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Meloni A, Maffei E, Positano V, Clemente A, De Gori C, Berti S, La Grutta L, Saba L, Bossone E, Mantini C, Cavaliere C, Punzo B, Celi S, Cademartiri F. Technical principles, benefits, challenges, and applications of photon counting computed tomography in coronary imaging: a narrative review. Cardiovasc Diagn Ther 2024; 14:698-724. [PMID: 39263472 PMCID: PMC11384460 DOI: 10.21037/cdt-24-52] [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: 01/29/2024] [Accepted: 06/27/2024] [Indexed: 09/13/2024]
Abstract
Background and Objective The introduction of photon-counting computed tomography (PCCT) represents the most recent groundbreaking advancement in clinical computed tomography (CT). PCCT has the potential to overcome the limitations of traditional CT and to provide new quantitative imaging information. This narrative review aims to summarize the technical principles, benefits, and challenges of PCCT and to provide a concise yet comprehensive summary of the applications of PCCT in the domain of coronary imaging. Methods A review of PubMed, Scopus, and Google Scholar was performed until October 2023 by using relevant keywords. Articles in English were considered. Key Content and Findings The main advantages of PCCT over traditional CT are enhanced spatial resolution, improved signal and contrast characteristics, diminished electronic noise and image artifacts, lower radiation exposure, and multi-energy capability with enhanced material discrimination. These key characteristics have made room for improved assessment of plaque volume and severity of stenosis, more precise assessment of coronary artery calcifications, also preserved in the case of a reduced radiation dose, improved assessment of plaque composition, possibility to provide details regarding the biological processes occurring within the plaque, enhanced quality and accuracy of coronary stent imaging, and improved radiomic analyses. Conclusions PCCT can significantly impact diagnostic and clinical pathways and improve the management of patients with coronary artery diseases (CADs).
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Affiliation(s)
- Antonella Meloni
- Bioengineering Unit, Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy
| | - Erica Maffei
- Department of Radiology, IRCCS SYNLAB SDN, Naples, Italy
| | - Vincenzo Positano
- Bioengineering Unit, Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy
| | - Alberto Clemente
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy
| | - Carmelo De Gori
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy
| | - Sergio Berti
- Diagnostic and Interventional Cardiology Department, Fondazione G. Monasterio CNR-Regione Toscana, Massa, Italy
| | - Ludovico La Grutta
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties - ProMISE, University of Palermo, Palermo, Italy
| | - Luca Saba
- Department of Radiology, University Hospital of Cagliari, Monserrato (CA), Italy
| | - Eduardo Bossone
- Department of Cardiology, Antonio Cardarelli Hospital, Naples, Italy
| | - Cesare Mantini
- Department of Radiology, "G. D'Annunzio" University, Chieti, Italy
| | | | - Bruna Punzo
- Department of Radiology, IRCCS SYNLAB SDN, Naples, Italy
| | - Simona Celi
- Bioengineering Unit, Fondazione G. Monasterio CNR-Regione Toscana, Massa, Italy
| | - Filippo Cademartiri
- Department of Radiology, Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy
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2
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Zook S, Tayal B, Kragholm K, Abdelkarim O, Tran D, Cocker M, Ramirez-Giraldo JC, Hallam K, Sexton C, Johnson S, Chang SM. Intraindividual Comparison of Dose Reduction and Coronary Calcium Scoring Accuracy Using Kilovolt-independent and Tin Filtration CT Protocols. Radiol Cardiothorac Imaging 2024; 6:e230246. [PMID: 38934769 PMCID: PMC11211948 DOI: 10.1148/ryct.230246] [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: 08/14/2023] [Revised: 04/11/2024] [Accepted: 05/30/2024] [Indexed: 06/28/2024]
Abstract
Purpose To investigate the ability of kilovolt-independent (hereafter, kV-independent) and tin filter spectral shaping to accurately quantify the coronary artery calcium score (CACS) and radiation dose reductions compared with the standard 120-kV CT protocol. Materials and Methods This prospective, blinded reader study included 201 participants (mean age, 60 years ± 9.8 [SD]; 119 female, 82 male) who underwent standard 120-kV CT and additional kV-independent and tin filter research CT scans from October 2020 to July 2021. Scans were reconstructed using a Qr36f kernel for standard scans and an Sa36f kernel for research scans simulating artificial 120-kV images. CACS, risk categorization, and radiation doses were compared by analyzing data with analysis of variance, Kruskal-Wallis test, Mann-Whitney test, Bland-Altman analysis, Pearson correlations, and κ analysis for agreement. Results There was no evidence of differences in CACS across standard 120-kV, kV-independent, and tin filter scans, with median CACS values of 1 (IQR, 0-48), 0.6 (IQR, 0-58), and 0 (IQR, 0-51), respectively (P = .85). Compared with standard 120-kV scans, kV-independent and tin filter scans showed excellent correlation in CACS values (r = 0.993 and r = 0.999, respectively), with high agreement in CACS risk categorization (κ = 0.95 and κ = 0.93, respectively). Standard 120-kV scans had a mean radiation dose of 2.09 mSv ± 0.84, while kV-independent and tin filter scans reduced it to 1.21 mSv ± 0.85 and 0.26 mSv ± 0.11, cutting doses by 42% and 87%, respectively (P < .001). Conclusion The kV-independent and tin filter research CT acquisition techniques showed excellent agreement and high accuracy in CACS estimation compared with standard 120-kV scans, with large reductions in radiation dose. Keywords: CT, Cardiac, Coronary Arteries, Radiation Safety, Coronary Artery Calcium Score, Radiation Dose Reduction, Low-Dose CT Scan, Tin Filter, kV-Independent Supplemental material is available for this article. © RSNA, 2024.
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Affiliation(s)
- Salma Zook
- From the Department of Cardiology, Houston Methodist DeBakey Heart
and Vascular Center, Houston Methodist Hospital, 6550 Fannin St, Ste 1801,
Houston, TX 77030 (S.Z., B.T., K.K., O.A., D.T., C.X., S.J., S.M.C.); Department
of Cardiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
(O.A.); and CT R&D Collaborations, Siemens Healthineers, Malvern, Pa
(M.C., J.C.R.G., K.H.)
| | - Bhupendar Tayal
- From the Department of Cardiology, Houston Methodist DeBakey Heart
and Vascular Center, Houston Methodist Hospital, 6550 Fannin St, Ste 1801,
Houston, TX 77030 (S.Z., B.T., K.K., O.A., D.T., C.X., S.J., S.M.C.); Department
of Cardiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
(O.A.); and CT R&D Collaborations, Siemens Healthineers, Malvern, Pa
(M.C., J.C.R.G., K.H.)
| | - Kristian Kragholm
- From the Department of Cardiology, Houston Methodist DeBakey Heart
and Vascular Center, Houston Methodist Hospital, 6550 Fannin St, Ste 1801,
Houston, TX 77030 (S.Z., B.T., K.K., O.A., D.T., C.X., S.J., S.M.C.); Department
of Cardiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
(O.A.); and CT R&D Collaborations, Siemens Healthineers, Malvern, Pa
(M.C., J.C.R.G., K.H.)
