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Otgonbaatar C, Kim H, Jeon PH, Jeon SH, Cha SJ, Ryu JK, Jung WB, Shim H, Ko SM, Kim JW. A preliminary study of super-resolution deep learning reconstruction with cardiac option for evaluation of endovascular-treated intracranial aneurysms. Br J Radiol 2024; 97:1492-1500. [PMID: 38917414 PMCID: PMC11256923 DOI: 10.1093/bjr/tqae117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 04/22/2024] [Accepted: 06/06/2024] [Indexed: 06/27/2024] Open
Abstract
OBJECTIVES To investigate the usefulness of super-resolution deep learning reconstruction (SR-DLR) with cardiac option in the assessment of image quality in patients with stent-assisted coil embolization, coil embolization, and flow-diverting stent placement compared with other image reconstructions. METHODS This single-centre retrospective study included 50 patients (mean age, 59 years; range, 44-81 years; 13 men) who were treated with stent-assisted coil embolization, coil embolization, and flow-diverting stent placement between January and July 2023. The images were reconstructed using filtered back projection (FBP), hybrid iterative reconstruction (IR), and SR-DLR. The objective image analysis included image noise in the Hounsfield unit (HU), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and full width at half maximum (FWHM). Subjectively, two radiologists evaluated the overall image quality for the visualization of the flow-diverting stent, coil, and stent. RESULTS The image noise in HU in SR-DLR was 6.99 ± 1.49, which was significantly lower than that in images reconstructed with FBP (12.32 ± 3.01) and hybrid IR (8.63 ± 2.12) (P < .001). Both the mean SNR and CNR were significantly higher in SR-DLR than in FBP and hybrid IR (P < .001 and P < .001). The FWHMs for the stent (P < .004), flow-diverting stent (P < .001), and coil (P < .001) were significantly lower in SR-DLR than in FBP and hybrid IR. The subjective visual scores were significantly higher in SR-DLR than in other image reconstructions (P < .001). CONCLUSIONS SR-DLR with cardiac option is useful for follow-up imaging in stent-assisted coil embolization and flow-diverting stent placement in terms of lower image noise, higher SNR and CNR, superior subjective image analysis, and less blooming artifact than other image reconstructions. ADVANCES IN KNOWLEDGE SR-DLR with cardiac option allows better visualization of the peripheral and smaller cerebral arteries. SR-DLR with cardiac option can be beneficial for CT imaging of stent-assisted coil embolization and flow-diverting stent.
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Affiliation(s)
- Chuluunbaatar Otgonbaatar
- Department of Radiology, College of Medicine, Seoul National University, Seoul, 03080, Republic of Korea
- Medical Imaging AI Research Center, Canon Medical Systems Korea, Seoul, 06173, Republic of Korea
| | - Hyunjung Kim
- Department of Radiology, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University of Korea, Wonju 26426, Republic of Korea
| | - Pil-Hyun Jeon
- Department of Radiology, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University of Korea, Wonju 26426, Republic of Korea
| | - Sang-Hyun Jeon
- Department of Radiology, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University of Korea, Wonju 26426, Republic of Korea
| | - Sung-Jin Cha
- Department of Radiology, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University of Korea, Wonju 26426, Republic of Korea
| | - Jae-Kyun Ryu
- Medical Imaging AI Research Center, Canon Medical Systems Korea, Seoul, 06173, Republic of Korea
| | - Won Beom Jung
- Korea Brain Research Institute (KBRI), Daegu, 41062, Republic of Korea
| | - Hackjoon Shim
- Medical Imaging AI Research Center, Canon Medical Systems Korea, Seoul, 06173, Republic of Korea
- ConnectAI Research Center, Yonsei University College of Medicine, Seoul, 03772, Republic of Korea
| | - Sung Min Ko
- Department of Radiology, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University of Korea, Wonju 26426, Republic of Korea
| | - Jin Woo Kim
- Department of Radiology, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University of Korea, Wonju 26426, Republic of Korea
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Tóth A, Chetta JA, Yazdani M, Matheus MG, O'Doherty J, Tipnis SV, Spampinato MV. Neurovascular Imaging with Ultra-High-Resolution Photon-Counting CT: Preliminary Findings on Image-Quality Evaluation. AJNR Am J Neuroradiol 2024:ajnr.A8350. [PMID: 38760079 DOI: 10.3174/ajnr.a8350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 05/07/2024] [Indexed: 05/19/2024]
Abstract
BACKGROUND AND PURPOSE The first-generation photon-counting detector CT was recently introduced into clinical practice and represents a promising innovation in high-resolution CT imaging. The purpose of this study was to assess the image quality of ultra-high-resolution photon-counting detector CT compared with energy-integrating detector CT and to explore different reconstruction kernel sharpness levels for the evaluation of intracranial aneurysms. MATERIALS AND METHODS Ten patients with intracranial saccular aneurysms who had previously undergone conventional energy-integrating detector CT were prospectively enrolled. CT angiograms were acquired on a clinical dual-source photon-counting detector CT in ultra-high-resolution mode and reconstructed with 4 vascular kernels (Bv36, Bv40, Bv44, Bv48). Quantitative and qualitative image-quality parameters of the intracranial arteries were evaluated. For the quantitative analysis (image noise, SNR, contrast-to-noise ratio), ROIs were manually placed at standard anatomic intracranial and extracranial locations by 1 author. In addition, vessel border sharpness was evaluated quantitatively. For the qualitative analysis, 3 blinded neuroradiologists rated photon-counting detector CT and energy-integrating detector CT image quality for the evaluation of the intracranial vessels (ie, the aneurysms and 9 standard vascular branching locations) on a 5-point Likert-type scale. Additionally, readers independently selected their preferred kernel among the 4 kernels evaluated on photon-counting detector CT. RESULTS In terms of quantitative image quality, Bv48, the sharpest kernel, yielded increased image noise and decreased SNR and contrast-to-noise ratio parameters compared with Bv36, the smoothest kernel. Compared with energy-integrating detector CT, the Bv48 kernel offered better quantitative image quality for the evaluation of small intracranial vessels (P < .001). Image-quality ratings of the Bv48 were superior to those of the energy-integrating detector CT and not significantly different from ratings of the B44 reconstruction kernel. When comparing side by side all 4 photon-counting detector reconstruction kernels, readers selected the B48 kernel as the best to visualize the aneurysms in 80% of cases. CONCLUSIONS Ultra-high-resolution photon-counting detector CT provides improved image quality for neurovascular imaging. Although the less sharp kernels provided superior SNR and contrast-to-noise ratio, the sharpest kernels delivered the best subjective image quality on photon-counting detector CT for the evaluation of intracranial aneurysms.
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Affiliation(s)
- Adrienn Tóth
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - Justin A Chetta
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - Milad Yazdani
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - M Gisele Matheus
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - Jim O'Doherty
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
- Siemens Medical Solutions (J.O.), Malvern, Pennsylvania
| | - Sameer V Tipnis
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - M Vittoria Spampinato
- From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
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Hagar MT, Soschynski M, Saffar R, Molina-Fuentes MF, Weiss J, Rau A, Schuppert C, Ruile P, Faby S, Schibilsky D, von Zur Muehlen C, Schlett CL, Bamberg F, Krauss T. Ultra-high-resolution photon-counting detector CT in evaluating coronary stent patency: a comparison to invasive coronary angiography. Eur Radiol 2024; 34:4273-4283. [PMID: 38177617 PMCID: PMC11213791 DOI: 10.1007/s00330-023-10516-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 10/02/2023] [Accepted: 10/25/2023] [Indexed: 01/06/2024]
Abstract
OBJECTIVES To determine the diagnostic accuracy of ultra-high-resolution photon-counting detector CT angiography (UHR PCD-CTA) for evaluating coronary stent patency compared to invasive coronary angiography (ICA). METHODS Consecutive, clinically referred patients with prior coronary stent implantation were prospectively enrolled between August 2022 and March 2023 and underwent UHR PCD-CTA (collimation, 120 × 0.2 mm). Two radiologists independently analyzed image quality of the in-stent lumen using a 5-point Likert scale, ranging from 1 ("excellent") to 5 ("non-diagnostic"), and assessed all coronary stents for the presence of in-stent stenosis (≥ 50% lumen narrowing). The diagnostic accuracy of UHR PCD-CTA was determined, with ICA serving as the standard of reference. RESULTS A total of 44 coronary stents in 18 participants (mean age, 83 years ± 6 [standard deviation]; 12 women) were included in the analysis. In 3/44 stents, both readers described image quality as non-diagnostic, whereas reader 2 noted a fourth stent to have non-diagnostic image quality. In comparison to ICA, UHR PCD-CTA demonstrated a sensitivity, specificity, and accuracy of 100% (95% CI [confidence interval] 47.8, 100), 92.3% (95% CI 79.1, 98.4), and 93.2% (95% CI 81.3, 98.6) for reader 1 and 100% (95% CI 47.8, 100), 87.2% (95% CI 72.6, 95.7), and 88.6% (95% CI 75.4, 96.2) for reader 2, respectively. Both readers observed a 100% negative predictive value (36/36 stents and 34/34 stents). Stent patency inter-reader agreement was 90.1%, corresponding to a substantial Cohen's kappa value of 0.72. CONCLUSIONS UHR PCD-CTA enables non-invasive assessment of coronary stent patency with high image quality and diagnostic accuracy. CLINICAL RELEVANCE STATEMENT Ultra-high-resolution photon-counting detector CT angiography represents a reliable and non-invasive method for assessing coronary stent patency. Its high negative predictive value makes it a promising alternative over invasive coronary angiography for the rule-out of in-stent stenosis. KEY POINTS • CT-based evaluation of coronary stent patency is limited by stent-induced artifacts and spatial resolution. • Ultra-high-resolution photon-counting detector CT accurately evaluates coronary stent patency compared to invasive coronary angiography. • Photon-counting detector CT represents a promising method for the non-invasive rule-out of in-stent stenosis.
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Affiliation(s)
- Muhammad Taha Hagar
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, University of Freiburg, Hugstetter Straße 55, Freiburg im Breisgau, 79106, Germany.
| | - Martin Soschynski
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, University of Freiburg, Hugstetter Straße 55, Freiburg im Breisgau, 79106, Germany
| | - Ruben Saffar
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, University of Freiburg, Hugstetter Straße 55, Freiburg im Breisgau, 79106, Germany
| | - Moisés Felipe Molina-Fuentes
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, University of Freiburg, Hugstetter Straße 55, Freiburg im Breisgau, 79106, Germany
| | - Jakob Weiss
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, University of Freiburg, Hugstetter Straße 55, Freiburg im Breisgau, 79106, Germany
| | - Alexander Rau
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, University of Freiburg, Hugstetter Straße 55, Freiburg im Breisgau, 79106, Germany
| | - Christopher Schuppert
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, University of Freiburg, Hugstetter Straße 55, Freiburg im Breisgau, 79106, Germany
| | - Philipp Ruile
- Department of Cardiology, Faculty of Medicine, University Hospital Freiburg Heart Centre, Freiburg, Germany, University of Freiburg, Freiburg, Germany
| | - Sebastian Faby
- Computed Tomography, Siemens Healthcare GmbH, Forchheim, 91301, Germany
| | - David Schibilsky
- Department of Cardiac and Vascular Surgery, Freiburg University, Freiburg, Germany
| | - Constantin von Zur Muehlen
- Department of Cardiology, Faculty of Medicine, University Hospital Freiburg Heart Centre, Freiburg, Germany, University of Freiburg, Freiburg, Germany
| | - Christopher L Schlett
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, University of Freiburg, Hugstetter Straße 55, Freiburg im Breisgau, 79106, Germany
| | - Fabian Bamberg
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, University of Freiburg, Hugstetter Straße 55, Freiburg im Breisgau, 79106, Germany
| | - Tobias Krauss
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, University of Freiburg, Hugstetter Straße 55, Freiburg im Breisgau, 79106, Germany
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Konst B, Ohlsson L, Henriksson L, Sandstedt M, Persson A, Ebbers T. Optimization of photon counting CT for cardiac imaging in patients with left ventricular assist devices: An in-depth assessment of metal artifacts. J Appl Clin Med Phys 2024; 25:e14386. [PMID: 38739330 PMCID: PMC11244676 DOI: 10.1002/acm2.14386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 03/22/2024] [Accepted: 04/21/2024] [Indexed: 05/14/2024] Open
Abstract
PURPOSE Photon counting CT (PCCT) holds promise for mitigating metal artifacts and can produce virtual mono-energetic images (VMI), while maintaining temporal resolution, making it a valuable tool for characterizing the heart. This study aimed to evaluate and optimize PCCT for cardiac imaging in patients during left ventricular assistance device (LVAD) therapy by conducting an in-depth objective assessment of metal artifacts and visual grading. METHODS Various scan and reconstruction settings were tested on a phantom and further evaluated on a patient acquisition to identify the optimal protocol settings. The phantom comprised an empty thoracic cavity, supplemented with heart and lungs from a cadaveric lamb. The heart was implanted with an LVAD (HeartMate 3) and iodine contrast. Scans were performed on a PCCT (NAEOTOM Alpha, Siemens Healthcare). Metal artifacts were assessed by three objective methods: Hounsfield units (HU)/SD measurements (DiffHU and SDARTIFACT), Fourier analysis (AmplitudeLowFreq), and depicted LVAD volume in the images (BloomVol). Radiologists graded metal artifacts and the diagnostic interpretability in the LVAD lumen, cardiac tissue, lung tissue, and spinal cord using a 5-point rating scale. Regression and correlation analysis were conducted to determine the assessment method most closely associated with acquisition and reconstruction parameters, as well as the objective method demonstrating the highest correlation with visual grading. RESULTS Due to blooming artifacts, the LVAD volume fluctuated between 27.0 and 92.7 cm3. This variance was primarily influenced by kVp, kernel, keV, and iMAR (R2 = 0.989). Radiologists favored pacemaker iMAR, 3 mm slice thickness, and T3D keV and kernel Bv56f for minimal metal artifacts in cardiac tissue assessment, and 110 keV and Qr40f for lung tissue interpretation. The model adequacy for DiffHU SDARTIFACT, AmplitueLowFreq, and BloomVol was 0.28, 0.76, 0.29, and 0.99 respectively for phantom data, and 0.95, 0.98, 1.00, and 0.99 for in-vivo data. For in-vivo data, the correlation between visual grading (VGSUM) and DiffHU SDARTIFACT, AmplitueLowFreq, and BloomVol was -0.16, -0.01, -0.48, and -0.40 respectively. CONCLUSION We found that optimal scan settings for LVAD imaging involved using 120 kVp and IQ level 80. Employing T3D with pacemaker iMAR, the sharpest allowed vascular kernel (Bv56f), and VMI at 110 keV with kernel Qr40 yields images suitable for cardiac imaging during LVAD-therapy. Volumetric measurements of the LVAD for determination of the extent of blooming artifacts was shown to be the best objective method to assess metal artifacts.
