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Leng S, Toia GV, Hoodeshenas S, Ramirez-Giraldo JC, Yagil Y, Maltz JS, Boedeker K, Li K, Baffour F, Fletcher JG. Standardizing technical parameters and terms for abdominopelvic photon-counting CT: laying the groundwork for innovation and evidence sharing. Abdom Radiol (NY) 2024:10.1007/s00261-024-04342-4. [PMID: 38769199 DOI: 10.1007/s00261-024-04342-4] [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: 03/01/2024] [Revised: 04/11/2024] [Accepted: 04/15/2024] [Indexed: 05/22/2024]
Abstract
Photon-counting detector CT (PCD-CT) is a new technology that has multiple diagnostic benefits including increased spatial resolution, iodine signal, and radiation dose efficiency, as well as multi-energy imaging capability, but which also has unique challenges in abdominal imaging. The purpose of this work is to summarize key features, technical parameters, and terms, which are common amongst current abdominopelvic PCD-CT systems and to propose standardized terminology (where none exists). In addition, user-selectable protocol parameters are highlighted to facilitate both scientific evaluation and early clinical adoption. Unique features of PCD-CT systems include photon-counting detectors themselves, energy thresholds and bins, and tube potential considerations for preserved spectral separation. Key parameters for describing different PCD-CT systems are reviewed and explained. While PCD-CT can generate multi-energy images like dual-energy CT, there are new types of images such as threshold images, energy bin images, and special spectral images. The standardized terms and concepts herein build upon prior interdisciplinary consensus and have been endorsed by the newly created Society of Abdominal Radiology Photon-counting CT Emerging Technology Commission.
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Affiliation(s)
- Shuai Leng
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Giuseppe V Toia
- Departments of Radiology and Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Safa Hoodeshenas
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | | | - Yoad Yagil
- PD CT/AMI R&D Advanced Development, Philips Medical Systems, Haifa, Israel
| | - Jonathan S Maltz
- Molecular Imaging and Computed Tomography, GE Healthcare, Waukesha, WI, USA
| | | | - Ke Li
- Departments of Radiology and Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Francis Baffour
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Joel G Fletcher
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
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Wang J, Duan X, Mahmood U, McKenney SE, Brady SL. An adult and pediatric size-based contrast administration reduction phantom study for single and dual-energy CT through preservation of contrast-to-noise ratio. J Appl Clin Med Phys 2024; 25:e14340. [PMID: 38605540 PMCID: PMC11087157 DOI: 10.1002/acm2.14340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 01/29/2024] [Accepted: 02/24/2024] [Indexed: 04/13/2024] Open
Abstract
BACKGROUND Global shortages of iodinated contrast media (ICM) during COVID-19 pandemic forced the imaging community to use ICM more strategically in CT exams. PURPOSE The purpose of this work is to provide a quantitative framework for preserving iodine CNR while reducing ICM dosage by either lowering kV in single-energy CT (SECT) or using lower energy virtual monochromatic images (VMI) from dual-energy CT (DECT) in a phantom study. MATERIALS AND METHODS In SECT study, phantoms with effective diameters of 9.7, 15.9, 21.1, and 28.5 cm were scanned on SECT scanners of two different manufacturers at a range of tube voltages. Statistical based iterative reconstruction and deep learning reconstruction were used. In DECT study, phantoms with effective diameters of 20, 29.5, 34.6, and 39.7 cm were scanned on DECT scanners from three different manufacturers. VMIs were created from 40 to 140 keV. ICM reduction by lowering kV levels for SECT or switching from SECT to DECT was calculated based on the linear relationship between iodine CNR and its concentration under different scanning conditions. RESULTS On SECT scanner A, while matching CNR at 120 kV, ICM reductions of 21%, 58%, and 72% were achieved at 100, 80, and 70 kV, respectively. On SECT scanner B, 27% and 80% ICM reduction was obtained at 80 and 100 kV. On the Fast-kV switch DECT, with CNR matched at 120 kV, ICM reductions were 35%, 30%, 23%, and 15% with VMIs at 40, 50, 60, and 68 keV, respectively. On the dual-source DECT, ICM reductions were 52%, 48%, 42%, 33%, and 22% with VMIs at 40, 50, 60, 70, and 80 keV. On the dual-layer DECT, ICM reductions were 74%, 62%, 45%, and 22% with VMIs at 40, 50, 60, and 70 keV. CONCLUSIONS Our work provided a quantitative baseline for other institutions to further optimize their scanning protocols to reduce the use of ICM.
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Affiliation(s)
- Jia Wang
- Department of Environmental Health & SafetyStanford UniversityStanfordCaliforniaUSA
| | - Xinhui Duan
- Department of RadiologyUT Southwestern Medical CenterDallasTexasUSA
| | - Usman Mahmood
- Department of Medical PhysicsMemorial Sloan Kettering Cancer CenterNew YorkUSA
| | - Sarah Eva McKenney
- Department of RadiologyUniversity of California, Davis Medical CenterSacramentoCaliforniaUSA
| | - Samuel Loren Brady
- Department of RadiologyCincinnati Children's Hospital Medical CenterUniversity of CincinnatiCincinnatiOhioUSA
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Schuppert C, Salatzki J, André F, Riffel J, Mangold DL, Melzig C, Hagar MT, Kauczor HU, Weber TF, Rengier F, Do TD. Feasibility of Reduced Iodine Loads for Vascular Assessment Prior to Transcatheter Aortic Valve Implantation (TAVI) Using Spectral Detector CT. Diagnostics (Basel) 2024; 14:879. [PMID: 38732294 PMCID: PMC11082960 DOI: 10.3390/diagnostics14090879] [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: 01/18/2024] [Revised: 03/31/2024] [Accepted: 04/11/2024] [Indexed: 05/13/2024] Open
Abstract
Reduced iodine loads for computed tomography (CT)-based vascular assessment prior to transcatheter aortic valve implantation (TAVI) may be feasible in conjunction with a spectral detector CT scanner. This prospective single-center study considered 100 consecutive patients clinically referred for pre-TAVI CT. They were examined on a dual-layer detector CT scanner to obtain an ECG-gated cardiac scan and a non-ECG-gated aortoiliofemoral scan. Either a standard contrast media (SCM) protocol using 80 mL Iohexol 350 mgI/mL (iodine load: 28 gI) or a body-mass-index adjusted reduced contrast media (RCM) protocol using 40-70 mL Iohexol 350 mgI/mL (iodine load: 14-24.5 gI) were employed. Conventional images and virtual monoenergetic images at 40-80 keV were reconstructed. A threshold of 250 HU was set for sufficient attenuation along the arterial access pathway. A qualitative assessment used a five-point Likert scale. Sufficient attenuation in the thoracic aorta was observed for all patients in both groups using conventional images. In the abdominal, iliac, and femoral segments, sufficient attenuation was observed for the majority of patients when using virtual monoenergetic images (SCM: 96-100% of patients, RCM: 88-94%) without statistical difference between both groups. Segments with attenuation measurements below the threshold remained qualitatively assessable as well. Likert scores were 'excellent' for virtual monoenergetic images 50 keV and 55 keV in both groups (RCM: 1.2-1.4, SCM: 1.2-1.3). With diagnostic image quality maintained, it can be concluded that reduced iodine loads of 14-24.5 gI are feasible for pre-TAVI vascular assessment on a spectral detector CT scanner.