| | - Ola Abdelkarim
- From the Department of Cardiology, Houston Methodist DeBakey Heart
and Vascular Center, Houston Methodist Hospital, 6550 Fannin St, Ste 1801,
Houston, TX 77030 (S.Z., B.T., K.K., O.A., D.T., C.X., S.J., S.M.C.); Department
of Cardiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
(O.A.); and CT R&D Collaborations, Siemens Healthineers, Malvern, Pa
(M.C., J.C.R.G., K.H.)
| | - Diana Tran
- From the Department of Cardiology, Houston Methodist DeBakey Heart
and Vascular Center, Houston Methodist Hospital, 6550 Fannin St, Ste 1801,
Houston, TX 77030 (S.Z., B.T., K.K., O.A., D.T., C.X., S.J., S.M.C.); Department
of Cardiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
(O.A.); and CT R&D Collaborations, Siemens Healthineers, Malvern, Pa
(M.C., J.C.R.G., K.H.)
| | - Myra Cocker
- From the Department of Cardiology, Houston Methodist DeBakey Heart
and Vascular Center, Houston Methodist Hospital, 6550 Fannin St, Ste 1801,
Houston, TX 77030 (S.Z., B.T., K.K., O.A., D.T., C.X., S.J., S.M.C.); Department
of Cardiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
(O.A.); and CT R&D Collaborations, Siemens Healthineers, Malvern, Pa
(M.C., J.C.R.G., K.H.)
| | - Juan Carlos Ramirez-Giraldo
- From the Department of Cardiology, Houston Methodist DeBakey Heart
and Vascular Center, Houston Methodist Hospital, 6550 Fannin St, Ste 1801,
Houston, TX 77030 (S.Z., B.T., K.K., O.A., D.T., C.X., S.J., S.M.C.); Department
of Cardiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
(O.A.); and CT R&D Collaborations, Siemens Healthineers, Malvern, Pa
(M.C., J.C.R.G., K.H.)
| | - Kristina Hallam
- From the Department of Cardiology, Houston Methodist DeBakey Heart
and Vascular Center, Houston Methodist Hospital, 6550 Fannin St, Ste 1801,
Houston, TX 77030 (S.Z., B.T., K.K., O.A., D.T., C.X., S.J., S.M.C.); Department
of Cardiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
(O.A.); and CT R&D Collaborations, Siemens Healthineers, Malvern, Pa
(M.C., J.C.R.G., K.H.)
| | - Colleen Sexton
- From the Department of Cardiology, Houston Methodist DeBakey Heart
and Vascular Center, Houston Methodist Hospital, 6550 Fannin St, Ste 1801,
Houston, TX 77030 (S.Z., B.T., K.K., O.A., D.T., C.X., S.J., S.M.C.); Department
of Cardiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
(O.A.); and CT R&D Collaborations, Siemens Healthineers, Malvern, Pa
(M.C., J.C.R.G., K.H.)
| | - Stephanie Johnson
- From the Department of Cardiology, Houston Methodist DeBakey Heart
and Vascular Center, Houston Methodist Hospital, 6550 Fannin St, Ste 1801,
Houston, TX 77030 (S.Z., B.T., K.K., O.A., D.T., C.X., S.J., S.M.C.); Department
of Cardiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
(O.A.); and CT R&D Collaborations, Siemens Healthineers, Malvern, Pa
(M.C., J.C.R.G., K.H.)
| | - Su Min Chang
- From the Department of Cardiology, Houston Methodist DeBakey Heart
and Vascular Center, Houston Methodist Hospital, 6550 Fannin St, Ste 1801,
Houston, TX 77030 (S.Z., B.T., K.K., O.A., D.T., C.X., S.J., S.M.C.); Department
of Cardiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
(O.A.); and CT R&D Collaborations, Siemens Healthineers, Malvern, Pa
(M.C., J.C.R.G., K.H.)
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3
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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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4
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Feldle P, Scheuber M, Grunz JP, Heidenreich JF, Pannenbecker P, Nora C, Huflage H, Bley TA, Petritsch B. Virtual non-iodine photon-counting CT-angiography for aortic valve calcification scoring. Sci Rep 2024; 14:4724. [PMID: 38413684 PMCID: PMC10899655 DOI: 10.1038/s41598-024-54918-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 02/18/2024] [Indexed: 02/29/2024] Open
Abstract
Photon-counting detector (PCD)-CT allows for reconstruction of virtual non-iodine (VNI) images from contrast-enhanced datasets. This study assesses the diagnostic performance of aortic valve calcification scoring (AVCS) derived from VNI datasets generated with a 1st generation clinical dual-source PCD-CT. AVCS was evaluated in 123 patients (statistical analysis only comprising patients with aortic valve calcifications [n = 56; 63.2 ± 11.6 years]), who underwent contrast enhanced electrocardiogram-gated (either prospective or retrospective or both) cardiac CT on a clinical PCD system. Patient data was reconstructed at 70 keV employing a VNI reconstruction algorithm. True non-contrast (TNC) scans at 70 keV without quantum iterative reconstruction served as reference in all individuals. Subgroup analysis was performed in 17 patients who received both, prospectively and retrospectively gated contrast enhanced scans (n = 8 with aortic valve calcifications). VNI images with prospective/retrospective gating had an overall sensitivity of 69.2%/56.0%, specificity of 100%/100%, accuracy of 85.4%/81.0%, positive predictive value of 100%/100%, and a negative predictive value of 78.2%/75.0%. VNI images with retrospective gating achieved similar results. For both gating approaches, AVCSVNI showed high correlation (r = 0.983, P < 0.001 for prospective; r = 0.986, P < 0.001 for retrospective) with AVCSTNC. Subgroup analyses demonstrated excellent intra-individual correlation between different acquisition modes (r = 0.986, P < 0.001). Thus, VNI images derived from cardiac PCD-CT allow for excellent diagnostic performance in the assessment of AVCS, suggesting potential for the omission of true non-contrast scans in the clinical workup of patients with aortic calcifications.
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Affiliation(s)
- Philipp Feldle
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, 97080, Würzburg, Germany.
