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Kämmerling N, Tesselaar E, Booij R, Fornander L, Persson A, Farnebo S. A comparative study of image quality and diagnostic confidence in diagnosis and follow-up of scaphoid fractures using photon-counting detector CT and energy-integrating detector CT. Eur J Radiol 2024; 173:111383. [PMID: 38377892 DOI: 10.1016/j.ejrad.2024.111383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/08/2024] [Accepted: 02/16/2024] [Indexed: 02/22/2024]
Abstract
PURPOSE Scaphoid fractures in patients and assessment of healing using PCD-CT have, as far as we know, not yet been studied. Therefore, the aim was to compare photon counting detector CT (PCD-CT) with energy integrating detector CT (EID-CT) in terms of fracture visibility and evaluation of fracture healing. METHOD Eight patients with scaphoid fracture were examined with EID-CT and PCD-CT within the first week post-trauma, and with additional scans at 4, 6 and 8 weeks. Our clinical protocol for wrist examination with EID-CT was used (CTDIvol 3.1 ± 0.1 mGy, UHR kernel Ur77). For PCD-CT matched radiation dose, reconstruction kernel Br89. Quantitative analyses of noise, CNR, trabecular and cortical sharpness, and bone volume fraction were conducted. Five radiologists evaluated the images for fracture visibility, fracture gap consolidation and image quality, and rated their confidence in the diagnosis. RESULTS The trabecular and cortical sharpness were superior in images obtained with PCD-CT compared with EID-CT. A successive reduction in trabecular bone volume fraction during the immobilized periods was found with both systems. Despite higher noise and lower CNR with PCD-CT, radiologists rated the image quality of PCD-CT as superior. The visibility of the fracture line within 1-week post-trauma was rated higher with PCD-CT as was diagnostic confidence, but the subsequent assessments of fracture gap consolidation during healing process and the confidence in diagnosis were found equivalent between both systems. CONCLUSION PCD-CT offers superior visibility of bone microstructure compared with EID-CT. The evaluation of fracture healing and confidence in diagnosis were rated equally with both systems, but the radiologists found primary fracture visibility and overall image quality superior with PCD-CT.
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Affiliation(s)
- Nina Kämmerling
- Department of Radiology, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
| | - Erik Tesselaar
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Department of Medical Radiation Physics, Linköping University, Linköping, Sweden
| | - Ronald Booij
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Department of Radiology & Nuclear Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Lotta Fornander
- Department of Orthopedic Surgery, Norrköping, and Department of Biomedical and Clinical Sciences, Linköping University, Norrköping, Sweden
| | - Anders Persson
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Simon Farnebo
- Department of Hand and Plastic Surgery, Linköping University, Linköping, Sweden
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2
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Chan HP, Helvie MA, Gao M, Hadjiiski L, Zhou C, Garver K, Klein KA, McLaughlin C, Oudsema R, Rahman WT, Roubidoux MA. Deep learning denoising of digital breast tomosynthesis: Observer performance study of the effect on detection of microcalcifications in breast phantom images. Med Phys 2023; 50:6177-6189. [PMID: 37145996 PMCID: PMC10592580 DOI: 10.1002/mp.16439] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 04/06/2023] [Accepted: 04/11/2023] [Indexed: 05/07/2023] Open
Abstract
BACKGROUND The noise in digital breast tomosynthesis (DBT) includes x-ray quantum noise and detector readout noise. The total radiation dose of a DBT scan is kept at about the level of a digital mammogram but the detector noise is increased due to acquisition of multiple projections. The high noise can degrade the detectability of subtle lesions, specifically microcalcifications (MCs). PURPOSE We previously developed a deep-learning-based denoiser to improve the image quality of DBT. In the current study, we conducted an observer performance study with breast radiologists to investigate the feasibility of using deep-learning-based denoising to improve the detection of MCs in DBT. METHODS We have a modular breast phantom set containing seven 1-cm-thick heterogeneous 50% adipose/50% fibroglandular slabs custom-made by CIRS, Inc. (Norfolk, VA). We made six 5-cm-thick breast phantoms embedded with 144 simulated MC clusters of four nominal speck sizes (0.125-0.150, 0.150-0.180, 0.180-0.212, 0.212-0.250 mm) at random locations. The phantoms were imaged with a GE Pristina DBT system using the automatic standard (STD) mode. The phantoms were also imaged with the STD+ mode that increased the average glandular dose by 54% to be used as a reference condition for comparison of radiologists' reading. Our previously trained and validated denoiser was deployed to the STD images to obtain a denoised DBT set (dnSTD). Seven breast radiologists participated as readers to detect the MCs in the DBT volumes of the six phantoms under the three conditions (STD, STD+, dnSTD), totaling 18 DBT volumes. Each radiologist read all the 18 DBT volumes sequentially, which were arranged in a different order for each reader in a counter-balanced manner to minimize any potential reading order effects. They marked the location of each detected MC cluster and provided a conspicuity rating and their confidence level for the perceived cluster. The visual grading characteristics (VGC) analysis was used to compare the conspicuity ratings and the confidence levels of the radiologists for the detection of MCs. RESULTS The average sensitivities over all MC speck sizes were 65.3%, 73.2%, and 72.3%, respectively, for the radiologists reading the STD, dnSTD, and STD+ volumes. The sensitivity for dnSTD was significantly higher than that for STD (p < 0.005, two-tailed Wilcoxon signed rank test) and comparable to that for STD+. The average false positive rates were 3.9 ± 4.6, 2.8 ± 3.7, and 2.7 ± 3.9 marks per DBT volume, respectively, for reading the STD, dnSTD, and STD+ images but the difference between dnSTD and STD or STD+ did not reach statistical significance. The overall conspicuity ratings and confidence levels by VGC analysis for dnSTD were significantly higher than those for both STD and STD+ (p ≤ 0.001). The critical alpha value for significance was adjusted to be 0.025 with Bonferroni correction. CONCLUSIONS This observer study using breast phantom images showed that deep-learning-based denoising has the potential to improve the detection of MCs in noisy DBT images and increase radiologists' confidence in differentiating noise from MCs without increasing radiation dose. Further studies are needed to evaluate the generalizability of these results to the wide range of DBTs from human subjects and patient populations in clinical settings.
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Affiliation(s)
- Heang-Ping Chan
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Mark A Helvie
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Mingjie Gao
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Lubomir Hadjiiski
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Chuan Zhou
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Kim Garver
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Katherine A Klein
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Carol McLaughlin
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Rebecca Oudsema
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - W Tania Rahman
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
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Lorentsson R, Hosseini N, Aurell Y, Collin D, Frösing E, Szaro P, Månsson LG, Båth M. Investigation of the Impact of Defective Ultrasound Transducers on Clinical Image Quality in Grayscale 2-D Still Images. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:2126-2133. [PMID: 37400301 DOI: 10.1016/j.ultrasmedbio.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 05/17/2023] [Accepted: 06/05/2023] [Indexed: 07/05/2023]
Abstract
OBJECTIVE There are several studies that show high defect rates of transducers in clinical use. The purpose of the present study was to investigate whether image quality and the risk for misdiagnosis is affected by using defective transducers. METHODS Four defective transducers with varying degrees of defect severity, still in clinical use, were selected. Forty artifact-affected clinical images from each transducer were compared with images acquired from fully functional transducers, of the same model, in an observer study where four experienced radiologists rated each of the 320 images. The rating tasks included if the artifacts were detectable, if the possible artifacts might affect the diagnosis, how well structural details were reproduced and, finally, an assessment of overall image quality. RESULTS The artifacts in the images were detectable for three of the four transducers (p < 0.05), and in 121 of 640 assessments of the images from the defective transducers the observers were confident that the artifacts could affect the diagnosis. All four faulty transducers were assessed to have decreased ability to resolve structural details (p < 0.05), and three of the four transducers were assessed to have worse overall image quality (p < 0.05). CONCLUSION The present study shows that image quality and the risk of misdiagnosis can be affected by using defective transducers. This highlights the importance of frequent quality control of the transducers to avoid decreased image quality and even misdiagnosis.
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Affiliation(s)
- Robert Lorentsson
- Department of Medical Radiation Sciences, Institute of Clinical Sciences at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden.
| | - Nasser Hosseini
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Ylva Aurell
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Department of Radiology, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - David Collin
- Department of Radiology, Sykehuset Innlandet, Tynset, Norway
| | - Eva Frösing
- Department of Radiology, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Pawel Szaro
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Department of Radiology, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Lars Gunnar Månsson
- Department of Medical Radiation Sciences, Institute of Clinical Sciences at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Magnus Båth
- Department of Medical Radiation Sciences, Institute of Clinical Sciences at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
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Fransson V, Mellander H, Ramgren B, Andersson H, Arena F, Ydström K, Ullberg T, Wassélius J. Image quality of spectral brain computed tomography angiography using halved dose of iodine contrast medium. Neuroradiology 2023; 65:1333-1342. [PMID: 37452885 PMCID: PMC10425475 DOI: 10.1007/s00234-023-03190-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 06/26/2023] [Indexed: 07/18/2023]
Abstract
PURPOSE Reduction in iodinated contrast medium (CM) dose is highly motivated. Our aim was to evaluate if a 50% reduction of CM, while preserving image quality, is possible in brain CT angiography (CTA) using virtual monoenergetic images (VMI) on spectral CT. As a secondary aim, we evaluated if VMI can salvage examinations with suboptimal CM timing. METHODS Consecutive patients older than 18 years without intracranial stenosis/occlusion were included. Three imaging protocols were used: group 1, full CM dose; group 2, 50% CM dose suboptimal timing; and group 3, 50% CM dose optimized timing. Attenuation, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured in the internal carotid artery, M2 segment of the middle cerebral artery, and white matter for conventional images (CI) and VMI (40-200 keV). Qualitative image quality for CI and VMI (50 and 60 keV) was rated by 4 experienced reviewers. RESULTS Qualitatively and quantitatively, VMI (40-60 keV) improved image quality within each group. Significantly higher attenuation and CNR was found for group 3 VMI 40-50 keV, with unchanged SNR, compared to group 1 CI. Group 3 VMI 50 keV also received significantly higher rating scores than group 1 CI. Group 2 VMI (40-50 keV) had significantly higher CNR compared to group 3 CI, but the subjective image quality was similar. CONCLUSION VMI of 50 keV with 50% CM dose increases qualitative and quantitative image quality over CI with full CM dose. Using VMI reduces non-diagnostic examinations and may salvage CTA examinations deemed non-diagnostic due to suboptimal timing.
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Affiliation(s)
- Veronica Fransson
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Helena Mellander
- Department of Medical Imaging and Physiology, Skåne University Hospital, 22185, Lund, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Birgitta Ramgren
- Department of Medical Imaging and Physiology, Skåne University Hospital, 22185, Lund, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Henrik Andersson
- Department of Medical Imaging and Physiology, Skåne University Hospital, 22185, Lund, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Francesco Arena
- Department of Medical Imaging and Physiology, Skåne University Hospital, 22185, Lund, Sweden
| | - Kristina Ydström
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
- Medical Radiation Physics, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Teresa Ullberg
- Neurology, Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Lund, Sweden
| | - Johan Wassélius
- Department of Medical Imaging and Physiology, Skåne University Hospital, 22185, Lund, Sweden.
- Department of Clinical Sciences, Lund University, Lund, Sweden.
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Svalkvist A, Fagman E, Vikgren J, Ku S, Diniz MO, Norrlund RR, Johnsson ÅA. Evaluation of deep-learning image reconstruction for chest CT examinations at two different dose levels. J Appl Clin Med Phys 2023; 24:e13871. [PMID: 36583696 PMCID: PMC10018655 DOI: 10.1002/acm2.13871] [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: 04/07/2022] [Revised: 11/17/2022] [Accepted: 11/29/2022] [Indexed: 12/31/2022] Open
Abstract
AIMS The aims of the present study were to, for both a full-dose protocol and an ultra-low dose (ULD) protocol, compare the image quality of chest CT examinations reconstructed using TrueFidelity (Standard kernel) with corresponding examinations reconstructed using ASIR-V (Lung kernel) and to evaluate if post-processing using an edge-enhancement filter affects the noise level, spatial resolution and subjective image quality of clinical images reconstructed using TrueFidelity. METHODS A total of 25 patients were examined with both a full-dose protocol and an ULD protocol using a GE Revolution APEX CT system (GE Healthcare, Milwaukee, USA). Three different reconstructions were included in the study: ASIR-V 40%, DLIR-H, and DLIR-H with additional post-processing using an edge-enhancement filter (DLIR-H + E2). Five observers assessed image quality in two separate visual grading characteristics (VGC) studies. The results from the studies were statistically analyzed using VGC Analyzer. Quantitative evaluations were based on determination of two-dimensional power spectrum (PS), contrast-to-noise ratio (CNR), and spatial resolution in the reconstructed patient images. RESULTS For both protocols, examinations reconstructed using TrueFidelity were statistically rated equal to or significantly higher than examinations reconstructed using ASIR-V 40%, but the ULD protocol benefitted more from TrueFidelity. In general, no differences in observer ratings were found between DLIR-H and DLIR-H + E2. For the three investigated image reconstruction methods, ASIR-V 40% showed highest noise and spatial resolution and DLIR-H the lowest, while the CNR was highest in DLIR-H and lowest in ASIR-V 40%. CONCLUSION The use of TrueFidelity for image reconstruction resulted in higher ratings on subjective image quality than ASIR-V 40%. The benefit of using TrueFidelity was larger for the ULD protocol than for the full-dose protocol. Post-processing of the TrueFidelity images using an edge-enhancement filter resulted in higher image noise and spatial resolution but did not affect the subjective image quality.
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Affiliation(s)
- Angelica Svalkvist
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden.,Department of Medical Radiation Sciences, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Erika Fagman
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden.,Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jenny Vikgren
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden.,Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Sara Ku
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Micael Oliveira Diniz
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden.,Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Rauni Rossi Norrlund
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden.,Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Åse A Johnsson
- Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden.,Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Sliwicka O, Swiderska-Chadaj Z, Snoeren M, Brink M, Salah K, Peters-Bax L, Stille T, van Amerongen MJ, Sechopoulos I, Habets J. Multireader image quality evaluation of dynamic myocardial computed tomography perfusion imaging with a novel four-dimensional noise reduction filter. Acta Radiol 2023; 64:999-1006. [PMID: 35765201 DOI: 10.1177/02841851221108804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Dynamic myocardial computed tomography perfusion (CTP) is a novel technique able to depict cardiac ischemia. PURPOSE To evaluate the impact of a four-dimensional noise reduction filter (similarity filter [4D-SF]) on image quality in dynamic CTP imaging, allowing for substantial radiation dose reduction. MATERIAL AND METHODS Dynamic CTP datasets of 30 patients (16 women) with suspected coronary artery disease, acquired with a 320-slice CT system, were retrieved, reconstructed with the deep learning-based algorithm of the system (DLR), and filtered with the 4D-SF. For each case, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in six regions of interest (33-38mm2) were calculated before and after filtering, in four-chamber and short-axis views, and t-tested. Furthermore, six radiologists of different expertise evaluated subjective image preference by answering five visual grading analysis-type questions (regarding acceptable level of noise, absence of artifacts, natural appearance, cardiac contour sharpness, diagnostic acceptability) using a 5-point scale. The results were analyzed using visual grade characteristics (VGC) and intraclass correlation coefficient (ICC). RESULTS Mean SNR in four-chamber view (unfiltered vs. filtered) were: septum=4.1 ± 2.1 versus 7.6 ± 5.6; lateral wall=4.5 ± 2.0 versus 8.0 ± 4.9; CNRseptum=16.6 ± 8.9 versus 31.7 ± 28; lateral wall=16.2 ± 8.9 versus 31.3 ± 28.9. Similar results were obtained in short-axis view. The perceived filtered image quality indicated decreased noise (VGCAUC=0.96) and artifacts (0.65), improved natural appearance (0.59), cardiac contour sharpness (0.74), and diagnostic acceptability (0.78). The inter-observer variability was excellent (ICC=0.79). All results were statistically significant (P < 0.05). CONCLUSION Similarity filtering after DLR improves image quality, possibly enabling dose reduction in dynamic CTP imaging in patient with suspected chronic coronary syndrome.