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Affiliation(s)
- Christopher Schuppert
- Department of Diagnostic and Interventional Radiology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg im Breisgau, Germany
- Clinic of Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Janek Salatzki
- Clinic of Cardiology, Angiology and Pneumology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Florian André
- Clinic of Cardiology, Angiology and Pneumology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Johannes Riffel
- Department of Cardiology and Angiology, Robert Bosch Hospital, 70376 Stuttgart, Germany
| | - David L. Mangold
- Clinic of Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Claudius Melzig
- Clinic of Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Muhammad Taha Hagar
- Department of Diagnostic and Interventional Radiology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg im Breisgau, Germany
| | - Hans-Ulrich Kauczor
- Clinic of Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Tim F. Weber
- Clinic of Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Fabian Rengier
- Clinic of Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Thuy D. Do
- Clinic of Diagnostic and Interventional Radiology, Heidelberg University Hospital, 69120 Heidelberg, Germany
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Leng Y, Liu Y, Li S, Wang X, Deng W, Wang Y, Gong L. Feasibility of using 8 mL of iodinated contrast media in cerebral computed tomographic angiography with a dual-layer spectral detector. Quant Imaging Med Surg 2024; 14:514-526. [PMID: 38223031 PMCID: PMC10784050 DOI: 10.21037/qims-23-914] [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: 06/24/2023] [Accepted: 10/24/2023] [Indexed: 01/16/2024]
Abstract
Background Virtual monoenergetic images (VMIs) at a low energy level can improve image quality when the amount of iodinated contrast media (CM) is reduced. The purpose was to evaluate the feasibility of using an extremely low CM volume and injection rate in cerebral computed tomography angiography (CTA) on a dual-layer spectral detector computed tomography (CT). Methods Patients who were clinically suspected of intracranial aneurysm or cerebrovascular diseases were included in our study (from June to November 2022). In this prospective study, 80 patients were randomly enrolled into group A (8 mL of CM with a 1-mL/s flow rate) or group B (40 mL of CM with 4-mL/s flow rate). The VMIs at 40-70 keV in group A and polychromatic conventional images in the 2 groups were reconstructed. CT attenuation, image noise, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) were evaluated via the t-test or Mann-Whitney test (2 groups), while analysis of variance or Kruskal-Wallis test (multiple groups). Subjective image quality was assessed on a 5-point scale. Results In group A, the subjective image quality score, CT attenuation, and CNR of the internal carotid artery (ICA) and middle cerebral artery (MCA) were the highest on VMIs at 40 keV. The image noise on VMIs at 40 keV was 5.08±0.84 Hounsfield units. The subjective image quality score, CT value of the ICA, MCA, and cerebral parenchyma on VMIs at 40 keV in group A were similar to those in group B (all P values >0.05). Compared to those in group B, the VMIs at 40 keV in group A demonstrated a significantly higher mean SNR and CNR of the ICA (mean SNR: 46.22±20.18 vs. 34.32±12.40, P=0.002; CNR: 55.47±13.43 vs. 46.18±12.30, P=0.002) and MCA [SNR: 13.66 (9.78, 20.29) vs. 9.99 (7.53, 14.00), P=0.003; CNR: 47.00±12.71 vs. 39.45±10.47, P=0.005]. Conclusions Cerebral CTA on VMIs at 40 keV with 8 mL of CM and a 1-mL/s injection rate can provide diagnostic image quality.
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Affiliation(s)
- Yinping Leng
- Department of Radiology, the Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Ying Liu
- Department of Radiology, the Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Shuhao Li
- Department of Radiology, the Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xiwen Wang
- Department of Radiology, the Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Weiwei Deng
- Clinical and Technical Support, Philips Healthcare, Shanghai, China
| | - Yu Wang
- Clinical and Technical Support, Philips Healthcare, Shanghai, China
| | - Lianggeng Gong
- Department of Radiology, the Second Affiliated Hospital of Nanchang University, Nanchang, China
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Wu D, Yin L, Zhang Y, Lin Y, Deng W, Zheng C, Liu H, Jiang F, Lan S, Wu Q, Li H, Tang J. Evaluation of microcirculation in asymptomatic cerebral infarction with multi-parameter imaging of spectral CT. Brain Res Bull 2023; 203:110775. [PMID: 37797749 DOI: 10.1016/j.brainresbull.2023.110775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 09/17/2023] [Accepted: 10/03/2023] [Indexed: 10/07/2023]
Abstract
OBJECTIVE To investigate the role of spectral CT multiparametric imaging in the evaluation of cerebral microcirculatory perfusion. METHODS The imaging data of 145 patients with asymptomatic cerebral infarction confirmed by MR were retrospectively analyzed, and all cases underwent head CTA and cranial CT perfusion imaging (CTP) on double-layer detector spectral CT. Single energy level images (MonoE45 keV), iodine density maps, and effective atomic number maps were reconstructed based on spectral CTA data, and CT values, iodine density values, and effective atomic number values were measured in the infarcted area, healthy control area, centrum semiovale and posterior limb of the internal capsule, respectively; perfusion values, such as cerebral blood volume (CBV) values, cerebral blood flow (CBF) values, time to peak (TTP) values, and mean passage time, were measured in the above-mentioned areas on CTP images. (TTP) values, and mean time to passage (MTT) values. CT values, iodine density values, effective atomic number values, and perfused CBV, CBF, TTP, and MTT values were compared between the infarcted area and the healthy side, the center of the hemianopia, and the posterior limb of the internal capsule. The role of spectral CT parameters and perfusion parameters in the evaluation of asymptomatic cerebral infarction was analyzed. RESULTS CT values, iodine density values, and effective atomic number values were statistically different between the infarcted area and the healthy side; CT values, iodine density values, and effective atomic number values were not statistically different between the infarcted side and the healthy side of the hemispheric centrum and the posterior limb of the internal capsule; CBV and CBF were statistically different between the infarcted side and the healthy side, and MTT and TTP were not statistically different. There were statistically significant differences in TTP between the infarcted area and the healthy side of the hemiaxial center, and no statistically significant differences in CBV, CBF, and MTT. There were no statistical differences in CBV, CBF, TTP, and MTT in the inner capsule area. ROC curve analysis of spectral CT-related parameters and CT perfusion parameters for the diagnosis of asymptomatic cerebral infarction: area under the curve of MonoE 45Kv 0.71, area under the curve of iodine density values 0.76, area under the curve of effective atomic number values 0.74; area under the curve of CBV value 0.64, area under the curve of CBF value 0.61, area under the curve of MTT value 0.50, The area under the TTP curve was 0.52. The area under the ROC curve of the multivariate logistic regression model based on spectral parameters is 0.76, which is higher than that of the logistic regression model with perfusion parameters (P < 0.05). CONCLUSION Spectral CT can better demonstrate small intracranial ischemic lesions, and iodine density values have a better evaluation of microcirculation in asymptomatic cerebral infarcts.