| | - Marit Scheuber
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, 97080, Würzburg, Germany
| | - Jan-Peter Grunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, 97080, Würzburg, Germany
| | - Julius F Heidenreich
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, 97080, Würzburg, Germany
| | - Pauline Pannenbecker
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, 97080, Würzburg, Germany
| | - Conrads Nora
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, 97080, Würzburg, Germany
| | - Henner Huflage
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, 97080, Würzburg, Germany
| | - Thorsten A Bley
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, 97080, Würzburg, Germany
| | - Bernhard Petritsch
- Department of Diagnostic and Interventional Radiology, Klinikum Klagenfurt am Wörthersee, Feschnigstr. 11, 9020, Klagenfurt am Wörthersee, Austria
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5
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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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6
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Foldyna B, Basmagi S, Zangeneh FA, Wagner M, Doktorov K, Matveeva A, Denecke T, Gohmann RF, Lücke C, Gutberlet M, Lehmkuhl L. CT-derived coronary artery calcium density is affected by regional lesion distribution and image reconstruction parameters. Clin Imaging 2023; 103:109980. [PMID: 37677856 DOI: 10.1016/j.clinimag.2023.109980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/17/2023] [Accepted: 08/28/2023] [Indexed: 09/09/2023]
Abstract
PURPOSE The prognostic relevance of coronary artery calcium (CAC) density, assessed from cardiac CT scans, is established. However, the influence of CAC distribution, volume, image reconstruction, and clinical factors on CAC density warrants further examination. METHODS In this study, 120 patients underwent non-contrast ECG-gated cardiac CT scans using a prospectively defined CAC scoring protocol with 1-, 3-, and 5-mm thick image reconstructions, both with and without a 20% image overlap. We segmented CAC in all reconstructions and assessed the relationship between CAC density, volume, and number of detected calcifications/patient. RESULTS Overall, 75/120 (63%) patients (66% men, mean age 63 ± 11 years) presented CAC across 342 segments. CAC density, CAC volume, and the number of detected calcifications decreased with increasing slice thickness (p < 0.001 for all); these effects were slightly reduced by image overlap (p < 0.001 for all). Higher CAC density correlated with greater CAC volume (ρ = 0.62; p < 0.001) and more calcified segments per person (ρ = 0.32; p = 0.006). Higher CAC density was also associated with lower patient weight (beta: -0.6, 95%CI: -1.1--0.1, p = 0.022) and increased high-density lipoprotein (HDL) levels (beta: 0.7, 95%CI: 0.0-1.4, p = 0.046). In a multivariable analysis adjusted for clinical covariates, lower CAC density was associated with broader CAC distribution (i.e., a higher number of calcified segments at a given CAC volume; beta-coefficient: -58.9; 95%CI: -84.7 to -33.1; p < 0.001). CONCLUSION CAC density is significantly impacted by regional CAC distribution and image reconstruction, potentially confounding its prognostic value. Accounting for these factors may improve patient risk assessment, management, and cardiovascular health outcomes.
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Affiliation(s)
- Borek Foldyna
- Cardiovascular Imaging Research Center, Massachusetts General Hospital - Harvard Medical School, 165 Cambridge Street, Suite 400, 02114 Boston, USA; Clinic for Radiology, Heart Center Bad Neustadt a.d. Saale, Bad Neustadt a.d. Saale, Germany.
| | - Said Basmagi
- Clinic for Radiology, Heart Center Bad Neustadt a.d. Saale, Bad Neustadt a.d. Saale, Germany
| | | | - Matthias Wagner
- Clinic for Radiology, Heart Center Bad Neustadt a.d. Saale, Bad Neustadt a.d. Saale, Germany
| | - Kalin Doktorov
- Clinic for Radiology, Heart Center Bad Neustadt a.d. Saale, Bad Neustadt a.d. Saale, Germany
| | - Anna Matveeva
- Clinic for Radiology, Heart Center Bad Neustadt a.d. Saale, Bad Neustadt a.d. Saale, Germany
| | - Timm Denecke
- Clinic for Diagnostic and Interventional Radiology, University of Leipzig, Leipzig, Germany
| | - Robin F Gohmann
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig at University of Leipzig, Leipzig, Germany
| | - Christian Lücke
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig at University of Leipzig, Leipzig, Germany
| | - Matthias Gutberlet
- Department of Diagnostic and Interventional Radiology, Heart Center Leipzig at University of Leipzig, Leipzig, Germany
| | - Lukas Lehmkuhl
- Clinic for Radiology, Heart Center Bad Neustadt a.d. Saale, Bad Neustadt a.d. Saale, Germany
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7
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Douek PC, Boccalini S, Oei EHG, Cormode DP, Pourmorteza A, Boussel L, Si-Mohamed SA, Budde RPJ. Clinical Applications of Photon-counting CT: A Review of Pioneer Studies and a Glimpse into the Future. Radiology 2023; 309:e222432. [PMID: 37787672 PMCID: PMC10623209 DOI: 10.1148/radiol.222432] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 03/24/2023] [Accepted: 04/11/2023] [Indexed: 10/04/2023]
Abstract
CT systems equipped with photon-counting detectors (PCDs), referred to as photon-counting CT (PCCT), are beginning to change imaging in several subspecialties, such as cardiac, vascular, thoracic, and musculoskeletal radiology. Evidence has been building in the literature underpinning the many advantages of PCCT for different clinical applications. These benefits derive from the distinct features of PCDs, which are made of semiconductor materials capable of converting photons directly into electric signal. PCCT advancements include, among the most important, improved spatial resolution, noise reduction, and spectral properties. PCCT spatial resolution on the order of 0.25 mm allows for the improved visualization of small structures (eg, small vessels, arterial walls, distal bronchi, and bone trabeculations) and their pathologies, as well as the identification of previously undetectable anomalies. In addition, blooming artifacts from calcifications, stents, and other dense structures are reduced. The benefits of the spectral capabilities of PCCT are broad and include reducing radiation and contrast material dose for patients. In addition, multiple types of information can be extracted from a single data set (ie, multiparametric imaging), including quantitative data often regarded as surrogates of functional information (eg, lung perfusion). PCCT also allows for a novel type of CT imaging, K-edge imaging. This technique, combined with new contrast materials specifically designed for this modality, opens the door to new applications for imaging in the future.
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Affiliation(s)
| | | | - Edwin H. G. Oei
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - David P. Cormode
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - Amir Pourmorteza
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - Loic Boussel
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - Salim A. Si-Mohamed
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
| | - Ricardo P. J. Budde
- From the University of Lyon, INSA-Lyon, Claude Bernard Lyon 1
University, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, France (P.C.D., L.B.,
S.A.S.M.); Department of Cardiovascular and Thoracic Radiology, Louis Pradel
Hospital, Hospices Civils de Lyon, 59 Boulevard Pinel, 69500 Bron, France
(P.C.D., S.B., L.B., S.A.S.M.); Claude Bernard Lyon 1 University, Villeurbanne,
France (S.B.); Department of Radiology and Nuclear Medicine, Erasmus Medical
Center, Rotterdam, the Netherlands (E.H.G.O., R.P.J.B.); Department of
Radiology, University of Pennsylvania, Philadelphia, Pa (D.P.C.); Department of
Radiology and Imaging Sciences, Emory University, Atlanta, Ga (A.P.); Department
of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga (A.P.);
and Winship Cancer Institute, Atlanta, Ga (A.P.)