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Affiliation(s)
- Olga Sliwicka
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Miranda Snoeren
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Monique Brink
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Khibar Salah
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Liesbeth Peters-Bax
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tip Stille
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Ioannis Sechopoulos
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jesse Habets
- Department of Medical Imaging, Radboud University Medical Center, Nijmegen, The Netherlands
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Lee HJ, Kim JS, Lee JK, Lee HA, Pak S. Ultra-low-dose hepatic multiphase CT using deep learning-based image reconstruction algorithm focused on arterial phase in chronic liver disease: A non-inferiority study. Eur J Radiol 2023; 159:110659. [PMID: 36584563 DOI: 10.1016/j.ejrad.2022.110659] [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: 10/04/2022] [Revised: 12/07/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022]
Abstract
PURPOSE This study determined whether image quality and detectability of ultralow-dose hepatic multiphase CT (ULDCT, 33.3% dose) using a vendor-agnostic deep learning model(DLM) are noninferior to those of standard-dose CT (SDCT, 100% dose) using model-based iterative reconstruction(MBIR) in patients with chronic liver disease focusing on arterial phase. METHODS Sixty-seven patients underwent hepatic multiphase CT using a dual-source scanner to obtain two different radiation dose CT scans (100%, SDCT and 33.3%, ULDCT). ULDCT using DLM and SDCT using MBIR were compared. A margin of -0.5 for the difference between the two protocols was pre-defined as noninferiority of the overall image quality of the arterial phase image. Quantitative image analysis (signal to noise ratio[SNR] and contrast to noise ratio[CNR]) was also conducted. The detectability of hepatic arterial focal lesions was compared using the Jackknife free-response receiver operating characteristic analysis. Non-inferiority was satisfied if the margin of the lower limit of 95%CI of the difference in figure-of-merit was less than -0.1. RESULTS Mean overall arterial phase image quality scores with ULDCT using DLM and SDCT using MBIR were 4.35 ± 0.57 and 4.08 ± 0.58, showing noninferiority (difference: -0.269; 95 %CI, -0.374 to -0.164). ULDCT using DLM showed a significantly superior contrast-to-noise ratio of arterial enhancing lesion (p < 0.05). Figure-of-merit for detectability of arterial hepatic focal lesion was 0.986 for ULDCT using DLM and 0.963 for SDCT using MBIR, showing noninferiority (difference: -0.023, 95 %CI: -0.016 to 0.063). CONCLUSION ULDCT using DLM with 66.7% dose reduction showed non-inferior overall image quality and detectability of arterial focal hepatic lesion compared to SDCT using MBIR.
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Affiliation(s)
- Hyun Joo Lee
- Department of Radiology, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Jin Sil Kim
- Department of Radiology, College of Medicine, Ewha Womans University, Seoul, Republic of Korea.
| | - Jeong Kyong Lee
- Department of Radiology, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Hye Ah Lee
- Clinical Trial Center, Mokdong Hospital, Ewha Womans University, Seoul, Republic of Korea
| | - Seongyong Pak
- Department of Biomedical Engineering, Asan Medical Institute of Convergence Science and Technology,Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
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8
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Booij R, Kämmerling NF, Oei EHG, Persson A, Tesselaar E. Assessment of visibility of bone structures in the wrist using normal and half of the radiation dose with photon-counting detector CT. Eur J Radiol 2023; 159:110662. [PMID: 36565594 DOI: 10.1016/j.ejrad.2022.110662] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/13/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
PURPOSE To quantitatively and qualitatively assess the visibility of bone structures in the wrist on photon-counting detector computed tomography (PCD-CT) images compared to state-of-the-art energy-integrating detector CT (EID-CT). METHOD Four human cadaveric wrist specimens were scanned with EID-CT and PCD-CT at identical CTDIvol of 12.2 mGy and with 6.1 mGy (half dose PCD-CT). Axial images were reconstructed using the thinnest possible slice thickness, i.e. 0.4 mm on EID-CT and 0.2 mm on PCD-CT, with the largest image matrix size possible using reconstruction kernels optimized for bone (EID-CT: Ur68, PCD-CT: Br92). Quantitative evaluation was performed to determine contrast-noise ratio (CNR) of bone/ fat, cortical and trabecular sharpness. An observer study using visual grading characteristics (VGC) analysis was performed by six observers to assess the visibility of nutrient canals, trabecular architecture, cortical bone and the general image quality. RESULTS At equal dose, images obtained with PCD-CT had 39 ± 6 % lower CNR (p = 0.001), 71 ± 57 % higher trabecular sharpness in the radius (p = 0.02) and 42 ± 8 % (p < 0.05) sharper cortical edges than those obtained with EID-CT. This was confirmed by VGC analysis showing a superior visibility of nutrient canals, trabeculae and cortical bone area under the curve (AUC) > 0.89) for PCD-CT, even at half dose. CONCLUSIONS Despite a lower CNR and increased noise, the trabecular and cortical sharpness were twofold higher with PCD-CT. Visual grading analysis demonstrated superior visibility of cortical bone, trabeculae, nutrient canals and an overall improved image quality with PCD-CT over EID-CT. At half dose, PCD-CT also yielded superior image quality, both in quantitative measures and as evaluated by radiologists.
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Affiliation(s)
- Ronald Booij
- Department of Radiology & Nuclear Medicine, Erasmus Medical Center, Rotterdam, the Netherlands; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
| | - Nina F Kämmerling
- Department of Radiology and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.
| | - Edwin H G Oei
- Department of Radiology & Nuclear Medicine, Erasmus Medical Center, Rotterdam, the Netherlands.
| | - Anders Persson
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
| | - Erik Tesselaar
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Department of Medical Radiation Physics, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.
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Whole-tumor apparent diffusion coefficient (ADC) analyses of breast lesions based on simultaneous multi-slice readout-segmented echo-planar diffusion-weighted imaging. Magn Reson Imaging 2022; 94:119-126. [PMID: 36191856 DOI: 10.1016/j.mri.2022.09.008] [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: 09/22/2021] [Revised: 01/28/2022] [Accepted: 09/27/2022] [Indexed: 11/24/2022]
Abstract
OBJECTIVE We aimed to evaluate the effectiveness of simultaneous multi-slice readout-segmented echo-planar diffusion-weighted imaging (SMS rs-EPI DWI), compared with readout-segmented echo-planar diffusion-weighted imaging (NOSMS rs-EPI DWI), in discriminating between benign and malignant breast lesions. MATERIALS AND METHODS This retrospective study evaluated breast lesions from 185 consecutive patients who had undergone preoperative breast MRI. The NOSMS rs-EPI DWI and the prototype SMS rs-EPI DWI sequences were performed on a 1.5-T MR scanner. Two independent radiologists evaluated the image quality of the two sequences using a 5-point scale (1 = poor, 5 = excellent) and then assessed the scores through visual grading characteristics analysis (VGC). The values of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and whole-tumor-based histogram parameter (ADCmedian) were compared between the two sequences using the Wilcoxon test. Then ROC curves were used for statistical analysis. RESULTS The visual assessment showed that the SMS rs-EPI yielded superior overall image quality and lesion delineation than the NOSMS rs-EPI (AUCVGC = 0.980 and 0.984, respectively; all Ps < 0.001). There were no significant differences in relevant artifacts between the two sequences (AUCVGC = 0.531, P = 0.462). The SNR values for SMS rs-EPI DWI were significantly lower than for NOSMS rs-EPI DWI (P = 0.019) while there was no significant difference in CNR values between the two sequences (P = 0.955). In addition, evaluation of the diagnostic performance demonstrated that the difference in ADCmedian values for both DWI sequences between the malignant and benign lesions was statistically significant (P < 0.001). In contrast, the AUC for ADCmedian was higher with SMS rs-EPI than NOSMS rs-EPI (0.879 for SMS vs. 0.839 for NOSMS, P = 0.025). CONCLUSION The SMS technique could further improve the image quality and the diagnostic performance of rs-EPI DWI in a comparable time.
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Kämmerling N, Sandstedt M, Farnebo S, Persson A, Tesselaar E. Assessment of image quality in photon-counting detector computed tomography of the wrist - An ex vivo study. Eur J Radiol 2022; 154:110442. [PMID: 35849959 DOI: 10.1016/j.ejrad.2022.110442] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/04/2022] [Accepted: 07/10/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE The aim of this study was to evaluate the effect of reconstruction parameters on image quality in wrist imaging using photon-counting detector CT (PCD-CT) and to compare the results with images from an energy-integrating detector CT (EID-CT). METHODS Twelve cadaveric wrist specimens were examined using a prototype PCD-CT and a clinical EID-CT using similar radiation dose. Reconstruction parameters were matched between scanners. Also, sharper reconstruction kernels, a larger matrix size, and smaller slice thicknesses were evaluated for PCD-CT. Image noise, contrast-to-noise ratio (CNR) and image sharpness in trabecular structures were quantitatively measured. Image quality with respect to the visibility of cortical and trabecular bone structures was assessed by six radiologists using visual grading methods. RESULTS Images obtained with PCD-CT had lower noise (42.6 ± 3.9 HU vs 75.1 ± 6.3 HU), higher CNR (38.9 ± 4.5 vs 19.0 ± 2.4) and higher trabecular sharpness (63.5 ± 6.0 vs 53.7 ± 8.5) than those obtained with EID-CT using similar scan and reconstruction parameters (p < 0.001). The image sharpness in trabecular structures was further improved by using sharper kernels, despite higher noise levels. Radiologists had a strong preference for PCD-CT images both in terms of spatial resolution and suitability for bone imaging. Visual grading analysis showed an improved visibility of cortical bone, trabeculae and nutritive canals (p < 0.005). CONCLUSION PCD-CT offers improved image quality regarding bone structures in the wrist relative to EID-CT systems, particularly when sharper reconstruction kernels, smaller slice thickness and a larger image matrix size are used.
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Affiliation(s)
- Nina Kämmerling
- Department of Radiology, 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, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Simon Farnebo
- Department of Hand Surgery, Plastic Surgery and Burns in Linköping, 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, Linköping, Sweden; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Erik Tesselaar
- Department of Medical Radiation Physics, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
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Werncke T, Meine TC, Hinrichs JB, Maschke SK, Becker LS, Brüsch I, Rumpel R, Wacker FK, Meyer BC. Tantalum-specific contrast-to-noise ratio or conventional detector dose-driven exposure control in angiography: radiation dose and image quality evaluation in a porcine model. Eur Radiol Exp 2022; 6:24. [PMID: 35578057 PMCID: PMC9110612 DOI: 10.1186/s41747-022-00275-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 04/12/2022] [Indexed: 11/10/2022] Open
Abstract
Background The aim of this animal study was to compare the fluoroscopic image quality (IQ) and radiation dose between a tantalum (Ta)-specific contrast-to-noise ratio-driven exposure control (Ta-CEC) and a detector dose-driven exposure control (DEC) in abdominal angiography. Methods Nine angiography scenarios were created in seven anaesthetised pigs using Ta-based embolisation material during percutaneous liver and kidney intervention. Fluoroscopic images were acquired using three DEC protocols with different dose levels and Ta-CEC protocols with different IQ levels, sampled in small steps. Polymethyl-methacrylate and aluminium plates were used to simulate attenuation of three water equivalent thicknesses (WET). Three blinded readers evaluated the IQ of DEC and dose equivalent Ta images and selected the Ta-IQ equivalent image corresponding to the DEC image. Results Interobserver agreement for the IQ assessment was 0.43 for DEC, 0.56 for Ta-CEC and for the assessment of incident air kerma at the interventional reference point (Ka,r) for the Ta-IQ equivalent image 0.73. The average IQ of the dose equivalent Ta images was superior compared to the DEC images (p < 0.001) and also for every WET (26, 31, or 36 cm) and dose level (p ≤ 0.022). The average Ka,r for the Ta-IQ equivalent images was 59 ± 16% (mean ± standard deviation) lower compared to the DEC images (p < 0.001). Conclusions Compared to DEC, Ta-CEC significantly improved the fluoroscopic depiction of Ta, while maintaining the Ka,r. Alternatively, the Ka,r can be significantly reduced by using Ta-CEC instead of DEC, while maintaining equivalent IQ.
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Thompson JD. Toward Consistent Design and Reporting of Observer Studies in Imaging. Radiology 2022; 303:531-532. [PMID: 35258379 DOI: 10.1148/radiol.220150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- John D Thompson
- From the Department of Radiography, University of Salford, Frederick Road Campus, Salford M6 6PU, UK
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Götestrand S, Björkman A, Björkman-Burtscher IM, Ab-Fawaz R, Kristiansson I, Lundin B, Geijer M. Visualization of wrist ligaments with 3D and 2D magnetic resonance imaging at 3 Tesla. Acta Radiol 2022; 63:368-375. [PMID: 33657847 DOI: 10.1177/0284185121994044] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Wrist ligaments are challenging to visualize using magnetic resonance imaging (MRI). Injuries involving the scapholunate ligament (SLL), the lunotriquetral ligament (LTL), and the triangular fibrocartilage complex (TFCC) are common and difficult to diagnose, often requiring diagnostic arthroscopy. PURPOSE To compare the visualization of wrist ligaments on a three-dimensional (3D) sequence with two-dimensional (2D) sequences on 3-T MRI. MATERIAL AND METHODS Eighteen healthy volunteers were examined with a 3D SPACE (sampling perfection with application optimized contrasts using different flip angle evolution) sequence and 2D coronal, axial, and sagittal proton density-weighted (PD) sequences. Four musculoskeletal radiologists graded the anatomical visibility of the SLL, LTL, TFCC, and the image quality, using five grades in a visual grading characteristics (VGC) evaluation. After Bonferroni correction, a P value ≤0.005 was considered statistically significant. RESULTS The 3D images were graded significantly better than the 2D images in the visualization of the dorsal and palmar parts of the SLL and the LTL. Regarding the TFCC, the 3D images were graded significantly better for visualization of the foveal attachment. 2D imaging was not found significantly superior to 3D imaging in any aspect. CONCLUSION The 3D SPACE sequence was scored as superior to the 2D sequences at 3 T in the assessment of the SLL, the LTL, and the foveal attachment of the TFCC. Thus, 3D SPACE can replace 2D PD sequences when these ligaments need to be assessed.