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Affiliation(s)
- Daoqing Wu
- Department of Imaging, The Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China.
| | - Lianhua Yin
- Medical Examination Center, The Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - You Zhang
- Department of Imaging, The Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Yuning Lin
- Department of Imaging, The Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Weiwei Deng
- Clinical and Technical Support, Philips Healthcare
| | - Chunhong Zheng
- Department of Imaging, The Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Huibin Liu
- Department of Imaging, The Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Feng Jiang
- Medical Examination Center, The Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Suting Lan
- Medical Examination Center, The Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Qiuhua Wu
- Global Health, Johns Hopkins Bloomberg School of Public Health, United States
| | - Huacan Li
- Department of Imaging, The Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China.
| | - Jinsong Tang
- Department of Imaging, The Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China.
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Agostini A, Borgheresi A, Mariotti F, Ottaviani L, Carotti M, Valenti M, Giovagnoni A. New frontiers in oncological imaging with Computed Tomography: from morphology to function. Semin Ultrasound CT MR 2023; 44:214-227. [DOI: 10.1053/j.sult.2023.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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Reduced Iodinated Contrast Media Administration in Coronary CT Angiography on a Clinical Photon-Counting Detector CT System: A Phantom Study Using a Dynamic Circulation Model. Invest Radiol 2023; 58:148-155. [PMID: 36165932 DOI: 10.1097/rli.0000000000000911] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE The aim of this study was to evaluate strategies to reduce contrast media volumes for coronary computed tomography (CT) angiography on a clinical first-generation dual-source photon-counting detector (PCD)-CT system using a dynamic circulation phantom. MATERIALS AND METHODS Coronary CT angiograph is an established method for the assessment of coronary artery disease that relies on the administration of iodinated contrast media. Reduction of contrast media volumes while maintaining diagnostic image quality is desirable. In this study, a dynamic phantom containing a 3-dimensional-printed model of the thoracic aorta and coronary arteries was evaluated using a clinical contrast injection protocol with stepwise reduced contrast agent concentrations (100%, 75%, 50%, 40%, 30%, and 20% contrast media content of the same 50 mL bolus, resulting in iodine delivery rates of 1.5, 1.1, 0.7, 0.6, 0.4 and 0.3 gl/s) on a first-generation, dual-source PCD-CT. Polychromatic images (T3D) and virtual monoenergetic images were reconstructed in the range of 40 to 70 keV in 5-keV steps. Attenuation and noise were measured in the coronary arteries and background material and the contrast-to-noise ratio (CNR) were calculated. Attenuation of 350 HU and a CNR of the reference protocol at 70 keV were regarded as sufficient for simulation of diagnostic purposes. Vessel sharpness and noise power spectra were analyzed for the aforementioned reconstructions. RESULTS The standard clinical contrast protocol (bolus with 100% contrast) yielded diagnostic coronary artery attenuation for all tested reconstructions (>398 HU). A 50% reduction in contrast media concentration demonstrated sufficient attenuation of the coronary arteries at 40 to 55 keV (>366 HU). Virtual monoenergetic image reconstructions of 40 to 45 and 40 keV allowed satisfactory attenuation of the coronary arteries for contrast concentrations of 40% and 30% of the original protocol. A reduction of contrast agent concentration to 20% of the initial concentration provided insufficient attenuation in the target vessels for all reconstructions. The highest CNR was found for virtual monoenergetic reconstructions at 40 keV for all contrast media injection protocols, yielding a sufficient CNR at a 50% reduction of contrast agent concentration. CONCLUSIONS Using virtual monoenergetic image reconstructions at 40 keV on a dual-source PCD-CT system, contrast media concentration could be reduced by 50% to obtain diagnostic attenuation and objective image quality for coronary CT angiography in a dynamic vessel phantom. These initial feasibility study results have to be validated in clinical studies.
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Borges AP, Antunes C, Curvo-Semedo L. Pros and Cons of Dual-Energy CT Systems: "One Does Not Fit All". Tomography 2023; 9:195-216. [PMID: 36828369 PMCID: PMC9964233 DOI: 10.3390/tomography9010017] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/22/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023] Open
Abstract
Dual-energy computed tomography (DECT) uses different energy spectrum x-ray beams for differentiating materials with similar attenuation at a certain energy. Compared with single-energy CT, it provides images with better diagnostic performance and a potential reduction of contrast agent and radiation doses. There are different commercially available DECT technologies, with machines that may display two x-ray sources and two detectors, a single source capable of fast switching between two energy levels, a specialized detector capable of acquiring high- and low-energy data sets, and a filter splitting the beam into high- and low-energy beams at the output. Sequential acquisition at different tube voltages is an alternative approach. This narrative review describes the DECT technique using a Q&A format and visual representations. Physical concepts, parameters influencing image quality, postprocessing methods, applicability in daily routine workflow, and radiation considerations are discussed. Differences between scanners are described, regarding design, image quality variabilities, and their advantages and limitations. Additionally, current clinical applications are listed, and future perspectives for spectral CT imaging are addressed. Acknowledging the strengths and weaknesses of different DECT scanners is important, as these could be adapted to each patient, clinical scenario, and financial capability. This technology is undoubtedly valuable and will certainly keep improving.