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8
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Fink N, Zsarnoczay E, Schoepf UJ, O'Doherty J, Halfmann MC, Allmendinger T, Hagenauer J, Griffith JP, Vecsey-Nagy M, Pinos D, Ebersberger U, Ricke J, Varga-Szemes A, Emrich T. Impact of Cardiac Motion on coronary artery calcium scoring using a virtual non-iodine algorithm on photon-counting detector CT: a dynamic phantom study. THE INTERNATIONAL JOURNAL OF CARDIOVASCULAR IMAGING 2023; 39:2083-2092. [PMID: 37452987 DOI: 10.1007/s10554-023-02912-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/27/2023] [Indexed: 07/18/2023]
Abstract
This study assessed the impact of cardiac motion and in-vessel attenuation on coronary artery calcium (CAC) scoring using virtual non-iodine (VNI) against virtual non-contrast (VNC) reconstructions on photon-counting detector CT. Two artificial vessels containing calcifications and different in-vessel attenuations (500, 800HU) were scanned without (static) and with cardiac motion (60, 80, 100 beats per minute [bpm]). Images were post-processed using a VNC and VNI algorithm at 70 keV and quantum iterative reconstruction (QIR) strength 2. Calcium mass, Agatston scores, cardiac motion susceptibility (CMS)-indices were compared to physical mass, static scores as well as between reconstructions, heart rates and in-vessel attenuations. VNI scores decreased with rising heart rate (p < 0.01) and showed less underestimation than VNC scores (p < 0.001). Only VNI scores were similar to the physical mass at static measurements, and to static scores at 60 bpm. Agatston scores using VNI were similar to static scores at 60 and 80 bpm. Standard deviation of CMS-indices was lower for VNI-based than for VNC-based CAC scoring. VNI scores were higher at 500 than 800HU (p < 0.001) and higher than VNC scores (p < 0.001) with VNI scores at 500 HU showing the lowest deviation from the physical reference. VNI-based CAC quantification is influenced by cardiac motion and in-vessel attenuation, but least when measuring Agatston scores, where it outperforms VNC-based CAC scoring.
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Affiliation(s)
- Nicola Fink
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Emese Zsarnoczay
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA
- Medical Imaging Center, Semmelweis University, Korányi Sándor utca 2, Budapest, 1083, Hungary
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA.
| | - Jim O'Doherty
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA
- Siemens Medical Solutions, Malvern, PA, 19355, USA
| | - Moritz C Halfmann
- Department of Diagnostic and Interventional Radiology, University Medical Center of Johannes Gutenberg- University, Langenbeckstr. 1, Mainz, 55131, Germany
| | | | - Junia Hagenauer
- Siemens Healthcare GmbH, Siemensstr. 1, Forchheim, 91301, Germany
- Faculty of Medicine, Friedrich Alexander University of Erlangen-Nuremberg, Krankenhausstr. 12, Erlangen, 91054, 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, USA
| | - Milán Vecsey-Nagy
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA
- MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, Varosmajor utca 68, Budapest, 1122, Hungary
| | - Daniel Pinos
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA
| | - Ullrich Ebersberger
- Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Munich, 80636, Germany
| | - Jens Ricke
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA
| | - Tilman Emrich
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC, 29425, USA
- Department of Diagnostic and Interventional Radiology, University Medical Center of Johannes Gutenberg- University, Langenbeckstr. 1, Mainz, 55131, Germany
- German Centre for Cardiovascular Research, Mainz, 55131, Germany
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9
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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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10
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Marsh JF, VanMeter PD, Rajendran K, Leng S, McCollough CH. Ex vivo coronary calcium volume quantification using a high-spatial-resolution clinical photon-counting-detector computed tomography. J Med Imaging (Bellingham) 2023; 10:043501. [PMID: 37408984 PMCID: PMC10319293 DOI: 10.1117/1.jmi.10.4.043501] [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: 09/21/2022] [Revised: 04/17/2023] [Accepted: 06/20/2023] [Indexed: 07/07/2023] Open
Abstract
Purpose Coronary artery calcification (CAC) is an important indicator of coronary disease. Accurate volume quantification of CAC is challenging using computed tomography (CT) due to calcium blooming, which is a consequence of limited spatial resolution. Ex vivo coronary specimens were scanned on an ultra-high-resolution (UHR) clinical photon-counting detector (PCD) CT scanner, and the accuracy of CAC volume estimation was compared with a state-of-the-art conventional energy-integrating detector (EID) CT, a previous-generation investigational PCD-CT, and micro-CT. Approach CAC specimens (n = 13 ) were scanned on EID-CT and PCD-CT using matched parameters (120 kV, 9.3 mGy CTDI vol ). EID-CT images were reconstructed using our institutional routine clinical protocol for CAC quantification. UHR PCD-CT data were reconstructed using a sharper kernel. An image-based denoising algorithm was applied to the PCD-CT images to achieve similar noise levels as EID-CT. Micro-CT images served as the volume reference standard. Calcification images were segmented, and their volume estimates were compared. The CT data were further compared with previous work using an investigational PCD-CT. Results Compared with micro-CT, CT volume estimates had a mean absolute percent error of 24.1 % ± 25.6 % for clinical PCD-CT, 60.1 % ± 48.2 % for EID-CT, and 51.1 % ± 41.7 % for previous-generation PCD-CT. Clinical PCD-CT absolute percent error was significantly (p < 0.01 ) lower than both EID-CT and previous generation PCD-CT. The mean calcification CT number and contrast-to-noise ratio were both significantly (p < 0.01 ) higher in clinical PCD-CT relative to EID-CT. Conclusions UHR clinical PCD-CT showed reduced calcium blooming artifacts and further enabled improved accuracy of CAC quantification beyond that of conventional EID-CT and previous generation PCD-CT systems.
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Affiliation(s)
- Jeffrey F. Marsh
- Mayo Clinic, Department of Radiology, Rochester, Minnesota, United States
| | | | - Kishore Rajendran
- Mayo Clinic, Department of Radiology, Rochester, Minnesota, United States
| | - Shuai Leng
- Mayo Clinic, Department of Radiology, Rochester, Minnesota, United States
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11
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Dobrolinska MM, van der Werf NR, van der Bie J, de Groen J, Dijkshoorn M, Booij R, Budde RPJ, Greuter MJW, van Straten M. Radiation dose optimization for photon-counting CT coronary artery calcium scoring for different patient sizes: a dynamic phantom study. Eur Radiol 2023; 33:4668-4675. [PMID: 36729174 PMCID: PMC10290002 DOI: 10.1007/s00330-023-09434-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 10/19/2022] [Accepted: 01/07/2023] [Indexed: 02/03/2023]
Abstract
PURPOSE To systematically assess the radiation dose reduction potential of coronary artery calcium (CAC) assessments with photon-counting computed tomography (PCCT) by changing the tube potential for different patient sizes with a dynamic phantom. METHODS A hollow artery, containing three calcifications of different densities, was translated at velocities corresponding to 0, < 60, 60-75, and > 75 beats per minute within an anthropomorphic phantom. Extension rings were used to simulate average- and large -sized patients. PCCT scans were made with the reference clinical protocol (tube potential of 120 kilovolt (kV)), and with 70, 90, Sn100, Sn140, and 140 kV at identical image quality levels. All acquisitions were reconstructed at a virtual monoenergetic energy level of 70 keV. For each calcification, Agatston scores and contrast-to-noise ratios (CNR) were determined, and compared to the reference with Wilcoxon signed-rank tests, with p < 0.05 indicating significant differences. RESULTS A decrease in radiation dose (22%) was achieved at Sn100 kV for the average-sized phantom. For the large phantom, Sn100 and Sn140 kV resulted in a decrease in radiation doses of 19% and 3%, respectively. Irrespective of CAC density, Sn100 and 140 kVp did not result in significantly different CNR. Only at Sn100 kV were there no significant differences in Agatston scores for all CAC densities, heart rates, and phantom sizes. CONCLUSION PCCT at tube voltage of 100 kV with added tin filtration and reconstructed at 70 keV enables a ≥ 19% dose reduction compared to 120 kV, independent of phantom size, CAC density, and heart rate. KEY POINTS • Photon-counting CT allows for reduced radiation dose acquisitions (up to 19%) for coronary calcium assessment by reducing tube voltage while reconstructing at a normal monoE level of 70 keV. • Tube voltage reduction is possible for medium and large patient sizes, without affecting the Agatston score outcome.