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Affiliation(s)
- Simon Götestrand
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
- Department of Radiology, Clinical Sciences, Lund University, Lund, Sweden
| | - Anders Björkman
- Department of Translational Medicine – Hand Surgery, Skåne University Hospital, Malmö, Sweden
- The Wallenberg Center for Molecular Medicine, Lund University, Sweden
| | - Isabella M Björkman-Burtscher
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Rana Ab-Fawaz
- Department of Radiology, Kristianstad Hospital, Kristianstad, Sweden
- European Telemedicine Clinic, Department of Musculoskeletal Radiology, Barcelona, Spain
| | - Ingvar Kristiansson
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
| | - Björn Lundin
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
- Department of Radiology, Clinical Sciences, Lund University, Lund, Sweden
| | - Mats Geijer
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
- Region Västra Götaland, Sahlgrenska University Hospital, Department of Radiology, Gothenburg, Sweden
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Nocum DJ, Robinson J, Halaki M, Båth M, Mekiš N, Liang E, Thompson N, Moscova M, Reed W. UTERINE ARTERY EMBOLISATION: CONTINUOUS QUALITY IMPROVEMENT REDUCES RADIATION DOSE WHILE MAINTAINING IMAGE QUALITY. RADIATION PROTECTION DOSIMETRY 2021; 196:159-166. [PMID: 34595527 DOI: 10.1093/rpd/ncab145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/01/2021] [Accepted: 09/09/2021] [Indexed: 06/13/2023]
Abstract
The purpose of this study was to introduce a continuous quality improvement (CQI) program for radiation dose optimisation during uterine artery embolisation (UAE) and assess its impact on dose reduction and image quality. The CQI program investigated the effects of optimising radiation dose parameters on the kerma-area product (KAP) and image quality when comparing a 'CQI intervention' group (n = 50) and 'Control' group (n = 50). Visual grading characteristics (VGC) analysis was used to assess image quality, using the 'Control' group as a reference. A significant reduction in KAP by 17% (P = 0.041, d = 0.2) and reference air kerma (Ka, r) by 20% (P = 0.027, d = 0.2) was shown between the two groups. The VGC analysis resulted in an area under the VGC curve (AUCVGC) of 0.54, indicating no significant difference in image quality between the two groups (P = 0.670). The implementation of the CQI program and optimisation of radiation dose parameters improved the UAE radiation dose practices at our centre. The dose reduction demonstrated no detrimental effects on image quality.
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Affiliation(s)
- Don J Nocum
- San Radiology & Nuclear Medicine, Sydney Adventist Hospital, Wahroonga, NSW, Australia
- Discipline of Medical Imaging Science, Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - John Robinson
- Discipline of Medical Imaging Science, Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- Medical Imaging Optimisation and Perception Group (MIOPeG), Discipline of Medical Imaging Science, Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Mark Halaki
- Discipline of Exercise and Sports Science, Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Magnus Båth
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy, University of Gothenburg, SE-413 45 Gothenburg, Sweden
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Nejc Mekiš
- Medical Imaging and Radiotherapy Department, Faculty of Health Sciences, University of Ljubljana, Ljubljana, Slovenia
| | - Eisen Liang
- San Radiology & Nuclear Medicine, Sydney Adventist Hospital, Wahroonga, NSW, Australia
- Sydney Adventist Hospital Clinical School, Faculty of Medicine and Health, University of Sydney, Wahroonga, NSW, Australia
| | - Nadine Thompson
- San Radiology & Nuclear Medicine, Sydney Adventist Hospital, Wahroonga, NSW, Australia
- Sydney Adventist Hospital Clinical School, Faculty of Medicine and Health, University of Sydney, Wahroonga, NSW, Australia
| | - Michelle Moscova
- School of Medical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Warren Reed
- Discipline of Medical Imaging Science, Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- Medical Imaging Optimisation and Perception Group (MIOPeG), Discipline of Medical Imaging Science, Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
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Hettinger E, Aurumskjöld ML, Sartor H, Holmquist F, Svärd D, Timberg P. EVALUATION OF MODEL-BASED ITERATIVE RECONSTRUCTION IN ABDOMINAL COMPUTED TOMOGRAPHY IMAGING AT TWO DIFFERENT DOSE LEVELS. RADIATION PROTECTION DOSIMETRY 2021; 195:205-211. [PMID: 33683328 DOI: 10.1093/rpd/ncab010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 01/04/2021] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
The purpose of this study was to qualitatively evaluate recently introduced Model-based iterative reconstruction method (IMR) and routinely used iterative reconstruction algorithm iDose4 to investigate future dose reduction possibilities for abdominal CT exams. The study contained data from 34 patients who underwent abdominal CT in SkåneUniversityHospital Lund, Sweden. A low-dose scan (CTDIvol3.4 mGy) reconstructed with both iDose4 and IMR and a standard-dose scan (CTDIvol 5.3 mG) reconstructed with iDose4 alone were visually graded in ViewDEX v2.0 by four radiologists using modified EU image criteria. The visual grading characteristics analysis for the evaluation comparing iDose4 standard dose with IMR low dose did not show any statistically significant difference in five of six criteria. In one of the criteria, iDose4 was superior to IMR. The result show promising possibilities are introduced for substantial radiation dose reduction (35%) in abdominal CT imaging when replacing iDose4 with IMR. Still, care should be taken when considering the reproduction of adrenal glands.
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Affiliation(s)
- E Hettinger
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
| | - M-L Aurumskjöld
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Sweden
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Skåne University Hospital, Malmö, Sweden
| | - H Sartor
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
- Diagnostic Radiology, Department of Translational Medicine, Lund University, Skåne University Hospital, Malmö, Sweden
| | - F Holmquist
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
| | - D Svärd
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
| | - P Timberg
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Sweden
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Skåne University Hospital, Malmö, Sweden
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Svahn TM, Gordon R, Ast JC, Riffel J, Hartbauer M. COMPARISON OF PHOTON-COUNTING AND FLAT-PANEL DIGITAL MAMMMOGRAPHY FOR THE PURPOSE OF 3D IMAGING USING A NOVEL IMAGE PROCESSING METHOD. RADIATION PROTECTION DOSIMETRY 2021; 195:454-461. [PMID: 34323279 DOI: 10.1093/rpd/ncab104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 05/29/2021] [Accepted: 06/10/2021] [Indexed: 06/13/2023]
Abstract
The purpose of the present work was to compare the quality of low-dose projections from a photon-counting with a flat-panel system, and to evaluate a novel image processing method. Images were acquired of phantoms in both systems at average glandular doses ranging from ~ 0.15 to 1.4 mGy. Automated detection of low-contrast features and modulation transfer functions were evaluated in phantom images. The novel image processing method was compared with standard processing in a series of clinical cases. At low-doses (~0.15) the photon-counting system out-performed the flat-panel system with a much higher detectability of low-contrast features. The novel algorithm was superior to both manufacturers' processing in terms of conspicuity of soft-tissue lesions (p > 0.05), whereas it was not significantly different in calcification conspicuity. Photon-counting should allow more low-dose projections to be acquired at the same total dose. The novel image enhancer can help to further increase the image quality.
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Affiliation(s)
- T M Svahn
- Centre for Research and Development, Uppsala University/Region Gävleborg, 801 88 Gävle, Sweden
| | - R Gordon
- Gulf Marine Specimen Laboratory, Panacea, FL 32346, USA
- C.S. Mott Center for Human Growth & Development, Department of Obstetrics & Gynecology, Wayne State University, Detroit, MI 48201, USA
| | - J C Ast
- Department of Organismal Biology, 752 36 Uppsala University, Uppsala, Sweden
| | - J Riffel
- Department of Clinical Radiology and Nuclear Medicine, 68167 Mannheim, University of Heidelberg, Germany
| | - M Hartbauer
- Institute of Biology, Universitätsplatz 2, University of Graz, 8010 Graz, Austria
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Hansson J, Månsson LG, Båth M. EVALUATION OF VGC ANALYZER BY COMPARISON WITH GOLD STANDARD ROC SOFTWARE AND ANALYSIS OF SIMULATED VISUAL GRADING DATA. RADIATION PROTECTION DOSIMETRY 2021; 195:378-390. [PMID: 33940628 PMCID: PMC8507457 DOI: 10.1093/rpd/ncab066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 03/09/2021] [Accepted: 04/03/2021] [Indexed: 06/12/2023]
Abstract
The purpose of the present work was to evaluate the use of resampling statistical methods for analysis of visual grading data-implemented in the software VGC Analyzer-by comparing the reanalyzed results from previously performed visual grading studies with the results calculated by gold standard receiver operating characteristic (ROC) methodology, Obuchowski-Rockette (OR)-Dorfman-Berbaum-Metz (DBM) multiple-readers and multiple-case (MRMC) and by analysis of simulated visual grading data where the true distribution was presumed to be known. The reanalysis was performed on two multiple-reader studies with non-paired data and paired data, respectively. The simulation study was performed by simulating a large number of visual grading characteristics (VGC) studies and by analyzing the statistical distribution of null hypothesis (H0) rejection rate. The comparison with OR-DBM MRMC showed good agreement when analyzing non-paired data for both fixed-reader and random-reader settings for the calculated area under the curve values and the confidence intervals (CIs). For paired data analysis, VGC Analyzer showed significantly lower CIs compared with the ROC software. This effect was also illustrated by the simulation study, where the VGC Analyzer, in general, showed good accuracy for simulated studies with stable statistical basis. For simulated studies with unstable statistics, the accuracy in the H0 rejection rate decreased. The present study has shown that resampling methodology can be used to accurately perform the statistical analysis of a VGC study, although the resampling technique used makes the method sensitive to small data sets.
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Affiliation(s)
| | - Lars Gunnar Månsson
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, Gothenburg SE-413 45, Sweden
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg SE-413 45, Sweden
| | - Magnus Båth
- Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, Gothenburg SE-413 45, Sweden
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg SE-413 45, Sweden
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Mirzai M, Meltzer C, Vikgren J, Norrlund RR, Gottfridsson B, Johnsson Å, Båth M, Svalkvist A. The Effect of Dose Reduction on Overall Image Quality in Clinical Chest Tomosynthesis. Acad Radiol 2021; 28:e289-e296. [PMID: 32709583 DOI: 10.1016/j.acra.2020.05.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/27/2020] [Accepted: 05/31/2020] [Indexed: 10/23/2022]
Abstract
RATIONALE AND OBJECTIVES To evaluate the effect of reduction in effective dose on the reproduction of anatomical structures in chest tomosynthesis (CTS). MATERIALS AND METHODS Twenty-four CTS examinations acquired at exposure settings resulting in an effective dose of 0.12 mSv for an average sized patient were included in the study. The examinations underwent simulated dose reduction to dose levels corresponding to 32%, 50%, and 70% of the original dose using a previously described and validated method. The image quality was evaluated by five thoracic radiologists who rated the fulfillment of specified image quality criteria in a visual grading study. The ratings for each image quality criterion in the dose-reduced images were compared to the corresponding ratings for the full-dose examinations using visual grading characteristics (VGC) analysis. The area under the resulting VGC curve (AUCVGC) provides a measure of the difference between the ratings, where an AUCVGC of 0.5 indicates no difference. RESULTS The dose reductions resulted in inferior reproduction of structures compared to the original dose level (AUCVGC <0.5). Structures in the central region of the lung obtained the lowest AUCVGC for each dose level whereas the reproduction of structures in the parenchyma was least affected by the dose reduction. CONCLUSION Although previous studies have shown that dose reduction in CTS is possible without affecting the performance of certain clinical tasks, the reproduction of normal anatomical structures is significantly degraded even at small reductions. It is therefore important to consider the clinical purpose of the CTS examinations before deciding on a permanent dose reduction.
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Sanderink WBG, Teuwen J, Appelman L, Moy L, Heacock L, Weiland E, Sechopoulos I, Mann RM. Diffusion weighted imaging for evaluation of breast lesions: Comparison between high b-value single-shot and routine readout-segmented sequences at 3 T. Magn Reson Imaging 2021; 84:35-40. [PMID: 34560230 DOI: 10.1016/j.mri.2021.09.007] [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: 07/02/2021] [Revised: 09/10/2021] [Accepted: 09/16/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE In this study, we compare readout-segmented echo-planar imaging (rs-EPI) Diffusion Weighted Imaging (DWI) to a work-in-progress single-shot EPI with modified Inversion Recovery Background Suppression (ss-EPI-mIRBS) sequence at 3 T using a b-value of 2000 s/mm2 on image quality, lesion visibility and evaluation time. METHOD From September 2017 to December 2018, 23 women (one case used for training) with known breast cancer were included in this study, after providing signed informed consent. Women were scanned with the conventional rs-EPI sequence and the work-in-progress ss-EPI-mIRBS during the same examination. Four breast radiologists (4-13 years of experience) independently scored both series for overall image quality (1: extremely poor to 9: excellent). All lesions (47 in total, 36 malignant, and 11 benign and high-risk) were evaluated for visibility (1: not visible, 2: visible if location is given, 3: visible) and probability of malignancy (BI-RADS 1 to 5). ADC values were determined by measuring signal intensity in the lesions using dynamic contrast-enhanced (DCE) images for reference. Evaluation times for all assessments were automatically recorded. Results were analyzed using the visual grading characteristics (VGC) and the resulting area under the curve (AUCVGC) method. Statistical analysis was performed in SPSS, with McNemar tests, and paired t-tests used for comparison. RESULTS No significant differences were detected between the two sequences in image quality (AUCVGC: 0.398, p = 0.087) and lesion visibility (AUCVGC: 0.534, p = 0.336) scores. Lesion characteristics (e.g benign and high-risk, versus malignant; small (≤10 mm) vs. larger (>10 mm)) did not result in different image quality or lesion visibility between sequences. Sensitivity (rs-EPI: 72.2% vs. ss-EPImIRBS: 78.5%, p = 0.108) and specificity (70.5% vs. 56.8%, p = 0.210, respectively) were comparable. In both sequences the mean ADC value was higher for benign and high-risk lesions than for malignant lesions (ss-EPI-mIRBS: p = 0.022 and rs-EPI: p = 0.055). On average, ss-EPI-mIRBS resulted in decreased overall reading time by 7.7 s/case (p = 0.067); a reduction of 17%. For malignant lesions, average reading time was significantly shorter using ss-EPI-mIRBS compared to rs-EPI (64.0 s/lesion vs. 75.9 s/lesion, respectively, p = 0.039). CONCLUSION Based on this study, the ss-EPI sequence using a b-value of 2000 s/mm2 enables for a mIRBS acquisition with quality and lesion conspicuity that is comparable to conventional rs-EPI, but with a decreased reading time.