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Affiliation(s)
- Ana P. Borges
- Medical Imaging Department, Coimbra University Hospitals, 3004-561 Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, 3000-370 Coimbra, Portugal
- Academic and Clinical Centre of Coimbra, 3000-370 Coimbra, Portugal
- Correspondence:
| | - Célia Antunes
- Medical Imaging Department, Coimbra University Hospitals, 3004-561 Coimbra, Portugal
- Academic and Clinical Centre of Coimbra, 3000-370 Coimbra, Portugal
| | - Luís Curvo-Semedo
- Medical Imaging Department, Coimbra University Hospitals, 3004-561 Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, 3000-370 Coimbra, Portugal
- Academic and Clinical Centre of Coimbra, 3000-370 Coimbra, Portugal
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Zhang X, Zhang G, Xu L, Bai X, Lu X, Yu S, Sun H, Jin Z. Utilisation of virtual non-contrast images and virtual mono-energetic images acquired from dual-layer spectral CT for renal cell carcinoma: image quality and radiation dose. Insights Imaging 2022; 13:12. [PMID: 35072807 PMCID: PMC8787008 DOI: 10.1186/s13244-021-01146-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 12/18/2021] [Indexed: 12/23/2022] Open
Abstract
Background Renal cell carcinoma (RCC) is the most common renal malignant tumour. We evaluated the potential value and dose reduction of virtual non-contrast (VNC) images and virtual monoenergetic images (VMIs) from dual-layer spectral CT (DL-CT) in the diagnosis of RCC. Results Sixty-two patients with pathologically confirmed RCC who underwent contrast-enhanced DL-CT were retrospectively analysed. For the comparison between true non-contrast (TNC) and VNC images of the excretory phase, the attenuation, image noise, signal-to-noise ratio (SNR) and subjective image quality of tumours and different abdominal organs and tissues were evaluated. To compare corticomedullary phase images and low keV VMIs (40 to 100 keV) from the nephrographic phase, the attenuation, image noise, SNR and subjective lesion visibility of the tumours and renal arteries were evaluated. For the tumours, significant differences were not observed in attenuation, noise or SNR between TNC and VNC images (p > 0.05). For the abdominal organs and tissues, except for fat, the difference in attenuation was 100% within 15 HU and 96.78% within 10 HU. The subjective image quality of TNC and VNC images was equivalent (p > 0.05). The attenuation of lesions in 40 keV VMIs and renal arteries in 60 keV VMIs were similar to those in the corticomedullary images (p > 0.05). The subjective lesion visibility in low keV VMIs is slightly lower than that in the corticomedullary images (p < 0.05). Using VNC and VMIs instead of TNC and corticomedullary phase images could decrease the radiation dose by 50.5%. Conclusion VNC images and VMIs acquired from DL-CT can maintain good image quality and decrease the radiation dose for diagnosis of RCC.
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Adam SZ, Rabinowich A, Kessner R, Blachar A. Spectral CT of the abdomen: Where are we now? Insights Imaging 2021; 12:138. [PMID: 34580788 PMCID: PMC8476679 DOI: 10.1186/s13244-021-01082-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 08/16/2021] [Indexed: 12/14/2022] Open
Abstract
Spectral CT adds a new dimension to radiological evaluation, beyond assessment of anatomical abnormalities. Spectral data allows for detection of specific materials, improves image quality while at the same time reducing radiation doses and contrast media doses, and decreases the need for follow up evaluation of indeterminate lesions. We review the different acquisition techniques of spectral images, mainly dual-source, rapid kV switching and dual-layer detector, and discuss the main spectral results available. We also discuss the use of spectral imaging in abdominal pathologies, emphasizing the strengths and pitfalls of the technique and its main applications in general and in specific organs.
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Affiliation(s)
- Sharon Z Adam
- Department of Diagnostic Radiology, Tel Aviv Sourasky Medical Center, 6 Weizmann St., 6423906, Tel Aviv, Israel. .,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Aviad Rabinowich
- Department of Diagnostic Radiology, Tel Aviv Sourasky Medical Center, 6 Weizmann St., 6423906, Tel Aviv, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Rivka Kessner
- Department of Diagnostic Radiology, Tel Aviv Sourasky Medical Center, 6 Weizmann St., 6423906, Tel Aviv, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Arye Blachar
- Department of Diagnostic Radiology, Tel Aviv Sourasky Medical Center, 6 Weizmann St., 6423906, Tel Aviv, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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Agostini A, Borgheresi A, Bruno F, Natella R, Floridi C, Carotti M, Giovagnoni A. New advances in CT imaging of pancreas diseases: a narrative review. Gland Surg 2021; 9:2283-2294. [PMID: 33447580 DOI: 10.21037/gs-20-551] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Computed tomography (CT) plays a pivotal role as a diagnostic tool in many diagnostic and diffuse pancreatic diseases. One of the major limits of CT is related to the radiation exposure of young patients undergoing repeated examinations. Besides the standard CT protocol, the most recent technological advances, such as low-voltage acquisitions with high performance X-ray tubes and iterative reconstructions, allow for significant optimization of the protocol with dose reduction. The variety of CT tools are further expanded by the introduction of dual energy: the production of energy-selective images (i.e., virtual monochromatic images) improves the image contrast and lesion detection while the material-selective images (e.g., iodine maps or virtual unenhanced images) are valuable for lesion detection and dose reduction. The perfusion techniques provide diagnostic and prognostic information lesion and parenchymal vascularization and interstitium. Both dual energy and perfusion CT have the potential for pushing the limits of conventional CT from morphological evaluation to quantitative imaging applied to inflammatory and oncological diseases. Advances in post-processing of CT images, such as pancreatic volumetry, texture analysis and radiomics provide relevant information for pancreatic function but also for the diagnosis, management and prognosis of pancreatic neoplasms. Artificial intelligence is promising for optimization of the workflow in qualitative and quantitative analyses. Finally, basic concepts on the role of imaging on screening of pancreatic diseases will be provided.
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Affiliation(s)
- Andrea Agostini
- Department of Clinical, Special and Dental Sciences, University Politecnica delle Marche, Ancona (AN), Italy.,Department of Radiology, University Hospital "Umberto I - Lancisi - Salesi", Ancona (AN), Italy
| | - Alessandra Borgheresi
- Department of Radiology, University Hospital "Umberto I - Lancisi - Salesi", Ancona (AN), Italy
| | - Federico Bruno
- Department of Biotechnological and Applied Sciences, University of L'Aquila, L'Aquila, Italy
| | - Raffaele Natella
- Department of Precision Medicine, University of Campania "L. Vanvitelli", Naples, Italy
| | - Chiara Floridi
- Department of Clinical, Special and Dental Sciences, University Politecnica delle Marche, Ancona (AN), Italy.,Department of Radiology, University Hospital "Umberto I - Lancisi - Salesi", Ancona (AN), Italy
| | - Marina Carotti
- Department of Clinical, Special and Dental Sciences, University Politecnica delle Marche, Ancona (AN), Italy.,Department of Radiology, University Hospital "Umberto I - Lancisi - Salesi", Ancona (AN), Italy
| | - Andrea Giovagnoni
- Department of Clinical, Special and Dental Sciences, University Politecnica delle Marche, Ancona (AN), Italy.,Department of Radiology, University Hospital "Umberto I - Lancisi - Salesi", Ancona (AN), Italy
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12
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Isaka Y, Hayashi H, Aonuma K, Horio M, Terada Y, Doi K, Fujigaki Y, Yasuda H, Sato T, Fujikura T, Kuwatsuru R, Toei H, Murakami R, Saito Y, Hirayama A, Murohara T, Sato A, Ishii H, Takayama T, Watanabe M, Awai K, Oda S, Murakami T, Yagyu Y, Joki N, Komatsu Y, Miyauchi T, Ito Y, Miyazawa R, Kanno Y, Ogawa T, Hayashi H, Koshi E, Kosugi T, Yasuda Y. Guideline on the use of iodinated contrast media in patients with kidney disease 2018. Clin Exp Nephrol 2020; 24:1-44. [PMID: 31709463 PMCID: PMC6949208 DOI: 10.1007/s10157-019-01750-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Yoshitaka Isaka
- Department of Nephrology, Osaka University Graduate School of Medicine, Osaka, Japan.