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Affiliation(s)
- Magdalena M Dobrolinska
- Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Division of Cardiology and Structural Heart Diseases, Medical University of Silesiain , Katowice, Katowice, Poland
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Niels R van der Werf
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Judith van der Bie
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Joël de Groen
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marcel Dijkshoorn
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ronald Booij
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ricardo P J Budde
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marcel J W Greuter
- Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Department of Robotics and Mechatronics, University of Twente, Enschede, The Netherlands
| | - Marcel van Straten
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
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12
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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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13
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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: 14] [Impact Index Per Article: 14.0] [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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14
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Fink N, Zsarnoczay E, Schoepf UJ, O'Doherty J, Griffith JP, Pinos D, Tesche C, Ricke J, Willemink MJ, Varga-Szemes A, Emrich T. Radiation Dose Reduction for Coronary Artery Calcium Scoring Using a Virtual Noniodine Algorithm on Photon-Counting Detector Computed-Tomography Phantom Data. Diagnostics (Basel) 2023; 13:diagnostics13091540. [PMID: 37174932 PMCID: PMC10177425 DOI: 10.3390/diagnostics13091540] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/14/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
Background: On the basis of the hypothesis that virtual noniodine (VNI)-based coronary artery calcium scoring (CACS) is feasible at reduced radiation doses, this study assesses the impact of radiation dose reduction on the accuracy of this VNI algorithm on a photon-counting detector (PCD)-CT. Methods: In a systematic in vitro setting, a phantom for CACS simulating three chest sizes was scanned on a clinical PCD-CT. The standard radiation dose was chosen at volumetric CT dose indices (CTDIVol) of 1.5, 3.3, 7.0 mGy for small, medium-sized, and large phantoms, and was gradually reduced by adjusting the tube current resulting in 100, 75, 50, and 25%, respectively. VNI images were reconstructed at 55 keV, quantum iterative reconstruction (QIR)1, and at 60 keV/QIR4, and evaluated regarding image quality (image noise (IN), contrast-to-noise ratio (CNR)), and CACS. All VNI results were compared to true noncontrast (TNC)-based CACS at 70 keV and standard radiation dose (reference). Results: INTNC was significantly higher than INVNI, and INVNI at 55 keV/QIR1 higher than at 60 keV/QIR4 (100% dose: 16.7 ± 1.9 vs. 12.8 ± 1.7 vs. 7.7 ± 0.9; p < 0.001 for every radiation dose). CNRTNC was higher than CNRVNI, but it was better to use 60 keV/QIR4 (p < 0.001). CACSVNI showed strong correlation and agreement at every radiation dose (p < 0.001, r > 0.9, intraclass correlation coefficient > 0.9). The coefficients of the variation in root-mean squared error were less than 10% and thus clinically nonrelevant for the CACSVNI of every radiation dose. Conclusion: This phantom study suggests that CACSVNI is feasible on PCD-CT, even at reduced radiation dose while maintaining image quality and CACS accuracy.
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Affiliation(s)
- Nicola Fink
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Emese Zsarnoczay
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
- Medical Imaging Center, Semmelweis University, Korányi Sándor utca 2, 1083 Budapest, Hungary
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
| | - Jim O'Doherty
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
- Siemens Medical Solutions, 40 Liberty Boulevard, Malvern, PA 19355, USA
| | - Joseph P Griffith
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
| | - Daniel Pinos
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
| | - Christian Tesche
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
- Department of Cardiology, Munich University Clinic, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany
| | - Jens Ricke
- Department of Radiology, University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany
| | - Martin J Willemink
- Department of Radiology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, USA
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
| | - Tilman Emrich
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, SC 29425, USA
- Department of Diagnostic and Interventional Radiology, University Medical Center of Johannes-Gutenberg-University, Langenbeckstr. 1, 55131 Mainz, Germany
- German Centre for Cardiovascular Research, Partner Site Rhine-Main, 55131 Mainz, Germany
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15
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Photon Counting Detector CT-Based Virtual Noniodine Reconstruction Algorithm for In Vitro and In Vivo Coronary Artery Calcium Scoring: Impact of Virtual Monoenergetic and Quantum Iterative Reconstructions. Invest Radiol 2023:00004424-990000000-00091. [PMID: 36822677 DOI: 10.1097/rli.0000000000000959] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
OBJECTIVES The aim of this study was to evaluate the impact of virtual monoenergetic imaging (VMI) and quantum iterative reconstruction (QIR) on the accuracy of coronary artery calcium scoring (CACS) using a virtual noniodine (VNI) reconstruction algorithm on a first-generation, clinical, photon counting detector computed tomography system. MATERIALS AND METHODS Coronary artery calcium scoring was evaluated in an anthropomorphic chest phantom simulating 3 different patient sizes by using 2 extension rings (small: 300 × 200 mm, medium: 350 × 250 mm, large: 400 × 300 mm) and in patients (n = 61; final analyses only in patients with coronary calcifications [n = 34; 65.4 ± 10.0 years; 73.5% male]), who underwent nonenhanced and contrast-enhanced, electrocardiogram-gated, cardiac computed tomography on a photon counting detector system. Phantom and patient data were reconstructed using a VNI reconstruction algorithm at different VMI (55-80 keV) and QIR (strength 1-4) levels (CACSVNI). True noncontrast (TNC) scans at 70 keV and QIR "off" were used as reference for phantom and patient studies (CACSTNC). RESULTS In vitro and in vivo CACSVNI showed strong correlation (r > 0.9, P < 0.001 for all) and excellent agreement (intraclass correlation coefficient > 0.9 for all) with CACSTNC at all investigated VMI and QIR levels. Phantom and patient CACSVNI significantly increased with decreasing keV levels (in vitro: from 475.2 ± 26.3 at 80 keV up to 652.5 ± 42.2 at 55 keV; in vivo: from 142.5 [7.4/737.7] at 80 keV up to 248.1 [31.2/1144] at 55 keV; P < 0.001 for all), resulting in an overestimation of CACSVNI at 55 keV compared with CACSTNC at 70 keV in some cases (in vitro: 625.8 ± 24.4; in vivo: 225.4 [35.1/959.7]). In vitro CACS increased with rising QIR at low keV. In vivo scores were significantly higher at QIR 1 compared with QIR 4 only at 60 and 80 keV (60 keV: 220.3 [29.6-1060] vs 219.5 [23.7/1048]; 80 keV: 152.0 [12.0/735.6] vs 142.5 [7.4/737.7]; P < 0.001). CACSVNI was closest to CACSTNC at 60 keV, QIR 2 (+0.1%) in the small; 55 keV, QIR 1 (±0%) in the medium; 55 keV, QIR 4 (-0.1%) in the large phantom; and at 60 keV, QIR 1 (-2.3%) in patients. CONCLUSIONS Virtual monoenergetic imaging reconstructions have a significant impact on CACSVNI. The effects of different QIR levels are less consistent and seem to depend on several individual conditions, which should be further investigated.