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Affiliation(s)
- Bente Konst
- Department of Health, Medicine and Caring SciencesLinköping UniversityLinköpingSweden
- Center for Medical Image Science and Visualization (CMIV)Linköping UniversityLinköpingSweden
- Department of RadiologyVestfold HospitalTønsbergNorway
| | - Linus Ohlsson
- Center for Medical Image Science and Visualization (CMIV)Linköping UniversityLinköpingSweden
- Department of Thoracic and Vascular Surgery in Östergötland, and Department of HealthMedicine and Caring SciencesLinköping UniversityLinköpingSweden
| | - Lilian Henriksson
- Center for Medical Image Science and Visualization (CMIV)Linköping UniversityLinköpingSweden
- Department of Radiology in Linköpingand Department of HealthMedicine and Caring SciencesLinköping UniversityLinköpingSweden
| | - Mårten Sandstedt
- Center for Medical Image Science and Visualization (CMIV)Linköping UniversityLinköpingSweden
- Department of Radiology in Linköpingand Department of HealthMedicine and Caring SciencesLinköping UniversityLinköpingSweden
| | - Anders Persson
- Center for Medical Image Science and Visualization (CMIV)Linköping UniversityLinköpingSweden
- Department of Radiology in Linköpingand Department of HealthMedicine and Caring SciencesLinköping UniversityLinköpingSweden
| | - Tino Ebbers
- Department of Health, Medicine and Caring SciencesLinköping UniversityLinköpingSweden
- Center for Medical Image Science and Visualization (CMIV)Linköping UniversityLinköpingSweden
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Vecsey-Nagy M, Varga-Szemes A, Schoepf UJ, Tremamunno G, Fink N, Zsarnoczay E, Szilveszter B, Graafen D, Halfmann MC, Vattay B, Boussoussou M, O'Doherty J, Suranyi PS, Maurovich-Horvat P, Emrich T. Ultra-high resolution coronary CT angiography on photon-counting detector CT: bi-centre study on the impact of quantum iterative reconstruction on image quality and accuracy of stenosis measurements. Eur J Radiol 2024; 176:111517. [PMID: 38805884 DOI: 10.1016/j.ejrad.2024.111517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Accepted: 05/17/2024] [Indexed: 05/30/2024]
Abstract
PURPOSE To assess the impact of different quantum iterative reconstruction (QIR) levels on objective and subjective image quality of ultra-high resolution (UHR) coronary CT angiography (CCTA) images and to determine the effect of strength levels on stenosis quantification using photon-counting detector (PCD)-CT. METHOD A dynamic vessel phantom containing two calcified lesions (25 % and 50 % stenosis) was scanned at heart rates of 60, 80 and 100 beats per minute with a PCD-CT system. In vivo CCTA examinations were performed in 102 patients. All scans were acquired in UHR mode (slice thickness0.2 mm) and reconstructed with four different QIR levels (1-4) using a sharp vascular kernel (Bv64). Image noise, signal-to-noise ratio (SNR), sharpness, and percent diameter stenosis (PDS) were quantified in the phantom, while noise, SNR, contrast-to-noise ratio (CNR), sharpness, and subjective quality metrics (noise, sharpness, overall image quality) were assessed in patient scans. RESULTS Increasing QIR levels resulted in significantly lower objective image noise (in vitro and in vivo: both p < 0.001), higher SNR (both p < 0.001) and CNR (both p < 0.001). Sharpness and PDS values did not differ significantly among QIRs (all pairwise p > 0.008). Subjective noise of in vivo images significantly decreased with increasing QIR levels, resulting in significantly higher image quality scores at increasing QIR levels (all pairwise p < 0.001). Qualitative sharpness, on the other hand, did not differ across different levels of QIR (p = 0.15). CONCLUSIONS The QIR algorithm may enhance the image quality of CCTA datasets without compromising image sharpness or accurate stenosis measurements, with the most prominent benefits at the highest strength level.
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Affiliation(s)
- Milan Vecsey-Nagy
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States; Heart and Vascular Centre, Semmelweis University, 68. Varosmajor street, Budapest 1122, Hungary
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States.
| | - Giuseppe Tremamunno
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States; Department of Medical Surgical Sciences and Translational Medicine, Sapienza University of Rome - Sant'Andrea University, Hospital Via di Grottarossa 1035-1039 00189 Rome, Italy
| | - Nicola Fink
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States; Department of Radiology, University Hospital, LMU Munich, Marchioninistraße 15, Munich 81377, Germany
| | - Emese Zsarnoczay
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States; MTA-SE Cardiovascular Imaging Research Group, Medical Imaging Centre, Semmelweis University, Koranyi Sandor street 2, Budapest 1083, Hungary
| | - Bálint Szilveszter
- Heart and Vascular Centre, Semmelweis University, 68. Varosmajor street, Budapest 1122, Hungary
| | - Dirk Graafen
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Langenbeckstraße 1, Mainz 55131, Germany
| | - Moritz C Halfmann
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Langenbeckstraße 1, Mainz 55131, Germany
| | - Borbála Vattay
- Heart and Vascular Centre, Semmelweis University, 68. Varosmajor street, Budapest 1122, Hungary
| | - Melinda Boussoussou
- Heart and Vascular Centre, Semmelweis University, 68. Varosmajor street, Budapest 1122, Hungary
| | - Jim O'Doherty
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States; Siemens Medical Solutions USA Inc, 40 Liberty Boulevard, Malvern, PA 19355, United States
| | - Pal Spruill Suranyi
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States
| | - Pál Maurovich-Horvat
- MTA-SE Cardiovascular Imaging Research Group, Medical Imaging Centre, Semmelweis University, Koranyi Sandor street 2, Budapest 1083, Hungary
| | - Tilman Emrich
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States; Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Langenbeckstraße 1, Mainz 55131, Germany
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Dirrichs T, Schröder J, Frick M, Huppertz M, Iwa R, Allmendinger T, Mecking I, Kuhl CK. Photon-Counting Versus Dual-Source CT for Transcatheter Aortic Valve Implantation Planning. Acad Radiol 2024:S1076-6332(24)00372-6. [PMID: 38906782 DOI: 10.1016/j.acra.2024.06.014] [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: 05/02/2024] [Revised: 06/07/2024] [Accepted: 06/07/2024] [Indexed: 06/23/2024]
Abstract
BACKGROUND Cardiovascular CT is required for planning transcatheter aortic valve implantation (TAVI). PURPOSE To compare image quality, suitability for TAVI planning, and radiation dose of photon-counting CT (PCCT) with that of dual-source CT (DSCT). MATERIAL AND METHODS Retrospective study on consecutive TAVI candidates with aortic valve stenosis who underwent contrast-enhanced aorto-ilio-femoral PCCT and/or DSCT between 01/2022 and 07/2023. Signal-to-noise (SNR) and contrast-to-noise ratio (CNR) were calculated by standardized ROI analysis. Image quality and suitability for TAVI planning were assessed by four independent expert readers (two cardiac radiologists, two cardiologists) on a 5-point-scale. CT dose index (CTDI) and dose-length-product (DLP) were used to calculate effective radiation dose (eRD). RESULTS 300 patients (136 female, median age: 81 years, IQR: 76-84) underwent 302 CT examinations, with PCCT in 202, DSCT in 100; two patients underwent both. Although SNR and CNR were significantly lower in PCCT vs. DSCT images (33.0 ± 10.5 vs. 47.3 ± 16.4 and 47.3 ± 14.8 vs. 59.3 ± 21.9, P < .001, respectively), visual image quality was higher in PCCT vs. DSCT (4.8 vs. 3.3, P < .001), with moderate overall interreader agreement among radiologists and among cardiologists (κ = 0.60, respectively). Image quality was rated as "excellent" in 160/202 (79.2%) of PCCT vs. 5/100 (5%) of DSCT cases. Readers found images suitable to depict the aortic valve hinge points and to map the femoral access path in 99% of PCCT vs. 85% of DSCT (P < 0.01), with suitability ranked significantly higher in PCCT vs. DSCT (4.8 vs. 3.3, P < .001). Mean CTDI and DLP, and thus eRD, were significantly lower for PCCT vs. DSCT (22.4 vs. 62.9; 519.4 vs. 895.5, and 8.8 ± 4.5 mSv vs. 15.3 ± 5.8 mSv; all P < .001). CONCLUSION PCCT improves image quality, effectively avoids non-diagnostic CT imaging for TAVI planning, and is associated with a lower radiation dose compared to state-of-the-art DSCT. Radiologists and cardiologists found PCCT images more suitable for TAVI planning.
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Affiliation(s)
- Timm Dirrichs
- Department of Diagnostic and Interventional Radiology, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany.
| | - Jörg Schröder
- Department of Cardiology, Angiology and Internal Intensive Care, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany
| | - Michael Frick
- Department of Cardiology, Angiology and Internal Intensive Care, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany
| | - Marc Huppertz
- Department of Diagnostic and Interventional Radiology, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany
| | - Roman Iwa
- Department of Diagnostic and Interventional Radiology, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany
| | | | - Ines Mecking
- Department of Diagnostic and Interventional Radiology, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany
| | - Christiane K Kuhl
- Department of Diagnostic and Interventional Radiology, University Hospital RWTH Aachen, Pauwelsstraße 30, Aachen 52074, Germany
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Higaki T, Tatsugami F, Ohana M, Nakamura Y, Kawashita I, Awai K. Super resolution deep learning reconstruction for coronary CT angiography: A structured phantom study. Eur J Radiol Open 2024; 12:100570. [PMID: 38828096 PMCID: PMC11140562 DOI: 10.1016/j.ejro.2024.100570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 05/14/2024] [Accepted: 05/15/2024] [Indexed: 06/05/2024] Open
Abstract
Purpose Super-resolution deep-learning-based reconstruction: SR-DLR is a newly developed and clinically available deep-learning-based image reconstruction method that can improve the spatial resolution of CT images. The image quality of the output from non-linear image reconstructions, such as DLR, is known to vary depending on the structure of the object being scanned, and a simple phantom cannot explicitly evaluate the clinical performance of SR-DLR. This study aims to accurately investigate the quality of the images reconstructed by SR-DLR by utilizing a structured phantom that simulates the human anatomy in coronary CT angiography. Methods The structural phantom had ribs and vertebrae made of plaster, a left ventricle filled with dilute contrast medium, a coronary artery with simulated stenosis, and an implanted stent graft. By scanning the structured phantom, we evaluated noise and spatial resolution on the images reconstructed with SR-DLR and conventional reconstructions. Results The spatial resolution of SR-DLR was higher than conventional reconstructions; the 10 % modulation transfer function of hybrid IR (HIR), DLR, and SR-DLR were 0.792-, 0.976-, and 1.379 cycle/mm, respectively. At the same time, image noise was lowest (HIR: 21.1-, DLR: 19.0-, and SR-DLR: 13.1 HU). SR-DLR could accurately assess coronary artery stenosis and the lumen of the implanted stent graft. Conclusions SR-DLR can obtain CT images with high spatial resolution and lower noise without special CT equipments, and will help diagnose coronary artery disease in CCTA and other CT examinations that require high spatial resolution.