| | - Hiromitsu Hayashi
- Department of Clinical Radiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Kazutaka Aonuma
- Cardiology Department, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan
| | | | - Yoshio Terada
- Department of Endocrinology, Metabolism and Nephrology, Kochi Medical School, Kochi University, Kochi, Japan
| | - Kent Doi
- Department of Acute Medicine, The University of Tokyo, Tokyo, Japan
| | - Yoshihide Fujigaki
- Division of Nephrology, Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Hideo Yasuda
- First Department of Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Taichi Sato
- First Department of Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Tomoyuki Fujikura
- First Department of Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Ryohei Kuwatsuru
- Department of Radiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan
| | - Hiroshi Toei
- Department of Radiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan
| | - Ryusuke Murakami
- Department of Clinical Radiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Yoshihiko Saito
- Department of Cardiovascular Medicine, Nara Medical University, Nara, Japan
| | | | - Toyoaki Murohara
- Department of Cardiology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Akira Sato
- Department of Cardiology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Hideki Ishii
- Department of Cardiology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Tadateru Takayama
- Division of General Medicine, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Makoto Watanabe
- Department of Cardiovascular Medicine, Nara Medical University, Nara, Japan
| | - Kazuo Awai
- Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Seitaro Oda
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Takamichi Murakami
- Department of Radiology, Kobe University Graduate School of Medicine, Hyogo, Japan
| | - Yukinobu Yagyu
- Department of Radiology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Nobuhiko Joki
- Division of Nephrology, Toho University Ohashi Medical Center, Tokyo, Japan
| | - Yasuhiro Komatsu
- Department of Healthcare Quality and Safety, Gunma University Graduate School of Medicine, Gunma, Japan
| | | | - Yugo Ito
- Department of Nephrology, St. Luke's International Hospital, Tokyo, Japan
| | - Ryo Miyazawa
- Department of Radiology, St. Luke's International Hospital, Tokyo, Japan
| | - Yoshihiko Kanno
- Department of Nephrology, Tokyo Medical University, Tokyo, Japan
| | - Tomonari Ogawa
- Department of Nephrology and Hypertension, Saitama Medical Center, Saitama, Japan
| | - Hiroki Hayashi
- Department of Nephrology, Fujita Health University School of Medicine, Aichi, Japan
| | - Eri Koshi
- Department of Nephrology, Komaki City Hospital, Aichi, Japan
| | - Tomoki Kosugi
- Nephrology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Yoshinari Yasuda
- Department of CKD Initiatives/Nephrology, Nagoya University Graduate School of Medicine, Aichi, Japan
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13
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Pawałowski B, Panek R, Szweda H, Piotrowski T. Combination of dual-energy computed tomography and iterative metal artefact reduction to increase general quality of imaging for radiotherapy patients with high dense materials. Phantom study. Phys Med 2020; 77:92-99. [PMID: 32818774 DOI: 10.1016/j.ejmp.2020.08.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/23/2020] [Accepted: 08/07/2020] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To evaluate the use of pseudo-monoenergetic reconstructions (PMR) from dual-energy computed tomography, combined with the iterative metal artefact reduction (iMAR) method. METHODS Pseudo-monoenergetic CT images were obtained using the dual-energy mode on the Siemens Somatom Definition AS scanner. A range of PMR combinations (70-130 keV) were used with and without iMAR. A Virtual Water™ phantom was used for quantitative assessment of error in the presence of high density materials: titanium, alloys 330 and 600. The absolute values of CT number differences (AD) and normalised standard deviations (NSD) were calculated for different phantom positions. Image quality was assessed using an anthropomorphic pelvic phantom with an embedded hip prosthesis. Image quality was scored blindly by five observers. RESULTS AD and NSD values revealed differences in CT number errors between tested sets. AD and NSD were reduced in the vicinity of metal for images with iMAR (p < 0.001 for AD/NSD). For ROIs away from metal, with and without iMAR, 70 keV PMR and pCT AD values were lower than for the other reconstructions (p = 0.039). Similarly, iMAR NSD values measured away from metal were lower for 130 keV and 70 keV PMR (p = 0.002). Image quality scores were higher for 70 keV and 130 keV PMR with iMAR (p = 0.034). CONCLUSION The use of 70 keV PMR with iMAR allows for significant metal artefact reduction and low CT number errors observed in the vicinity of dense materials. It is therefore an attractive alternative to high keV imaging when imaging patients with metallic implants, especially in the context of radiotherapy planning.
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Affiliation(s)
- Bartosz Pawałowski
- Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland; Department of Technical Physics, Poznan University of Technology, Poznań, Poland
| | - Rafał Panek
- Medical Physics & Clinical Engineering, Nottingham University Hospitals NHS Trust, Nottingham, UK; School of Medicine, University of Nottingham, Nottingham, UK
| | - Hubert Szweda
- Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland
| | - Tomasz Piotrowski
- Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland; Department of Electroradiology, Poznań University of Medical Sciences, Poznań, Poland.