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Affiliation(s)
- Wendelien B G Sanderink
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA Nijmegen, the Netherlands.
| | - Jonas Teuwen
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA Nijmegen, the Netherlands; Department of Radiology, the Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066, CX, Amsterdam, the Netherlands
| | - Linda Appelman
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA Nijmegen, the Netherlands
| | - Linda Moy
- Department of Radiology, New York University Langone Medical Center, 660 First Avenue, 4(th) floor, New York, NY 10016, United States
| | - Laura Heacock
- Department of Radiology, New York University Langone Medical Center, 660 First Avenue, 4(th) floor, New York, NY 10016, United States
| | - Elisabeth Weiland
- MR Application Predevelopment, Siemens Healthcare, Allee am Roethelheimpark 2, 91052 Erlangen, Germany
| | - Ioannis Sechopoulos
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA Nijmegen, the Netherlands
| | - Ritse M Mann
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA Nijmegen, the Netherlands; Department of Radiology, the Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066, CX, Amsterdam, the Netherlands
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Götestrand S, Björkman A, Björkman-Burtscher IM, Kristiansson I, Aksyuk E, Szaro P, Markenroth Bloch K, Geijer M. Visualization of wrist anatomy-a comparison between 7T and 3T MRI. Eur Radiol 2021; 32:1362-1370. [PMID: 34378077 PMCID: PMC8795032 DOI: 10.1007/s00330-021-08165-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/16/2021] [Accepted: 06/24/2021] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Injuries to the wrist are, due to its small size and complex anatomical structures, difficult to assess by MR, and surgical interventions such as diagnostic arthroscopy are often necessary. Therefore, improved visualization using non-invasive methods could be of clinical value. As a first step of improvement, the purpose of this study was to evaluate visualization of anatomical structures at 7T compared with 3T MR. METHODS Eighteen healthy volunteers (three males and three females from each age decade between 20 and 49 years) were examined with 7T and 3T MR. Four musculoskeletal radiologists graded 2D and 3D images on a five-level grading scale for visibility of ligaments, cartilage, nerves, trabecular bone, and tendons, as well as overall image quality (i.e., edge sharpness, perceived tissue contrast, and presence of artefacts). Statistical analysis was done using a visual grading characteristics (VGC) analysis. RESULTS Visibility of cartilage, trabecular bone, tendons, nerves, and ligaments was graded significantly higher at 7T with an area under the curve (AUCVGC) of 0.62-0.88 (95% confidence interval [CI] 0.50-0.97, p = < 0.0001-0.03) using either 2D or 3D imaging. Imaging with 3T was not graded as superior to 7T for any structure. Image quality was also significantly superior at 7T, except for artefacts, where no significant differences were found. CONCLUSIONS Tendons, trabecular bone, nerves, and ligaments were all significantly better visualized at 7T compared to 3T. KEY POINTS • MRI of the wrist at 7T with a commercially available wrist coil is feasible at similar acquisition times as for 3T MRI. • The current study showed 7T to be superior to 3T in the visualization of anatomical structures of the wrist, including ligaments, tendons, nerves, and trabecular bone. • Image quality was significantly superior at 7T, except for artefacts, where no significant differences were found.
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Affiliation(s)
- Simon Götestrand
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden. .,Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden.
| | - Anders Björkman
- Department of Hand Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Sahlgrenska University Hospital, Region Västra Götaland, Gothenburg, Sweden
| | - Isabella M Björkman-Burtscher
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Radiology, Sahlgrenska University Hospital, Region Västra Götaland, Gothenburg, Sweden
| | - Ingvar Kristiansson
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
| | - Elenya Aksyuk
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden.,Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Pawel Szaro
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | | | - Mats Geijer
- Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden.,Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Radiology, Sahlgrenska University Hospital, Region Västra Götaland, Gothenburg, Sweden
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21
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Boita J, van Engen RE, Mackenzie A, Tingberg A, Bosmans H, Bolejko A, Zackrisson S, Wallis MG, Ikeda DM, van Ongeval C, Pijnappel R, Broeders M, Sechopoulos I. Validation of a candidate instrument to assess image quality in digital mammography using ROC analysis. Eur J Radiol 2021; 139:109686. [PMID: 33819803 DOI: 10.1016/j.ejrad.2021.109686] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 11/24/2022]
Abstract
PURPOSE To validate a candidate instrument, to be used by different professionals to assess image quality in digital mammography (DM), against detection performance results. METHODS A receiver operating characteristics (ROC) study was conducted to assess the detection performance in DM images with four different image quality levels due to different quality issues. Fourteen expert breast radiologists from five countries assessed a set of 80 DM cases, containing 60 lesions (40 cancers, 20 benign findings) and 20 normal cases. A visual grading analysis (VGA) study using a previously-described candidate instrument was conducted to evaluate a subset of 25 of the images used in the ROC study. Eight radiologists that had participated in the ROC study, and seven expert breast-imaging physicists, evaluated this subset. The VGA score (VGAS) and the ROC and visual grading characteristics (VGC) areas under the curve (AUCROC and AUCVGC) were compared. RESULTS No large differences in image quality among the four levels were detected by either ROC or VGA studies. However, the ranking of the four levels was consistent: level 1 (partial AUCROC: 0.070, VGAS: 6.77) performed better than levels 2 (0.066, 6.15), 3 (0.061, 5.82), and 4 (0.062, 5.37). Similarity between radiologists' and physicists' assessments was found (average VGAS difference of 10 %). CONCLUSIONS The results from the candidate instrument were found to correlate with those from ROC analysis, when used by either observer group. Therefore, it may be used by different professionals, such as radiologists, radiographers, and physicists, to assess clinically-relevant image quality variations in DM.
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Affiliation(s)
- Joana Boita
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, the Netherlands; Dutch Expert Centre for Screening (LRCB), Wijchenseweg 101, 6538 SW, Nijmegen, the Netherlands
| | - Ruben E van Engen
- Dutch Expert Centre for Screening (LRCB), Wijchenseweg 101, 6538 SW, Nijmegen, the Netherlands
| | - Alistair Mackenzie
- National Coordinating Centre for the Physics of Mammography, Royal Surrey NHS Foundation Trust, Guildford, GU2 7XX, UK
| | - Anders Tingberg
- Department of Medical Radiation Physics, Translational Medicine Malmö, Lund University, Skåne University Hospital, Carl Bertil Laurells gata 9, SE-20502 Malmö, Sweden
| | - Hilde Bosmans
- Department of Imaging and Pathology, Radiology, KUL, Herestraat 49, Leuven B-3000, Belgium; Department of Radiology, Radiology, UZ Gasthuisberg, Herestraat 49, Leuven B-3000, Belgium
| | - Anetta Bolejko
- Department of Medical Imaging and Physiology, Translational Medicine Malmö, Lund University, Skåne University Hospital, Carl Bertil Laurells gata 9, SE-20502 Malmö, Sweden
| | - Sophia Zackrisson
- Department of Medical Imaging and Physiology, Translational Medicine Malmö, Lund University, Skåne University Hospital, Carl Bertil Laurells gata 9, SE-20502 Malmö, Sweden
| | - Matthew G Wallis
- Cambridge Breast Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge & NIHR Cambridge Biomedical Research Centre, Cambridge, CB2 0QQ, UK
| | - Debra M Ikeda
- Department of Radiology, Stanford University School of Medicine, 875 Blake Wilbur Dr, Stanford, CA, 94305, USA
| | - Chantal van Ongeval
- Department of Radiology, Radiology, UZ Gasthuisberg, Herestraat 49, Leuven B-3000, Belgium
| | - Ruud Pijnappel
- Dutch Expert Centre for Screening (LRCB), Wijchenseweg 101, 6538 SW, Nijmegen, the Netherlands; Department of Radiology, University Medical Center Utrecht, PO Box 85500, 3508 GA, Utrecht, Utrecht University, the Netherlands
| | - Mireille Broeders
- Dutch Expert Centre for Screening (LRCB), Wijchenseweg 101, 6538 SW, Nijmegen, the Netherlands; Department for Health Evidence, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, the Netherlands
| | - Ioannis Sechopoulos
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, the Netherlands; Dutch Expert Centre for Screening (LRCB), Wijchenseweg 101, 6538 SW, Nijmegen, the Netherlands.
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22
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Kusk MW, Jensen JM, Gram EH, Nielsen J, Precht H. Anode heel effect: Does it impact image quality in digital radiography? A systematic literature review. Radiography (Lond) 2021; 27:976-981. [PMID: 33741222 DOI: 10.1016/j.radi.2021.02.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 01/28/2023]
Abstract
INTRODUCTION The anode heel effect can be used to optimize image quality and/or patient dose in digital radiography (DR). In film-screen radiography, the effect can equalize optical density in regions of varying attenuation. Clinical experience suggests that the implementation of DR has led to less awareness of anode orientation. Post-processing is assumed to compensate, but may also alter image impression and potentially obscure image details. Published evidence was examined for the influence of the anode heel effect on image quality in DR. METHOD A systematic literature search was carried out using PubMed, Embase, and Web of Science databases. Title and abstracts were screened blinded by three authors, according to in-/exclusion criteria, followed by full-text analysis for final inclusion. Studies where technical and/or visual image quality were reported, was included. All studies were analyzed and assigned quality scores, according to relevant questions. The authors devised a scoring system based on reported information pertaining to reproducibility, interpretation, and generalizability of the methods and conclusions. RESULTS Five studies were included of heterogeneous design, each with methodological shortcomings. Only a few anatomical areas were covered. Very few patients were examined, and in no studies were images evaluated by radiologists or reporting radiographers. Relevant information such as post-processing, image quality criteria and analysis was insufficient in most studies, making reproduction difficult. Results were contradictory, especially concerning technical vs visual image quality. CONCLUSION Limited published evidence was found quantifying the influence of the anode heel effect on image quality using DR technology. More methodologically, robust studies are needed. The published evidence neither proves nor disproves the impact of the heel effect on image quality in DR. IMPLICATIONS FOR PRACTICE Based on a systematic review, no firm recommendations for anode orientation relating to image quality in DR can be provided.
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Affiliation(s)
- M W Kusk
- Department of Radiology & Nuclear Medicine, Hospital of Southwest Jutland, University Hospital of Southern Denmark, Finsensgade 35, 6700 Esbjerg, Denmark.
| | - J M Jensen
- UCL University College, Niels Bohrs Allé 1, 5230 Odense M, Denmark.
| | - E H Gram
- Department of Radiology & Nuclear Medicine, Hospital of Southwest Jutland, University Hospital of Southern Denmark, Finsensgade 35, 6700 Esbjerg, Denmark; UCL University College, Niels Bohrs Allé 1, 5230 Odense M, Denmark.
| | - J Nielsen
- UCL University College, Niels Bohrs Allé 1, 5230 Odense M, Denmark.
| | - H Precht
- UCL University College, Niels Bohrs Allé 1, 5230 Odense M, Denmark; Department of Radiology, Lillebaelt Hospital, University Hospital of Southern Denmark, Sygehusvej 24, 6000 Kolding, Denmark; University of Southern Denmark, Department of Regional Health Research, Winsløwparken 19- 3, 5000 Odense C, Denmark.
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23
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Sanderink WBG, Teuwen J, Appelman L, Moy L, Heacock L, Weiland E, Karssemeijer N, Baltzer PAT, Sechopoulos I, Mann RM. Comparison of simultaneous multi-slice single-shot DWI to readout-segmented DWI for evaluation of breast lesions at 3T MRI. Eur J Radiol 2021; 138:109626. [PMID: 33711569 DOI: 10.1016/j.ejrad.2021.109626] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 02/15/2021] [Accepted: 03/01/2021] [Indexed: 01/09/2023]
Abstract
PURPOSE To compare diffusion-weighted imaging of the breast performed with a conventional readout-segmented echo-planar imaging (rs-EPI) sequence to when using a prototype simultaneous multi-slice single-shot EPI (SMS-ss-EPI) acquisition. METHOD From September 2017 to December 2018, 26 women with histologically proven breast cancer were scanned with the conventional rs-EPI and the SMS-ss-EPI at 3 T during the same imaging examination. Four breast radiologists (4-13 years of experience) independently scored both acquired series of 25 women (one case was used for training) for overall image quality (1: extremely poor to 9: excellent) and artifacts (1: very disturbing to 5: not present). All lesions (n = 52; 40 malignant, 12 benign) were also evaluated for visibility (1: not visible, 2: visible if location is given, 3: visible). In addition, lesion characteristics were rated, and a BI-RADS score was given. Results were analyzed using visual grading characteristics and the resulting area under the curve (AUCVGC), weighted kappa, McNemar test, and dependent-samples t-test when appropriate. RESULTS Overall, radiologists significantly preferred the image quality in rs-EPI over that of SMS-ss-EPI (AUCVGC: 0.698, P = 0.002). Infolding and ghosting, and distortion artifacts were significantly less apparent in the rs-EPI (AUCVGC: 0.660, P = 0.022 and AUCVGC: 0.700 P = 0.002, respectively). Lesions were, however, significantly better visible on the SMS-ss-EPI images (AUCVGC: 0.427, P = 0.016). Malignant lesions had significantly higher visibility with SMS-ss-EPI (P = 0.035). Sensitivity and specificity were comparable between both sequences (P = 0.760 and P = 0.549, respectively). CONCLUSIONS Despite the perceived lower image quality and the increased presence of artifacts in the SMS-ss-EPI sequence, malignant lesions are better visualized using this sequence.