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Affiliation(s)
- Toru Higaki
- Graduate School of Advanced Science and Engineering, Hiroshima University, Japan
| | - Fuminari Tatsugami
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Japan
| | | | - Yuko Nakamura
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Japan
| | - Ikuo Kawashita
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Japan
| | - Kazuo Awai
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Japan
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Qin L, Zhou S, Dong H, Li J, Zhang R, Yang C, Liu P, Xu Z, Yan F, Yang W. Improvement of coronary stent visualization using ultra-high-resolution photon-counting detector CT. Eur Radiol 2024:10.1007/s00330-024-10760-1. [PMID: 38676731 DOI: 10.1007/s00330-024-10760-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 03/27/2024] [Accepted: 04/07/2024] [Indexed: 04/29/2024]
Abstract
OBJECTIVES This study aimed to compare the image quality and diagnostic performance of standard-resolution (SR) and ultra-high-resolution (UHR) coronary CT angiography (CCTA) based on photon-counting detector CT (PCD-CT) of coronary stents and explore the best reconstruction kernel for stent imaging. METHODS From July 2023 to September 2023, patients were enrolled to undergo CCTA using a dual-source PCD-CT system after coronary angioplasty with stent placement. SR images with a slice thickness/increment of 0.6/0.4 mm were reconstructed using a vascular kernel (Bv48), while UHR images with a slice thickness/increment of 0.2/0.2 mm were reconstructed using vascular kernels of six sharpness levels (Bv48, Bv56, Bv60, Bv64, Bv72, and Bv76). The in-stent lumen diameters were evaluated. Subjective image quality was also evaluated by a 5-point Likert scale. Invasive coronary angiography was conducted in 12 patients (25 stents). RESULTS Sixty-nine patients (68.0 [61.0, 73.0] years, 46 males) with 131 stents were included. All UHR images had significantly larger in-stent lumen diameter than SR images (p < 0.001). Specifically, UHR-Bv72 and UHR-Bv76 for in-stent lumen diameter (2.17 [1.93, 2.63] mm versus 2.20 [1.93, 2.59] mm) ranked the two best kernels. The subjective analysis demonstrated that UHR-Bv72 images had the most pronounced effect on reducing blooming artifacts, showcasing in-stent lumen and stent demonstration, and diagnostic confidence (p < 0.001). Furthermore, SR and UHR-Bv72 images showed a diagnostic accuracy of 78.3% (95% confidence interval [CI]: 56.3%-92.5%) and 88.0% (95%CI: 68.8%-97.5%), respectively. CONCLUSION UHR CCTA by PCD-CT leads to significantly improved visualization and diagnostic performance of coronary stents, and Bv72 is the optimal reconstruction kernel showing the stent struts and in-stent lumen. CLINICAL RELEVANCE STATEMENT The significantly improved visualization of coronary stents using ultra-high resolution CCTA could increase the diagnostic accuracy for in-stent restenosis and avoid unnecessary invasive quantitative coronary angiography, thus changing the clinical management for patients after percutaneous coronary intervention. KEY POINTS Coronary stent imaging is challenging with energy-integrating detector CT due to "blooming artifacts." UHR images using a PCD-CT enhanced coronary stent visualization. UHR coronary stent imaging demonstrated improved diagnostic accuracy in clinical settings.
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Affiliation(s)
- Le Qin
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
| | - Shanshui Zhou
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
- College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine, No. 150 Ruijin Er Road, Shanghai, 200025, China
| | - Haipeng Dong
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
| | - Jiqiang Li
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
| | - Ruiyan Zhang
- Department of Cardiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
| | - Chendie Yang
- Department of Cardiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
| | - Peng Liu
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
| | - Zhihan Xu
- CT Collaboration, Siemens Healthineers, 399 West Haiyang Road, Shanghai, 200126, China
| | - Fuhua Yan
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China
- College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine, No. 150 Ruijin Er Road, Shanghai, 200025, China
| | - Wenjie Yang
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai, 200025, China.
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Meloni A, Maffei E, Clemente A, De Gori C, Occhipinti M, Positano V, Berti S, La Grutta L, Saba L, Cau R, Bossone E, Mantini C, Cavaliere C, Punzo B, Celi S, Cademartiri F. Spectral Photon-Counting Computed Tomography: Technical Principles and Applications in the Assessment of Cardiovascular Diseases. J Clin Med 2024; 13:2359. [PMID: 38673632 PMCID: PMC11051476 DOI: 10.3390/jcm13082359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
Spectral Photon-Counting Computed Tomography (SPCCT) represents a groundbreaking advancement in X-ray imaging technology. The core innovation of SPCCT lies in its photon-counting detectors, which can count the exact number of incoming x-ray photons and individually measure their energy. The first part of this review summarizes the key elements of SPCCT technology, such as energy binning, energy weighting, and material decomposition. Its energy-discriminating ability represents the key to the increase in the contrast between different tissues, the elimination of the electronic noise, and the correction of beam-hardening artifacts. Material decomposition provides valuable insights into specific elements' composition, concentration, and distribution. The capability of SPCCT to operate in three or more energy regimes allows for the differentiation of several contrast agents, facilitating quantitative assessments of elements with specific energy thresholds within the diagnostic energy range. The second part of this review provides a brief overview of the applications of SPCCT in the assessment of various cardiovascular disease processes. SPCCT can support the study of myocardial blood perfusion and enable enhanced tissue characterization and the identification of contrast agents, in a manner that was previously unattainable.
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Affiliation(s)
- Antonella Meloni
- Bioengineering Unit, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.)
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Erica Maffei
- Department of Radiology, Istituto di Ricovero e Cura a Carattere Scientifico SYNLAB SDN, 80131 Naples, Italy; (E.M.); (C.C.); (B.P.)
| | - Alberto Clemente
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Carmelo De Gori
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Mariaelena Occhipinti
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Vicenzo Positano
- Bioengineering Unit, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.)
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
| | - Sergio Berti
- Diagnostic and Interventional Cardiology Department, Fondazione G. Monasterio CNR-Regione Toscana, 54100 Massa, Italy;
| | - Ludovico La Grutta
- Department of Radiology, University Hospital “P. Giaccone”, 90127 Palermo, Italy;
| | - Luca Saba
- Department of Radiology, University Hospital of Cagliari, 09042 Monserrato (CA), Italy; (L.S.); (R.C.)
| | - Riccardo Cau
- Department of Radiology, University Hospital of Cagliari, 09042 Monserrato (CA), Italy; (L.S.); (R.C.)
| | - Eduardo Bossone
- Department of Cardiology, Ospedale Cardarelli, 80131 Naples, Italy;
| | - Cesare Mantini
- Department of Radiology, “G. D’Annunzio” University, 66100 Chieti, Italy;
| | - Carlo Cavaliere
- Department of Radiology, Istituto di Ricovero e Cura a Carattere Scientifico SYNLAB SDN, 80131 Naples, Italy; (E.M.); (C.C.); (B.P.)
| | - Bruna Punzo
- Department of Radiology, Istituto di Ricovero e Cura a Carattere Scientifico SYNLAB SDN, 80131 Naples, Italy; (E.M.); (C.C.); (B.P.)
| | - Simona Celi
- BioCardioLab, Fondazione G. Monasterio CNR-Regione Toscana, 54100 Massa, Italy;
| | - Filippo Cademartiri
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.C.); (C.D.G.); (M.O.)
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Rajagopal JR, Schwartz FR, McCabe C, Farhadi F, Zarei M, Ria F, Abadi E, Segars P, Ramirez-Giraldo JC, Jones EC, Henry T, Marin D, Samei E. Technology Characterization Through Diverse Evaluation Methodologies: Application to Thoracic Imaging in Photon-Counting Computed Tomography. J Comput Assist Tomogr 2024:00004728-990000000-00312. [PMID: 38626754 DOI: 10.1097/rct.0000000000001608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2024]
Abstract
OBJECTIVE Different methods can be used to condition imaging systems for clinical use. The purpose of this study was to assess how these methods complement one another in evaluating a system for clinical integration of an emerging technology, photon-counting computed tomography (PCCT), for thoracic imaging. METHODS Four methods were used to assess a clinical PCCT system (NAEOTOM Alpha; Siemens Healthineers, Forchheim, Germany) across 3 reconstruction kernels (Br40f, Br48f, and Br56f). First, a phantom evaluation was performed using a computed tomography quality control phantom to characterize noise magnitude, spatial resolution, and detectability. Second, clinical images acquired using conventional and PCCT systems were used for a multi-institutional reader study where readers from 2 institutions were asked to rank their preference of images. Third, the clinical images were assessed in terms of in vivo image quality characterization of global noise index and detectability. Fourth, a virtual imaging trial was conducted using a validated simulation platform (DukeSim) that models PCCT and a virtual patient model (XCAT) with embedded lung lesions imaged under differing conditions of respiratory phase and positional displacement. Using known ground truth of the patient model, images were evaluated for quantitative biomarkers of lung intensity histograms and lesion morphology metrics. RESULTS For the physical phantom study, the Br56f kernel was shown to have the highest resolution despite having the highest noise and lowest detectability. Readers across both institutions preferred the Br56f kernel (71% first rank) with a high interclass correlation (0.990). In vivo assessments found superior detectability for PCCT compared with conventional computed tomography but higher noise and reduced detectability with increased kernel sharpness. For the virtual imaging trial, Br40f was shown to have the best performance for histogram measures, whereas Br56f was shown to have the most precise and accurate morphology metrics. CONCLUSION The 4 evaluation methods each have their strengths and limitations and bring complementary insight to the evaluation of PCCT. Although no method offers a complete answer, concordant findings between methods offer affirmatory confidence in a decision, whereas discordant ones offer insight for added perspective. Aggregating our findings, we concluded the Br56f kernel best for high-resolution tasks and Br40f for contrast-dependent tasks.
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Affiliation(s)
| | - Fides R Schwartz
- Duke University Health System, Department of Radiology, Duke University Medical Center, Durham, NC
| | - Cindy McCabe
- From the Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC
| | | | - Mojtaba Zarei
- From the Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC
| | - Francesco Ria
- From the Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC
| | - Ehsan Abadi
- From the Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC
| | - Paul Segars
- From the Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC
| | | | - Elizabeth C Jones
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD
| | - Travis Henry
- Duke University Health System, Department of Radiology, Duke University Medical Center, Durham, NC
| | - Daniele Marin
- Duke University Health System, Department of Radiology, Duke University Medical Center, Durham, NC
| | - Ehsan Samei
- From the Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, NC
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11
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van der Bie J, Bos D, Dijkshoorn ML, Booij R, Budde RPJ, van Straten M. Thin slice photon-counting CT coronary angiography compared to conventional CT: Objective image quality and clinical radiation dose assessment. Med Phys 2024; 51:2924-2932. [PMID: 38358113 DOI: 10.1002/mp.16992] [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: 08/28/2023] [Revised: 01/30/2024] [Accepted: 02/02/2024] [Indexed: 02/16/2024] Open
Abstract
BACKGROUND Photon-counting CT (PCCT) is the next-generation CT scanner that enables improved spatial resolution and spectral imaging. For full spectral processing, higher tube voltages compared to conventional CT are necessary to achieve the required spectral separation. This generated interest in the potential influence of thin slice high tube voltage PCCT on overall image quality and consequently on radiation dose. PURPOSE This study first evaluated tube voltages and radiation doses applied in patients who underwent coronary CT angiography with PCCT and energy-integrating detector CT (EID-CT). Next, image quality of PCCT and EID-CT was objectively evaluated in a phantom study simulating different patient sizes at these tube voltages and radiation doses. METHODS We conducted a retrospective analysis of clinical doses of patients scanned on a conventional and PCCT system. Average patient water equivalent diameters for different tube voltages were extracted from the dose reports for both EID-CT and PCCT. A conical phantom made of polyethylene with multiple diameters (26/31/36 cm) representing different patient sizes and containing an iodine insert was scanned with a EID-CT scanner using tube voltages and phantom diameters that match the patient scans and characteristics. Next, phantom scans were made with PCCT at a fixed tube voltage of 120 kV and with CTDIVOL values and phantom diameters identical to the EID-CT scans. Clinical image reconstructions at 0.6 mm slice thickness for conventional CT were compared to PCCT images with 0.4 mm slice thickness. Image quality was quantified using the detectability index (d'), which estimated the visibility of a 3 mm diameter contrast-enhanced coronary artery by considering noise, contrast, resolution, and human visual perception. Alongside d', noise, contrast and resolution were also individually assessed. In addition, the influence of various kernels (Bv40/Bv44/Bv48/Bv56), quantum iterative reconstruction strengths (QIR, 3/4) and monoenergetic levels (40/45/50/55 keV) for PCCT on d' was investigated. RESULTS In this study, 143 patients were included: 47 were scanned on PCCT (120 kV) and the remaining on EID-CT (74 small-sized at 70 kV, 18 medium-sized at 80 kV and four large-sized at 90 kV). EID-CT showed 7%-17% higher d' than PCCT with Bv40 kernel and strength four for small/medium patients. Lower monoenergetic images (40 keV) helped mitigate the difference to 1%-6%. For large patients, PCCT's detectability was up to 31% higher than EID-CT. PCCT has thinner slices but similar noise levels for similar reconstruction parameters. The noise increased with lower keV levels in PCCT (≈30% increase), but higher QIR strengths reduced noise. PCCT's iodine contrast was stable across patient sizes, while EID-CT had 33% less contrast in large patients than in small-sized patients. CONCLUSION At 120 kV, thin slice PCCT enables CCTA in phantom scans representing large patients without raising radiation dose or affecting vessel detectability. However, higher doses are needed for small and medium-sized patients to obtain a similar image quality as in EID-CT. The alternative of using lower mono-energetic levels requires further evaluation in clinical practice.