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14
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McCollough CH, Boedeker K, Cody D, Duan X, Flohr T, Halliburton SS, Hsieh J, Layman RR, Pelc NJ. Principles and applications of multienergy CT: Report of AAPM Task Group 291. Med Phys 2020; 47:e881-e912. [DOI: 10.1002/mp.14157] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 02/11/2020] [Accepted: 03/10/2020] [Indexed: 12/14/2022] Open
Affiliation(s)
| | - Kirsten Boedeker
- Canon (formerly Toshiba) Medical Systems Corporation 1440 Warnall Ave Los Angeles CA 90024 USA
| | - Dianna Cody
- University of Texas, M.D. Anderson Cancer Center 7163 Spanish Grant Galveston TX 77554‐7756 USA
| | - Xinhui Duan
- Southwestern Medical Center University of Texas 5323 Harry Hines Blvd Dallas TX 75390‐9071 USA
| | - Thomas Flohr
- Siemens Healthcare GmbH Siemensstr. 3 Forchheim BY 91031 Germany
| | | | - Jiang Hsieh
- GE Healthcare Technologies 3000 N. Grandview Blvd. W-1190 Waukesha WI 53188 USA
| | - Rick R. Layman
- University of Texas, M.D. Anderson Cancer Center 7163 Spanish Grant Galveston TX 77554‐7756 USA
| | - Norbert J. Pelc
- Stanford University 443 Via Ortega, Room 203 Stanford CA 94305‐4125 USA
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15
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Venous-phase chest CT with reduced contrast medium dose: Utilization of spectral low keV monoenergetic images improves image quality. Eur J Radiol 2019; 122:108756. [PMID: 31786505 DOI: 10.1016/j.ejrad.2019.108756] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 11/06/2019] [Accepted: 11/18/2019] [Indexed: 11/21/2022]
Abstract
PURPOSE Intravenous contrast administration is crucial in many CT examinations but also poses a potential risk to the patient. Monoenergetic images (MonoE) of dual-energy CT systems can virtually increase iodine attenuation and might improve image quality (IQ) if contrast dose is reduced. In this study, we investigated the influence of MonoE on lymph node (LN) delineation and IQ in chest CT examinations with significantly reduced contrast dose (50 %) of a novel dual-layer CT (DLCT). METHOD 30 patients with clinically indicated reduced contrast dose underwent venous-phase chest DLCT scans. Conventional polyenergetic (PolyE) and MonoE images at 40 keV were calculated. The contrast difference of hilar lymph nodes (LN-CD) to the adjacent right pulmonary artery, their signal-to-noise (SNR) and contrast-to-noise-ratio (CNR) were determined. Subjective IQ was evaluated by 2 readers with respect to LN delineation and overall contrast enhancement (CE) using a 5-point-Likert-scale. RESULTS LN-CD, SNR and CNR were significantly higher in MonoE than in PolyE images (LN-CD 92.3 ± 37.9 vs. 33.1 ± 14.5 HU, SNR 8.4 ± 3.4 vs. 4.0 ± 1.2, CNR 9.2 ± 6.3 vs. 2.6 ± 1.5; all p < 0.01). The LN delineation (3.7 ± 0.9 vs.1.8 ± 0.7; p < 0.01) and the CE (3.9 ± 0.7 vs. 2.3 ± 0.7; p < 0.01) were rated significantly better for MonoE than for PolyE images. There was no MonoE examination classified as non-diagnostic. CONCLUSIONS Subjective and objective IQ parameters can be significantly improved for venous-phase chest CT examinations with reduced contrast doses by utilization of low-keV MonoE reconstructions. All MonoE images provided sufficient overall CE and therefore reduced contrast doses might be considered in a wider range of DLCT examinations and patients.
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16
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Isaka Y, Hayashi H, Aonuma K, Horio M, Terada Y, Doi K, Fujigaki Y, Yasuda H, Sato T, Fujikura T, Kuwatsuru R, Toei H, Murakami R, Saito Y, Hirayama A, Murohara T, Sato A, Ishii H, Takayama T, Watanabe M, Awai K, Oda S, Murakami T, Yagyu Y, Joki N, Komatsu Y, Miyauchi T, Ito Y, Miyazawa R, Kanno Y, Ogawa T, Hayashi H, Koshi E, Kosugi T, Yasuda Y. Guideline on the Use of Iodinated Contrast Media in Patients With Kidney Disease 2018. Circ J 2019; 83:2572-2607. [PMID: 31708511 DOI: 10.1253/circj.cj-19-0783] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yoshitaka Isaka
- Japanese Society of Nephrology.,Department of Nephrology, Osaka University Graduate School of Medicine
| | - Hiromitsu Hayashi
- Japan Radiological Society.,Department of Clinical Radiology, Graduate School of Medicine, Nippon Medical School
| | - Kazutaka Aonuma
- the Japanese Circulation Society.,Cardiology Department, Institute of Clinical Medicine, University of Tsukuba
| | - Masaru Horio
- Japanese Society of Nephrology.,Kansai Medical Hospital
| | - Yoshio Terada
- Japanese Society of Nephrology.,Department of Endocrinology, Metabolism and Nephrology, Kochi Medical School, Kochi University
| | - Kent Doi
- Japanese Society of Nephrology.,Department of Acute Medicine, The University of Tokyo
| | - Yoshihide Fujigaki
- Japanese Society of Nephrology.,Division of Nephrology, Department of Internal Medicine, Teikyo University School of Medicine
| | - Hideo Yasuda
- Japanese Society of Nephrology.,First Department of Medicine, Hamamatsu University School of Medicine
| | - Taichi Sato
- Japanese Society of Nephrology.,First Department of Medicine, Hamamatsu University School of Medicine
| | - Tomoyuki Fujikura
- Japanese Society of Nephrology.,First Department of Medicine, Hamamatsu University School of Medicine
| | - Ryohei Kuwatsuru
- Japan Radiological Society.,Department of Radiology, Graduate School of Medicine, Juntendo University
| | - Hiroshi Toei
- Japan Radiological Society.,Department of Radiology, Graduate School of Medicine, Juntendo University
| | - Ryusuke Murakami
- Japan Radiological Society.,Department of Clinical Radiology, Graduate School of Medicine, Nippon Medical School
| | - Yoshihiko Saito
- the Japanese Circulation Society.,Department of Cardiovascular Medicine, Nara Medical University
| | - Atsushi Hirayama
- the Japanese Circulation Society.,Department of Cardiology, Osaka Police Hospital
| | - Toyoaki Murohara
- the Japanese Circulation Society.,Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Akira Sato
- the Japanese Circulation Society.,Department of Cardiology, Faculty of Medicine, University of Tsukuba
| | - Hideki Ishii
- the Japanese Circulation Society.,Department of Cardiology, Nagoya University Graduate School of Medicine
| | - Tadateru Takayama
- the Japanese Circulation Society.,Division of General Medicine, Department of Medicine, Nihon University School of Medicine
| | - Makoto Watanabe
- the Japanese Circulation Society.,Department of Cardiovascular Medicine, Nara Medical University
| | - Kazuo Awai
- Japan Radiological Society.,Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University
| | - Seitaro Oda
- Japan Radiological Society.,Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University
| | - Takamichi Murakami
- Japan Radiological Society.,Department of Radiology, Kobe University Graduate School of Medicine
| | - Yukinobu Yagyu
- Japan Radiological Society.,Department of Radiology, Kindai University, Faculty of Medicine
| | - Nobuhiko Joki
- Japanese Society of Nephrology.,Division of Nephrology, Toho University Ohashi Medical Center
| | - Yasuhiro Komatsu
- Japanese Society of Nephrology.,Department of Healthcare Quality and Safety, Gunma University Graduate School of Medicine
| | | | - Yugo Ito
- Japanese Society of Nephrology.,Department of Nephrology, St. Luke's International Hospital