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Affiliation(s)
- Wendelien B G Sanderink
- Medical Imaging, Radboud University Medical Centre, Geert Grooteplein Zuid 10, Nijmegen, 6525GA, the Netherlands.
| | - Jonas Teuwen
- Medical Imaging, Radboud University Medical Centre, Geert Grooteplein Zuid 10, Nijmegen, 6525GA, the Netherlands
| | - Linda Appelman
- Medical Imaging, Radboud University Medical Centre, Geert Grooteplein Zuid 10, Nijmegen, 6525GA, the Netherlands
| | - Linda Moy
- Department of Radiology, New York University Langone Medical Center, 660 First Avenue, 4(th) Floor, New York, NY, 10016, United States
| | - Laura Heacock
- Department of Radiology, New York University Langone Medical Center, 660 First Avenue, 4(th) Floor, New York, NY, 10016, United States
| | - Elisabeth Weiland
- MR Application Predevelopment, Siemens Healthcare, Allee am Roethelheimpark 2, Erlangen, 91052, Germany
| | - Nico Karssemeijer
- Medical Imaging, Radboud University Medical Centre, Geert Grooteplein Zuid 10, Nijmegen, 6525GA, the Netherlands
| | - Pascal A T Baltzer
- Department of Biomedical Imaging and Image-guided Therapy, Vienna General Hospital, Währinger Gürtel 18-20, Vienna, 1090, Austria
| | - Ioannis Sechopoulos
- Medical Imaging, Radboud University Medical Centre, Geert Grooteplein Zuid 10, Nijmegen, 6525GA, the Netherlands
| | - Ritse M Mann
- Medical Imaging, Radboud University Medical Centre, Geert Grooteplein Zuid 10, Nijmegen, 6525GA, the Netherlands
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24
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Tavakoli Taba S, Arhatari BD, Nesterets YI, Gadomkar Z, Mayo SC, Thompson D, Fox J, Kumar B, Prodanovic Z, Hausermann D, Maksimenko A, Hall C, Dimmock M, Pavlov KM, Lockie D, Gity M, Peele A, Quiney HM, Lewis S, Gureyev TE, Brennan PC. Propagation-Based Phase-Contrast CT of the Breast Demonstrates Higher Quality Than Conventional Absorption-Based CT Even at Lower Radiation Dose. Acad Radiol 2021; 28:e20-e26. [PMID: 32035759 DOI: 10.1016/j.acra.2020.01.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/31/2019] [Accepted: 01/07/2020] [Indexed: 01/07/2023]
Abstract
RATIONALE AND OBJECTIVES Propagation-based phase-contrast CT (PB-CT) is an advanced X-ray imaging technology that exploits both refraction and absorption of the transmitted X-ray beam. This study was aimed at optimizing the experimental conditions of PB-CT for breast cancer imaging and examined its performance relative to conventional absorption-based CT (AB-CT) in terms of image quality and radiation dose. MATERIALS AND METHODS Surgically excised breast mastectomy specimens (n = 12) were scanned using both PB-CT and AB-CT techniques under varying imaging conditions. To evaluate the radiological image quality, visual grading characteristics (VGC) analysis was used in which 11 breast specialist radiologists compared the overall image quality of PB-CT images with respect to the corresponding AB-CT images. The area under the VGC curve was calculated to measure the differences between PB-CT and AB-CT images. RESULTS The highest radiological quality was obtained for PB-CT images using a 32 keV energy X-ray beam and by applying the Homogeneous Transport of Intensity Equation phase retrieval with the value of its parameter γ set to one-half of the theoretically optimal value for the given materials. Using these optimized conditions, the image quality of PB-CT images obtained at 4 mGy and 2 mGy mean glandular dose was significantly higher than AB-CT images at 4 mGy (AUCVGC = 0.901, p = 0.001 and AUCVGC = 0.819, p = 0.011, respectively). CONCLUSION PB-CT achieves a higher radiological image quality compared to AB-CT even at a considerably lower mean glandular dose. Successful translation of the PB-CT technique for breast cancer imaging can potentially result in improved breast cancer diagnosis.
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Grob D, Oostveen LJ, Jacobs C, Scholten E, Prokop M, Schaefer-Prokop CM, Sechopoulos I, Brink M. Pulmonary nodule enhancement in subtraction CT and dual-energy CT: A comparison study. Eur J Radiol 2020; 134:109443. [PMID: 33310553 DOI: 10.1016/j.ejrad.2020.109443] [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: 08/18/2020] [Revised: 11/10/2020] [Accepted: 11/25/2020] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To compare nodule enhancement on subtraction CT iodine maps to that on dual-energy CT iodine maps using CT datasets acquired simultaneously. METHODS A previously-acquired set of lung subtraction and dual-energy CT maps consisting of thirty patients with 95 solid pulmonary nodules (≥4 mm diameter) was used. Nodules were annotated and segmented on CT angiography, and mean nodule enhancement in the iodine maps calculated. Three radiologists scored nodule visibility with both techniques on a 4-point scale. RESULTS Mean nodule enhancement was higher (p < 0.001) at subtraction CT (34.9 ± 12.9 HU) than at dual-energy CT (25.4 ± 21.0 HU). Nodule enhancement at subtraction CT was judged more often to be "highly visible" for each observers (p < 0.001) with an area under the curve of 0.81. CONCLUSIONS Subtraction CT is able to depict iodine enhancement in pulmonary nodules better than dual-energy CT.
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Affiliation(s)
- Dagmar Grob
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, the Netherlands.
| | - Luuk J Oostveen
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, the Netherlands.
| | - Colin Jacobs
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, the Netherlands.
| | - Ernst Scholten
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, the Netherlands.
| | - Mathias Prokop
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, the Netherlands.
| | - Cornelia M Schaefer-Prokop
- Department of Radiology and Nuclear Medicine, Meander Medical Centre, Maatweg 3, 3813 TZ, Amersfoort, the Netherlands.
| | - Ioannis Sechopoulos
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, the Netherlands.
| | - Monique Brink
- Department of Medical Imaging, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, the Netherlands.
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Enevoldsen S, Kusk MW. Image quality of bedside chest radiographs in intensive care beds with integrated detector tray: A phantom study. Radiography (Lond) 2020; 27:453-458. [PMID: 33158751 DOI: 10.1016/j.radi.2020.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/18/2020] [Accepted: 10/19/2020] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Vendors offer intensive care beds with integrated detector trays for bedside radiography, promoting better ergonomics and patient comfort. However, no documentation of the effects on diagnostic image quality has been located. This study examines measured and subjective image quality of supine bedside chest radiographs with and without use of such a detector tray. METHODS A contrast-detail phantom (CDRAD 2.0) was exposed using standard supine chest exposure parameters. Plexiglass plates of 16 and 21 cm were placed in front to simulate patient attenuation for standard and adipose patients. Exposures were repeated with the detector placed in tray and directly in bed. Images were analysed using dedicated software giving a figure-of-merit IQFinv. Results were compared using ANOVA. Then an anthropomorphic chest phantom (Lungman) was exposed using the same parameters, and the same placements of the detector. Exposures were done with and without extra conformal tissue to simulate varying patient sizes, and with and without added typical intensive care equipment. Images were analysed by two radiologists using a three-point scale, on five image quality criteria. Radiologist also stated whether the images were sufficient for diagnosis. Results were compared using Visual Grading Characteristics, using dedicated software, resulting in Areas Under the Curve (AUC-VGC) for each combination and criteria. Inter- and intra-rater reliability were assessed with kappa statistics. Composite Visual Grading Analysis (VGAS) scores were calculated for each image. Both IQFinv and were normalized and compared. RESULTS For all criteria both IQFinv and AUC-VGC was significantly better when exposing the detector directly in bed, than with the detector placed in the tray across all exposures. When stratified into thin and adipose patients, IQFinv decreased significantly for thin patients, while VGAS-scores did not. For adipose patients, both figures were significantly lower with the detector in the tray. CONCLUSION Use of detector tray for bedside chest imaging decreases image quality. IMPLICATIONS FOR PRACTICE Radiographers should critically evaluate image quality and experimentally determine optimal exposure factors, when taking equipment with integrated trays into use.
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Affiliation(s)
- S Enevoldsen
- University Hospital Southwest Denmark, Department of Radiology and Nuclear Medicine, Finsensgade 35, 6700 Esbjerg, Denmark.
| | - M W Kusk
- University Hospital Southwest Denmark, Department of Radiology and Nuclear Medicine, Finsensgade 35, 6700 Esbjerg, Denmark.
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Comparison of Magnetic Resonance Angiography and Digital Subtraction Angiography for the Assessment of Infrapopliteal Arterial Occlusive Lesions, Based on the TASC II Classification Criteria. Diagnostics (Basel) 2020; 10:diagnostics10110892. [PMID: 33142848 PMCID: PMC7693383 DOI: 10.3390/diagnostics10110892] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 10/29/2020] [Accepted: 10/29/2020] [Indexed: 11/16/2022] Open
Abstract
This paper aimed to study the agreement and repeatability, both intra- and interobserver, of infrapopliteal lesion assessment with magnetic resonance angiography (MRA), using the TransAtlantic Inter-Society Consensus (TASC) II criteria, with perioperative digital subtraction angiography (DSA) as a reference. Sixty-eight patients with an MRA preceding an endovascular infrapopliteal revascularization were included. Preoperative MRAs and perioperative DSAs were evaluated in random order by three independent observers using the TASC II classification. The results were analyzed using visual grading characteristics (VGC) analysis and Krippendorff’s α. No systematic difference was found between modalities: area under the VGC curve (AUCVGC) = 0.48 (p = 0.58) or intraobserver; AUCVGC for Observer 1 and 2 respectively, 0.49 (p = 0.85) and 0.53 (p = 0.52) for MRA compared with 0.54 (p = 0.30) and 0.49 (p = 0.81) for DSA. Interobserver differences were seen: AUCVGC of 0.63 (p < 0.01) for DSA and 0.80 (p < 0.01) for MRA. These results were confirmed using Krippendorff’s α for the three observers showing 0.13 (95% confidence interval (CI) −0.07–0.31) for MRA and 0.39 (95% CI 0.23–0.53) for DSA. Poor interobserver agreement was also found in the choice of a target vessel on preoperative MRA: Krippendorff’s α = 0.19 (95% CI 0.01‒0.36). In conclusion, infrapopliteal lesions can be reliably determined on preoperative MRA, but interobserver variability regarding the choice of a target vessel is a major concern that appears to affect the overall TASC II grade.
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Lisson CG, Lisson CS, Vogele D, Strauss B, Schuetze K, Cintean R, Beer M, Schmidt SA. Improvement of image quality applying iterative scatter correction for grid-less skeletal radiography in trauma room setting. Acta Radiol 2020; 61:768-775. [PMID: 31569948 DOI: 10.1177/0284185119878348] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Iterative reconstruction is well established for CT. Plain radiography also takes advantage of iterative algorithms to reduce scatter radiation and improve image quality. First applications have been described for bedside chest X-ray. A recent experimental approach also provided proof of principle for skeletal imaging. PURPOSE To examine clinical applicability of iterative scatter correction for skeletal imaging in the trauma setting. MATERIAL AND METHODS In this retrospective single-center study, 209 grid-less radiographs were routinely acquired in the trauma room for 12 months, with imaging of the chest (n = 31), knee (n = 111), pelvis (n = 14), shoulder (n = 24), and other regions close to the trunk (n = 29). Radiographs were postprocessed with iterative scatter correction, doubling the number of images. The radiographs were then independently evaluated by three radiologists and three surgeons. A five-step rating scale and visual grading characteristics analysis were used. The area under the VGC curve (AUCVGC) quantified differences in image quality. RESULTS Images with iterative scatter correction were generally rated significantly better (AUCVGC = 0.59, P < 0.01). This included both radiologists (AUCVGC = 0.61, P < 0.01) and surgeons (AUCVGC = 0.56, P < 0.01). The image-improving effect was significant for all body regions; in detail: chest (AUCVGC = 0.64, P < 0.01), knee (AUCVGC = 0.61, P < 0.01), pelvis (AUCVGC = 0.60, P = 0.01), shoulder (AUCVGC = 0.59, P = 0.02), and others close to the trunk (AUCVGC = 0.59, P < 0.01). CONCLUSION Iterative scatter correction improves the image quality of grid-less skeletal radiography in the clinical setting for a wide range of body regions. Therefore, iterative scatter correction may be the future method of choice for free exposure imaging when an anti-scatter grid is omitted due to high risk of tube-detector misalignment.
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Affiliation(s)
- Christoph G Lisson
- Department of Diagnostic and Interventional Radiology, Ulm University Medical Center, Ulm, Germany
| | - Catharina S Lisson
- Department of Diagnostic and Interventional Radiology, Ulm University Medical Center, Ulm, Germany
| | - Daniel Vogele
- Department of Diagnostic and Interventional Radiology, Ulm University Medical Center, Ulm, Germany
| | - Beatrice Strauss
- Department of Orthopedic Trauma, Hand, Plastic and Reconstructive Surgery, Ulm University Medical Center, Ulm, Germany
| | - Konrad Schuetze
- Department of Orthopedic Trauma, Hand, Plastic and Reconstructive Surgery, Ulm University Medical Center, Ulm, Germany
| | - Raffael Cintean
- Department of Orthopedic Trauma, Hand, Plastic and Reconstructive Surgery, Ulm University Medical Center, Ulm, Germany
| | - Meinrad Beer
- Department of Diagnostic and Interventional Radiology, Ulm University Medical Center, Ulm, Germany
| | - Stefan A Schmidt
- Department of Diagnostic and Interventional Radiology, Ulm University Medical Center, Ulm, Germany
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Sá Dos Reis C, Soares F, Bartoli G, Dastan K, Dhlamini ZS, Hussain A, Kroode D, McEntee MF, Mekis N, Thompson JD. Reduction of visual acuity decreases capacity to evaluate radiographic image quality. Radiography (Lond) 2020; 26 Suppl 2:S79-S87. [PMID: 32423840 DOI: 10.1016/j.radi.2020.04.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 04/07/2020] [Accepted: 04/22/2020] [Indexed: 11/24/2022]
Abstract
INTRODUCTION To determine the impact of reduced visual acuity on the evaluation of a test object and appendicular radiographs. METHODS Visual acuity was reduced by two different magnitudes using simulation glasses and compared to normal vision (no glasses). During phase one phantom images were produced for the purpose of counting objects by 13 observers and on phase 2 image appraisal of anatomical structures was performed on anonymized radiographic images by 7 observers. The monitors were calibrated (SMPTE RP133 test pattern) and the room lighting was maintained at 7 ± 1 lux. Image display and data on grading were managed using ViewDEX (v.2.0) and the area under the visual grading characteristic (AUCVGC) was calculated using VGC Analyzer (v1.0.2). Inferential statistics were calculated using SPSS. RESULTS For the evaluation of appendicular radiographs the total interpretation time was longer when visual acuity was reduced with 2 pairs of simulation glasses (15.4 versus 8.9 min). Visual grading analysis showed that observers can lose the ability to detect anatomical and contrast differences when they have a simulated visual acuity reduction, being more challenging to differentiate low contrast details. No simulation glasses, compared to 1 pair gives an AUCVGC of 0.302 (0.280, 0.333), that decreases to 0.197 (0.175, 0.223) when using 2 pairs of glasses. CONCLUSIONS Reduced visual acuity has a significant negative impact on the evaluation of test objects and clinical images. Further work is required to test the impact of reduced visual acuity on visual search, technical evaluation of a wider range of images as well as pathology detection/characterization performance. IMPLICATIONS FOR PRACTICE It seems that visual performance needs to be considered to reduce the risks associated with incomplete or incorrect diagnosis. If employers or professional bodies were to introduce regular eye tests into health screening it may reduce the risk of misinterpretation as a result of poor vision.
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Affiliation(s)
- C Sá Dos Reis
- School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland(HES-SO), Av de Beaumont 21, 1011 Lausanne, Switzerland.
| | - F Soares
- Academic Department of Health and Services, Instituto Federal de Santa Catarina (IFSC), Av. Mauro Ramos, 950, Florianopolis, Brazil.
| | - G Bartoli
- School of Health Sciences (HESAV), University of Applied Sciences and Arts Western Switzerland(HES-SO), Av de Beaumont 21, 1011 Lausanne, Switzerland.
| | - K Dastan
- School of Health and Society, Department of Radiography Mary Seacole Building, University of Salford, Frederick Road Campus, Salford, M6 6PU, United Kingdom.
| | - Z S Dhlamini
- Central University of Technology, 20 President Brand St, Bloemfontein Central, Bloemfontein, 9301, South Africa.
| | - A Hussain
- University of Derby, Kedleston Rd, Derby DE22 1GB, UK.
| | - D Kroode
- Hanze University of Applied Sciences, Groningen, Postbus 30030, 9700, RM, Groningen.
| | - M F McEntee
- University College Cork, Discipline of Diagnostic Radiography, UG 12 Áras Watson, Brookfield Health Sciences, College Road, Cork, T12 AK54.
| | - N Mekis
- University of Ljubljana, Faculty of Health Sciences, Medical Imaging and Radiotherapy Department, Zdravstvena Pot 5, 1000 Ljubljana, Slovenia.
| | - J D Thompson
- School of Health and Society, Department of Radiography Mary Seacole Building, University of Salford, Frederick Road Campus, Salford, M6 6PU, United Kingdom.
