/j.jcct.2023.11.079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/19/2023] [Accepted: 11/24/2023] [Indexed: 02/26/2024]
Abstract
BACKGROUND We sought to compare the degree of maximal stenosis and the rate of invasive coronary angiography (ICA) recommendations in patients who underwent coronary CT angiography (CCTA) with photon-counting detector CT (PCD-CT) versus those who underwent CCTA with whole heart coverage energy-integrating detector CT (EID-CT). METHODS In our retrospective single-center study, we included consecutive patients with suspected CAD who underwent CCTA performed with either PCD-CT or a 280-slice EID-CT. The degree of coronary stenosis was classified as no CAD, minimal (1-24 %), mild (25-49 %), moderate (50-69 %), severe stenosis (70-99 %), or occlusion. RESULTS A total of 812 consecutive patients were included in the analysis, 401 patients scanned with EID-CT and 411 patients with PCD-CT (mean age: 58.4 ± 12.4 years, 45.4 % female). Despite the higher total coronary artery calcium score (CACS) in the PCD-CT group (10 [interquartile range (IQR) = 0-152.8] vs 1 [IQR = 0-94], p < 0.001), obstructive CAD was more frequently reported in the EID-CT vs PCD-CT group (no CAD: 28.7 % vs 26.0 %, minimal: 23.2 % vs 30.9 %, mild: 19.7 % vs 23.4 %, moderate: 14.5 % vs 9.7 %, severe: 11.5 % vs 8.5 % and occlusion: 2.5 % vs 1.5 %, respectively, p = 0.025). EID-CT was independently associated with downstream ICA (OR = 2.76 [95%CI = 1.58-4.97] p < 0.001) in the overall patient population, in patients with CACS<400 (OR = 2.18 [95%CI = 1.13-4.39] p = 0.024) and in patients with CACS≥400 (OR = 3.83 [95%CI = 1.42-11.05] p = 0.010). CONCLUSION In patients who underwent CCTA with PCD-CT the number of subsequent ICAs was lower as compared to patients who were scanned with EID-CT. This difference was greater in patients with extensive coronary calcification.
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Affiliation(s)
- Judit Simon
- MTA-SE Cardiovascular Imaging Research Group, Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
| | - Áron Hrenkó
- MTA-SE Cardiovascular Imaging Research Group, Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
| | - Nóra Melinda Kerkovits
- MTA-SE Cardiovascular Imaging Research Group, Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
| | - Kristóf Nagy
- MTA-SE Cardiovascular Imaging Research Group, Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
| | - Miklós Vértes
- MTA-SE Cardiovascular Imaging Research Group, Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
| | - Hanna Balogh
- MTA-SE Cardiovascular Imaging Research Group, Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
| | - Norbert Nagy
- MTA-SE Cardiovascular Imaging Research Group, Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
| | - Tamás Munkácsi
- MTA-SE Cardiovascular Imaging Research Group, Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
| | - Tilman Emrich
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany; Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | | | - Borbála Vattay
- Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Milán Vecsey-Nagy
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA; Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Márton Kolossváry
- Gottsegen National Cardiovascular Center, Budapest, Hungary; Physiological Controls Research Center, University Research and Innovation Center, Óbuda University, Hungary
| | | | - Béla Merkely
- Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Pál Maurovich-Horvat
- MTA-SE Cardiovascular Imaging Research Group, Department of Radiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary.
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Flohr T, Schmidt B, Ulzheimer S, Alkadhi H. Cardiac imaging with photon counting CT. Br J Radiol 2023; 96:20230407. [PMID: 37750856 PMCID: PMC10646663 DOI: 10.1259/bjr.20230407] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/17/2023] [Accepted: 08/24/2023] [Indexed: 09/27/2023] Open
Abstract
CT of the heart, in particular ECG-controlled coronary CT angiography (cCTA), has become clinical routine due to rapid technical progress with ever new generations of CT equipment. Recently, CT scanners with photon-counting detectors (PCD) have been introduced which have the potential to address some of the remaining challenges for cardiac CT, such as limited spatial resolution and lack of high-quality spectral data. In this review article, we briefly discuss the technical principles of photon-counting detector CT, and we give an overview on how the improved spatial resolution of photon-counting detector CT and the routine availability of spectral data can benefit cardiac applications. We focus on coronary artery calcium scoring, cCTA, and on the evaluation of the myocardium.
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Affiliation(s)
- Thomas Flohr
- Siemens Healthcare GmbH, Computed Tomography, Forchheim, Germany
| | - Bernhard Schmidt
- Siemens Healthcare GmbH, Computed Tomography, Forchheim, Germany
| | - Stefan Ulzheimer
- Siemens Healthcare GmbH, Computed Tomography, Forchheim, Germany
| | - Hatem Alkadhi
- Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
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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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Chang S, Ren L, Tang S, Marsh JF, Hsieh S, McCollough CH, Leng S. Technical note: Exploring the detectability of coronary calcification using ultra-high-resolution photon-counting-detector CT. Med Phys 2023; 50:6836-6843. [PMID: 37650788 PMCID: PMC10841095 DOI: 10.1002/mp.16712] [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: 04/01/2023] [Revised: 08/16/2023] [Accepted: 08/16/2023] [Indexed: 09/01/2023] Open
Abstract
BACKGROUND Coronary calcification is a strong indicator of coronary artery disease, and patients with a "zero" coronary calcification score have a much lower risk of future cardiac events than those with even small amounts of calcium. However, false-negative (incorrect zero scores) may occur if small calcifications are missed at CT due to limited spatial resolution. PURPOSE To demonstrate lower limits of detection for coronary calcification using an ultra-high-resolution (UHR) mode on a clinical photon-counting-detector CT (PCD-CT), compared to a conventional energy-integrating-detector CT (EID-CT). METHODS Chicken eggshell fragments (0.4-0.8 mm) mimicking coronary calcifications were scanned on a clinical PCD-CT (NAEOTOM Alpha) in UHR mode and a conventional EID-CT (SOMATOM Force) with matched tube potential and radiation dose levels to the PCD-CT. PCD-CT images were reconstructed with a sharp kernel (Qr68) and a quantum iterative algorithm (QIR-3). Two sets of EID-CT images were reconstructed: routine clinical kernel (Qr36, ADMIRE-3) and a sharper kernel (Qr54) with similar noise to PCD-CT images. With institutional review board approval, in vivo exams performed with the PCD-CT in UHR mode were compared against patients' clinical EID-CT exams. The visibility of calcifications on PCD-CT and EID-CT images was assessed and compared qualitatively. RESULTS PCD-CT images visualized all calcified fragments, while EID-CT failed to detect those below 0.6 mm using a routine protocol. EID-CT with Qr54 improved visibility but distorted boundaries. Calcifications were less visible on EID-CT than PCD-CT as phantom sizes increased. 0.6- and 0.7-mm calcified fragments were barely visible on 35- and 40-cm phantom EID-CT images. Patient cases showed small calcifications missed on EID-CT but detected on PCD-CT. CONCLUSION At matched radiation dose, PCD-CT in UHR mode provided higher spatial resolution and improved the detectability of small calcified fragments for different phantom/patient sizes in comparison to EID-CT.