| | - Ryo Miyazawa
- Japan Radiological Society.,Department of Radiology, St. Luke's International Hospital
| | - Yoshihiko Kanno
- Japanese Society of Nephrology.,Department of Nephrology, Tokyo Medical University
| | - Tomonari Ogawa
- Japanese Society of Nephrology.,Department of Nephrology & Hypertension, Saitama Medical Center
| | - Hiroki Hayashi
- Japanese Society of Nephrology.,Department of Nephrology, Fujita Health University School of Medicine
| | - Eri Koshi
- Japanese Society of Nephrology.,Department of Nephrology, Komaki City Hospital
| | - Tomoki Kosugi
- Japanese Society of Nephrology.,Nephrology, Nagoya University Graduate School of Medicine
| | - Yoshinari Yasuda
- Japanese Society of Nephrology.,Department of CKD Initiatives/Nephrology, Nagoya University Graduate School of Medicine
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17
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Isaka Y, Hayashi H, Aonuma K, Horio M, Terada Y, Doi K, Fujigaki Y, Yasuda H, Sato T, Fujikura T, Kuwatsuru R, Toei H, Murakami R, Saito Y, Hirayama A, Murohara T, Sato A, Ishii H, Takayama T, Watanabe M, Awai K, Oda S, Murakami T, Yagyu Y, Joki N, Komatsu Y, Miyauchi T, Ito Y, Miyazawa R, Kanno Y, Ogawa T, Hayashi H, Koshi E, Kosugi T, Yasuda Y. Guideline on the use of iodinated contrast media in patients with kidney disease 2018. Jpn J Radiol 2019; 38:3-46. [PMID: 31709498 DOI: 10.1007/s11604-019-00850-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Yoshitaka Isaka
- Department of Nephrology, Osaka University Graduate School of Medicine, Osaka, Japan.
| | - Hiromitsu Hayashi
- Department of Clinical Radiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Kazutaka Aonuma
- Cardiology Department, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan
| | | | - Yoshio Terada
- Department of Endocrinology, Metabolism and Nephrology, Kochi Medical School, Kochi University, Kochi, Japan
| | - Kent Doi
- Department of Acute Medicine, The University of Tokyo, Tokyo, Japan
| | - Yoshihide Fujigaki
- Division of Nephrology, Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Hideo Yasuda
- First Department of Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Taichi Sato
- First Department of Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Tomoyuki Fujikura
- First Department of Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Ryohei Kuwatsuru
- Department of Radiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan
| | - Hiroshi Toei
- Department of Radiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan
| | - Ryusuke Murakami
- Department of Clinical Radiology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Yoshihiko Saito
- Department of Cardiovascular Medicine, Nara Medical University, Nara, Japan
| | | | - Toyoaki Murohara
- Department of Cardiology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Akira Sato
- Department of Cardiology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Hideki Ishii
- Department of Cardiology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Tadateru Takayama
- Division of General Medicine, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Makoto Watanabe
- Department of Cardiovascular Medicine, Nara Medical University, Nara, Japan
| | - Kazuo Awai
- Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Seitaro Oda
- Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Takamichi Murakami
- Department of Radiology, Kobe University Graduate School of Medicine, Hyogo, Japan
| | - Yukinobu Yagyu
- Department of Radiology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Nobuhiko Joki
- Division of Nephrology, Toho University Ohashi Medical Center, Tokyo, Japan
| | - Yasuhiro Komatsu
- Department of Healthcare Quality and Safety, Gunma University Graduate School of Medicine, Gunma, Japan
| | | | - Yugo Ito
- Department of Nephrology, St. Luke's International Hospital, Tokyo, Japan
| | - Ryo Miyazawa
- Department of Radiology, St. Luke's International Hospital, Tokyo, Japan
| | - Yoshihiko Kanno
- Department of Nephrology, Tokyo Medical University, Tokyo, Japan
| | - Tomonari Ogawa
- Department of Nephrology and Hypertension, Saitama Medical Center, Saitama, Japan
| | - Hiroki Hayashi
- Department of Nephrology, Fujita Health University School of Medicine, Aichi, Japan
| | - Eri Koshi
- Department of Nephrology, Komaki City Hospital, Aichi, Japan
| | - Tomoki Kosugi
- Nephrology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Yoshinari Yasuda
- Department of CKD Initiatives/Nephrology, Nagoya University Graduate School of Medicine, Aichi, Japan
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18
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Pawałowski B, Szweda H, Dudkowiak A, Piotrowski T. Quality evaluation of monoenergetic images generated by dual-energy computed tomography for radiotherapy: A phantom study. Phys Med 2019; 63:48-55. [PMID: 31221408 DOI: 10.1016/j.ejmp.2019.05.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 04/08/2019] [Accepted: 05/25/2019] [Indexed: 12/15/2022] Open
Abstract
PURPOSE Quantification analysis for monoenergetic computed tomography (CT) images obtained from dual-energy CT scanning was performed in the light of their potential use for structures delineation during radiotherapy. METHODS Parameters that describe the quality of the images are: linearity, low and high contrast resolution, uniformity, noise and signal to noise ratio (SNR). To evaluate these parameters, a Catphan phantom was scanned using a dual-energy mode at Somatom Definition AS. Based on the polyenergetic CT images, sixteen monoenergetic series (ranged from 40 keV to 190 keV) were created by CT scanner software and automatically analyzed using Artiscan software. RESULTS Analysis of linearity shows that a potential use of any monoenergetic images in radiotherapy planning requires that individual calibration curves are implemented for each of them. While the results of the high contrast resolution analysis were comparable for each energy (5 lp/cm), the results of the analyses for uniformity, low contrast resolution, noise and SNR allowed us to select the best imaging energies. The highest relative uniformity was detected for images reconstructed for energies of 60 keV and 70 keV (98.54% and 98.61%). Similar results were observed for low contrast resolution, where the largest number of disks was detected for these energies, and the noise values (0.42% for 60 keV, 0.44% for 70 keV). The best SNR was observed for images reconstructed for energy of 60 keV. CONCLUSIONS Taking into account these results, the energy of 70 keV was selected as potentially the best for reconstruction of monoenergetic images used for structures delineation during radiotherapy.
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Affiliation(s)
- Bartosz Pawałowski
- Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland; Department of Technical Physics, Poznan University of Technology, Poznan, Poland
| | - Hubert Szweda
- Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland
| | - Alina Dudkowiak
- Department of Technical Physics, Poznan University of Technology, Poznan, Poland
| | - Tomasz Piotrowski
- Department of Medical Physics, Greater Poland Cancer Centre, Poznań, Poland; Department of Electroradiology, Poznań University of Medical Sciences, Poznań, Poland.