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Wilson S, Thompson JD. Comparison of two Meglumine-Diatrizoate based bowel preparations for computed tomography colonography: Comparison of patient symptoms and bowel preparation quality. Radiography (Lond) 2020; 26:e290-e296. [PMID: 32376192 DOI: 10.1016/j.radi.2020.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 04/11/2020] [Accepted: 04/13/2020] [Indexed: 02/06/2023]
Abstract
INTRODUCTION To investigate the impact of two Meglumine-Diatrizoate based bowel preparation regimes for computed tomography colonography (CTC) on the patient experience and image quality. METHODS 100 patients consumed Meglumine-Diatrizoate at 24 h and 12 h prior to the CTC examination. 50 patients followed regime 1 (50:50), 50 ml of Meglumine-Diatrizoate at both 24 and 12 h prior to the examination. 50 patients followed regime 2 (75:25), 75 ml of Meglumine-Diatrizoate at 24 h prior to the examination and 25 ml of Meglumine-Diatrizoate at 12 h prior to the examination. All patients completed a questionnaire to indicate the time of onset of adverse effects and when they were most severe. Five advanced practitioners assessed the image quality in a visual grading study. Visual grading characteristic (VGC) analysis was applied with regime 1 as the reference condition and regime 2 and test condition; test alpha was set at 0.05. RESULTS Image quality was assessed with successful bowel cleansing as the scoring criteria for the visual grading study. The bowel cleansing as provided by the two Meglumine-Diatrizoate regimes was revealed not to be statistically different, with the area under the VGC curve and 95% confidence intervals 0.487 (0.287, 0.701), p = 0.887. Patients taking the 75:25 bowel preparation experienced a shorter median time to the onset of adverse effects. CONCLUSION There was no observed difference in Image quality criteria score for the two Meglumine-Diatrizoate based bowel preparation with more predictable adverse effects of Meglumine-Diatrizoate with the 75:25 preparation. IMPLICATIONS FOR PRACTICE Providing patients with a higher contrast burden 24 h prior to CTC may have a positive impact on the patient experience without compromising image quality.
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Affiliation(s)
- S Wilson
- North West Anglia NHS Foundation Trust, North West Anglia NHS Foundation Trust, Peterborough, PE3 9GZ, UK.
| | - J D Thompson
- University of Salford, University of Salford, Manchester, M6 6PU, UK.
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Holmquist F, Söderberg M, Nyman U, Fält T, Siemund R, Geijer M. 80-kV p hepatic CT to reduce contrast medium dose in azotemic patients: a feasibility study. Acta Radiol 2020; 61:441-449. [PMID: 31378079 DOI: 10.1177/0284185119866807] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background Low peak kilovoltage (kVp) computed tomography (CT) may be used to reduce contrast medium doses in patients at risk of contrast medium-induced acute kidney injury if image noise can be controlled by increasing X-ray tube loading (mAs). Purpose To evaluate objective and subjective image quality in 80-kVp CT with reduced contrast medium dose and compensated mAs for unchanged image noise in patients with estimated glomerular filtration rate <45 mL/min compared with the standard 120-kVp protocol. Material and Methods 80-kVp CT with 300 mg I/kg in 40 patients (body mass index 18–32 kg/m2, glomerular filtration rate <45 mL/min) and 120-kVp CT with 500 mg I/kg in 40 patients (body mass index = 17–30 kg/m2, glomerular filtration rate ≥45 mL/min) was compared on mean hepatic attenuation, image noise, contrast medium enhancement, signal-to-noise ratio, contrast-to-noise ratio, effective radiation dose, and subjective image quality. Results There were no significant differences regarding median hepatic post-contrast attenuation, image noise, contrast medium enhancement, signal-to-noise ratio, contrast-to-noise ratio, or effective dose between the 80-kVp and 120-kVp cohorts: 114/110 HU; 14/14 HU; 57/53 HU; 8.0/7.4; 3.8/3.5; and 5.3/5.9 mSv, respectively. However, subjective image visual grading showed statistically significantly inferior scores for 80 kVp for six of eight items. After exclusion of seven inferior examinations not caused by the chosen kVp technique, only three items showed inferior scores for 80 kVp. Only 5% of gradings regarding overall image quality were <3 of 5 points. Conclusion Despite lower subjective image quality, objective data indicate that 80-kVp CT with reduced contrast medium doses and compensated mAs may have the potential to provide satisfactory diagnostic quality in patients with body mass index <30 kg/m2, which could benefit patients at risk of contrast medium-induced acute kidney injury.
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Affiliation(s)
- Fredrik Holmquist
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund University, Lund, Sweden
| | - Marcus Söderberg
- Department of Translational Medicine, Medical Radiation Physics, Skåne University Hospital, Lund University, Malmö, Sweden.,Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Malmö, Sweden
| | - Ulf Nyman
- Department of Translational Medicine, Division of Medical Radiology, Skåne University Hospital, Lund University, Malmö, Sweden
| | - Tobias Fält
- Department of Translational Medicine, Division of Medical Radiology, Skåne University Hospital, Lund University, Malmö, Sweden
| | - Roger Siemund
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund University, Lund, Sweden
| | - Mats Geijer
- Institute of Clinical Sciences, Department of Radiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden
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Holmquist F, Söderberg M, Nyman U, Fält T, Siemund R, Geijer M. Can iterative reconstruction algorithms replace tube loading compensation in low kVp hepatic CT? Subjective versus objective image quality. Acta Radiol Open 2020; 9:2058460120910575. [PMID: 32206344 PMCID: PMC7076580 DOI: 10.1177/2058460120910575] [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: 11/14/2019] [Accepted: 02/10/2020] [Indexed: 11/16/2022] Open
Abstract
Background Hepatic computed tomography (CT) with decreased peak kilovoltage (kVp) may be used to reduce contrast medium doses in patients at risk of contrast-induced acute kidney injury (CI-AKI); however, it increases image noise. To preserve image quality, noise has been controlled by X-ray tube loading (mAs) compensation (TLC), i.e. increased mAs. Another option to control image noise would be to use iterative reconstructions (IR) algorithms without TLC (No-TLC). It is unclear whether this may preserve image quality or only reduce image noise. Purpose To evaluate image quality of 80 kVp hepatic CT with TLC and filtered back projection (FBP) compared with 80 kVp with No-TLC and IR algorithms (SAFIRE 3 and 5) in patients with eGFR <45 mL/min. Material and Methods Forty patients (BMI 18–32 kg/m2) were examined with both protocols following injection of 300 mg I/kg. Hepatic attenuation, image noise, enhancement, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and subjective image quality were evaluated for each patient. Results Comparing TLC/FBP with No-TLC/IR-S5, there were no significant differences regarding hepatic attenuation, image noise, enhancement, SNR and CNR: 114 vs. 115 HU, 14 vs. 14 HU, 55 vs. 57 HU, 8.0 vs. 8.4, and 3.8 vs. 4.0 in median, respectively. No-TLC/IR-S3 resulted in higher image noise and lower SNR and CNR than TLC/FBP. Subjective image quality scoring with visual grading showed statistically significantly inferior scores for IR-S5 images. Conclusion CT of 80 kVp to reduce contrast medium dose in patients at risk of CI-AKI combined with IR algorithms with unchanged tube loading to control image noise does not provide sufficient diagnostic quality.
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Affiliation(s)
- Fredrik Holmquist
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund University, Lund, Sweden
| | - Marcus Söderberg
- Medical Radiation Physics, Department of Translational Medicine, Skåne University Hospital, Lund University, Malmö, Sweden.,Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Malmö, Sweden
| | - Ulf Nyman
- Department of Translational Medicine, Division of Medical Radiology, Skåne University Hospital, Lund University, Malmö, Sweden
| | - Tobias Fält
- Department of Translational Medicine, Division of Medical Radiology, Skåne University Hospital, Lund University, Malmö, Sweden
| | - Roger Siemund
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund University, Lund, Sweden
| | - Mats Geijer
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund University, Lund, Sweden.,Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Region Västra Götaland, Sahlgrenska University Hospital, Department of Radiology, Gothenburg, Sweden
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Cristofaro M, Busi Rizzi E, Piselli P, Pianura E, Petrone A, Fusco N, Di Stefano F, Schinina' V. Image quality and radiation dose reduction in chest CT in pulmonary infection. Radiol Med 2020; 125:451-460. [PMID: 32048157 DOI: 10.1007/s11547-020-01139-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 01/16/2020] [Indexed: 12/17/2022]
Abstract
PURPOSE To evaluate the effect of dose reduction with iterative reconstruction (IR) on image quality of chest CT scan comparing two protocols. MATERIALS AND METHODS Fifty-nine patients were enrolled. The two CT protocols were applied using Iterative Reconstruction (ASIR™) 40% but different noise indexes, recording dose-length product (DLP) and volume computed tomography dose index (CTDIvol). The subjective IQ was rated based on the distinction of anatomic details using a 4-point Likert scale based on the European Guidelines on Quality Criteria for CT. For each patient, two single CTs, at enrollment (group 1) and at follow-up after lowering the dose (group 2), were evaluated by two radiologists evaluating, for each examination, five different lung regions (central zone-CZ; peripheral zone-PZ; sub-pleural region-SPR; centrilobular region-CLR; and apical zone-AZ). An inter-observer agreement was expressed by weighted Cohen's kappa statistics (k) and intra-individual differences of subjective image analysis through visual grading characteristic (VGC) analysis. RESULTS An average 50.4% reduction in CTDIvol and 51.5% reduction in DLP delivered were observed using the dose-reduced protocol. An agreement between observers evaluating group 1 CTs was perfect (100%) and moderate to good in group 2 examinations (k-Cohen ranging from 0.56 for PZ and AZ to 0.70 for SPR). In the VGC analysis, image quality ratings were significantly better for group 1 than group 2 scans for all regions (AUCVGC ranging from 0.56 for CZ to 0.62). However, disagreement was limited to a score 4 (excellent)-to-score 3 (good) IQ transition; apart from a single case in PZ, both the observers scored the IQ at follow-up as 2 (sufficient) starting from a score 4 (excellent). CONCLUSION Dose reduction achieved in the follow-up CT scans, although a lower IQ still allows a good diagnostic confidence.
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Affiliation(s)
- Massimo Cristofaro
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
| | - Elisa Busi Rizzi
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
| | - Pierluca Piselli
- Clinical Epidemiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy.
| | - Elisa Pianura
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
| | - Ada Petrone
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
| | - Nicoletta Fusco
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
| | - Federica Di Stefano
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
| | - Vincenzo Schinina'
- Radiology Unit, National Institute for Infectious Diseases "L. Spallanzani" IRCCS, Via Portuense 292, 00149, Rome, Italy
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Tavakoli Taba S, Baran P, Nesterets YI, Pacile S, Wienbeck S, Dullin C, Pavlov K, Maksimenko A, Lockie D, Mayo SC, Quiney HM, Dreossi D, Arfelli F, Tromba G, Lewis S, Gureyev TE, Brennan PC. Comparison of propagation-based CT using synchrotron radiation and conventional cone-beam CT for breast imaging. Eur Radiol 2020; 30:2740-2750. [DOI: 10.1007/s00330-019-06567-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 10/29/2019] [Accepted: 10/31/2019] [Indexed: 01/08/2023]
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Shahgeldi K, Sjöberg T, Nordström J, Lesanu R, Svahn TM. OPTIMIZING IMAGE QUALITY, RADIATION DOSAGE TO THE PATIENT AND TO THE DETECTOR IN PEDIATRIC CHEST RADIOGRAPHY: A PHANTOM STUDY OF A PORTABLE DIGITAL RADIOGRAPHY SYSTEM. RADIATION PROTECTION DOSIMETRY 2019; 185:414-420. [PMID: 30916753 DOI: 10.1093/rpd/ncz028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/21/2018] [Accepted: 02/18/2019] [Indexed: 06/09/2023]
Abstract
The present work aimed to optimize exposure settings in pediatric digital chest radiography (DR) with regard to image quality and radiation dosage. A pediatric phantom was imaged with a portable DR unit to examine different exposure settings (range: 75-109 kVp; 0.3-1.28 mAs) for patients of 10-20 kg. Fourteen experienced radiologists compared the structural image quality of the images with a reference image (85 kVp/1.28 mAs). A multiple-reader multiple-case analysis of the radiologists' interpretations was performed. Effective dose was computed and standardized exposure indices (EIs) were extracted for the different exposure settings. For the lowest tube voltage setting (75 kVp/1.28 mAs), radiation dosage could be reduced with 35% relative the reference settings without compromising image quality (p > 0.05). EI was within recommendations (250 ± 100). Lower tube voltage in pediatric DR permitted a dose reduction at maintained quality for the physical aspects and diagnostic performance. Other weight-classes should be examined and adjusted accordingly.
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Affiliation(s)
- Kaveh Shahgeldi
- Centre for Research and Development, Uppsala University/Region Gävleborg, 80188 Gävle, Sweden
| | - Tommy Sjöberg
- Department of Surgical Science, Uppsala University, 75185 Uppsala, Sweden
| | - Jonny Nordström
- Centre for Research and Development, Uppsala University/Region Gävleborg, 80188 Gävle, Sweden
| | - Radu Lesanu
- Department of Imaging and Functional Medicine, Division Diagnostics, Gävle Hospital, Region Gävleborg, 80188 Gävle, Sweden
| | - Tony Martin Svahn
- Centre for Research and Development, Uppsala University/Region Gävleborg, 80188 Gävle, Sweden
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Svenson B, Båth M, Karlsson R, Persson B. A comparison of perceived diagnostic image quality in direct digital panoramic images between standard and advanced external GOP image processing. Acta Odontol Scand 2019; 77:560-565. [PMID: 31146623 DOI: 10.1080/00016357.2019.1618912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Objective: The objective of the present study was to study the effect of adaptive image processing (GOP processing) on the visibility of anatomical structures in direct digital panoramic images. Material and methods: The study comprised panoramic images of 50 consecutive adult individuals aged 18-60 years. Nine dentists working with dental radiology compared the structural image quality of all standard-processed and GOP-processed panoramic images for six anatomical structures, using a six-point scale for visual grading characteristics analysis. Results: For all anatomic structures a statistically significant difference in favour of the GOP was found. Conclusions: The present study shows that it is possible to improve perceived diagnostic image quality of direct digital panoramic radiography using GOP technology compared to the manufacturers' standard processing. Manufacturers' image-processing programs can be further developed, as there is a possibility of improving the perceived diagnostic content of an image with external processing.