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Affiliation(s)
- Judith van der Bie
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Daniel Bos
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Marcel L Dijkshoorn
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Ronald Booij
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Ricardo P J Budde
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Marcel van Straten
- Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
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Park H, Oh YW, Lee KY, Yong HS, Kim C, Hwang SH. [Visualization of Borderline Coronary Artery Lesions by CT Angiography and Coronary Artery Disease Reporting and Data System]. JOURNAL OF THE KOREAN SOCIETY OF RADIOLOGY 2024; 85:297-307. [PMID: 38617850 PMCID: PMC11009128 DOI: 10.3348/jksr.2023.0141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 03/01/2024] [Accepted: 03/20/2024] [Indexed: 04/16/2024]
Abstract
Coronary artery disease (CAD) narrows vessel lumens at the sites of atherosclerosis, increasing the risk of myocardial ischemia or infarction. Early and accurate diagnosis of CAD is crucial to significantly improve prognosis and management. CT angiography (CTA) is a noninvasive imaging technique that enables assessment of vascular structure and stenosis with high resolution and contrast. Coronary CTA is useful in the diagnosis of CAD. Recently, the CAD-reporting and data system (CAD-RADS), a diagnostic classification system based on coronary CTA, has been developed to improve intervention efficacy in patients suspected of CAD. While the CAD-RAD is based on CTA, it includes borderline categories where interpreting the coronary artery status solely based on CTA findings may be challenging. This review introduces CTA findings that fall within the CAD-RADS categories that necessitate additional tests to decide to perform invasive coronary angiography and discusses appropriate management strategies.
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Funama Y, Oda S, Teramoto F, Aoki Y, Takahashi I, Kojima S, Goto T, Tanaka K, Kidoh M, Nagayama Y, Nakaura T, Hirai T. Improving Visualization of In-stent Lumen Using Prototype Photon-counting Detector Computed Tomography with High-resolution Plaque Kernel. J Med Phys 2024; 49:127-132. [PMID: 38828063 PMCID: PMC11141743 DOI: 10.4103/jmp.jmp_163_23] [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: 11/28/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 06/05/2024] Open
Abstract
The study aimed to compare the performance of photon-counting detector computed tomography (PCD CT) with high-resolution (HR)-plaque kernel with that of the energy-integrating detector CT (EID CT) in terms of the visualization of the lumen size and the in-stent stenotic portion at different coronary vessel angles. The lumen sizes in PCD CT and EID CT images were 2.13 and 1.80 mm at 0°, 2.20 and 1.77 mm at 45°, and 2.27 mm and 1.67 mm at 90°, respectively. The lumen sizes in PCD CT with HR-plaque kernel were wider than those in EID CT. The mean degree of the in-stent stenotic portion at 50% was 69.7% for PCD CT and 90.4% for EID CT. PCD CT images with HR-plaque kernel enable improved visualization of lumen size and accurate measurements of the in-stent stenotic portion compared to conventional EID CT images regardless of the stent direction.
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Affiliation(s)
- Yoshinori Funama
- Department of Medical Radiation Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Seitaro Oda
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Fuyuhiko Teramoto
- Medical System Research and Development Center, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Yuko Aoki
- Medical System Research and Development Center, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Isao Takahashi
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Shinichi Kojima
- Innovative Technology Laboratory, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Taiga Goto
- Medical System Research and Development Center, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Kana Tanaka
- Medical System Research and Development Center, FUJIFILM Healthcare Corporation, Tokyo, Japan
| | - Masafumi Kidoh
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Yasunori Nagayama
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Takeshi Nakaura
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Toshinori Hirai
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
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14
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Zanon C, Cademartiri F, Toniolo A, Bini C, Clemente A, Colacchio EC, Cabrelle G, Mastro F, Antonello M, Quaia E, Pepe A. Advantages of Photon-Counting Detector CT in Aortic Imaging. Tomography 2023; 10:1-13. [PMID: 38276249 PMCID: PMC10821336 DOI: 10.3390/tomography10010001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/08/2023] [Accepted: 12/11/2023] [Indexed: 01/27/2024] Open
Abstract
Photon-counting Computed Tomography (PCCT) is a promising imaging technique. Using detectors that count the number and energy of photons in multiple bins, PCCT offers several advantages over conventional CT, including a higher image quality, reduced contrast agent volume, radiation doses, and artifacts. Although PCCT is well established for cardiac imaging in assessing coronary artery disease, its application in aortic imaging remains limited. This review summarizes the available literature and provides an overview of the current use of PCCT for the diagnosis of aortic imaging, focusing mainly on endoleaks detection and characterization after endovascular aneurysm repair (EVAR), contrast dose volume, and radiation exposure reduction, particularly in patients with chronic kidney disease and in those requiring follow-up CT.
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Affiliation(s)
- Chiara Zanon
- Department of Radiology, University of Padua, 35128 Padua, Italy
| | - Filippo Cademartiri
- Department of Radiology, Fondazione Toscana Gabriele Monasterio, 56124 Pisa, Italy
| | | | - Costanza Bini
- Department of Radiology, University of Padua, 35128 Padua, Italy
| | - Alberto Clemente
- Department of Radiology, Fondazione Toscana Gabriele Monasterio, 56124 Pisa, Italy
| | - Elda Chiara Colacchio
- Vascular and Endovascular Surgery Section, Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padua, 35128 Padua, Italy
| | - Giulio Cabrelle
- Department of Radiology, University of Padua, 35128 Padua, Italy
| | - Florinda Mastro
- Division of Cardiac Surgery, University of Padua, 35128 Padua, Italy
| | - Michele Antonello
- Vascular and Endovascular Surgery Section, Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padua, 35128 Padua, Italy
| | - Emilio Quaia
- Department of Radiology, University of Padua, 35128 Padua, Italy
| | - Alessia Pepe
- Department of Radiology, University of Padua, 35128 Padua, Italy
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Gruschwitz P, Hartung V, Ergün S, Peter D, Lichthardt S, Huflage H, Hendel R, Pannenbecker P, Augustin AM, Kunz AS, Feldle P, Bley TA, Grunz JP. Comparison of ultrahigh and standard resolution photon-counting CT angiography of the femoral arteries in a continuously perfused in vitro model. Eur Radiol Exp 2023; 7:83. [PMID: 38110729 PMCID: PMC10728414 DOI: 10.1186/s41747-023-00398-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 10/17/2023] [Indexed: 12/20/2023] Open
Abstract
BACKGROUND With the emergence of photon-counting CT, ultrahigh-resolution (UHR) imaging can be performed without dose penalty. This study aims to directly compare the image quality of UHR and standard resolution (SR) scan mode in femoral artery angiographies. METHODS After establishing continuous extracorporeal perfusion in four fresh-frozen cadaveric specimens, photon-counting CT angiographies were performed with a radiation dose of 5 mGy and tube voltage of 120 kV in both SR and UHR mode. Images were reconstructed with dedicated convolution kernels (soft: Body-vascular (Bv)48; sharp: Bv60; ultrasharp: Bv76). Six radiologists evaluated the image quality by means of a pairwise forced-choice comparison tool. Kendall's concordance coefficient (W) was calculated to quantify interrater agreement. Image quality was further assessed by measuring intraluminal attenuation and image noise as well as by calculating signal-to-noise ratio (SNR) and contrast-to-noise ratios (CNR). RESULTS UHR yielded lower noise than SR for identical reconstructions with kernels ≥ Bv60 (p < 0.001). UHR scans exhibited lower intraluminal attenuation compared to SR (Bv60: 406.4 ± 25.1 versus 418.1 ± 30.1 HU; p < 0.001). Irrespective of scan mode, SNR and CNR decreased while noise increased with sharper kernels but UHR scans were objectively superior to SR nonetheless (Bv60: SNR 25.9 ± 6.4 versus 20.9 ± 5.3; CNR 22.7 ± 5.8 versus 18.4 ± 4.8; p < 0.001). Notably, UHR scans were preferred in subjective assessment when images were reconstructed with the ultrasharp Bv76 kernel, whereas SR was rated superior for Bv60. Interrater agreement was high (W = 0.935). CONCLUSIONS Combinations of UHR scan mode and ultrasharp convolution kernel are able to exploit the full image quality potential in photon-counting CT angiography of the femoral arteries. RELEVANCE STATEMENT The UHR scan mode offers improved image quality and may increase diagnostic accuracy in CT angiography of the peripheral arterial runoff when optimized reconstruction parameters are chosen. KEY POINTS • UHR photon-counting CT improves image quality in combination with ultrasharp convolution kernels. • UHR datasets display lower image noise compared with identically reconstructed standard resolution scans. • Scans in UHR mode show decreased intraluminal attenuation compared with standard resolution imaging.
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Affiliation(s)
- Philipp Gruschwitz
- Department of Diagnostic and Interventional Radiology, University Hospital of Würzburg, Würzburg, Germany.
| | - Viktor Hartung
- Department of Diagnostic and Interventional Radiology, University Hospital of Würzburg, Würzburg, Germany
| | - Süleyman Ergün
- Institute of Anatomy and Cell Biology, University of Würzburg, Würzburg, Germany
| | - Dominik Peter
- Department of General, Visceral, Transplant, Vascular, and Pediatric Surgery, University Hospital of Würzburg, Würzburg, Germany
| | - Sven Lichthardt
- Department of General, Visceral, Transplant, Vascular, and Pediatric Surgery, University Hospital of Würzburg, Würzburg, Germany
| | - Henner Huflage
- Department of Diagnostic and Interventional Radiology, University Hospital of Würzburg, Würzburg, Germany
| | - Robin Hendel
- Department of Diagnostic and Interventional Radiology, University Hospital of Würzburg, Würzburg, Germany
| | - Pauline Pannenbecker
- Department of Diagnostic and Interventional Radiology, University Hospital of Würzburg, Würzburg, Germany
| | - Anne Marie Augustin
- Department of Diagnostic and Interventional Radiology, University Hospital of Würzburg, Würzburg, Germany
| | - Andreas Steven Kunz
- Department of Diagnostic and Interventional Radiology, University Hospital of Würzburg, Würzburg, Germany
| | - Philipp Feldle
- Department of Diagnostic and Interventional Radiology, University Hospital of Würzburg, Würzburg, Germany
| | - Thorsten Alexander Bley
- Department of Diagnostic and Interventional Radiology, University Hospital of Würzburg, Würzburg, Germany
| | - Jan-Peter Grunz
- Department of Diagnostic and Interventional Radiology, University Hospital of Würzburg, Würzburg, Germany
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Dell’Aversana S, Ascione R, Vitale RA, Cavaliere F, Porcaro P, Basile L, Napolitano G, Boccalatte M, Sibilio G, Esposito G, Franzone A, Di Costanzo G, Muscogiuri G, Sironi S, Cuocolo R, Cavaglià E, Ponsiglione A, Imbriaco M. CT Coronary Angiography: Technical Approach and Atherosclerotic Plaque Characterization. J Clin Med 2023; 12:7615. [PMID: 38137684 PMCID: PMC10744060 DOI: 10.3390/jcm12247615] [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: 11/11/2023] [Revised: 12/08/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
Coronary computed tomography angiography (CCTA) currently represents a robust imaging technique for the detection, quantification and characterization of coronary atherosclerosis. However, CCTA remains a challenging task requiring both high spatial and temporal resolution to provide motion-free images of the coronary arteries. Several CCTA features, such as low attenuation, positive remodeling, spotty calcification, napkin-ring and high pericoronary fat attenuation index have been proved as associated to high-risk plaques. This review aims to explore the role of CCTA in the characterization of high-risk atherosclerotic plaque and the recent advancements in CCTA technologies with a focus on radiomics plaque analysis.