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Affiliation(s)
- Shaojie Chang
- Department of Radiology, Mayo Clinic, Rochester, MN, US
| | - Liqiang Ren
- Department of Radiology, Mayo Clinic, Rochester, MN, US
| | - Shanshan Tang
- Department of Radiology, Mayo Clinic, Rochester, MN, US
| | | | - Scott Hsieh
- Department of Radiology, Mayo Clinic, Rochester, MN, US
| | | | - Shuai Leng
- Department of Radiology, Mayo Clinic, Rochester, MN, US
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Foldyna B, Basmagi S, Zangeneh FA, Wagner M, Doktorov K, Matveeva A, Denecke T, Gohmann RF, Lücke C, Gutberlet M, Lehmkuhl L. CT-derived coronary artery calcium density is affected by regional lesion distribution and image reconstruction parameters. Clin Imaging 2023; 103:109980. [PMID: 37677856 DOI: 10.1016/j.clinimag.2023.109980] [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: 05/23/2023] [Revised: 08/17/2023] [Accepted: 08/28/2023] [Indexed: 09/09/2023]
Abstract
PURPOSE The prognostic relevance of coronary artery calcium (CAC) density, assessed from cardiac CT scans, is established. However, the influence of CAC distribution, volume, image reconstruction, and clinical factors on CAC density warrants further examination. METHODS In this study, 120 patients underwent non-contrast ECG-gated cardiac CT scans using a prospectively defined CAC scoring protocol with 1-, 3-, and 5-mm thick image reconstructions, both with and without a 20% image overlap. We segmented CAC in all reconstructions and assessed the relationship between CAC density, volume, and number of detected calcifications/patient. RESULTS Overall, 75/120 (63%) patients (66% men, mean age 63 ± 11 years) presented CAC across 342 segments. CAC density, CAC volume, and the number of detected calcifications decreased with increasing slice thickness (p < 0.001 for all); these effects were slightly reduced by image overlap (p < 0.001 for all). Higher CAC density correlated with greater CAC volume (ρ = 0.62; p < 0.001) and more calcified segments per person (ρ = 0.32; p = 0.006). Higher CAC density was also associated with lower patient weight (beta: -0.6, 95%CI: -1.1--0.1, p = 0.022) and increased high-density lipoprotein (HDL) levels (beta: 0.7, 95%CI: 0.0-1.4, p = 0.046). In a multivariable analysis adjusted for clinical covariates, lower CAC density was associated with broader CAC distribution (i.e., a higher number of calcified segments at a given CAC volume; beta-coefficient: -58.9; 95%CI: -84.7 to -33.1; p < 0.001). CONCLUSION CAC density is significantly impacted by regional CAC distribution and image reconstruction, potentially confounding its prognostic value. Accounting for these factors may improve patient risk assessment, management, and cardiovascular health outcomes.
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Affiliation(s)
- Borek Foldyna
- Cardiovascular Imaging Research Center, Massachusetts General Hospital - Harvard Medical School, 165 Cambridge Street, Suite 400, 02114 Boston, USA; Clinic for Radiology, Heart Center Bad Neustadt a.d. Saale, Bad Neustadt a.d. Saale, Germany.
| | - Said Basmagi
- Clinic for Radiology, Heart Center Bad Neustadt a.d. Saale, Bad Neustadt a.d. Saale, Germany
| | | | - Matthias Wagner
- Clinic for Radiology, Heart Center Bad Neustadt a.d. Saale, Bad Neustadt a.d. Saale, Germany
| | - Kalin Doktorov
- Clinic for Radiology, Heart Center Bad Neustadt a.d. Saale, Bad Neustadt a.d. Saale, Germany
| | - Anna Matveeva
- Clinic for Radiology, Heart Center Bad Neustadt a.d. Saale, Bad Neustadt a.d. Saale, Germany
| | - Timm Denecke
- Clinic for Diagnostic and Interventional Radiology, University of Leipzig, Leipzig, Germany
| | - Robin F Gohmann
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig at University of Leipzig, Leipzig, Germany
| | - Christian Lücke
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig at University of Leipzig, Leipzig, Germany
| | - Matthias Gutberlet
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig at University of Leipzig, Leipzig, Germany
| | - Lukas Lehmkuhl
- Clinic for Radiology, Heart Center Bad Neustadt a.d. Saale, Bad Neustadt a.d. Saale, Germany
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10
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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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Meloni A, Cademartiri F, Positano V, Celi S, Berti S, Clemente A, La Grutta L, Saba L, Bossone E, Cavaliere C, Punzo B, Maffei E. Cardiovascular Applications of Photon-Counting CT Technology: A Revolutionary New Diagnostic Step. J Cardiovasc Dev Dis 2023; 10:363. [PMID: 37754792 PMCID: PMC10531582 DOI: 10.3390/jcdd10090363] [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: 08/04/2023] [Revised: 08/16/2023] [Accepted: 08/18/2023] [Indexed: 09/28/2023] Open
Abstract
Photon-counting computed tomography (PCCT) is an emerging technology that can potentially transform clinical CT imaging. After a brief description of the PCCT technology, this review summarizes its main advantages over conventional CT: improved spatial resolution, improved signal and contrast behavior, reduced electronic noise and artifacts, decreased radiation dose, and multi-energy capability with improved material discrimination. Moreover, by providing an overview of the existing literature, this review highlights how the PCCT benefits have been harnessed to enhance and broaden the diagnostic capabilities of CT for cardiovascular applications, including the detection of coronary artery calcifications, evaluation of coronary plaque extent and composition, evaluation of coronary stents, and assessment of myocardial tissue characteristics and perfusion.
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Affiliation(s)
- Antonella Meloni
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
- Unità Operativa Complessa di Bioingegneria, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy
| | - Filippo Cademartiri
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
| | - Vicenzo Positano
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
- Unità Operativa Complessa di Bioingegneria, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy
| | - Simona Celi
- BioCardioLab, Fondazione G. Monasterio CNR-Regione Toscana, 54100 Massa, Italy;
| | - Sergio Berti
- Diagnostic and Interventional Cardiology Department, Fondazione G. Monasterio CNR-Regione Toscana, 54100 Massa, Italy;
| | - Alberto Clemente
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
| | - Ludovico La Grutta
- Department of Radiology, University Hospital “P. Giaccone”, 90127 Palermo, Italy;
| | - Luca Saba
- Department of Radiology, University Hospital of Cagliari, 09042 Monserrato, CA, Italy;
| | - Eduardo Bossone
- Department of Cardiology, Ospedale Cardarelli, 80131 Naples, Italy;
| | - Carlo Cavaliere
- Department of Radiology, Istituto di Ricerca e Cura a Carattere Scientifico SynLab-SDN, 80131 Naples, Italy; (C.C.); (B.P.)
| | - Bruna Punzo
- Department of Radiology, Istituto di Ricerca e Cura a Carattere Scientifico SynLab-SDN, 80131 Naples, Italy; (C.C.); (B.P.)