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Affiliation(s)
- Björn Svenson
- Department of Dental Research, Postgraduate Dental Education Center, Örebro, Sweden
- School of Health and Medical Sciences, Örebro University, Örebro, Sweden
| | - Magnus Båth
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
- Department of Radiation Physics, Institute of Clinical Sciences at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Reet Karlsson
- Department of Radiology, Skaraborg Hospital Skövde, Skövde, Sweden
| | - Bo Persson
- Department of Radiology, Skaraborg Hospital Skövde, Skövde, Sweden
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Krammer J, Zolotarev S, Hillman I, Karalis K, Stsepankou D, Vengrinovich V, Hesser J, M Svahn T. Evaluation of a new image reconstruction method for digital breast tomosynthesis: effects on the visibility of breast lesions and breast density. Br J Radiol 2019; 92:20190345. [PMID: 31453718 DOI: 10.1259/bjr.20190345] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To compare image quality and breast density of two reconstruction methods, the widely-used filtered-back projection (FBP) reconstruction and the iterative heuristic Bayesian inference reconstruction (Bayesian inference reconstruction plus the method of total variation applied, HBI). METHODS Thirty-two clinical DBT data sets with malignant and benign findings, n = 27 and 17, respectively, were reconstructed using FBP and HBI. Three experienced radiologists evaluated the images independently using a 5-point visual grading scale and classified breast density according to the American College of Radiology Breast Imaging-Reporting And Data System Atlas, fifth edition. Image quality metrics included lesion conspicuity, clarity of lesion borders and spicules, noise level, artifacts surrounding the lesion, visibility of parenchyma and breast density. RESULTS For masses, the image quality of HBI reconstructions was superior to that of FBP in terms of conspicuity,clarity of lesion borders and spicules (p < 0.01). HBI and FBP were not significantly different in calcification conspicuity. Overall, HBI reduced noise and supressed artifacts surrounding the lesions better (p < 0.01). The visibility of fibroglandular parenchyma increased using the HBI method (p < 0.01). On average, five cases per radiologist were downgraded from BI-RADS breast density category C/D to A/B. CONCLUSION HBI significantly improves lesion visibility compared to FBP. HBI-visibility of breast parenchyma increased, leading to a lower breast density rating. Applying the HBIR algorithm should improve the diagnostic performance of DBT and decrease the need for additional imaging in patients with dense breasts. ADVANCES IN KNOWLEDGE Iterative heuristic Bayesian inference (HBI) image reconstruction substantially improves the image quality of breast tomosynthesis leading to a better visibility of breast carcinomas and reduction of the perceived breast density compared to the widely-used filtered-back projection (FPB) reconstruction. Applying HBI should improve the accuracy of breast tomosynthesis and reduce the number of unnecessary breast biopsies. It may also reduce the radiation dose for the patients, which is especially important in the screening context.
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Affiliation(s)
- Julia Krammer
- Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Heidelberg University Mannheim, Mannheim, Germany
| | - Sergei Zolotarev
- National Academy of Science of Belarus, Institute of Applied Physics, Minsk, Belarus
| | - Inge Hillman
- Mammography Section, Gävle Hospital, Gävle, Sweden
| | | | - Dzmitry Stsepankou
- Department of Experimental Radiooncology, Medical Faculty Mannheim, Heidelberg University, Germany
| | - Valeriy Vengrinovich
- National Academy of Science of Belarus, Institute of Applied Physics, Minsk, Belarus
| | - Jürgen Hesser
- National Academy of Science of Belarus, Institute of Applied Physics, Minsk, Belarus.,Central Institute for Computer Engineering (ZITI), Heidelberg University, Germany.,Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Germany
| | - Tony M Svahn
- Centre for Research and Development, Uppsala University/Region Gävleborg, Gävle, Sweden.,Department of Imaging and functional medicine, Division diagnostics, Gävle hospital, Gävle, Region Gävleborg, Sweden
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Precht H, Hansson J, Outzen C, Hogg P, Tingberg A. Radiographers' perspectives' on Visual Grading Analysis as a scientific method to evaluate image quality. Radiography (Lond) 2019; 25 Suppl 1:S14-S18. [PMID: 31481182 DOI: 10.1016/j.radi.2019.06.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/25/2019] [Accepted: 06/26/2019] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Radiographers routinely undertake many initiatives to balance image quality with radiation dose (optimisation). For optimisation studies to be successful image quality needs to be carefully evaluated. Purpose was to 1) discuss the strengths and limitations of a Visual Grading Analysis (VGA) method for image quality evaluation and 2) to outline the method from a radiographer's perspective. METHODS A possible method for investigating and discussing the relationship between radiographic image quality parameters and the interpretation and perception of X-ray images is the VGA method. VGA has a number of advantages such as being low cost and a detailed image quality assessment, although it is limited to ensure the images convey the relevant clinical information and relate the task based radiography. RESULTS Comparing the experience of using VGA and Receiver Operating Characteristic (ROC) it is obviously that less papers are published on VGA (Pubmed n=1.384) compared to ROC (Pubmed n=122.686). Hereby the scientific experience of the VGA method is limited compared to the use of ROC. VGA is, however, a much newer method and it is slowly gaining more and more attention. CONCLUSION The success of VGA requires a number of steps to be completed, such as defining the VGA criteria, choosing the VGA method (absolute or relative), including observers, finding the best image display platforms, training observers and selecting the best statistical method for the study purpose should be thoroughly considered. IMPLICATION FOR PRACTICE Detailed evaluation of image quality for optimisation studies related to technical definition of image quality.
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Affiliation(s)
- H Precht
- Conrad Research Programme, University College Lillebelt, Niels Bohrs Alle 1, 5230, Odense M, Denmark; Medical Research Department, Odense University Hospital, Baagøes Àlle 15, 5700, Svendborg, Denmark; Department of Clinical Research, University of Southern Denmark, Winsløwsparken, 5000, Odense C, Denmark.
| | - J Hansson
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45, Gothenburg, Sweden; Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, SE-413 45, Gothenburg, Sweden
| | - C Outzen
- Conrad Research Programme, University College Lillebelt, Niels Bohrs Alle 1, 5230, Odense M, Denmark
| | - P Hogg
- School of Health and Society, University of Salford, Manchester, UK
| | - A Tingberg
- Medical Radiation Physics, Department of Clinical Sciences, Lund University, Sweden; Skåne University Hospital, 205 02, Malmö, Sweden
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Svenson B, Båth M, Karlsson R. Can adaptive post-processing of storage phosphor plate panoramic radiographs provide better image quality? A comparison of anatomical image quality of panoramic radiographs before and after adaptive processing. Acta Odontol Scand 2019; 77:328-333. [PMID: 30623704 DOI: 10.1080/00016357.2018.1556801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE The objective of the present study was to study the effect of adaptive image processing on the visibility of anatomical structures in storage phosphor plate (SPP) panoramic images. MATERIALS AND METHODS Three hundred SPP panoramic X-ray radiographs of children and adolescents were used. The radiographs were post-processed using general operator processor (GOP) technology, resulting in both a standard-processed and a GOP-processed radiograph. Four specialists in dental radiology compared the structural image quality of all standard-processed and GOP-processed panorama images for six anatomical structures, using a six-point scale for visual grading characteristics (VGC) analysis. RESULTS For three of the anatomic structures - the root canal space of the mandibular left first premolar, mandibular canal left side and periodontal ligament space of the mandibular right first molar - there was a statistically significant difference to the GOP's advantage. For the three remaining structures - dentino-enamel junction of the maxillary right first molar, crista alveolaris of the mandibular left molar area and floor of maxillary sinus right side - no significant difference between standard processing and GOP processing was obtained. CONCLUSIONS The study demonstrates that it is possible to improve the quality of SPP radiographs and the visibility of anatomical structures by using the GOP technique. Manufacturers' image-processing programs can be further developed, as there is a possibility of improving the diagnostic content of an image with external processing.
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Affiliation(s)
- Björn Svenson
- Dental Research Department, Postgraduate Dental Education Center, Örebro, Sweden
- School of Health and Medical Sciences, Örebro University, Örebro, Sweden
| | - Magnus Båth
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
- Department of Radiation Physics, Institute of Clinical Sciences at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Reet Karlsson
- Department of Radiology, Skaraborg Hospital, Skövde, Sweden
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Lisson CG, Lisson CS, Kleiner S, Regier M, Beer M, Schmidt SA. Iterative scatter correction for grid-less skeletal radiography allows improved image quality equal to an antiscatter grid in adjunct with dose reduction: a visual grading study of 20 body donors. Acta Radiol 2019; 60:735-741. [PMID: 30149748 DOI: 10.1177/0284185118796668] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Iterative scatter correction (ISC) is a new technique applicable to plain radiography; comparable to iterative reconstruction for computed tomography, it promises dose reduction and image quality improvement. ISC for bedside chest X-rays has been applied and evaluated for some time and has recently been commercially offered for plain skeletal radiography. PURPOSE To analyze the potential of ISC for plain skeletal radiography with regard to image quality improvement, dose reduction, and replacement for an antiscatter grid. MATERIAL AND METHODS A total of 385 radiographs with different imaging protocols of the pelvis and cervical spine were acquired from 20 body donors. Radiographs were rated by four radiologists. Ratings were analyzed with visual grading characteristics (VGC) analysis. The area under the VGC curve was used as a measure of difference in image quality. RESULTS Without ISC, the grid-less images were rated significantly worse than their grid-based counterparts (0.389, P = 0.005); adding ISC made image quality equal (0.498; P = 0.963). In grid-less imaging, reduction of dose by 50% led to significant image quality impairment (0.415, P = 0.001); this was fully counterbalanced when ISC was added (0.512; P = 0.588). CONCLUSION ISC for plain skeletal radiography has the ability to replace the antiscatter grid without image quality impairment, to improve image quality in grid-less imaging, and to reduce patient radiation dose by 50% without substantial loss in image quality.
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Affiliation(s)
- Christoph G Lisson
- Department of Diagnostic and Interventional Radiology, University Hospital of Ulm, Ulm, Germany
| | - Catharina S Lisson
- Department of Diagnostic and Interventional Radiology, University Hospital of Ulm, Ulm, Germany
| | - Sebastian Kleiner
- Department of Diagnostic and Interventional Radiology, University Hospital of Ulm, Ulm, Germany
| | - Marc Regier
- Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Meinrad Beer
- Department of Diagnostic and Interventional Radiology, University Hospital of Ulm, Ulm, Germany
| | - Stefan A Schmidt
- Department of Diagnostic and Interventional Radiology, University Hospital of Ulm, Ulm, Germany
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Söderman C, Johnsson ÅA, Vikgren J, Norrlund RR, Molnar D, Mirzai M, Svalkvist A, Månsson LG, Båth M. Detection of Pulmonary Nodule Growth with Chest Tomosynthesis: A Human Observer Study Using Simulated Nodules. Acad Radiol 2019; 26:508-518. [PMID: 29903641 DOI: 10.1016/j.acra.2018.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/08/2018] [Accepted: 05/13/2018] [Indexed: 12/20/2022]
Abstract
RATIONALE AND OBJECTIVES Chest tomosynthesis has been suggested as a suitable alternative to CT for follow-up of pulmonary nodules. The aim of the present study was to investigate the possibility of detecting pulmonary nodule growth using chest tomosynthesis. MATERIALS AND METHODS Simulated nodules with volumes of approximately 100 mm3 and 300 mm3 as well as additional versions with increasing volumes were created. The nodules were inserted into images from pairs of chest tomosynthesis examinations, simulating cases where the nodule had either remained stable in size or increased in size between the two imaging occasions. Nodule volume growths ranging from 11% to 252% were included. A simulated dose reduction was applied to a subset of the cases. Cases differing in terms of nodule size, dose level, and nodule position relative to the plane of image reconstruction were included. Observers rated their confidence that the nodules were stable in size or not. The rating data for the nodules that were stable in size was compared to the rating data for the nodules simulated to have increased in size using ROC analysis. RESULTS Area under the curve values ranging from 0.65 to 1 were found. The lowest area under the curve values were found when there was a mismatch in nodule position relative to the reconstructed image plane between the two examinations. Nodule size and dose level affected the results. CONCLUSION The study indicates that chest tomosynthesis can be used to detect pulmonary nodule growth. Nodule size, dose level, and mismatch in position relative to the image reconstruction plane in the baseline and follow-up examination may affect the precision.
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Comparison of breast cancer detection and depiction between planar and rotating synthetic mammography generated from breast tomosynthesis. Eur J Radiol 2018; 108:78-83. [DOI: 10.1016/j.ejrad.2018.09.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/17/2018] [Accepted: 09/18/2018] [Indexed: 11/19/2022]
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Schmidt D, Söderberg M, Nilsson M, Lindvall H, Christoffersen C, Leander P. Evaluation of image quality and radiation dose of abdominal dual-energy CT. Acta Radiol 2018; 59:845-852. [PMID: 28927299 DOI: 10.1177/0284185117732806] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background Dual-energy computed tomography (DECT) has conceptually been known since the late 1970s and commercially available as dual-source CT (DSCT) systems since 2006; however, the technique has not yet seen widespread implementation in routine protocols. Part of the cause for this is likely due to misconceptions about radiation dose and/or image quality when using DECT. Purpose To compare image quality and radiation dose of single-energy CT (SECT) and DECT abdominal examinations obtained in clinical practice on a second generation DSCT. Material and Methods A total of 495 included patients (mean age = 70.9 years) were retrospectively analyzed after undergoing either SECT (120 kVp and age-based mAs) or DECT examinations (80/Sn140 kVp and age-based mAs). The patients were divided into two groups based on examination type (247 SECT, 248 DECT), which were then subdivided into two groups, each based on age. Image noise was measured in the liver and image quality was subjectively assessed in 100 randomly selected patients. Results Noise levels were significantly lower in DECT (13.9 HU) compared with SECT (14.7 HU) ( P < 0.05). No significant differences in subjective image quality were found between DECT and SECT, except for one criterion in the 50-74-year age group. The mean dose-length product (DLP) (376 mGy-cm) and effective dose (6.1 mSv) of DECT were significantly lower than the DLP (513 mGy-cm) and effective dose (8.4 mSv) of SECT ( P < 0.05). Conclusion DECT can be implemented in routine clinical use without negatively impacting image quality while lowering radiation dose to the patient.