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Affiliation(s)
- Serena Dell’Aversana
- Department of Radiology, Santa Maria Delle Grazie Hospital, ASL Napoli 2 Nord, 80078 Pozzuoli, Italy; (S.D.); (G.D.C.); (E.C.)
| | - Raffaele Ascione
- Department of Advanced Biomedical Sciences, University of Naples Federico II, 80131 Naples, Italy; (R.A.); (R.A.V.); (F.C.); (P.P.); (L.B.); (G.E.); (A.F.); (M.I.)
| | - Raffaella Antonia Vitale
- Department of Advanced Biomedical Sciences, University of Naples Federico II, 80131 Naples, Italy; (R.A.); (R.A.V.); (F.C.); (P.P.); (L.B.); (G.E.); (A.F.); (M.I.)
| | - Fabrizia Cavaliere
- Department of Advanced Biomedical Sciences, University of Naples Federico II, 80131 Naples, Italy; (R.A.); (R.A.V.); (F.C.); (P.P.); (L.B.); (G.E.); (A.F.); (M.I.)
| | - Piercarmine Porcaro
- Department of Advanced Biomedical Sciences, University of Naples Federico II, 80131 Naples, Italy; (R.A.); (R.A.V.); (F.C.); (P.P.); (L.B.); (G.E.); (A.F.); (M.I.)
| | - Luigi Basile
- Department of Advanced Biomedical Sciences, University of Naples Federico II, 80131 Naples, Italy; (R.A.); (R.A.V.); (F.C.); (P.P.); (L.B.); (G.E.); (A.F.); (M.I.)
| | | | - Marco Boccalatte
- Coronary Care Unit, Santa Maria delle Grazie Hospital, ASL Napoli 2 Nord, 80078 Pozzuoli, Italy; (M.B.); (G.S.)
| | - Gerolamo Sibilio
- Coronary Care Unit, Santa Maria delle Grazie Hospital, ASL Napoli 2 Nord, 80078 Pozzuoli, Italy; (M.B.); (G.S.)
| | - Giovanni Esposito
- Department of Advanced Biomedical Sciences, University of Naples Federico II, 80131 Naples, Italy; (R.A.); (R.A.V.); (F.C.); (P.P.); (L.B.); (G.E.); (A.F.); (M.I.)
| | - Anna Franzone
- Department of Advanced Biomedical Sciences, University of Naples Federico II, 80131 Naples, Italy; (R.A.); (R.A.V.); (F.C.); (P.P.); (L.B.); (G.E.); (A.F.); (M.I.)
| | - Giuseppe Di Costanzo
- Department of Radiology, Santa Maria Delle Grazie Hospital, ASL Napoli 2 Nord, 80078 Pozzuoli, Italy; (S.D.); (G.D.C.); (E.C.)
| | - Giuseppe Muscogiuri
- Department of Radiology, ASST Papa Giovanni XXIII Hospital, Piazza OMS 1, 24127 Bergamo, Italy; (G.M.); (S.S.)
| | - Sandro Sironi
- Department of Radiology, ASST Papa Giovanni XXIII Hospital, Piazza OMS 1, 24127 Bergamo, Italy; (G.M.); (S.S.)
- School of Medicine and Surgery, University of Milano Bicocca, 20126 Milan, Italy
| | - Renato Cuocolo
- Department of Medicine, Surgery and Dentistry, University of Salerno, 84081 Baronissi, Italy;
| | - Enrico Cavaglià
- Department of Radiology, Santa Maria Delle Grazie Hospital, ASL Napoli 2 Nord, 80078 Pozzuoli, Italy; (S.D.); (G.D.C.); (E.C.)
| | - Andrea Ponsiglione
- Department of Advanced Biomedical Sciences, University of Naples Federico II, 80131 Naples, Italy; (R.A.); (R.A.V.); (F.C.); (P.P.); (L.B.); (G.E.); (A.F.); (M.I.)
| | - Massimo Imbriaco
- Department of Advanced Biomedical Sciences, University of Naples Federico II, 80131 Naples, Italy; (R.A.); (R.A.V.); (F.C.); (P.P.); (L.B.); (G.E.); (A.F.); (M.I.)
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Flohr T, Schmidt B, Ulzheimer S, Alkadhi H. Cardiac imaging with photon counting CT. Br J Radiol 2023; 96:20230407. [PMID: 37750856 PMCID: PMC10646663 DOI: 10.1259/bjr.20230407] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/17/2023] [Accepted: 08/24/2023] [Indexed: 09/27/2023] Open
Abstract
CT of the heart, in particular ECG-controlled coronary CT angiography (cCTA), has become clinical routine due to rapid technical progress with ever new generations of CT equipment. Recently, CT scanners with photon-counting detectors (PCD) have been introduced which have the potential to address some of the remaining challenges for cardiac CT, such as limited spatial resolution and lack of high-quality spectral data. In this review article, we briefly discuss the technical principles of photon-counting detector CT, and we give an overview on how the improved spatial resolution of photon-counting detector CT and the routine availability of spectral data can benefit cardiac applications. We focus on coronary artery calcium scoring, cCTA, and on the evaluation of the myocardium.
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Affiliation(s)
- Thomas Flohr
- Siemens Healthcare GmbH, Computed Tomography, Forchheim, Germany
| | - Bernhard Schmidt
- Siemens Healthcare GmbH, Computed Tomography, Forchheim, Germany
| | - Stefan Ulzheimer
- Siemens Healthcare GmbH, Computed Tomography, Forchheim, Germany
| | - Hatem Alkadhi
- Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
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18
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Schmidt TG, Sidky EY, Pan X, Barber RF, Grönberg F, Sjölin M, Danielsson M. Constrained one-step material decomposition reconstruction of head CT data from a silicon photon-counting prototype. Med Phys 2023; 50:6008-6021. [PMID: 37523258 PMCID: PMC11073613 DOI: 10.1002/mp.16649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 06/23/2023] [Accepted: 07/15/2023] [Indexed: 08/02/2023] Open
Abstract
BACKGROUND Spectral CT material decomposition provides quantitative information but is challenged by the instability of the inversion into basis materials. We have previously proposed the constrained One-Step Spectral CT Image Reconstruction (cOSSCIR) algorithm to stabilize the material decomposition inversion by directly estimating basis material images from spectral CT data. cOSSCIR was previously investigated on phantom data. PURPOSE This study investigates the performance of cOSSCIR using head CT datasets acquired on a clinical photon-counting CT (PCCT) prototype. This is the first investigation of cOSSCIR for large-scale, anatomically complex, clinical PCCT data. The cOSSCIR decomposition is preceded by a spectrum estimation and nonlinear counts correction calibration step to address nonideal detector effects. METHODS Head CT data were acquired on an early prototype clinical PCCT system using an edge-on silicon detector with eight energy bins. Calibration data of a step wedge phantom were also acquired and used to train a spectral model to account for the source spectrum and detector spectral response, and also to train a nonlinear counts correction model to account for pulse pileup effects. The cOSSCIR algorithm optimized the bone and adipose basis images directly from the photon counts data, while placing a grouped total variation (TV) constraint on the basis images. For comparison, basis images were also reconstructed by a two-step projection-domain approach of Maximum Likelihood Estimation (MLE) for decomposing basis sinograms, followed by filtered backprojection (MLE + FBP) or a TV minimization algorithm (MLE + TVmin ) to reconstruct basis images. We hypothesize that the cOSSCIR approach will provide a more stable inversion into basis images compared to two-step approaches. To investigate this hypothesis, the noise standard deviation in bone and soft-tissue regions of interest (ROIs) in the reconstructed images were compared between cOSSCIR and the two-step methods for a range of regularization constraint settings. RESULTS cOSSCIR reduced the noise standard deviation in the basis images by a factor of two to six compared to that of MLE + TVmin , when both algorithms were constrained to produce images with the same TV. The cOSSCIR images demonstrated qualitatively improved spatial resolution and depiction of fine anatomical detail. The MLE + TVmin algorithm resulted in lower noise standard deviation than cOSSCIR for the virtual monoenergetic images (VMIs) at higher energy levels and constraint settings, while the cOSSCIR VMIs resulted in lower noise standard deviation at lower energy levels and overall higher qualitative spatial resolution. There were no statistically significant differences in the mean values within the bone region of images reconstructed by the studied algorithms. There were statistically significant differences in the mean values within the soft-tissue region of the reconstructed images, with cOSSCIR producing mean values closer to the expected values. CONCLUSIONS The cOSSCIR algorithm, combined with our previously proposed spectral model estimation and nonlinear counts correction method, successfully estimated bone and adipose basis images from high resolution, large-scale patient data from a clinical PCCT prototype. The cOSSCIR basis images were able to depict fine anatomical details with a factor of two to six reduction in noise standard deviation compared to that of the MLE + TVmin two-step approach.
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Affiliation(s)
- Taly Gilat Schmidt
- Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Emil Y Sidky
- Department of Radiology, University of Chicago, Chicago, Illinois, USA
| | - Xiaochuan Pan
- Department of Radiology, University of Chicago, Chicago, Illinois, USA
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19
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Stein T, Taron J, Verloh N, Doppler M, Rau A, Hagar MT, Faby S, Baltas D, Westermann D, Ayx I, Schönberg SO, Nikolaou K, Schlett CL, Bamberg F, Weiss J. Photon-counting computed tomography of coronary and peripheral artery stents: a phantom study. Sci Rep 2023; 13:14806. [PMID: 37684412 PMCID: PMC10491813 DOI: 10.1038/s41598-023-41854-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 09/01/2023] [Indexed: 09/10/2023] Open
Abstract
Accurate small vessel stent visualization using CT remains challenging. Photon-counting CT (PCD-CT) may help to overcome this issue. We systematically investigate PCD-CT impact on small vessel stent assessment compared to energy-integrating-CT (EID). 12 water-contrast agent filled stents (3.0-8 mm) were scanned with patient-equivalent phantom using clinical PCD-CT and EID-CT. Images were reconstructed using dedicated vascular kernels. Subjective image quality was evaluated by 5 radiologists independently (5-point Likert-scale; 5 = excellent). Objective image quality was evaluated by calculating multi-row intensity profiles including edge rise slope (ERS) and coefficient-of-variation (CV). Highest overall reading scores were found for PCD-CT-Bv56 (3.6[3.3-4.3]). In pairwise comparison, differences were significant for PCD-CT-Bv56 vs. EID-CT-Bv40 (p ≤ 0.04), for sharpness and blooming respectively (all p < 0.05). Highest diagnostic confidence was found for PCD-CT-Bv56 (p ≤ 0.2). ANOVA revealed a significant effect of kernel strength on ERS (p < 0.001). CV decreased with stronger PCD-CT kernels, reaching its lowest in PCD-CT-Bv56 and highest in EID-CT reconstruction (p ≤ 0.05). We are the first study to verify, by phantom setup adapted to real patient settings, PCD-CT with a sharp vascular kernel provides the most favorable image quality for small vessel stent imaging. PCD-CT may reduce the number of invasive coronary angiograms, however, more studies needed to apply our results in clinical practice.
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Affiliation(s)
- Thomas Stein
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - Jana Taron
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Niklas Verloh
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Michael Doppler
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Alexander Rau
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Muhammad Taha Hagar
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sebastian Faby
- Computed Tomography, Siemens Healthcare GmbH, Forchheim, Germany
| | - Dimos Baltas
- Division of Medical Physics, Department of Radiation Oncology, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- German Cancer Consortium (DKTK), Partner Site Freiburg, Freiburg, Germany
| | - Dirk Westermann
- Department of Cardiology and Angiology, Interdisciplinary Vascular Center Freiburg-Bad Krozingen, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Isabelle Ayx
- Department of Radiology and Nuclear Medicine, Medical Faculty Mannheim, University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
| | - Stefan O Schönberg
- Department of Radiology and Nuclear Medicine, Medical Faculty Mannheim, University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
| | - Konstantin Nikolaou
- Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen, Germany
| | - Christopher L Schlett
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Fabian Bamberg
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jakob Weiss
- Department of Diagnostic and Interventional Radiology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Meloni A, Cademartiri F, Positano V, Celi S, Berti S, Clemente A, La Grutta L, Saba L, Bossone E, Cavaliere C, Punzo B, Maffei E. Cardiovascular Applications of Photon-Counting CT Technology: A Revolutionary New Diagnostic Step. J Cardiovasc Dev Dis 2023; 10:363. [PMID: 37754792 PMCID: PMC10531582 DOI: 10.3390/jcdd10090363] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/16/2023] [Accepted: 08/18/2023] [Indexed: 09/28/2023] Open
Abstract
Photon-counting computed tomography (PCCT) is an emerging technology that can potentially transform clinical CT imaging. After a brief description of the PCCT technology, this review summarizes its main advantages over conventional CT: improved spatial resolution, improved signal and contrast behavior, reduced electronic noise and artifacts, decreased radiation dose, and multi-energy capability with improved material discrimination. Moreover, by providing an overview of the existing literature, this review highlights how the PCCT benefits have been harnessed to enhance and broaden the diagnostic capabilities of CT for cardiovascular applications, including the detection of coronary artery calcifications, evaluation of coronary plaque extent and composition, evaluation of coronary stents, and assessment of myocardial tissue characteristics and perfusion.