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16
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Meyer S, Liu LP, Litt HI, Halliburton SS, Shapira N, Noël PB. Phantom-based quantification of the spectral accuracy in dual-layer spectral CT for pediatric imaging at 100 kVp. Quant Imaging Med Surg 2023; 13:924-934. [PMID: 36819257 PMCID: PMC9929380 DOI: 10.21037/qims-22-552] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 11/07/2022] [Indexed: 01/05/2023]
Abstract
Background To determine the spectral accuracy in detector-based dual-energy CT (DECT) at 100 kVp and wide (8 cm) collimation width for dose levels and object sizes relevant to pediatric imaging. Methods A spectral CT phantom containing tissue-equivalent materials and iodine inserts of varying concentrations was scanned on the latest generation detector-based DECT system. Two 3D-printed extension rings were used to mimic varying pediatric patient sizes. Scans were performed at 100 and 120 kVp, 4 and 8 cm collimation widths, and progressively reduced radiation dose levels, down to 0.9 mGy CTDIvol. Virtual mono-energetic, iodine density, effective atomic number, and electron density results were quantified and compared to their expected values for all acquisition settings and phantom sizes. Results DECT scans at 100 kVp provided highly accurate spectral results; however, a size dependence was observed for iodine quantification. For the medium phantom configuration (15 cm diameter), measurement errors in iodine density, effective atomic number, and electron density (ED) were below 0.3 mg/mL, 0.2 and 1.8 %EDwater, respectively. The average accuracy was slightly different from scans at 120 kVp; however, not statistically significant for all configurations. Collimation width had no substantial impact. Spectral results were accurate and reliable for radiation exposures down to 0.9 mGy CTDIvol. Conclusions Detector-based DECT at 100 kVp can provide on-demand or retrospective spectral information with high accuracy even at extremely low doses, thereby making it an attractive solution for pediatric imaging.
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Affiliation(s)
- Sebastian Meyer
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Leening P. Liu
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Harold I. Litt
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Nadav Shapira
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Peter B. Noël
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA;,Department of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, München, Germany
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17
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Wolf EV, Halfmann MC, Schoepf UJ, Zsarnoczay E, Fink N, Griffith JP, Aquino GJ, Willemink MJ, O’Doherty J, Hell MM, Suranyi P, Kabakus IM, Baruah D, Varga-Szemes A, Emrich T. Intra-individual comparison of coronary calcium scoring between photon counting detector- and energy integrating detector-CT: Effects on risk reclassification. Front Cardiovasc Med 2023; 9:1053398. [PMID: 36741832 PMCID: PMC9892711 DOI: 10.3389/fcvm.2022.1053398] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 12/28/2022] [Indexed: 01/20/2023] Open
Abstract
Purpose To compare coronary artery calcium volume and score (CACS) between photon-counting detector (PCD) and conventional energy integrating detector (EID) computed tomography (CT) in a phantom and prospective patient study. Methods A commercially available CACS phantom was scanned with a standard CACS protocol (120 kVp, slice thickness/increment 3/1.5 mm, and a quantitative Qr36 kernel), with filtered back projection on the EID-CT, and with monoenergetic reconstruction at 70 keV and quantum iterative reconstruction off on the PCD-CT. The same settings were used to prospectively acquire data in patients (n = 23, 65 ± 12.1 years), who underwent PCD- and EID-CT scans with a median of 5.5 (3.0-12.5) days between the two scans in the period from August 2021 to March 2022. CACS was quantified using a commercially available software solution. A regression formula was obtained from the aforementioned comparison and applied to simulate risk reclassification in a pre-existing cohort of 514 patients who underwent a cardiac EID-CT between January and December 2021. Results Based on the phantom experiment, CACS PCD-CT showed a more accurate measurement of the reference CAC volumes (overestimation of physical volumes: PCD-CT 66.1 ± 1.6% vs. EID-CT: 77.2 ± 0.5%). CACS EID-CT and CACS PCD-CT were strongly correlated, however, the latter measured significantly lower values in the phantom (CACS PCD-CT : 60.5 (30.2-170.3) vs CACS EID-CT 74.7 (34.6-180.8), p = 0.0015, r = 0.99, mean bias -9.7, Limits of Agreement (LoA) -36.6/17.3) and in patients (non-significant) (CACS PCD-CT : 174.3 (11.1-872.7) vs CACS EID-CT 218.2 (18.5-876.4), p = 0.10, r = 0.94, mean bias -41.1, LoA -315.3/232.5). The systematic lower measurements of Agatston score on PCD-CT system led to reclassification of 5.25% of our simulated patient cohort to a lower classification class. Conclusion CACS PCD-CT is feasible and correlates strongly with CACS EID-CT , however, leads to lower CACS values. PCD-CT may provide results that are more accurate for CACS than EID-CT.
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Affiliation(s)
- Elias V. Wolf
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany,Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Moritz C. Halfmann
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany,German Centre for Cardiovascular Research, Partner Site Rhine-Main, Mainz, Germany
| | - U. Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Emese Zsarnoczay
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States,MTA-SE Cardiovascular Imaging Research Group, Medical Imaging Center, Semmelweis University, Budapest, Hungary
| | - Nicola Fink
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States,Department of Radiology, University Hospital Munich, LMU Munich, Munich, Germany
| | - Joseph P. Griffith
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Gilberto J. Aquino
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Martin J. Willemink
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, United States,Segmed, Inc., Palo Alto, CA, United States
| | - Jim O’Doherty
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States,Siemens Medical Solutions USA, Inc., Malvern, PA, United States
| | - Michaela M. Hell
- Department of Cardiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Pal Suranyi
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Ismael M. Kabakus
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Dhiraj Baruah
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States
| | - Tilman Emrich
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany,Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States,German Centre for Cardiovascular Research, Partner Site Rhine-Main, Mainz, Germany,*Correspondence: Tilman Emrich,
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18
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First-generation clinical dual-source photon-counting CT: ultra-low-dose quantitative spectral imaging. Eur Radiol 2022; 32:8579-8587. [PMID: 35708838 PMCID: PMC10071880 DOI: 10.1007/s00330-022-08933-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 04/16/2022] [Accepted: 05/30/2022] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Evaluation of image characteristics at ultra-low radiation dose levels of a first-generation dual-source photon-counting computed tomography (PCCT) compared to a dual-source dual-energy CT (DECT) scanner. METHODS A multi-energy CT phantom was imaged with and without an extension ring on both scanners over a range of radiation dose levels (CTDIvol 0.4-15.0 mGy). Scans were performed in different modes of acquisition for PCCT with 120 kVp and DECT with 70/Sn150 kVp and 100/Sn150 kVp. Various tissue inserts were used to characterize the precision and repeatability of Hounsfield units (HUs) on virtual mono-energetic images between 40 and 190 keV. Image noise was additionally investigated at an ultra-low radiation dose to illustrate PCCT's ability to remove electronic background noise. RESULTS Our results demonstrate the high precision of HU measurements for a wide range of inserts and radiation exposure levels with PCCT. We report high performance for both scanners across a wide range of radiation exposure levels, with PCCT outperforming at low exposures compared to DECT. PCCT scans at the lowest radiation exposures illustrate significant reduction in electronic background noise, with a mean percent reduction of 74% (p value ~ 10-8) compared to DECT 70/Sn150 kVp and 60% (p value ~ 10-6) compared to DECT 100/Sn150 kVp. CONCLUSIONS This paper reports the first experiences with a clinical dual-source PCCT. PCCT provides reliable HUs without disruption from electronic background noise for a wide range of dose values. Diagnostic benefits are not only for quantification at an ultra-low dose but also for imaging of obese patients. KEY POINTS PCCT scanners provide precise and reliable Hounsfield units at ultra-low dose levels. The influence of electronic background noise can be removed at ultra-low-dose acquisitions with PCCT. Both spectral platforms have high performance along a wide range of radiation exposure levels, with PCCT outperforming at low radiation exposures.