| | - Erica Maffei
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
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12
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Greffier J, Si-Mohamed SA, Lacombe H, Labour J, Djabli D, Boccalini S, Varasteh M, Villien M, Yagil Y, Erhard K, Boussel L, Beregi JP, Douek PC. Virtual monochromatic images for coronary artery imaging with a spectral photon-counting CT in comparison to dual-layer CT systems: a phantom and a preliminary human study. Eur Radiol 2023; 33:5476-5488. [PMID: 36920517 PMCID: PMC10326132 DOI: 10.1007/s00330-023-09529-9] [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: 07/04/2022] [Revised: 01/09/2023] [Accepted: 02/06/2023] [Indexed: 03/16/2023]
Abstract
OBJECTIVES To evaluate the quality of virtual monochromatic images (VMIs) from spectral photon-counting CT (SPCCT) and two energy-integrating detector dual-energy CT (EID-DECT) scanners from the same manufacturer, for the coronary lumen. METHODS A 21-cm section of the Mercury v4.0 phantom was scanned using a cardiac CT protocol. VMIs from 40 to 90 keV were reconstructed using high-resolution (HR) parameters for EID-DECT and SPCCT (CB and HRB kernels at 0.67 mm slice thickness, respectively). Ultra-high-resolution (UHR) parameters were used in addition to SPCCT (detailed-2 kernel, 0.43 mm slice thickness). Noise-power-spectrum (NPS), task-based transfer function (TTF), and detectability index (d') were computed for 2-mm-diameter lumen detection. In consensus, two radiologists analyzed the quality of the images from 8 patients who underwent coronary CTA on both CT systems. RESULTS For all keV images, fpeak, f50, and d' were higher with SPCCT. The fpeak and f50 were higher with UHR-SPCCT with greater noise and lower d' compared to those of the HR-SPCCT images. Noise magnitude was constant for all energy levels (keV) with both systems, and lower with HR images, and d' decreased as keV decreased. Subjective analysis showed greater lumen sharpness and overall quality for HR and UHR-SPCCT images using all keV, with a greater difference at low keV compared to HR-EID-DECT images. CONCLUSION HR and UHR-SPCCT images gave greater detectability of the coronary lumen for 40 to 90 keV VMIs compared to two EID-DECT systems, with benefits of higher lumen sharpness and overall quality. KEY POINTS • Compared with 2 dual-energy CT systems, spectral photon-counting CT (SPCCT) improved spatial resolution, noise texture, noise magnitude, and detectability of the coronary lumen. • Use of ultra-high-resolution parameters with SPCCT improved spatial resolution and noise texture and provided high detectability of the coronary lumen, despite an increase in noise magnitude. • In eight patients, radiologists found greater overall image quality with SPCCT for all virtual monochromatic images with a greater difference at low keV, compared with dual-energy CT systems.
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Affiliation(s)
- Joel Greffier
- IMAGINE UR UM 103, Montpellier University, Department of Medical Imaging, Nîmes University Hospital, Nîmes, France
| | - Salim A Si-Mohamed
- University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, 7 Avenue Jean Capelle O, 69100, Villeurbanne, France.
- Department of Cardiothoracic Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500, Bron, France.
| | - Hugo Lacombe
- University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, 7 Avenue Jean Capelle O, 69100, Villeurbanne, France
| | - Joey Labour
- University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, 7 Avenue Jean Capelle O, 69100, Villeurbanne, France
| | - Djamel Djabli
- IMAGINE UR UM 103, Montpellier University, Department of Medical Imaging, Nîmes University Hospital, Nîmes, France
| | - Sara Boccalini
- University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, 7 Avenue Jean Capelle O, 69100, Villeurbanne, France
- Department of Cardiothoracic Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500, Bron, France
| | - Mohammad Varasteh
- University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, 7 Avenue Jean Capelle O, 69100, Villeurbanne, France
| | | | | | | | - Loic Boussel
- University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, 7 Avenue Jean Capelle O, 69100, Villeurbanne, France
- Department of Cardiothoracic Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500, Bron, France
- Department of Radiology, Croix Rousse Hospital, Hospices Civils de Lyon, 103 Gd Rue de la Croix-Rousse, 69004, Lyon, France
| | - Jean-Paul Beregi
- IMAGINE UR UM 103, Montpellier University, Department of Medical Imaging, Nîmes University Hospital, Nîmes, France
| | - Philippe C Douek
- University Lyon, INSA-Lyon, University Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, 7 Avenue Jean Capelle O, 69100, Villeurbanne, France
- Department of Cardiothoracic Radiology, Louis Pradel Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500, Bron, France
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13
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Dobrolinska MM, van der Werf NR, van der Bie J, de Groen J, Dijkshoorn M, Booij R, Budde RPJ, Greuter MJW, van Straten M. Radiation dose optimization for photon-counting CT coronary artery calcium scoring for different patient sizes: a dynamic phantom study. Eur Radiol 2023; 33:4668-4675. [PMID: 36729174 PMCID: PMC10290002 DOI: 10.1007/s00330-023-09434-1] [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: 10/19/2022] [Revised: 10/19/2022] [Accepted: 01/07/2023] [Indexed: 02/03/2023]
Abstract
PURPOSE To systematically assess the radiation dose reduction potential of coronary artery calcium (CAC) assessments with photon-counting computed tomography (PCCT) by changing the tube potential for different patient sizes with a dynamic phantom. METHODS A hollow artery, containing three calcifications of different densities, was translated at velocities corresponding to 0, < 60, 60-75, and > 75 beats per minute within an anthropomorphic phantom. Extension rings were used to simulate average- and large -sized patients. PCCT scans were made with the reference clinical protocol (tube potential of 120 kilovolt (kV)), and with 70, 90, Sn100, Sn140, and 140 kV at identical image quality levels. All acquisitions were reconstructed at a virtual monoenergetic energy level of 70 keV. For each calcification, Agatston scores and contrast-to-noise ratios (CNR) were determined, and compared to the reference with Wilcoxon signed-rank tests, with p < 0.05 indicating significant differences. RESULTS A decrease in radiation dose (22%) was achieved at Sn100 kV for the average-sized phantom. For the large phantom, Sn100 and Sn140 kV resulted in a decrease in radiation doses of 19% and 3%, respectively. Irrespective of CAC density, Sn100 and 140 kVp did not result in significantly different CNR. Only at Sn100 kV were there no significant differences in Agatston scores for all CAC densities, heart rates, and phantom sizes. CONCLUSION PCCT at tube voltage of 100 kV with added tin filtration and reconstructed at 70 keV enables a ≥ 19% dose reduction compared to 120 kV, independent of phantom size, CAC density, and heart rate. KEY POINTS • Photon-counting CT allows for reduced radiation dose acquisitions (up to 19%) for coronary calcium assessment by reducing tube voltage while reconstructing at a normal monoE level of 70 keV. • Tube voltage reduction is possible for medium and large patient sizes, without affecting the Agatston score outcome.
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Affiliation(s)
- Magdalena M Dobrolinska
- Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Division of Cardiology and Structural Heart Diseases, Medical University of Silesiain , Katowice, Katowice, Poland
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Niels R van der Werf
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Judith van der Bie
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Joël de Groen
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marcel Dijkshoorn
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ronald Booij
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ricardo P J Budde
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marcel J W Greuter
- Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Department of Robotics and Mechatronics, University of Twente, Enschede, The Netherlands
| | - Marcel van Straten
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
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14
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McCollough CH, Rajendran K, Leng S. Standardization and Quantitative Imaging With Photon-Counting Detector CT. Invest Radiol 2023; 58:451-458. [PMID: 36728452 PMCID: PMC10272018 DOI: 10.1097/rli.0000000000000948] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
ABSTRACT Computed tomography (CT) images display anatomic structures across 3 dimensions and are highly quantitative; they are the reference standard for 3-dimensional geometric measurements and are used for 3-dimensional printing of anatomic models and custom implants, as well as for radiation therapy treatment planning. The pixel intensity in CT images represents the linear x-ray attenuation coefficient of the imaged materials after linearly scaling the coefficients into a quantity known as CT numbers that is conveyed in Hounsfield units. When measured with the same scanner model, acquisition, and reconstruction parameters, the mean CT number of a material is highly reproducible, and quantitative applications of CT scanning that rely on the measured CT number, such as for assessing bone mineral density or coronary artery calcification, are well established. However, the strong dependence of CT numbers on x-ray beam spectra limits quantitative applications and standardization from achieving robust widespread success. This article reviews several quantitative applications of CT and the challenges they face, and describes the benefits brought by photon-counting detector (PCD) CT technology. The discussed benefits of PCD-CT include that it is inherently multienergy, expands material decomposition capabilities, and improves spatial resolution and geometric quantification. Further, the utility of virtual monoenergetic images to standardize CT numbers is discussed, as virtual monoenergetic images can be the default image type in PCD-CT due to the full-time spectral nature of the technology.