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Affiliation(s)
- Antonella Meloni
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
- Unità Operativa Complessa di Bioingegneria, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy
| | - Filippo Cademartiri
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
| | - Vicenzo Positano
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
- Unità Operativa Complessa di Bioingegneria, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy
| | - Simona Celi
- BioCardioLab, Fondazione G. Monasterio CNR-Regione Toscana, 54100 Massa, Italy;
| | - Sergio Berti
- Diagnostic and Interventional Cardiology Department, Fondazione G. Monasterio CNR-Regione Toscana, 54100 Massa, Italy;
| | - Alberto Clemente
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
| | - Ludovico La Grutta
- Department of Radiology, University Hospital “P. Giaccone”, 90127 Palermo, Italy;
| | - Luca Saba
- Department of Radiology, University Hospital of Cagliari, 09042 Monserrato, CA, Italy;
| | - Eduardo Bossone
- Department of Cardiology, Ospedale Cardarelli, 80131 Naples, Italy;
| | - Carlo Cavaliere
- Department of Radiology, Istituto di Ricerca e Cura a Carattere Scientifico SynLab-SDN, 80131 Naples, Italy; (C.C.); (B.P.)
| | - Bruna Punzo
- Department of Radiology, Istituto di Ricerca e Cura a Carattere Scientifico SynLab-SDN, 80131 Naples, Italy; (C.C.); (B.P.)
| | - Erica Maffei
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, 56124 Pisa, Italy; (A.M.); (V.P.); (A.C.); (E.M.)
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Lell M, Kachelrieß M. Computed Tomography 2.0: New Detector Technology, AI, and Other Developments. Invest Radiol 2023; 58:587-601. [PMID: 37378467 PMCID: PMC10332658 DOI: 10.1097/rli.0000000000000995] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 05/04/2023] [Indexed: 06/29/2023]
Abstract
ABSTRACT Computed tomography (CT) dramatically improved the capabilities of diagnostic and interventional radiology. Starting in the early 1970s, this imaging modality is still evolving, although tremendous improvements in scan speed, volume coverage, spatial and soft tissue resolution, as well as dose reduction have been achieved. Tube current modulation, automated exposure control, anatomy-based tube voltage (kV) selection, advanced x-ray beam filtration, and iterative image reconstruction techniques improved image quality and decreased radiation exposure. Cardiac imaging triggered the demand for high temporal resolution, volume acquisition, and high pitch modes with electrocardiogram synchronization. Plaque imaging in cardiac CT as well as lung and bone imaging demand for high spatial resolution. Today, we see a transition of photon-counting detectors from experimental and research prototype setups into commercially available systems integrated in patient care. Moreover, with respect to CT technology and CT image formation, artificial intelligence is increasingly used in patient positioning, protocol adjustment, and image reconstruction, but also in image preprocessing or postprocessing. The aim of this article is to give an overview of the technical specifications of up-to-date available whole-body and dedicated CT systems, as well as hardware and software innovations for CT systems in the near future.
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Koons EK, Thorne JE, Huber N, Chang S, Rajendran K, McCollough CH, Leng S. Quantifying lumen diameter in coronary artery stents with high-resolution photon counting detector CT and convolutional neural network denoising. Med Phys 2023; 50:4173-4181. [PMID: 37069830 PMCID: PMC10524296 DOI: 10.1002/mp.16415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 03/07/2023] [Accepted: 03/30/2023] [Indexed: 04/19/2023] Open
Abstract
BACKGROUND Small coronary arteries containing stents pose a challenge in CT imaging due to metal-induced blooming artifact. High spatial resolution imaging capability is as the presence of highly attenuating materials limits noninvasive assessment of luminal patency. PURPOSE The purpose of this study was to quantify the effective lumen diameter within coronary stents using a clinical photon-counting-detector (PCD) CT in concert with a convolutional neural network (CNN) denoising algorithm, compared to an energy-integrating-detector (EID) CT system. METHODS Seven coronary stents of different materials and inner diameters between 3.43 and 4.72 mm were placed in plastic tubes of diameters 3.96-4.87 mm containing 20 mg/mL of iodine solution, mimicking stented contrast-enhanced coronary arteries. Tubes were placed parallel with or perpendicular to the scanner's z-axis in an anthropomorphic phantom emulating an average-sized patient and scanned with a clinical EID-CT and PCD-CT. EID scans were performed using our standard coronary computed tomography angiography (cCTA) protocol (120 kV, 180 quality reference mAs). PCD scans were performed using the ultra-high-resolution (UHR) mode (120 × 0.2 mm collimation) at 120 kV with tube current adjusted so that CTDIvol was matched to that of EID scans. EID images were reconstructed per our routine clinical protocol (Br40, 0.6 mm thickness), and with the sharpest available kernel (Br69). PCD images were reconstructed at a thickness of 0.6 mm and a dedicated sharp kernel (Br89) which is only possible with the PCD UHR mode. To address increased image noise introduced by the Br89 kernel, an image-based CNN denoising algorithm was applied to the PCD images of stents scanned parallel to the scanner's z-axis. Stents were segmented based on full-width half maximum thresholding and morphological operations, from which effective lumen diameter was calculated and compared to reference sizes measured with a caliper. RESULTS Substantial blooming artifacts were observed on EID Br40 images, resulting in larger stent struts and reduced lumen diameter (effective diameter underestimated by 41% and 47% for parallel and perpendicular orientations, respectively). Blooming artifacts were observed on EID Br69 images with 19% and 31% underestimation of lumen diameter compared to the caliper for parallel and perpendicular scans, respectively. Overall image quality was substantially improved on PCD, with higher spatial resolution and reduced blooming artifacts, resulting in the clearer delineation of stent struts. Effective lumen diameters were underestimated by 9% and 19% relative to the reference for parallel and perpendicular scans, respectively. CNN reduced image noise by about 50% on PCD images without impacting lumen quantification (<0.3% difference). CONCLUSION The PCD UHR mode improved in-stent lumen quantification for all seven stents as compared to EID images due to decreased blooming artifacts. Implementation of CNN denoising algorithms to PCD data substantially improved image quality.
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Affiliation(s)
- Emily K. Koons
- Department of Radiology, Mayo Clinic, Rochester, MN
- Department of Biomedical Engineering and Physiology, Mayo Clinic, Rochester, MN
| | | | - Nathan Huber
- Department of Radiology, Mayo Clinic, Rochester, MN
| | | | | | | | - Shuai Leng
- Department of Radiology, Mayo Clinic, Rochester, MN
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Zsarnóczay E, Varga-Szemes A, Emrich T, Szilveszter B, van der Werf NR, Mastrodicasa D, Maurovich-Horvat P, Willemink MJ. Characterizing the Heart and the Myocardium With Photon-Counting CT. Invest Radiol 2023; 58:505-514. [PMID: 36822653 DOI: 10.1097/rli.0000000000000956] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
ABSTRACT Noninvasive cardiac imaging has rapidly evolved during the last decade owing to improvements in computed tomography (CT)-based technologies, among which we highlight the recent introduction of the first clinical photon-counting detector CT (PCD-CT) system. Multiple advantages of PCD-CT have been demonstrated, including increased spatial resolution, decreased electronic noise, and reduced radiation exposure, which may further improve diagnostics and may potentially impact existing management pathways. The benefits that can be obtained from the initial experiences with PCD-CT are promising. The implementation of this technology in cardiovascular imaging allows for the quantification of coronary calcium, myocardial extracellular volume, myocardial radiomics features, epicardial and pericoronary adipose tissue, and the qualitative assessment of coronary plaques and stents. This review aims to discuss these major applications of PCD-CT with a focus on cardiac and myocardial characterization.
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Affiliation(s)
| | - Akos Varga-Szemes
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston
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Mastrodicasa D, Aquino GJ, Ordovas KG, Vargas D, Fleischmann D, Abbara S, Hanneman K. Radiology: Cardiothoracic Imaging Highlights 2022. Radiol Cardiothorac Imaging 2023; 5:e230042. [PMID: 37404783 PMCID: PMC10316293 DOI: 10.1148/ryct.230042] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/07/2023] [Accepted: 05/08/2023] [Indexed: 07/06/2023]
Abstract
Since its inaugural issue in 2019, Radiology: Cardiothoracic Imaging has disseminated the latest scientific advances and technical developments in cardiac, vascular, and thoracic imaging. In this review, we highlight select articles published in this journal between October 2021 and October 2022. The scope of the review encompasses various aspects of coronary artery and congenital heart diseases, vascular diseases, thoracic imaging, and health services research. Key highlights include changes in the revised Coronary Artery Disease Reporting and Data System 2.0, the value of coronary CT angiography in informing prognosis and guiding treatment decisions, cardiac MRI findings after COVID-19 vaccination or infection, high-risk features at CT angiography to identify patients with aortic dissection at risk for late adverse events, and CT-guided fiducial marker placement for preoperative planning for pulmonary nodules. Ongoing research and future directions include photon-counting CT and artificial intelligence applications in cardiovascular imaging. Keywords: Pediatrics, CT Angiography, CT-Perfusion, CT-Spectral Imaging, MR Angiography, PET/CT, Transcatheter Aortic Valve Implantation/Replacement (TAVI/TAVR), Cardiac, Pulmonary, Vascular, Aorta, Coronary Arteries © RSNA, 2023.
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Mergen V, Ghouse S, Sartoretti T, Manka R, Euler A, Kasel AM, Alkadhi H, Eberhard M. Cardiac Virtual Noncontrast Images for Calcium Quantification with Photon-counting Detector CT. Radiol Cardiothorac Imaging 2023; 5:e220307. [PMID: 37404795 PMCID: PMC10316300 DOI: 10.1148/ryct.220307] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/29/2023] [Accepted: 05/08/2023] [Indexed: 07/06/2023]
Abstract
Purpose To assess the accuracy of aortic valve calcium (AVC), mitral annular calcium (MAC), and coronary artery calcium (CAC) quantification and risk stratification using virtual noncontrast (VNC) images from late enhancement photon-counting detector CT as compared with true noncontrast images. Materials and Methods This retrospective, institutional review board-approved study evaluated patients undergoing photon-counting detector CT between January and September 2022. VNC images were reconstructed from late enhancement cardiac scans at 60, 70, 80, and 90 keV using quantum iterative reconstruction (QIR) strengths of 2-4. AVC, MAC, and CAC were quantified on VNC images and compared with quantification of AVC, MAC, and CAC on true noncontrast images using Bland-Altman analyses, regression models, intraclass correlation coefficients (ICC), and Wilcoxon tests. Agreement between severe aortic stenosis likelihood categories and CAC risk categories determined from VNC and true noncontrast images was assessed by weighted κ analysis. Results Ninety patients were included (mean age, 80 years ± 8 [SD]; 49 male patients). Scores were similar on true noncontrast images and VNC images at 80 keV for AVC and MAC, regardless of QIR strengths, and VNC images at 70 keV with QIR 4 for CAC (all P > .05). The best results were achieved using VNC images at 80 keV with QIR 4 for AVC (mean difference, 3; ICC = 0.992; r = 0.98) and MAC (mean difference, 6; ICC = 0.998; r = 0.99), and VNC images at 70 keV with QIR 4 for CAC (mean difference, 28; ICC = 0.996; r = 0.99). Agreement between calcification categories was excellent on VNC images at 80 keV for AVC (κ = 0.974) and on VNC images at 70 keV for CAC (κ = 0.967). Conclusion VNC images from cardiac photon-counting detector CT enables patient risk stratification and accurate quantification of AVC, MAC, and CAC.Keywords: Coronary Arteries, Aortic Valve, Mitral Valve, Aortic Stenosis, Calcifications, Photon-counting Detector CT Supplemental material is available for this article © RSNA, 2023.