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Affiliation(s)
- David Schmidt
- Department of Translational Medicine – Medical Radiology, Lund University, Lund, Sweden
| | - Marcus Söderberg
- Department of Translational Medicine – Medical Radiation Physics, Lund University, Lund, Sweden
| | - Mats Nilsson
- Department of Translational Medicine – Medical Radiation Physics, Lund University, Lund, Sweden
| | - Håkan Lindvall
- Department of Translational Medicine – Medical Radiology, Lund University, Lund, Sweden
| | | | - Peter Leander
- Department of Translational Medicine – Medical Radiology, Lund University, Lund, Sweden
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Aurumskjöld ML, Söderberg M, Stålhammar F, von Steyern KV, Tingberg A, Ydström K. Evaluation of an iterative model-based reconstruction of pediatric abdominal CT with regard to image quality and radiation dose. Acta Radiol 2018; 59:740-747. [PMID: 28825319 DOI: 10.1177/0284185117728415] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background In pediatric patients, computed tomography (CT) is important in the medical chain of diagnosing and monitoring various diseases. Because children are more radiosensitive than adults, they require minimal radiation exposure. One way to achieve this goal is to implement new technical solutions, like iterative reconstruction. Purpose To evaluate the potential of a new, iterative, model-based method for reconstructing (IMR) pediatric abdominal CT at a low radiation dose and determine whether it maintains or improves image quality, compared to the current reconstruction method. Material and Methods Forty pediatric patients underwent abdominal CT. Twenty patients were examined with the standard dose settings and 20 patients were examined with a 32% lower radiation dose. Images from the standard examination were reconstructed with a hybrid iterative reconstruction method (iDose4), and images from the low-dose examinations were reconstructed with both iDose4 and IMR. Image quality was evaluated subjectively by three observers, according to modified EU image quality criteria, and evaluated objectively based on the noise observed in liver images. Results Visual grading characteristics analyses showed no difference in image quality between the standard dose examination reconstructed with iDose4 and the low dose examination reconstructed with IMR. IMR showed lower image noise in the liver compared to iDose4 images. Inter- and intra-observer variance was low: the intraclass coefficient was 0.66 (95% confidence interval = 0.60-0.71) for the three observers. Conclusion IMR provided image quality equivalent or superior to the standard iDose4 method for evaluating pediatric abdominal CT, even with a 32% dose reduction.
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Affiliation(s)
- Marie-Louise Aurumskjöld
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Skåne University Hospital, Malmö, Sweden
| | - Marcus Söderberg
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Skåne University Hospital, Malmö, Sweden
| | - Fredrik Stålhammar
- Department of Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden
| | | | - Anders Tingberg
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Skåne University Hospital, Malmö, Sweden
| | - Kristina Ydström
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Skåne University Hospital, Malmö, Sweden
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Jadidi M, Båth M, Nyrén S. Dependency of image quality on acquisition protocol and image processing in chest tomosynthesis-a visual grading study based on clinical data. Br J Radiol 2018; 91:20170683. [PMID: 29565673 DOI: 10.1259/bjr.20170683] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE To compare the quality of images obtained with two different protocols with different acquisition time and the influence from image post processing in a chest digital tomosynthesis (DTS) system. METHODS 20 patients with suspected lung cancer were imaged with a chest X-ray equipment with tomosynthesis option. Two examination protocols with different acquisition times (6.3 and 12 s) were performed on each patient. Both protocols were presented with two different image post-processing (standard DTS processing and more advanced processing optimised for chest radiography). Thus, 4 series from each patient, altogether 80 series, were presented anonymously and in a random order. Five observers rated the quality of the reconstructed section images according to predefined quality criteria in three different classes. Visual grading characteristics (VGC) was used to analyse the data and the area under the VGC curve (AUCVGC) was used as figure-of-merit. The 12 s protocol and the standard DTS processing were used as references in the analyses. RESULTS The protocol with 6.3 s acquisition time had a statistically significant advantage over the vendor-recommended protocol with 12 s acquisition time for the classes of criteria, Demarcation (AUCVGC = 0.56, p = 0.009) and Disturbance (AUCVGC = 0.58, p < 0.001). A similar value of AUCVGC was found also for the class Structure (definition of bone structures in the spine) (0.56) but it could not be statistically separated from 0.5 (p = 0.21). For the image processing, the VGC analysis showed a small but statistically significant advantage for the standard DTS processing over the more advanced processing for the classes of criteria Demarcation (AUCVGC = 0.45, p = 0.017) and Disturbance (AUCVGC = 0.43, p = 0.005). A similar value of AUCVGC was found also for the class Structure (0.46), but it could not be statistically separated from 0.5 (p = 0.31). CONCLUSION The study indicates that the protocol with 6.3 s acquisition time yields slightly better image quality than the vender-recommended protocol with acquisition time 12 s for several anatomical structures. Furthermore, the standard gradation processing (the vendor-recommended post-processing for DTS), yields to some extent advantage over the gradation processing/multiobjective frequency processing/flexible noise control processing in terms of image quality for all classes of criteria. Advances in knowledge: The study proves that the image quality may be strongly affected by the selection of DTS protocol and that the vendor-recommended protocol may not always be the optimal choice.
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Affiliation(s)
- Masoud Jadidi
- 1 Departments of Clinical Science, Intervention and Technology, Karolinska Institutet , Stockholm , Sweden
| | - Magnus Båth
- 2 Department of Radiation Physics, Sahlgrenska Academy at University of Gothenburg , Gothenburg , Sweden.,3 Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital , Gothenburg , Sweden
| | - Sven Nyrén
- 4 Molecular medicine and surgery, Karolinska intitutet , Stockholm , Sweden.,5 Department of Thoracic radiology, Karolinska University Hospital , Stockholm , Sweden
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Fyrdahl A, Vargas Paris R, Nyrén S, Holst K, Ugander M, Lindholm P, Sigfridsson A. Pulmonary artery imaging under free-breathing using golden-angle radial bSSFP MRI: a proof of concept. Magn Reson Med 2018. [PMID: 29542200 DOI: 10.1002/mrm.27177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE To evaluate the feasibility of an improved motion and flow robust methodology for imaging the pulmonary vasculature using non-contrast-enhanced, free-breathing, golden-angle radial MRI. METHODS Healthy volunteers (n = 10, age 46 ± 11 years, 50% female) and patients (n = 2, ages 27 and 84, both female) were imaged at 1.5 T using a Cartesian and golden-angle radial 2D balanced SSFP pulse sequence. The acquisitions were made under free breathing without contrast agent enhancement. The radial acquisitions were reconstructed at 3 temporal footprints. All series were scored from 1 to 5 for perceived diagnostic quality, artifact level, and vessel sharpness in multiple anatomical locations. In addition, vessel sharpness and blood-to-blood clot contrast were measured. RESULTS Quantitative measurements showed higher vessel sharpness for golden-angle radial (n = 76, 0.79 ± 0.11 versus 0.71 ± 0.16, p < .05). Blood-to-blood clot contrast was found to be 23% higher in golden-angle radial in the 2 patients. At comparable temporal footprints, golden-angle radial was scored higher for diagnostic quality (mean ± SD, 2.3 ± 0.7 versus 2.2 ± 0.6, p < .01) and vessel sharpness (2.2 ± 0.8 versus 2.1 ± 0.5, p < .01), whereas the artifact level did not differ (3.0 ± 0.9 versus 3.0 ± 1.0, p = .80). The ability to retrospectively choose a temporal resolution and perform sliding-window reconstructions was demonstrated in patients. CONCLUSION In pulmonary artery imaging, the motion and flow robustness of a radial trajectory does both improve image quality over Cartesian trajectory in healthy volunteers, and allows for flexible selection of temporal footprints and the ability to perform real-time sliding window reconstructions, which could potentially provide further diagnostic insight.
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Affiliation(s)
- Alexander Fyrdahl
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Roberto Vargas Paris
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.,Department of Radiology, Karolinska University Hospital, Stockholm, Sweden
| | - Sven Nyrén
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Thoracic Radiology, Karolinska University Hospital, Stockholm, Sweden
| | - Karen Holst
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Martin Ugander
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Peter Lindholm
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.,Department of Thoracic Radiology, Karolinska University Hospital, Stockholm, Sweden
| | - Andreas Sigfridsson
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
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Svensson F, Söderman C, Svalkvist A, Rossi Norrlund R, Vikgren J, Johnsson ÅA, Båth M. Evaluation of a corrected implementation of a method of simulating pulmonary nodules in chest tomosynthesis. Acta Radiol 2017; 58:408-413. [PMID: 27382042 DOI: 10.1177/0284185116654330] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background A method of simulating pulmonary nodules in tomosynthesis images has previously been developed and evaluated. An unknown feature of a rounding function included in the computer code was later found to introduce an artifact, affecting simulated nodules in low-signal regions of the images. The computer code has now been corrected. Purpose To perform a thorough evaluation of the corrected nodule-simulation method, comparing the detection rate and visual appearance of artificial nodules with those of real nodules in an observer performance experiment. Material and Methods A cohort of 64 patients with a total of 129 pulmonary nodules was used in the study. Artificial nodules, each matching a corresponding real nodule by size, attenuation, and anatomical location, were generated and simulated into the tomosynthesis images of the different patients. The detection rate and visual appearance of artificial nodules generated using both the corrected and uncorrected computer code were compared to those of real nodules. The results were evaluated using modified receiver operating characteristic (ROC) analyses. Results The difference in detection rate between artificial and real nodules slightly increased using the corrected computer code (uncorrected code: area under the curve [AUC], 0.47; 95% CI, 0.43-0.51; corrected code: AUC, 0.42; 95% CI, 0.38-0.46). The visual appearance was however substantially improved using the corrected computer code (uncorrected code: AUC, 0.70; 95% CI, 0.63-0.76; corrected code: AUC, 0.49; 95% CI, 0.29-0.65). Conclusion The computer code including a correct rounding function generates simulated nodules that are more visually realistic than simulated nodules generated using the uncorrected computer code, but have a slightly different detection rate compared to real nodules.
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Affiliation(s)
- Frida Svensson
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Sweden
| | - Christina Söderman
- Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden
| | - Angelica Svalkvist
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Sweden
- Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden
| | - Rauni Rossi Norrlund
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Sweden
| | - Jenny Vikgren
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Sweden
| | - Åse Allansdotter Johnsson
- Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden
- Department of Radiology, Sahlgrenska University Hospital, Sweden
| | - Magnus Båth
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Sweden
- Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Sweden
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Hansson J, Månsson LG, Båth M. THE VALIDITY OF USING ROC SOFTWARE FOR ANALYSING VISUAL GRADING CHARACTERISTICS DATA: AN INVESTIGATION BASED ON THE NOVEL SOFTWARE VGC ANALYZER. RADIATION PROTECTION DOSIMETRY 2016; 169:54-59. [PMID: 26979808 DOI: 10.1093/rpd/ncw035] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The purpose of the present work was to investigate the validity of using single-reader-adapted receiver operating characteristics (ROC) software for analysis of visual grading characteristics (VGC) data. VGC data from four published VGC studies on optimisation of X-ray examinations, previously analysed using ROCFIT, were reanalysed using a recently developed software dedicated to VGC analysis (VGC Analyzer), and the outcomes [the mean and 95 % confidence interval (CI) of the area under the VGC curve (AUCVGC) and the p-value] were compared. The studies included both paired and non-paired data and were reanalysed both for the fixed-reader and the random-reader situations. The results showed good agreement between the softwares for the mean AUCVGC For non-paired data, wider CIs were obtained with VGC Analyzer than previously reported, whereas for paired data, the previously reported CIs were similar or even broader. Similar observations were made for the p-values. The results indicate that the use of single-reader-adapted ROC software such as ROCFIT for analysing non-paired VGC data may lead to an increased risk of committing Type I errors, especially in the random-reader situation. On the other hand, the use of ROC software for analysis of paired VGC data may lead to an increased risk of committing Type II errors, especially in the fixed-reader situation.
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Affiliation(s)
- Jonny Hansson
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Radiation Physics, Institute of Clinical Sciences, the Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Lars Gunnar Månsson
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Radiation Physics, Institute of Clinical Sciences, the Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Magnus Båth
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Radiation Physics, Institute of Clinical Sciences, the Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
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Mangat J, Morgan J, Benson E, Båth M, Lewis M, Reilly A. A STUDY OF THE IMAGE QUALITY OF COMPUTED TOMOGRAPHY ADAPTIVE STATISTICAL ITERATIVE RECONSTRUCTED BRAIN IMAGES USING SUBJECTIVE AND OBJECTIVE METHODS. RADIATION PROTECTION DOSIMETRY 2016; 169:92-99. [PMID: 27103646 DOI: 10.1093/rpd/ncw084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 02/26/2016] [Indexed: 06/05/2023]
Abstract
The recent reintroduction of iterative reconstruction in computed tomography has facilitated the realisation of major dose saving. The aim of this article was to investigate the possibility of achieving further savings at a site with well-established Adaptive Statistical iterative Reconstruction (ASiR™) (GE Healthcare) brain protocols. An adult patient study was conducted with observers making visual grading assessments using image quality criteria, which were compared with the frequency domain metrics, noise power spectrum and modulation transfer function. Subjective image quality equivalency was found in the 40-70% ASiR™ range, leading to the proposal of ranges for the objective metrics defining acceptable image quality. Based on the findings of both the patient-based and objective studies of the ASiR™/tube-current combinations tested, 60%/305 mA was found to fall within all, but one, of these ranges. Therefore, it is recommended that an ASiR™ level of 60%, with a noise index of 12.20, is a viable alternative to the currently used protocol featuring a 40% ASiR™ level and a noise index of 11.20, potentially representing a 16% dose saving.
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Affiliation(s)
- J Mangat
- Cardiac CT Department, Barts Heart Centre, Bartshealth NHS Trust, London, UK
| | - J Morgan
- Radiography Department, School of Health Sciences, City University, London, UK
| | - E Benson
- Medical Engineering and Physics Department, Kings College Hospital, London, UK
| | - M Båth
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - M Lewis
- Medical Physics Department, Guy's and St. Thomas' Hospital, London, UK
| | - A Reilly
- Department of Radiotherapy Physics, Altnagelvin Hospital, Londonderry, UK
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50
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Ceder E, Danielson B, Kovàč P, Fogel H, Svalkvist A, Vikgren J, Båth M. THORACIC SPINE IMAGING: A COMPARISON BETWEEN RADIOGRAPHY AND TOMOSYNTHESIS USING VISUAL GRADING CHARACTERISTICS. RADIATION PROTECTION DOSIMETRY 2016; 169:204-210. [PMID: 26868012 DOI: 10.1093/rpd/ncv559] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The aim of the present study was to evaluate digital tomosynthesis (DTS) in thoracic spine imaging, comparing the reproduction of anatomical structures with that achieved using digital radiography (DR). In a prospective visual grading study, 23 patients referred in 2014 for elective radiographic examination of the thoracic spine were examined using lateral DR and DTS. The DR image and the DTS section images were read in random order by four radiologists, evaluating the ability of the modalities to present a clear reproduction of nine specific relevant structures of the thoracic vertebrae 3, 6 and 9 (T3, T6 and T9). The data were analysed using visual grading characteristics (VGC) analysis. The VGC analysis revealed a statistically significant difference in favour of DTS for all evaluated structures, except for the anterior vertebral edges and lower end plate surfaces of T6 and T9 and the cancellous bone of T9. The difference was most striking in T3 and for posterior structures. For no structure in any vertebra was the reproduction rated significantly better for DR. In conclusion, DTS of the thoracic spine appears to be a promising alternative to DR, especially in areas where the problem of overlaying anatomy is accentuated, such as posterior and upper thoracic structures.
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Affiliation(s)
- Erik Ceder
- Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Barbro Danielson
- Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Peter Kovàč
- Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Hanna Fogel
- Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Angelica Svalkvist
- Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Jenny Vikgren
- Department of Radiology, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Magnus Båth
- Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
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