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Affiliation(s)
- Cynthia H. McCollough
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
| | - Kishore Rajendran
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
| | - Shuai Leng
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
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15
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Zsarnóczay E, Varga-Szemes A, Emrich T, Szilveszter B, van der Werf NR, Mastrodicasa D, Maurovich-Horvat P, Willemink MJ. Characterizing the Heart and the Myocardium With Photon-Counting CT. Invest Radiol 2023; 58:505-514. [PMID: 36822653 DOI: 10.1097/rli.0000000000000956] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
ABSTRACT Noninvasive cardiac imaging has rapidly evolved during the last decade owing to improvements in computed tomography (CT)-based technologies, among which we highlight the recent introduction of the first clinical photon-counting detector CT (PCD-CT) system. Multiple advantages of PCD-CT have been demonstrated, including increased spatial resolution, decreased electronic noise, and reduced radiation exposure, which may further improve diagnostics and may potentially impact existing management pathways. The benefits that can be obtained from the initial experiences with PCD-CT are promising. The implementation of this technology in cardiovascular imaging allows for the quantification of coronary calcium, myocardial extracellular volume, myocardial radiomics features, epicardial and pericoronary adipose tissue, and the qualitative assessment of coronary plaques and stents. This review aims to discuss these major applications of PCD-CT with a focus on cardiac and myocardial characterization.
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Affiliation(s)
| | - Akos Varga-Szemes
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston
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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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17
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Cademartiri F, Meloni A, Pistoia L, Degiorgi G, Clemente A, Gori CD, Positano V, Celi S, Berti S, Emdin M, Panetta D, Menichetti L, Punzo B, Cavaliere C, Bossone E, Saba L, Cau R, Grutta LL, Maffei E. Dual-Source Photon-Counting Computed Tomography-Part I: Clinical Overview of Cardiac CT and Coronary CT Angiography Applications. J Clin Med 2023; 12:jcm12113627. [PMID: 37297822 DOI: 10.3390/jcm12113627] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/15/2023] [Accepted: 05/17/2023] [Indexed: 06/12/2023] Open
Abstract
The photon-counting detector (PCD) is a new computed tomography detector technology (photon-counting computed tomography, PCCT) that provides substantial benefits for cardiac and coronary artery imaging. Compared with conventional CT, PCCT has multi-energy capability, increased spatial resolution and soft tissue contrast with near-null electronic noise, reduced radiation exposure, and optimization of the use of contrast agents. This new technology promises to overcome several limitations of traditional cardiac and coronary CT angiography (CCT/CCTA) including reduction in blooming artifacts in heavy calcified coronary plaques or beam-hardening artifacts in patients with coronary stents, and a more precise assessment of the degree of stenosis and plaque characteristic thanks to its better spatial resolution. Another potential application of PCCT is the use of a double-contrast agent to characterize myocardial tissue. In this current overview of the existing PCCT literature, we describe the strengths, limitations, recent applications, and promising developments of employing PCCT technology in CCT.
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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, Italy
| | - Riccardo Cau
- Department of Radiology, University Hospital, 09042 Monserrato, Italy
| | - Ludovico La Grutta
- 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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18
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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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19
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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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20
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Photon Counting Detector CT-Based Virtual Noniodine Reconstruction Algorithm for In Vitro and In Vivo Coronary Artery Calcium Scoring: Impact of Virtual Monoenergetic and Quantum Iterative Reconstructions. Invest Radiol 2023:00004424-990000000-00091. [PMID: 36822677 DOI: 10.1097/rli.0000000000000959] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
OBJECTIVES The aim of this study was to evaluate the impact of virtual monoenergetic imaging (VMI) and quantum iterative reconstruction (QIR) on the accuracy of coronary artery calcium scoring (CACS) using a virtual noniodine (VNI) reconstruction algorithm on a first-generation, clinical, photon counting detector computed tomography system. MATERIALS AND METHODS Coronary artery calcium scoring was evaluated in an anthropomorphic chest phantom simulating 3 different patient sizes by using 2 extension rings (small: 300 × 200 mm, medium: 350 × 250 mm, large: 400 × 300 mm) and in patients (n = 61; final analyses only in patients with coronary calcifications [n = 34; 65.4 ± 10.0 years; 73.5% male]), who underwent nonenhanced and contrast-enhanced, electrocardiogram-gated, cardiac computed tomography on a photon counting detector system. Phantom and patient data were reconstructed using a VNI reconstruction algorithm at different VMI (55-80 keV) and QIR (strength 1-4) levels (CACSVNI). True noncontrast (TNC) scans at 70 keV and QIR "off" were used as reference for phantom and patient studies (CACSTNC). RESULTS In vitro and in vivo CACSVNI showed strong correlation (r > 0.9, P < 0.001 for all) and excellent agreement (intraclass correlation coefficient > 0.9 for all) with CACSTNC at all investigated VMI and QIR levels. Phantom and patient CACSVNI significantly increased with decreasing keV levels (in vitro: from 475.2 ± 26.3 at 80 keV up to 652.5 ± 42.2 at 55 keV; in vivo: from 142.5 [7.4/737.7] at 80 keV up to 248.1 [31.2/1144] at 55 keV; P < 0.001 for all), resulting in an overestimation of CACSVNI at 55 keV compared with CACSTNC at 70 keV in some cases (in vitro: 625.8 ± 24.4; in vivo: 225.4 [35.1/959.7]). In vitro CACS increased with rising QIR at low keV. In vivo scores were significantly higher at QIR 1 compared with QIR 4 only at 60 and 80 keV (60 keV: 220.3 [29.6-1060] vs 219.5 [23.7/1048]; 80 keV: 152.0 [12.0/735.6] vs 142.5 [7.4/737.7]; P < 0.001). CACSVNI was closest to CACSTNC at 60 keV, QIR 2 (+0.1%) in the small; 55 keV, QIR 1 (±0%) in the medium; 55 keV, QIR 4 (-0.1%) in the large phantom; and at 60 keV, QIR 1 (-2.3%) in patients. CONCLUSIONS Virtual monoenergetic imaging reconstructions have a significant impact on CACSVNI. The effects of different QIR levels are less consistent and seem to depend on several individual conditions, which should be further investigated.