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Cademartiri F, Meloni A, Pistoia L, Degiorgi G, Clemente A, Gori CD, Positano V, Celi S, Berti S, Emdin M, Panetta D, Menichetti L, Punzo B, Cavaliere C, Bossone E, Saba L, Cau R, Grutta LL, Maffei E. Dual-Source Photon-Counting Computed Tomography-Part I: Clinical Overview of Cardiac CT and Coronary CT Angiography Applications. J Clin Med 2023; 12:jcm12113627. [PMID: 37297822 DOI: 10.3390/jcm12113627] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/15/2023] [Accepted: 05/17/2023] [Indexed: 06/12/2023] Open
Abstract
The photon-counting detector (PCD) is a new computed tomography detector technology (photon-counting computed tomography, PCCT) that provides substantial benefits for cardiac and coronary artery imaging. Compared with conventional CT, PCCT has multi-energy capability, increased spatial resolution and soft tissue contrast with near-null electronic noise, reduced radiation exposure, and optimization of the use of contrast agents. This new technology promises to overcome several limitations of traditional cardiac and coronary CT angiography (CCT/CCTA) including reduction in blooming artifacts in heavy calcified coronary plaques or beam-hardening artifacts in patients with coronary stents, and a more precise assessment of the degree of stenosis and plaque characteristic thanks to its better spatial resolution. Another potential application of PCCT is the use of a double-contrast agent to characterize myocardial tissue. In this current overview of the existing PCCT literature, we describe the strengths, limitations, recent applications, and promising developments of employing PCCT technology in CCT.
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Affiliation(s)
| | - Antonella Meloni
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
- Department of Bioengineering, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Laura Pistoia
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Giulia Degiorgi
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Alberto Clemente
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Carmelo De Gori
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Vincenzo Positano
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
- Department of Bioengineering, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Simona Celi
- BioCardioLab, Department of Bioengineering, Fondazione Monasterio/CNR, 54100 Massa, Italy
| | - Sergio Berti
- Cardiology Unit, Ospedale del Cuore, Fondazione Monasterio/CNR, 54100 Massa, Italy
| | - Michele Emdin
- Department of Cardiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
| | - Daniele Panetta
- Institute of Clinical Physiology, National Council of Research, 56124 Pisa, Italy
| | - Luca Menichetti
- Institute of Clinical Physiology, National Council of Research, 56124 Pisa, Italy
| | - Bruna Punzo
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy
| | - Carlo Cavaliere
- Department of Radiology, IRCCS SynLab-SDN, 80131 Naples, Italy
| | - Eduardo Bossone
- Department of Cardiology, Ospedale Cardarelli, 80131 Naples, Italy
| | - Luca Saba
- Department of Radiology, University Hospital, 09042 Monserrato, Italy
| | - Riccardo Cau
- Department of Radiology, University Hospital, 09042 Monserrato, Italy
| | - Ludovico La Grutta
- Department of Radiology, University Hospital "P. Giaccone", 90127 Palermo, Italy
| | - Erica Maffei
- Department of Radiology, Fondazione Monasterio/CNR, 56124 Pisa, Italy
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Verelst E, Buls N, De Mey J, Nieboer KH, Vandenbergh F, Crotty D, Deak P, Sundvall A, Holmin S, De Smet A, Provyn S, Van Gompel G. Stent appearance in a novel silicon-based photon-counting CT prototype: ex vivo phantom study in head-to-head comparison with conventional energy-integrating CT. Eur Radiol Exp 2023; 7:23. [PMID: 37097376 PMCID: PMC10130245 DOI: 10.1186/s41747-023-00333-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 02/23/2023] [Indexed: 04/26/2023] Open
Abstract
BACKGROUND In this study, stent appearance in a novel silicon-based photon-counting computed tomography (Si-PCCT) prototype was compared with a conventional energy-integrating detector CT (EIDCT) system. METHODS An ex vivo phantom was created, consisting of a 2% agar-water mixture, in which human-resected and stented arteries were individually embedded. Using similar technique parameters, helical scan data was acquired using a novel prototype Si-PCCT and a conventional EIDCT system at a volumetric CT dose index (CTDIvol) of 9 mGy. Reconstructions were made at 502 and 1502 mm2 field-of-views (FOVs) using a bone kernel and adaptive statistical iterative reconstruction with 0% blending. Using a 5-point Likert scale, reader evaluations were performed on stent appearance, blooming and inter-stent visibility. Quantitative image analysis was performed on stent diameter accuracy, blooming and inter-stent distinction. Qualitative and quantitative differences between Si-PCCT and EIDCT systems were tested with a Wilcoxon signed-rank test and a paired samples t-test, respectively. Inter- and intra-reader agreement was assessed using the intraclass correlation coefficient (ICC). RESULTS Qualitatively, Si-PCCT images were rated higher than EIDCT images at 150-mm FOV, based on stent appearance (p = 0.026) and blooming (p = 0.015), with a moderate inter- (ICC = 0.50) and intra-reader (ICC = 0.60) agreement. Quantitatively, Si-PCCT yielded more accurate diameter measurements (p = 0.001), reduced blooming (p < 0.001) and improved inter-stent distinction (p < 0.001). Similar trends were observed for the images reconstructed at 50-mm FOV. CONCLUSIONS When compared to EIDCT, the improved spatial resolution of Si-PCCT yields enhanced stent appearance, more accurate diameter measurements, reduced blooming and improved inter-stent distinction. KEY POINTS • This study evaluated stent appearance in a novel silicon-based photon-counting computed tomography (Si-PCCT) prototype. • Compared to standard CT, Si-PCCT resulted in more accurate stent diameter measurements. • Si-PCCT also reduced blooming artefacts and improved inter-stent visibility.
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Affiliation(s)
- Emma Verelst
- Department of Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZB), Laarbeeklaan 101, 1090, Brussels, Belgium.
| | - Nico Buls
- Department of Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZB), Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Johan De Mey
- Department of Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZB), Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Koenraad Hans Nieboer
- Department of Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZB), Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Frans Vandenbergh
- Department of Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZB), Laarbeeklaan 101, 1090, Brussels, Belgium
| | | | - Paul Deak
- GE Healthcare, Waukesha, WI, 53188, USA
| | - Albert Sundvall
- Department of Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, 171 76, Stockholm, Sweden
| | - Staffan Holmin
- Department of Clinical Neuroscience, Karolinska Institutet and Department of Neuroradiology, 171 74, Stockholm, Sweden
| | - Aron De Smet
- Anatomical Research Training and Education, Vrije Universiteit Brussel, 1090, Brussels, Belgium
| | - Steven Provyn
- Anatomical Research Training and Education, Vrije Universiteit Brussel, 1090, Brussels, Belgium
| | - Gert Van Gompel
- Department of Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZB), Laarbeeklaan 101, 1090, Brussels, Belgium
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Zsarnoczay E, Fink N, Schoepf UJ, O'Doherty J, Allmendinger T, Hagenauer J, Wolf EV, Griffith JP, Maurovich-Horvat P, Varga-Szemes A, Emrich T. Ultra-high resolution photon-counting coronary CT angiography improves coronary stenosis quantification over a wide range of heart rates - A dynamic phantom study. Eur J Radiol 2023; 161:110746. [PMID: 36821957 DOI: 10.1016/j.ejrad.2023.110746] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 02/01/2023] [Accepted: 02/12/2023] [Indexed: 02/18/2023]
Abstract
PURPOSE To investigate the effect of using photon-counting detector (PCD)-CT with ultra-high resolution (UHR) on stenosis quantification accuracy and blooming artifacts from low to high heart rates in a dynamic motion phantom. METHOD Two vessel phantoms (diameter: 4 mm) containing solid calcified lesions (25%, 50% stenoses), filled with different concentrations of iodine, inside an anthropomorphic thorax phantom attached to a coronary motion simulator were used. Scanning was performed on a PCD-CT system using an ECG-gated mode at UHR and standard resolution (SR) (0.2, 0.6 mm slice thickness, respectively). Images were reconstructed at 60, 80 and 100 beats per minute (bpm) (UHR: Bv56 kernel, quantum iterative reconstruction (QIR) level 3; SR: 55 keV, Bv40 kernel, QIR3). Percent diameter stenosis (PDS) and blooming artifacts were measured by two readers. RESULTS PDS measurements derived from UHR were more accurate than SR for both lesions at every heart rate (p ≤ 0.005 for all, e.g. 50% lesion SR vs. UHR: at 60 bpm 57.1% [55.2-59.2] vs. 50.0% [48.5-51.2], at 100 bpm 61.0% [58.6-64.3] vs. 52.4% [51.3-54.3]). Overall mean difference across heart rates and lesions compared to the nominal stenoses was 9.2% (Limit of Agreement (LoA), 2.4%/16.0%) for SR vs. 2.4% (LoA, -2.8%/7.5%) for UHR. Blooming artifacts decreased with UHR compared to SR for both lesions at every heart rate (p < 0.001 for all, e.g. 50% lesion SR vs. UHR: at 60 bpm 63.8% [60.6-69.5] vs. 52.5% [50.0-57.5], at 100 bpm 70.2% [64.8-78.1] vs. 56.1% [51.2-60.8]). CONCLUSIONS This motion phantom study demonstrates improved stenosis quantification accuracy and reduced blooming artifacts with UHR-PCD-CT compared to SR, independent of heart rate.
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Affiliation(s)
- Emese Zsarnoczay
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States; MTA-SE Cardiovascular Imaging Research Group, Medical Imaging Center, Semmelweis University, Korányi Sándor utca 2, Budapest 1083, Hungary.
| | - Nicola Fink
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States; Department of Radiology, University Hospital, LMU Munich, Marchioninistraße 15, Munich 81377, Germany.
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States.
| | - Jim O'Doherty
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States; Siemens Medical Solutions USA Inc, 40 Liberty Boulevard, Malvern, PA 19355, United States.
| | | | - Junia Hagenauer
- Siemens Healthcare GmbH, Siemensstraße 1, Forchheim 91301, Germany; Faculty of Medicine, Friedrich Alexander University of Erlangen-Nuremberg, Krankenhausstraße 12, Erlangen 91054, Germany.
| | - Elias V Wolf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States; Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Langenbeckstraße 1, Mainz 55131, Germany.
| | - Joseph P Griffith
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States.
| | - Pál Maurovich-Horvat
- MTA-SE Cardiovascular Imaging Research Group, Medical Imaging Center, Semmelweis University, Korányi Sándor utca 2, Budapest 1083, Hungary.
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States.
| | - Tilman Emrich
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, United States; Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Langenbeckstraße 1, Mainz 55131, Germany; German Centre for Cardiovascular Research, Partner Site Rhine-Main, Mainz 55131, Germany.
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Ultrahigh-Resolution Photon-Counting Detector CT of the Lungs: Association of Reconstruction Kernel and Slice Thickness With Image Quality. AJR Am J Roentgenol 2023; 220:672-680. [PMID: 36475813 DOI: 10.2214/ajr.22.28515] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND. Prior work has shown improved image quality for photon-counting detector (PCD) CT of the lungs compared with energy-integrating detector CT. A paucity of the literature has compared PCD CT of the lungs using different reconstruction parameters. OBJECTIVE. The purpose of this study is to the compare the image quality of ultra-high-resolution (UHR) PCD CT image sets of the lungs that were reconstructed using different kernels and slice thicknesses. METHODS. This retrospective study included 29 patients (17 women and 12 men; median age, 56 years) who underwent noncontrast chest CT from February 15, 2022, to March 15, 2022, by use of a commercially available PCD CT scanner. All acquisitions used UHR mode (1024 × 1024 matrix). Nine image sets were reconstructed for all combinations of three sharp kernels (BI56, BI60, and BI64) and three slice thicknesses (0.2, 0.4, and 1.0 mm). Three radiologists independently reviewed reconstructions for measures of visualization of pulmonary anatomic structures and pathologies; reader assessments were pooled. Reconstructions were compared with the clinical reference reconstruction (obtained using the BI64 kernel and a 1.0-mm slice thickness [BI641.0-mm]). RESULTS. The median difference in the number of bronchial divisions identified versus the clinical reference reconstruction was higher for reconstructions with BI640.4-mm (0.5), BI600.4-mm (0.3), BI640.2-mm (0.5), and BI600.2-mm (0.2) (all p < .05). The median bronchial wall sharpness versus the clinical reference reconstruction was higher for reconstructions with BI640.4-mm (0.3) and BI640.2-mm (0.3) and was lower for BI561.0-mm (-0.7) and BI560.4-mm (-0.3) (all p < .05). Median pulmonary fissure sharpness versus the clinical reference reconstruction was higher for reconstructions with BI640.4-mm (0.3), BI600.4-mm (0.3), BI560.4-mm (0.5), BI640.2-mm (0.5), BI600.2-mm (0.5), and BI560.2-mm (0.3) (all p < .05). Median pulmonary vessel sharpness versus the clinical reference reconstruction was lower for reconstructions with BI561.0-mm (-0.3), BI60 0.4-mm (-0.3), BI560.4-mm (-0.7), BI640.2-mm (-0.7), BI600.2-mm (-0.7), and BI560.2-mm (-0.7). Median lung nodule conspicuity versus the clinical reference reconstruction was lower for reconstructions with BI561.0-mm (-0.3) and BI560.4-mm (-0.3) (both p < .05). Median conspicuity of all other pathologies versus the clinical reference reconstruction was lower for reconstructions with BI561.0 mm (-0.3), BI560.4-mm (-0.3), BI640.2-mm (-0.3), BI600.2-mm (-0.3), and BI560.2-mm (-0.3). Other comparisons among reconstructions were not significant (all p > .05). CONCLUSION. Only the reconstruction using BI640.4-mm yielded improved bronchial division identification and bronchial wall and pulmonary fissure sharpness without a loss in pulmonary vessel sharpness or conspicuity of nodules or other pathologies. CLINICAL IMPACT. The findings of this study may guide protocol optimization for UHR PCD CT of the lungs.