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19
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Tin-filtered 100 kV Ultra-low-dose Abdominal CT for Calculi Detection in the Urinary Tract: A Comparative Study of 510 Cases. Acad Radiol 2022; 30:1033-1038. [PMID: 35963837 DOI: 10.1016/j.acra.2022.07.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/14/2022] [Accepted: 07/14/2022] [Indexed: 11/23/2022]
Abstract
OBJECTIVES For detection of urinary calculi, unenhanced low-dose computed tomography is the method of choice, outperforming radiography and ultrasound. This retrospective monocentric study aims to compare a clinically established, dedicated low-dose imaging protocol for detection of urinary calculi with an ultra-low-dose protocol employing tin prefiltration at a standardized tube voltage of 100 kVp. METHODS Two study arms included a total of 510 cases. The "low-dose group" was comprised of 290 individuals (96 women; age 49 ± 16 years; BMI 27.23 ± 5.60 kg/m2). The "ultra-low-dose group" with Sn100 kVp consisted of 220 patients (84 women; age 47 ± 17 years; BMI 26.82 ± 5.62 kg/m2). No significant difference was ascertained for comparison of age (p = 0.132) and BMI (p = 0.207) between cohorts. For quantitative assessment of image quality, image noise was assessed. RESULTS No significant difference regarding frequency of calculi detection was found between groups (p = 0.596). Compared to the low-dose protocol (3.08 mSv; IQR 2.22-4.02 mSv), effective dose was reduced by 62.35% with the ultra-low-dose protocol employing spectral shaping (1.16 mSv; IQR 0.89-1.54 mSv). Image noise was calculated at 18.90 (IQR 17.39-21.20) for the low-dose protocol and at 18.69 (IQR 17.30-21.62) for the ultra-low-dose spectral shaping protocol. No significant difference was ascertained for comparison between groups (p = 0.793). CONCLUSION For urinary calculi detection, ultra-low-dose scans utilizing spectral shaping by means of tin prefiltration at 100 kVp allow for considerable dose reduction of up to 62% over conventional low-dose CT without compromising image quality.
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20
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van der Werf NR, Booij R, Greuter MJW, Bos D, van der Lugt A, Budde RPJ, van Straten M. Reproducibility of coronary artery calcium quantification on dual-source CT and dual-source photon-counting CT: a dynamic phantom study. Int J Cardiovasc Imaging 2022; 38:1613-1619. [PMID: 35113282 PMCID: PMC11142942 DOI: 10.1007/s10554-022-02540-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 01/24/2022] [Indexed: 12/19/2022]
Abstract
To systematically compare coronary artery calcium (CAC) quantification between conventional computed tomography (CT) and photon-counting CT (PCCT) at different virtual monoenergetic (monoE) levels for different heart rates. A dynamic (heart rates of 0, < 60, 60-75, and > 75 bpm) anthropomorphic phantom with three calcification densities was scanned using routine clinical CAC protocols with CT and PCCT. In addition to the standard clinical protocol of 70 keV, PCCT images were reconstructed at monoE levels of 72, 74, and 76 keV. CAC was quantified using Agatston, volume, and mass scores. Agatston scores 95% confidence intervals (CI) were calculated and compared between PCCT and CT. Volume and mass scores were compared with physical quantities. For all CAC densities, routine clinical protocol Agatston scores of static CAC were higher for PCCT compared to CT. At < 60 bpm, Agatston scores at 74 and 76 keV reconstructions were reproducible (overlapping CI) for PCCT and CT. Increased heart rates yielded different Agatston scores for PCCT in comparison with CT, for all monoE levels. Low density CAC volume scores showed the largest deviation from physical volume, with mean deviations of 59% and 77% for CT and PCCT, respectively. Overall, mass scores underestimated physical mass by 10%, 38%, and 59% for low, medium, and high density CAC, respectively. PCCT allows for reproducible Agatston scores for dynamic CAC (< 60 bpm) when reconstructed at monoE levels of 74 or 76 keV, regardless of CAC density. Deviations from physical volume and mass were, in general, large for both CT and PCCT.
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Affiliation(s)
- Niels R van der Werf
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Ronald Booij
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marcel J W Greuter
- Department of Radiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Robotics and Mechatronics, University of Twente, Enschede, The Netherlands
| | - Daniel Bos
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - A van der Lugt
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - R P J Budde
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marcel van Straten
- Department of Radiology & Nuclear Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
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21
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Sartoretti T, Racine D, Mergen V, Jungblut L, Monnin P, Flohr TG, Martini K, Frauenfelder T, Alkadhi H, Euler A. Quantum Iterative Reconstruction for Low-Dose Ultra-High-Resolution Photon-Counting Detector CT of the Lung. Diagnostics (Basel) 2022; 12:522. [PMID: 35204611 PMCID: PMC8871296 DOI: 10.3390/diagnostics12020522] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/10/2022] [Accepted: 02/14/2022] [Indexed: 02/06/2023] Open
Abstract
The aim of this study was to characterize image quality and to determine the optimal strength levels of a novel iterative reconstruction algorithm (quantum iterative reconstruction, QIR) for low-dose, ultra-high-resolution (UHR) photon-counting detector CT (PCD-CT) of the lung. Images were acquired on a clinical dual-source PCD-CT in the UHR mode and reconstructed with a sharp lung reconstruction kernel at different strength levels of QIR (QIR-1 to QIR-4) and without QIR (QIR-off). Noise power spectrum (NPS) and target transfer function (TTF) were analyzed in a cylindrical phantom. 52 consecutive patients referred for low-dose UHR chest PCD-CT were included (CTDIvol: 1 ± 0.6 mGy). Quantitative image quality analysis was performed computationally which included the calculation of the global noise index (GNI) and the global signal-to-noise ratio index (GSNRI). The mean attenuation of the lung parenchyma was measured. Two readers graded images qualitatively in terms of overall image quality, image sharpness, and subjective image noise using 5-point Likert scales. In the phantom, an increase in the QIR level slightly decreased spatial resolution and considerably decreased noise amplitude without affecting the frequency content. In patients, GNI decreased from QIR-off (202 ± 34 HU) to QIR-4 (106 ± 18 HU) (p < 0.001) by 48%. GSNRI increased from QIR-off (4.4 ± 0.8) to QIR-4 (8.2 ± 1.6) (p < 0.001) by 87%. Attenuation of lung parenchyma was highly comparable among reconstructions (QIR-off: -849 ± 53 HU to QIR-4: -853 ± 52 HU, p < 0.001). Subjective noise was best in QIR-4 (p < 0.001), while QIR-3 was best for sharpness and overall image quality (p < 0.001). Thus, our phantom and patient study indicates that QIR-3 provides the optimal iterative reconstruction level for low-dose, UHR PCD-CT of the lungs.