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21
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Wolf EV, Halfmann MC, Schoepf UJ, Zsarnoczay E, Fink N, Griffith JP, Aquino GJ, Willemink MJ, O’Doherty J, Hell MM, Suranyi P, Kabakus IM, Baruah D, Varga-Szemes A, Emrich T. Intra-individual comparison of coronary calcium scoring between photon counting detector- and energy integrating detector-CT: Effects on risk reclassification. Front Cardiovasc Med 2023; 9:1053398. [PMID: 36741832 PMCID: PMC9892711 DOI: 10.3389/fcvm.2022.1053398] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 12/28/2022] [Indexed: 01/20/2023] Open
Abstract
Purpose To compare coronary artery calcium volume and score (CACS) between photon-counting detector (PCD) and conventional energy integrating detector (EID) computed tomography (CT) in a phantom and prospective patient study. Methods A commercially available CACS phantom was scanned with a standard CACS protocol (120 kVp, slice thickness/increment 3/1.5 mm, and a quantitative Qr36 kernel), with filtered back projection on the EID-CT, and with monoenergetic reconstruction at 70 keV and quantum iterative reconstruction off on the PCD-CT. The same settings were used to prospectively acquire data in patients (n = 23, 65 ± 12.1 years), who underwent PCD- and EID-CT scans with a median of 5.5 (3.0-12.5) days between the two scans in the period from August 2021 to March 2022. CACS was quantified using a commercially available software solution. A regression formula was obtained from the aforementioned comparison and applied to simulate risk reclassification in a pre-existing cohort of 514 patients who underwent a cardiac EID-CT between January and December 2021. Results Based on the phantom experiment, CACS PCD-CT showed a more accurate measurement of the reference CAC volumes (overestimation of physical volumes: PCD-CT 66.1 ± 1.6% vs. EID-CT: 77.2 ± 0.5%). CACS EID-CT and CACS PCD-CT were strongly correlated, however, the latter measured significantly lower values in the phantom (CACS PCD-CT : 60.5 (30.2-170.3) vs CACS EID-CT 74.7 (34.6-180.8), p = 0.0015, r = 0.99, mean bias -9.7, Limits of Agreement (LoA) -36.6/17.3) and in patients (non-significant) (CACS PCD-CT : 174.3 (11.1-872.7) vs CACS EID-CT 218.2 (18.5-876.4), p = 0.10, r = 0.94, mean bias -41.1, LoA -315.3/232.5). The systematic lower measurements of Agatston score on PCD-CT system led to reclassification of 5.25% of our simulated patient cohort to a lower classification class. Conclusion CACS PCD-CT is feasible and correlates strongly with CACS EID-CT , however, leads to lower CACS values. PCD-CT may provide results that are more accurate for CACS than EID-CT.
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Affiliation(s)
- Elias V. Wolf
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany,Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Moritz C. Halfmann
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany,German Centre for Cardiovascular Research, Partner Site Rhine-Main, Mainz, Germany
| | - U. Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Emese Zsarnoczay
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States,MTA-SE Cardiovascular Imaging Research Group, Medical Imaging Center, Semmelweis University, Budapest, Hungary
| | - Nicola Fink
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States,Department of Radiology, University Hospital Munich, LMU Munich, Munich, Germany
| | - Joseph P. Griffith
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Gilberto J. Aquino
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Martin J. Willemink
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, United States,Segmed, Inc., Palo Alto, CA, United States
| | - Jim O’Doherty
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States,Siemens Medical Solutions USA, Inc., Malvern, PA, United States
| | - Michaela M. Hell
- Department of Cardiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Pal Suranyi
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Ismael M. Kabakus
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Dhiraj Baruah
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Tilman Emrich
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany,Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States,German Centre for Cardiovascular Research, Partner Site Rhine-Main, Mainz, Germany,*Correspondence: Tilman Emrich,
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22
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Greffier J, Villani N, Defez D, Dabli D, Si-Mohamed S. Spectral CT imaging: Technical principles of dual-energy CT and multi-energy photon-counting CT. Diagn Interv Imaging 2022; 104:167-177. [PMID: 36414506 DOI: 10.1016/j.diii.2022.11.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 11/11/2022] [Indexed: 11/21/2022]
Abstract
Spectral computed tomography (CT) imaging encompasses a unique generation of CT systems based on a simple principle that makes use of the energy-dependent information present in CT images. Over the past two decades this principle has been expanded with the introduction of dual-energy CT systems. The first generation of spectral CT systems, represented either by dual-source or dual-layer technology, opened up a new imaging approach in the radiology community with their ability to overcome the limitations of tissue characterization encountered with conventional CT. Its expansion worldwide can also be considered as an important leverage for the recent groundbreaking technology based on a new chain of detection available on photon counting CT systems, which holds great promise for extending CT towards multi-energy CT imaging. The purpose of this article was to detail the basic principles and techniques of spectral CT with a particular emphasis on the newest technical developments of dual-energy and multi-energy CT systems.
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23
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van der Werf NR, Booij R, Greuter MJW, Bos D, van der Lugt A, Budde RPJ, van Straten M. Reproducibility of coronary artery calcium quantification on dual-source CT and dual-source photon-counting CT: a dynamic phantom study. Int J Cardiovasc Imaging 2022; 38:1613-1619. [PMID: 35113282 PMCID: PMC11142942 DOI: 10.1007/s10554-022-02540-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 01/24/2022] [Indexed: 12/19/2022]
Abstract
To systematically compare coronary artery calcium (CAC) quantification between conventional computed tomography (CT) and photon-counting CT (PCCT) at different virtual monoenergetic (monoE) levels for different heart rates. A dynamic (heart rates of 0, < 60, 60-75, and > 75 bpm) anthropomorphic phantom with three calcification densities was scanned using routine clinical CAC protocols with CT and PCCT. In addition to the standard clinical protocol of 70 keV, PCCT images were reconstructed at monoE levels of 72, 74, and 76 keV. CAC was quantified using Agatston, volume, and mass scores. Agatston scores 95% confidence intervals (CI) were calculated and compared between PCCT and CT. Volume and mass scores were compared with physical quantities. For all CAC densities, routine clinical protocol Agatston scores of static CAC were higher for PCCT compared to CT. At < 60 bpm, Agatston scores at 74 and 76 keV reconstructions were reproducible (overlapping CI) for PCCT and CT. Increased heart rates yielded different Agatston scores for PCCT in comparison with CT, for all monoE levels. Low density CAC volume scores showed the largest deviation from physical volume, with mean deviations of 59% and 77% for CT and PCCT, respectively. Overall, mass scores underestimated physical mass by 10%, 38%, and 59% for low, medium, and high density CAC, respectively. PCCT allows for reproducible Agatston scores for dynamic CAC (< 60 bpm) when reconstructed at monoE levels of 74 or 76 keV, regardless of CAC density. Deviations from physical volume and mass were, in general, large for both CT and PCCT.