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Sartoretti T, Wildberger JE, Flohr T, Alkadhi H. Photon-counting detector CT: early clinical experience review. Br J Radiol 2023:20220544. [PMID: 36744809 DOI: 10.1259/bjr.20220544] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Since its development in the 1970s, X-ray CT has emerged as a landmark diagnostic imaging modality of modern medicine. Technological advances have been crucial to the success of CT imaging, as they have increasingly enabled improvements in image quality and diagnostic value at increasing radiation dose efficiency. With recent advances in engineering and physics, a novel technology has emerged with the potential to surpass several shortcomings and limitations of current CT systems. Photon-counting detector (PCD)-CT might substantially improve and expand the applicability of CT imaging by offering intrinsic spectral capabilities, increased spatial resolution, reduced electronic noise and improved image contrast. In this review we sought to summarize the first clinical experience of PCD-CT. We focused on most recent prototype and first clinically approved PCD-CT systems thereby reviewing initial publications and presenting corresponding clinical cases.
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Affiliation(s)
- Thomas Sartoretti
- Diagnostic and Interventional Radiology, University Hospital Zürich, University of Zürich, Zürich, Switzerland.,Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.,Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Joachim E Wildberger
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.,Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Thomas Flohr
- Siemens Healthcare GmbH, Computed Tomography, Forchheim, Germany
| | - Hatem Alkadhi
- Diagnostic and Interventional Radiology, University Hospital Zürich, University of Zürich, Zürich, Switzerland
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Photon-Counting Computed Tomography (PCCT): Technical Background and Cardio-Vascular Applications. Diagnostics (Basel) 2023; 13:diagnostics13040645. [PMID: 36832139 PMCID: PMC9955798 DOI: 10.3390/diagnostics13040645] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 01/28/2023] [Accepted: 02/07/2023] [Indexed: 02/12/2023] Open
Abstract
Photon-counting computed tomography (PCCT) is a new advanced imaging technique that is going to transform the standard clinical use of computed tomography (CT) imaging. Photon-counting detectors resolve the number of photons and the incident X-ray energy spectrum into multiple energy bins. Compared with conventional CT technology, PCCT offers the advantages of improved spatial and contrast resolution, reduction of image noise and artifacts, reduced radiation exposure, and multi-energy/multi-parametric imaging based on the atomic properties of tissues, with the consequent possibility to use different contrast agents and improve quantitative imaging. This narrative review first briefly describes the technical principles and the benefits of photon-counting CT and then provides a synthetic outline of the current literature on its use for vascular imaging.
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Michaud K, Jacobsen C, Basso C, Banner J, Blokker BM, de Boer HH, Dedouit F, O'Donnell C, Giordano C, Magnin V, Grabherr S, Suvarna SK, Wozniak K, Parsons S, van der Wal AC. Application of postmortem imaging modalities in cases of sudden death due to cardiovascular diseases-current achievements and limitations from a pathology perspective : Endorsed by the Association for European Cardiovascular Pathology and by the International Society of Forensic Radiology and Imaging. Virchows Arch 2023; 482:385-406. [PMID: 36565335 PMCID: PMC9931788 DOI: 10.1007/s00428-022-03458-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/11/2022] [Accepted: 11/15/2022] [Indexed: 12/25/2022]
Abstract
Postmortem imaging (PMI) is increasingly used in postmortem practice and is considered a potential alternative to a conventional autopsy, particularly in case of sudden cardiac deaths (SCD). In 2017, the Association for European Cardiovascular Pathology (AECVP) published guidelines on how to perform an autopsy in such cases, which is still considered the gold standard, but the diagnostic value of PMI herein was not analyzed in detail. At present, significant progress has been made in the PMI diagnosis of acute ischemic heart disease, the most important cause of SCD, while the introduction of postmortem CT angiography (PMCTA) has improved the visualization of several parameters of coronary artery pathology that can support a diagnosis of SCD. Postmortem magnetic resonance (PMMR) allows the detection of acute myocardial injury-related edema. However, PMI has limitations when compared to clinical imaging, which severely impacts the postmortem diagnosis of myocardial injuries (ischemic versus non-ischemic), the age-dating of coronary occlusion (acute versus old), other potentially SCD-related cardiac lesions (e.g., the distinctive morphologies of cardiomyopathies), aortic diseases underlying dissection or rupture, or pulmonary embolism. In these instances, PMI cannot replace a histopathological examination for a final diagnosis. Emerging minimally invasive techniques at PMI such as image-guided biopsies of the myocardium or the aorta, provide promising results that warrant further investigations. The rapid developments in the field of postmortem imaging imply that the diagnosis of sudden death due to cardiovascular diseases will soon require detailed knowledge of both postmortem radiology and of pathology.
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Affiliation(s)
- Katarzyna Michaud
- University Center of Legal Medicine Lausanne - Geneva, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
| | - Christina Jacobsen
- Section of Forensic Pathology, Department of Forensic Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Cristina Basso
- Cardiovascular Pathology Unit, Department of Cardiac, Thoracic and Vascular Sciences and Public Health, University of Padua, Padua, Italy
| | - Jytte Banner
- Section of Forensic Pathology, Department of Forensic Medicine, University of Copenhagen, Copenhagen, Denmark
| | | | - Hans H de Boer
- Department of Forensic Medicine, Victorian Institute of Forensic Medicine, Monash University, Melbourne, Australia
| | - Fabrice Dedouit
- GRAVIT, Groupe de Recherche en Autopsie Virtuelle et Imagerie Thanatologique, Forensic Department, University Hospital, Rangueil, Toulouse, France
| | - Chris O'Donnell
- Department of Forensic Medicine, Victorian Institute of Forensic Medicine, Monash University, Melbourne, Australia
| | - Carla Giordano
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Rome, Italy
| | - Virginie Magnin
- University Center of Legal Medicine Lausanne - Geneva, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Geneva University Hospital, University of Geneva, Geneva, Switzerland
| | - Silke Grabherr
- University Center of Legal Medicine Lausanne - Geneva, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Geneva University Hospital, University of Geneva, Geneva, Switzerland
| | - S Kim Suvarna
- Department of Histopathology, Northern General Hospital, The University of Sheffield, Sheffield, UK
| | - Krzysztof Wozniak
- Department of Forensic Medicine, Jagiellonian University Medical College, Krakow, Poland
| | - Sarah Parsons
- Department of Forensic Medicine, Victorian Institute of Forensic Medicine, Monash University, Melbourne, Australia
| | - Allard C van der Wal
- Department of Pathology, Amsterdam UMC, Academic Medical Center, Amsterdam, The Netherlands.
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An introduction to photon-counting detector CT (PCD CT) for radiologists. Jpn J Radiol 2023; 41:266-282. [PMID: 36255601 PMCID: PMC9974724 DOI: 10.1007/s11604-022-01350-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 10/01/2022] [Indexed: 10/24/2022]
Abstract
The basic performance of photon-counting detector computed tomography (PCD CT) is superior to conventional CT (energy-integrating detector CT: EID CT) because its spatial- and contrast resolution of soft tissues is higher, and artifacts are reduced. Because the X-ray photon energy separation is better with PCD CT than conventional EID-based dual-energy CT, it has the potential to improve virtual monochromatic- and virtual non-contrast images, material decomposition including quantification of the iodine distribution, and K-edge imaging. Therefore, its clinical applicability may be increased. Although the image quality of PCD CT scans is superior to that of EID CT currently, further improvement may be possible. The introduction of iterative image reconstruction and reconstruction with deep convolutional neural networks will be useful.
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Mergen V, Sartoretti T, Baer-Beck M, Schmidt B, Petersilka M, Wildberger JE, Euler A, Eberhard M, Alkadhi H. Ultra-High-Resolution Coronary CT Angiography With Photon-Counting Detector CT: Feasibility and Image Characterization. Invest Radiol 2022; 57:780-788. [PMID: 35640019 PMCID: PMC10184822 DOI: 10.1097/rli.0000000000000897] [Citation(s) in RCA: 71] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 05/11/2022] [Indexed: 12/26/2022]
Abstract
OBJECTIVES The aim of this study was to evaluate the feasibility and quality of ultra-high-resolution coronary computed tomography angiography (CCTA) with dual-source photon-counting detector CT (PCD-CT) in patients with a high coronary calcium load, including an analysis of the optimal reconstruction kernel and matrix size. MATERIALS AND METHODS In this institutional review board-approved study, 20 patients (6 women; mean age, 79 ± 10 years; mean body mass index, 25.6 ± 4.3 kg/m 2 ) undergoing PCD-CCTA in the ultra-high-resolution mode were included. Ultra-high-resolution CCTA was acquired in an electrocardiography-gated dual-source spiral mode at a tube voltage of 120 kV and collimation of 120 × 0.2 mm. The field of view (FOV) and matrix sizes were adjusted to the resolution properties of the individual reconstruction kernels using a FOV of 200 × 200 mm 2 or 150 × 150 mm 2 and a matrix size of 512 × 512 pixels or 1024 × 1024 pixels, respectively. Images were reconstructed using vascular kernels of 8 sharpness levels (Bv40, Bv44, Bv56, Bv60, Bv64, Bv72, Bv80, and Bv89), using quantum iterative reconstruction (QIR) at a strength level of 4, and a slice thickness of 0.2 mm. Images with the Bv40 kernel, QIR at a strength level of 4, and a slice thickness of 0.6 mm served as the reference. Image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), vessel sharpness, and blooming artifacts were quantified. For subjective image quality, 2 blinded readers evaluated image noise and delineation of coronary artery plaques and the adjacent vessel lumen using a 5-point discrete visual scale. A phantom scan served to characterize image noise texture by calculating the noise power spectrum for every reconstruction kernel. RESULTS Maximum spatial frequency (f peak ) gradually shifted to higher values for reconstructions with the Bv40 to Bv64 kernel (0.15 to 0.56 mm -1 ), but not for reconstructions with the Bv72 to Bv89 kernel. Ultra-high-resolution CCTA was feasible in all patients (median calcium score, 479). In patients, reconstructions with the Bv40 kernel and a slice thickness of 0.6 mm showed largest blooming artifacts (55.2% ± 9.8%) and lowest vessel sharpness (477.1 ± 73.6 ΔHU/mm) while achieving highest SNR (27.4 ± 5.6) and CNR (32.9 ± 6.6) and lowest noise (17.1 ± 2.2 HU). Considering reconstructions with a slice thickness of 0.2 mm, image noise, SNR, CNR, vessel sharpness, and blooming artifacts significantly differed across kernels (all P 's < 0.001). With higher kernel sharpness, SNR and CNR continuously decreased, whereas image noise and vessel sharpness increased, with highest sharpness for the Bv89 kernel (2383.4 ± 787.1 ΔHU/mm). Blooming artifacts continuously decreased for reconstructions with the Bv40 (slice thickness, 0.2 mm; 52.8% ± 9.2%) to the Bv72 kernel (39.7% ± 9.1%). Subjective noise was perceived by both readers in agreement with the objective measurements. Considering delineation of coronary artery plaques and the adjacent vessel lumen, reconstructions with the Bv64 and Bv72 kernel (for both, median score of 5) were favored by the readers providing an excellent anatomic delineation of plaque characteristics and vessel lumen. CONCLUSIONS Ultra-high-resolution CCTA with PCD-CT is feasible and enables the visualization of calcified coronaries with an excellent image quality, high sharpness, and reduced blooming. Coronary plaque characterization and delineation of the adjacent vessel lumen are possible with an optimal quality using Bv64 kernel, a FOV of 200 × 200 mm 2 , and a matrix size of 512 × 512 pixels.
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Affiliation(s)
- Victor Mergen
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Thomas Sartoretti
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center
- Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, the Netherlands
| | | | | | | | - Joachim Ernst Wildberger
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center
- Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, the Netherlands
| | - André Euler
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Matthias Eberhard
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Hatem Alkadhi
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
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