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Affiliation(s)
- Thomas Sartoretti
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, CH-8091 Zurich, Switzerland; (T.S.); (V.M.); (L.J.); (K.M.); (T.F.); (H.A.)
| | - Damien Racine
- Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV), University of Lausanne (UNIL), CH-1010 Lausanne, Switzerland; (D.R.); (P.M.)
| | - Victor Mergen
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, CH-8091 Zurich, Switzerland; (T.S.); (V.M.); (L.J.); (K.M.); (T.F.); (H.A.)
| | - Lisa Jungblut
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, CH-8091 Zurich, Switzerland; (T.S.); (V.M.); (L.J.); (K.M.); (T.F.); (H.A.)
| | - Pascal Monnin
- Institute of Radiation Physics (IRA), Lausanne University Hospital (CHUV), University of Lausanne (UNIL), CH-1010 Lausanne, Switzerland; (D.R.); (P.M.)
| | | | - Katharina Martini
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, CH-8091 Zurich, Switzerland; (T.S.); (V.M.); (L.J.); (K.M.); (T.F.); (H.A.)
| | - Thomas Frauenfelder
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, CH-8091 Zurich, Switzerland; (T.S.); (V.M.); (L.J.); (K.M.); (T.F.); (H.A.)
| | - Hatem Alkadhi
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, CH-8091 Zurich, Switzerland; (T.S.); (V.M.); (L.J.); (K.M.); (T.F.); (H.A.)
| | - André Euler
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, CH-8091 Zurich, Switzerland; (T.S.); (V.M.); (L.J.); (K.M.); (T.F.); (H.A.)
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22
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Rotzinger DC, Racine D, Becce F, Lahoud E, Erhard K, Si-Mohamed SA, Greffier J, Viry A, Boussel L, Meuli RA, Yagil Y, Monnin P, Douek PC. Performance of Spectral Photon-Counting Coronary CT Angiography and Comparison with Energy-Integrating-Detector CT: Objective Assessment with Model Observer. Diagnostics (Basel) 2021; 11:2376. [PMID: 34943611 PMCID: PMC8700425 DOI: 10.3390/diagnostics11122376] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/02/2021] [Accepted: 12/14/2021] [Indexed: 11/16/2022] Open
Abstract
AIMS To evaluate spectral photon-counting CT's (SPCCT) objective image quality characteristics in vitro, compared with standard-of-care energy-integrating-detector (EID) CT. METHODS We scanned a thorax phantom with a coronary artery module at 10 mGy on a prototype SPCCT and a clinical dual-layer EID-CT under various conditions of simulated patient size (small, medium, and large). We used filtered back-projection with a soft-tissue kernel. We assessed noise and contrast-dependent spatial resolution with noise power spectra (NPS) and target transfer functions (TTF), respectively. Detectability indices (d') of simulated non-calcified and lipid-rich atherosclerotic plaques were computed using the non-pre-whitening with eye filter model observer. RESULTS SPCCT provided lower noise magnitude (9-38% lower NPS amplitude) and higher noise frequency peaks (sharper noise texture). Furthermore, SPCCT provided consistently higher spatial resolution (30-33% better TTF10). In the detectability analysis, SPCCT outperformed EID-CT in all investigated conditions, providing superior d'. SPCCT reached almost perfect detectability (AUC ≈ 95%) for simulated 0.5-mm-thick non-calcified plaques (for large-sized patients), whereas EID-CT had lower d' (AUC ≈ 75%). For lipid-rich atherosclerotic plaques, SPCCT achieved 85% AUC vs. 77.5% with EID-CT. CONCLUSIONS SPCCT outperformed EID-CT in detecting simulated coronary atherosclerosis and might enhance diagnostic accuracy by providing lower noise magnitude, markedly improved spatial resolution, and superior lipid core detectability.
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Affiliation(s)
- David C. Rotzinger
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV), Rue du Bugnon 46, CH 1011 Lausanne, Switzerland; (F.B.); (R.A.M.)
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), CH 1015 Lausanne, Switzerland; (D.R.); (A.V.); (P.M.)
| | - Damien Racine
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), CH 1015 Lausanne, Switzerland; (D.R.); (A.V.); (P.M.)
- Institute of Radiation Physics, Lausanne University Hospital (CHUV), CH 1007 Lausanne, Switzerland
| | - Fabio Becce
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV), Rue du Bugnon 46, CH 1011 Lausanne, Switzerland; (F.B.); (R.A.M.)
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), CH 1015 Lausanne, Switzerland; (D.R.); (A.V.); (P.M.)
| | - Elias Lahoud
- CT/AMI Research and Development, Philips Medical Systems, Haifa 31004, Israel; (E.L.); (Y.Y.)
| | - Klaus Erhard
- Philips GmbH Innovative Technologies, Philips Research Laboratories, 22335 Hamburg, Germany;
| | - Salim A. Si-Mohamed
- Radiology Department, Hospices Civils de Lyon, 69500 Lyon, France; (S.A.S.-M.); (L.B.); (P.C.D.)
- Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, CREATIS, CNRS UMR 5220, INSERM U1206, INSA-Lyon, 69100 Lyon, France
| | - Joël Greffier
- Department of Medical Imaging, CHU Nimes, University of Montpellier, 30900 Nimes, France;
| | - Anaïs Viry
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), CH 1015 Lausanne, Switzerland; (D.R.); (A.V.); (P.M.)
- Institute of Radiation Physics, Lausanne University Hospital (CHUV), CH 1007 Lausanne, Switzerland
| | - Loïc Boussel
- Radiology Department, Hospices Civils de Lyon, 69500 Lyon, France; (S.A.S.-M.); (L.B.); (P.C.D.)
- Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, CREATIS, CNRS UMR 5220, INSERM U1206, INSA-Lyon, 69100 Lyon, France
| | - Reto A. Meuli
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV), Rue du Bugnon 46, CH 1011 Lausanne, Switzerland; (F.B.); (R.A.M.)
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), CH 1015 Lausanne, Switzerland; (D.R.); (A.V.); (P.M.)
| | - Yoad Yagil
- CT/AMI Research and Development, Philips Medical Systems, Haifa 31004, Israel; (E.L.); (Y.Y.)
| | - Pascal Monnin
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), CH 1015 Lausanne, Switzerland; (D.R.); (A.V.); (P.M.)
- Institute of Radiation Physics, Lausanne University Hospital (CHUV), CH 1007 Lausanne, Switzerland
| | - Philippe C. Douek
- Radiology Department, Hospices Civils de Lyon, 69500 Lyon, France; (S.A.S.-M.); (L.B.); (P.C.D.)
- Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, CREATIS, CNRS UMR 5220, INSERM U1206, INSA-Lyon, 69100 Lyon, France
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