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Affiliation(s)
- Niels R van der Werf
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Ronald Booij
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marcel J W Greuter
- Department of Radiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Robotics and Mechatronics, University of Twente, Enschede, The Netherlands
| | - Daniel Bos
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - A van der Lugt
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - R P J Budde
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marcel van Straten
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
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24
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van der Werf NR, Rodesch PA, Si-Mohamed S, van Hamersvelt RW, Greuter MJW, Leiner T, Boussel L, Willemink MJ, Douek P. Improved coronary calcium detection and quantification with low-dose full field-of-view photon-counting CT: a phantom study. Eur Radiol 2022; 32:3447-3457. [PMID: 34997284 DOI: 10.1007/s00330-021-08421-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 08/31/2021] [Accepted: 10/17/2021] [Indexed: 12/19/2022]
Abstract
OBJECTIVE The aim of the current study was to systematically assess coronary artery calcium (CAC) detection and quantification for spectral photon-counting CT (SPCCT) in comparison to conventional CT and, in addition, to evaluate the possibility of radiation dose reduction. METHODS Routine clinical CAC CT protocols were used for data acquisition and reconstruction of two CAC containing cylindrical inserts which were positioned within an anthropomorphic thorax phantom. In addition, data was acquired at 50% lower radiation dose by reducing tube current, and slice thickness was decreased. Calcifications were considered detectable when three adjacent voxels exceeded the CAC scoring threshold of 130 Hounsfield units (HU). Quantification of CAC (as volume and mass score) was assessed by comparison with known physical quantities. RESULTS In comparison with CT, SPCCT detected 33% and 7% more calcifications for the small and large phantoms, respectively. At reduced radiation dose and reduced slice thickness, small phantom CAC detection increased by 108% and 150% for CT and SPCCT, respectively. For the large phantom size, noise levels interfered with CAC detection. Although comparable between CT and SPCCT, routine protocols CAC quantification showed large deviations (up to 134%) from physical CAC volume. At reduced radiation dose and slice thickness, physical volume overestimations decreased to 96% and 72% for CT and SPCCT, respectively. In comparison with volume scores, mass score deviations from physical quantities were smaller. CONCLUSION CAC detection on SPCCT is superior to CT, and was even preserved at a reduced radiation dose. Furthermore, SPCCT allows for improved physical volume estimation. KEY POINTS • In comparison with conventional CT, increased coronary artery calcium detection (up to 156%) for spectral photon-counting CT was found, even at 50% radiation dose reduction. • Spectral photon-counting CT can more accurately measure physical volumes than conventional CT, especially at reduced slice thickness and for high-density coronary artery calcium. • For both conventional and spectral photon-counting CT, reduced slice thickness reconstructions result in more accurate physical mass approximation.
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Affiliation(s)
- N R van der Werf
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands. .,Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - P A Rodesch
- Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Lyon, France.,Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, Lyon, France
| | - S Si-Mohamed
- Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Lyon, France.,Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, Lyon, France
| | - R W van Hamersvelt
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - M J W Greuter
- Department of Radiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - T Leiner
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - L Boussel
- Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Lyon, France.,Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, Lyon, France
| | - M J Willemink
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - P Douek
- Louis Pradel Cardiology Hospital, Hospices Civils de Lyon, Lyon, France.,Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, Lyon, France
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25
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Skoog S, Henriksson L, Gustafsson H, Sandstedt M, Elvelind S, Persson A. Comparison of the Agatston score acquired with photon-counting detector CT and energy-integrating detector CT: ex vivo study of cadaveric hearts. Int J Cardiovasc Imaging 2022; 38:1145-1155. [PMID: 34988781 PMCID: PMC11142966 DOI: 10.1007/s10554-021-02494-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 12/10/2021] [Indexed: 11/05/2022]
Abstract
The purpose of this study was to compare the correlation and agreement between AS derived from either an energy-integrating detector CT (EID-CT) or a photon-counting detector CT (PCD-CT). Reproducibility was also compared. In total, 26 calcified coronary lesions (from five cadaveric hearts) were identified for inclusion. The hearts were positioned in a chest phantom and scanned in both an EID-CT and a prototype PCD-CT. The EID-CT and PCD-CT acquisition and reconstruction parameters were matched. To evaluate the reproducibility, the phantom was manually repositioned, and an additional scan was performed using both methods. The EID-CT reconstructions were performed using the dedicated calcium score kernel Sa36. The PCD-CT reconstructions were performed with a vendor-recommended kernel (Qr36). Several monoenergetic energy levels (50-150 keV) were evaluated to find the closest match with the EID-CT scans. A semi-automatic evaluation of calcium score was performed on a post-processing multimodality workplace. The best match with Sa36 was PCD-CT Qr36 images, at a monoenergetic level of 72 keV. Statistical analyses showed excellent correlation and agreement. The correlation and agreement with regards to the Agatston score (AS) between the two methods, for each position as well as between the two positions for each method, were assessed with the Spearman´s rank correlation. The correlation coefficient, rho, was 0.98 and 0.97 respectively 0.99 and 0.98. The corresponding agreements were investigated by means of Bland-Altman plots. High correlation and agreement was observed between the AS derived from the EID-CT and a PCD-CT. Both methods also demonstrated excellent reproducibility.
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Affiliation(s)
- Susann Skoog
- Department of Radiology and Department of Health, Medicine and Caring Sciences, Linköping University, 581 85, Linköping, Sweden.
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
| | - Lilian Henriksson
- Department of Radiology and Department of Health, Medicine and Caring Sciences, Linköping University, 581 85, Linköping, Sweden
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Håkan Gustafsson
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
- Department of Medical Radiation Physics, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Mårten Sandstedt
- Department of Radiology and Department of Health, Medicine and Caring Sciences, Linköping University, 581 85, Linköping, Sweden
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Sebastian Elvelind
- Department of Clinical Pathology, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Anders Persson
- Department of Radiology and Department of Health, Medicine and Caring Sciences, Linköping University, 581 85, Linköping, Sweden
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
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Tortora M, Gemini L, D’Iglio I, Ugga L, Spadarella G, Cuocolo R. Spectral Photon-Counting Computed Tomography: A Review on Technical Principles and Clinical Applications. J Imaging 2022; 8:jimaging8040112. [PMID: 35448239 PMCID: PMC9029331 DOI: 10.3390/jimaging8040112] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/11/2022] [Accepted: 04/14/2022] [Indexed: 01/01/2023] Open
Abstract
Photon-counting computed tomography (CT) is a technology that has attracted increasing interest in recent years since, thanks to new-generation detectors, it holds the promise to radically change the clinical use of CT imaging. Photon-counting detectors overcome the major limitations of conventional CT detectors by providing very high spatial resolution without electronic noise, providing a higher contrast-to-noise ratio, and optimizing spectral images. Additionally, photon-counting CT can lead to reduced radiation exposure, reconstruction of higher spatial resolution images, reduction of image artifacts, optimization of the use of contrast agents, and create new opportunities for quantitative imaging. The aim of this review is to briefly explain the technical principles of photon-counting CT and, more extensively, the potential clinical applications of this technology.
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Affiliation(s)
- Mario Tortora
- Department of Advanced Biomedical Sciences, University of Naples “Federico II”, Via Sergio Pansini 5, 80131 Naples, Italy; (M.T.); (L.G.); (I.D.); (L.U.); (G.S.)
| | - Laura Gemini
- Department of Advanced Biomedical Sciences, University of Naples “Federico II”, Via Sergio Pansini 5, 80131 Naples, Italy; (M.T.); (L.G.); (I.D.); (L.U.); (G.S.)
| | - Imma D’Iglio
- Department of Advanced Biomedical Sciences, University of Naples “Federico II”, Via Sergio Pansini 5, 80131 Naples, Italy; (M.T.); (L.G.); (I.D.); (L.U.); (G.S.)
| | - Lorenzo Ugga
- Department of Advanced Biomedical Sciences, University of Naples “Federico II”, Via Sergio Pansini 5, 80131 Naples, Italy; (M.T.); (L.G.); (I.D.); (L.U.); (G.S.)
| | - Gaia Spadarella
- Department of Advanced Biomedical Sciences, University of Naples “Federico II”, Via Sergio Pansini 5, 80131 Naples, Italy; (M.T.); (L.G.); (I.D.); (L.U.); (G.S.)
| | - Renato Cuocolo
- Department of Clinical Medicine and Surgery, University of Naples “Federico II”, Via Sergio Pansini 5, 80131 Naples, Italy
- Department of Medicine, Surgery and Dentistry, University of Salerno, Via Salvador Allende 43, 84081 Baronissi, Italy
- Correspondence:
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Mergen V, Higashigaito K, Allmendinger T, Manka R, Euler A, Alkadhi H, Eberhard M. Tube voltage-independent coronary calcium scoring on a first-generation dual-source photon-counting CT-a proof-of-principle phantom study. THE INTERNATIONAL JOURNAL OF CARDIOVASCULAR IMAGING 2022; 38:905-912. [PMID: 34780012 DOI: 10.1007/s10554-021-02466-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 11/02/2021] [Indexed: 10/19/2022]
Abstract
To evaluate the accuracy of coronary artery calcium (CAC) scoring at various tube voltages and different monoenergetic image reconstructions on a first-generation dual-source photon-counting detector CT (PCD-CT). A commercially available anthropomorphic chest phantom with calcium inserts was scanned at different tube voltages (90 kV, Sn100kV, 120 kV, and Sn140kV) on a first-generation dual-source PCD-CT system with quantum technology using automatic exposure control with an image quality (IQ) level of 20. The same phantom was also scanned on a conventional energy-integrating detector CT (120 kV; weighted filtered back projection) for reference. Extension rings were used to emulate different patient sizes. Virtual monoenergetic images at 65 keV and 70 keV applying different levels of quantum iterative reconstruction (QIR) were reconstructed from the PCD-CT data sets. CAC scores were determined and compared to the reference. Radiation doses were noted. At an IQ level of 20, radiation doses ranged between 1.18 mGy and 4.64 mGy, depending on the tube voltage and phantom size. Imaging at 90 kV or Sn100kV was associated with a size-dependent radiation dose reduction between 23% and 48% compared to 120 kV. Tube voltage adapted image reconstructions with 65 keV and QIR 3 at 90 kV and with 70 keV and QIR 1 at Sn100kV allowed to calculate CAC scores comparable to conventional EID-CT scans with a percentage deviation of ≤ 5% for all phantom sizes. Our phantom study indicates that CAC scoring with dual-source PCD-CT is accurate at various tube voltages, offering the possibility of substantial radiation dose reduction.
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Affiliation(s)
- V Mergen
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, CH-8091, Zurich, Switzerland
| | - K Higashigaito
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, CH-8091, Zurich, Switzerland
| | | | - R Manka
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, CH-8091, Zurich, Switzerland
- Department of Cardiology, University Heart Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - A Euler
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, CH-8091, Zurich, Switzerland
| | - H Alkadhi
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, CH-8091, Zurich, Switzerland
| | - M Eberhard
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, CH-8091, Zurich, Switzerland.
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Coronary Computed Tomography Angiography-Based Calcium Scoring: In Vitro and In Vivo Validation of a Novel Virtual Noniodine Reconstruction Algorithm on a Clinical, First-Generation Dual-Source Photon Counting-Detector System. Invest Radiol 2022; 57:536-543. [PMID: 35318969 DOI: 10.1097/rli.0000000000000868] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The aim of this study was to evaluate coronary computed tomography angiography (CCTA)-based in vitro and in vivo coronary artery calcium scoring (CACS) using a novel virtual noniodine reconstruction (PureCalcium) on a clinical first-generation photon-counting detector-computed tomography system compared with virtual noncontrast (VNC) reconstructions and true noncontrast (TNC) acquisitions. MATERIALS AND METHODS Although CACS and CCTA are well-established techniques for the assessment of coronary artery disease, they are complementary acquisitions, translating into increased scan time and patient radiation dose. Hence, accurate CACS derived from a single CCTA acquisition would be highly desirable. In this study, CACS based on PureCalcium, VNC, and TNC, reconstructions was evaluated in a CACS phantom and in 67 patients (70 [59/80] years, 58.2% male) undergoing CCTA on a first-generation photon counting detector-computed tomography system. Coronary artery calcium scores were quantified for the 3 reconstructions and compared using Wilcoxon test. Agreement was evaluated by Pearson and Spearman correlation and Bland-Altman analysis. Classification of coronary artery calcium score categories (0, 1-10, 11-100, 101-400, and >400) was compared using Cohen κ. RESULTS Phantom studies demonstrated strong agreement between CACSPureCalcium and CACSTNC (60.7 ± 90.6 vs 67.3 ± 88.3, P = 0.01, r = 0.98, intraclass correlation [ICC] = 0.98; mean bias, 6.6; limits of agreement [LoA], -39.8/26.6), whereas CACSVNC showed a significant underestimation (42.4 ± 75.3 vs 67.3 ± 88.3, P < 0.001, r = 0.94, ICC = 0.89; mean bias, 24.9; LoA, -87.1/37.2). In vivo comparison confirmed a high correlation but revealed an underestimation of CACSPureCalcium (169.3 [0.7/969.4] vs 232.2 [26.5/1112.2], P < 0.001, r = 0.97, ICC = 0.98; mean bias, -113.5; LoA, -470.2/243.2). In comparison, CACSVNC showed a similarly high correlation, but a substantially larger underestimation (24.3 [0/272.3] vs 232.2 [26.5/1112.2], P < 0.001, r = 0.97, ICC = 0.54; mean bias, -551.6; LoA, -2037.5/934.4). CACSPureCalcium showed superior agreement of CACS classification (κ = 0.88) than CACSVNC (κ = 0.60). CONCLUSIONS The accuracy of CACS quantification and classification based on PureCalcium reconstructions of CCTA outperforms CACS derived from VNC reconstructions.
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Schuijf JD, Lima JA, Boedeker KL, Takagi H, Tanaka R, Yoshioka K, Arbab-Zadeh A. CT imaging with ultra-high-resolution: opportunities for cardiovascular imaging in clinical practice. J Cardiovasc Comput Tomogr 2022; 16:388-396. [DOI: 10.1016/j.jcct.2022.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 02/03/2022] [Accepted: 02/05/2022] [Indexed: 10/19/2022]
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Rotzinger DC, Racine D, Becce F, Lahoud E, Erhard K, Si-Mohamed SA, Greffier J, Viry A, Boussel L, Meuli RA, Yagil Y, Monnin P, Douek PC. Performance of Spectral Photon-Counting Coronary CT Angiography and Comparison with Energy-Integrating-Detector CT: Objective Assessment with Model Observer. Diagnostics (Basel) 2021; 11:2376. [PMID: 34943611 PMCID: PMC8700425 DOI: 10.3390/diagnostics11122376] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/02/2021] [Accepted: 12/14/2021] [Indexed: 11/16/2022] Open
Abstract
AIMS To evaluate spectral photon-counting CT's (SPCCT) objective image quality characteristics in vitro, compared with standard-of-care energy-integrating-detector (EID) CT. METHODS We scanned a thorax phantom with a coronary artery module at 10 mGy on a prototype SPCCT and a clinical dual-layer EID-CT under various conditions of simulated patient size (small, medium, and large). We used filtered back-projection with a soft-tissue kernel. We assessed noise and contrast-dependent spatial resolution with noise power spectra (NPS) and target transfer functions (TTF), respectively. Detectability indices (d') of simulated non-calcified and lipid-rich atherosclerotic plaques were computed using the non-pre-whitening with eye filter model observer. RESULTS SPCCT provided lower noise magnitude (9-38% lower NPS amplitude) and higher noise frequency peaks (sharper noise texture). Furthermore, SPCCT provided consistently higher spatial resolution (30-33% better TTF10). In the detectability analysis, SPCCT outperformed EID-CT in all investigated conditions, providing superior d'. SPCCT reached almost perfect detectability (AUC ≈ 95%) for simulated 0.5-mm-thick non-calcified plaques (for large-sized patients), whereas EID-CT had lower d' (AUC ≈ 75%). For lipid-rich atherosclerotic plaques, SPCCT achieved 85% AUC vs. 77.5% with EID-CT. CONCLUSIONS SPCCT outperformed EID-CT in detecting simulated coronary atherosclerosis and might enhance diagnostic accuracy by providing lower noise magnitude, markedly improved spatial resolution, and superior lipid core detectability.
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Affiliation(s)
- David C. Rotzinger
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV), Rue du Bugnon 46, CH 1011 Lausanne, Switzerland; (F.B.); (R.A.M.)
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), CH 1015 Lausanne, Switzerland; (D.R.); (A.V.); (P.M.)
| | - Damien Racine
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), CH 1015 Lausanne, Switzerland; (D.R.); (A.V.); (P.M.)
- Institute of Radiation Physics, Lausanne University Hospital (CHUV), CH 1007 Lausanne, Switzerland
| | - Fabio Becce
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV), Rue du Bugnon 46, CH 1011 Lausanne, Switzerland; (F.B.); (R.A.M.)
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), CH 1015 Lausanne, Switzerland; (D.R.); (A.V.); (P.M.)
| | - Elias Lahoud
- CT/AMI Research and Development, Philips Medical Systems, Haifa 31004, Israel; (E.L.); (Y.Y.)
| | - Klaus Erhard
- Philips GmbH Innovative Technologies, Philips Research Laboratories, 22335 Hamburg, Germany;
| | - Salim A. Si-Mohamed
- Radiology Department, Hospices Civils de Lyon, 69500 Lyon, France; (S.A.S.-M.); (L.B.); (P.C.D.)
- Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, CREATIS, CNRS UMR 5220, INSERM U1206, INSA-Lyon, 69100 Lyon, France
| | - Joël Greffier
- Department of Medical Imaging, CHU Nimes, University of Montpellier, 30900 Nimes, France;
| | - Anaïs Viry
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), CH 1015 Lausanne, Switzerland; (D.R.); (A.V.); (P.M.)
- Institute of Radiation Physics, Lausanne University Hospital (CHUV), CH 1007 Lausanne, Switzerland
| | - Loïc Boussel
- Radiology Department, Hospices Civils de Lyon, 69500 Lyon, France; (S.A.S.-M.); (L.B.); (P.C.D.)
- Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, CREATIS, CNRS UMR 5220, INSERM U1206, INSA-Lyon, 69100 Lyon, France
| | - Reto A. Meuli
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV), Rue du Bugnon 46, CH 1011 Lausanne, Switzerland; (F.B.); (R.A.M.)
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), CH 1015 Lausanne, Switzerland; (D.R.); (A.V.); (P.M.)
| | - Yoad Yagil
- CT/AMI Research and Development, Philips Medical Systems, Haifa 31004, Israel; (E.L.); (Y.Y.)
| | - Pascal Monnin
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), CH 1015 Lausanne, Switzerland; (D.R.); (A.V.); (P.M.)
- Institute of Radiation Physics, Lausanne University Hospital (CHUV), CH 1007 Lausanne, Switzerland
| | - Philippe C. Douek
- Radiology Department, Hospices Civils de Lyon, 69500 Lyon, France; (S.A.S.-M.); (L.B.); (P.C.D.)
- Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, CREATIS, CNRS UMR 5220, INSERM U1206, INSA-Lyon, 69100 Lyon, France
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Spectral Photon-Counting CT Technology in Chest Imaging. J Clin Med 2021; 10:jcm10245757. [PMID: 34945053 PMCID: PMC8704215 DOI: 10.3390/jcm10245757] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 11/30/2021] [Accepted: 12/02/2021] [Indexed: 12/17/2022] Open
Abstract
The X-ray imaging field is currently undergoing a period of rapid technological innovation in diagnostic imaging equipment. An important recent development is the advent of new X-ray detectors, i.e., photon-counting detectors (PCD), which have been introduced in recent clinical prototype systems, called PCD computed tomography (PCD-CT) or photon-counting CT (PCCT) or spectral photon-counting CT (SPCCT) systems. PCD allows a pixel up to 200 microns pixels at iso-center, which is much smaller than that can be obtained with conventional energy integrating detectors (EID). PCDs have also a higher dose efficiency than EID mainly because of electronic noise suppression. In addition, the energy-resolving capabilities of these detectors allow generating spectral basis imaging, such as the mono-energetic images or the water/iodine material images as well as the K-edge imaging of a contrast agent based on atoms of high atomic number. In recent years, studies have therefore been conducted to determine the potential of PCD-CT as an alternative to conventional CT for chest imaging.
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Dose Reduction in Coronary Artery Calcium Scoring Using Mono-Energetic Images from Reduced Tube Voltage Dual-Source Photon-Counting CT Data: A Dynamic Phantom Study. Diagnostics (Basel) 2021; 11:diagnostics11122192. [PMID: 34943428 PMCID: PMC8699960 DOI: 10.3390/diagnostics11122192] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/17/2021] [Accepted: 11/21/2021] [Indexed: 12/23/2022] Open
Abstract
In order to assess coronary artery calcium (CAC) quantification reproducibility for photon-counting computed tomography (PCCT) at reduced tube potential, an anthropomorphic thorax phantom with low-, medium-, and high-density CAC inserts was scanned with PCCT (NAEOTOM Alpha, Siemens Healthineers) at two heart rates: 0 and 60–75 beats per minute (bpm). Five imaging protocols were used: 120 kVp standard dose (IQ level 16, reference), 90 kVp at standard (IQ level 16), 75% and 45% dose and tin-filtered 100 kVp at standard dose (IQ level 16). Each scan was repeated five times. Images were reconstructed using monoE reconstruction at 70 keV. For each heart rate, CAC values, quantified as Agatston scores, were compared with the reference, whereby deviations >10% were deemed clinically relevant. Reference protocol radiation dose (as volumetric CT dose index) was 4.06 mGy. Radiation dose was reduced by 27%, 44%, 67%, and 46% for the 90 kVp standard dose, 90 kVp 75% dose, 90 kVp 45% dose, and Sn100 standard dose protocol, respectively. For the low-density CAC, all reduced tube current protocols resulted in clinically relevant differences with the reference. For the medium- and high-density CAC, the implemented 90 kVp protocols and heart rates revealed no clinically relevant differences in Agatston score based on 95% confidence intervals. In conclusion, PCCT allows for reproducible Agatston scores at a reduced tube voltage of 90 kVp with radiation dose reductions up to 67% for medium- and high-density CAC.
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