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19
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Kessner R, Große Hokamp N, Ciancibello L, Ramaiya N, Herrmann KA. Renal cystic lesions characterization using spectral detector CT (SDCT): Added value of spectral results. Br J Radiol 2019; 92:20180915. [PMID: 31124701 DOI: 10.1259/bjr.20180915] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVES To evaluate the added value of spectral results derived from Spectral Detector CT (SDCT) to the characterization of renal cystic lesions (RCL). METHODS This retrospective study was approved by the local Institutional review board. 70 consecutive patients who underwent abdominopelvic SDCT and had at least one RCL were included. 84 RCL were categorized as simple, complex or neoplastic based on attenuation values on single-phase post-contrast images. Attenuation values were measured in each lesion on standard conventional CT images (stCI) and virtual monoenergetic images of 40keV and 100keV. A spectral curve slope was calculated and intra lesional iodine concentration (IC) was measured using iodine-density maps. Reference standard was established using histopathologic correlation, prior and follow-up imaging. Analysis of variance (ANOVA) was used to compare between the groups. RESULTS Mean attenuation values for benign simple and complex RCL differed significantly (42 ± 16 vs 8 ± 3 HU; p < 0.001). IC was almost identical in benign simple and complex RCL (0.23 ± 0.04 mg ml-1 vs 0.24 ± 0.04 mg ml-1), while IC in neoplastic RCL was significantly higher (2.10 ± 0.08 mg ml-1 ; p < 0.001). The mean spectral curve slope did not differ significantly between simple and complex RCL (0.30 ± 0.03 vs 0.33 ± 0.05) but was significantly higher in neoplastic RCL (2.60 ± 0.10; p < 0.001). CONCLUSIONS Spectral results of SDCT are highly promising in distinguishing benign complex RCL from enhancing neoplastic RCL based on single-phase post-contrast imaging only. ADVANCES IN KNOWLEDGE SDCT can assist in differentiating between benign complex and neoplastic renal cystic lesions.
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Affiliation(s)
- Rivka Kessner
- 1 Department of Radiology, University Hospitals Cleveland Medical Center and Case Western Reserve University, Cleveland, Ohio, USA.,2 Department of Diagnostic Imaging, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Nils Große Hokamp
- 1 Department of Radiology, University Hospitals Cleveland Medical Center and Case Western Reserve University, Cleveland, Ohio, USA.,3 University Hospital Cologne, Institute for Diagnostic and Interventional Radiology, Cologne, Germany
| | - Les Ciancibello
- 1 Department of Radiology, University Hospitals Cleveland Medical Center and Case Western Reserve University, Cleveland, Ohio, USA
| | - Nikhil Ramaiya
- 1 Department of Radiology, University Hospitals Cleveland Medical Center and Case Western Reserve University, Cleveland, Ohio, USA
| | - Karin A Herrmann
- 1 Department of Radiology, University Hospitals Cleveland Medical Center and Case Western Reserve University, Cleveland, Ohio, USA
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20
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Oda S, Emoto T, Nakaura T, Kidoh M, Utsunomiya D, Funama Y, Nagayama Y, Takashio S, Ueda M, Yamashita T, Tsujita K, Ando Y, Yamashita Y. Myocardial Late Iodine Enhancement and Extracellular Volume Quantification with Dual-Layer Spectral Detector Dual-Energy Cardiac CT. Radiol Cardiothorac Imaging 2019; 1:e180003. [PMID: 33778497 PMCID: PMC7977749 DOI: 10.1148/ryct.2019180003] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 02/01/2019] [Accepted: 02/06/2019] [Indexed: 04/23/2023]
Abstract
PURPOSE To explore the usefulness of myocardial late iodine enhancement (LIE) and extracellular volume (ECV) quantification by using dual-energy cardiac CT. MATERIALS AND METHODS In this single-center retrospective study, a total of 40 patients were evaluated with LIE CT by using a dual-layer spectral detector CT system. Among these, 21 also underwent cardiac MRI. Paired image sets were created by using standard imaging at 120 kVp, virtual monochromatic imaging (VMI) at 50 keV, and iodine density imaging. The contrast-to-noise ratio and image quality were then compared. Two observers assessed the presence of LIE and calculated the interobserver agreements. Agreement between CT and cardiac MRI when detecting late-enhancing lesions and calculating the ECV was also assessed. RESULTS The contrast-to-noise ratio was significantly higher by using VMI than by using standard 120-kVp imaging, and the mean visual image quality score was significantly higher by using VMI than by using either standard or iodine density imaging. For interobserver agreement of visual detection of LIE, the agreement for VMI was excellent and the κ value (κ, 0.87) was higher than that for the standard 120-kVp (κ, 0.70) and iodine density (κ, 0.83) imaging. For detecting late-enhancing lesions, agreement with cardiac MRI was excellent by using VMI (κ, 0.90) and iodine density imaging (κ, 0.87) but was only good by using standard 120-kVp imaging (κ, 0.66). Quantitative comparisons of the ECV calculations by using CT and cardiac MRI showed excellent correlation (r 2 = 0.94). CONCLUSION Dual-energy cardiac CT can assess myocardial LIE and quantify ECV, with results comparable to those obtained by using cardiac MRI.© RSNA, 2019See also the commentary by Litt in this issue.
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Nagayama Y, Nakaura T, Oda S, Taguchi N, Utsunomiya D, Funama Y, Kidoh M, Namimoto T, Sakabe D, Hatemura M, Yamashita Y. Dual-layer detector CT of chest, abdomen, and pelvis with a one-third iodine dose: image quality, radiation dose, and optimal monoenergetic settings. Clin Radiol 2018; 73:1058.e21-1058.e29. [DOI: 10.1016/j.crad.2018.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 08/24/2018] [Indexed: 12/12/2022]
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Parakh A, Macri F, Sahani D. Dual-Energy Computed Tomography: Dose Reduction, Series Reduction, and Contrast Load Reduction in Dual-Energy Computed Tomography. Radiol Clin North Am 2018; 56:601-624. [PMID: 29936950 DOI: 10.1016/j.rcl.2018.03.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Evolution in computed tomography technology and image reconstruction have significantly changed practice. Dual energy computed tomography is being increasingly adopted owing to benefits of material separation, quantification, and improved contrast-to-noise ratio. The radiation dose can match that from single energy computed tomography. Spectral information derived from a polychromatic x-ray beam at different energies yields in image reconstructions that reduce the number of phases in a multiphasic examination and decrease the absolute amount of contrast media. This increased analytical and image processing capability provides new avenues for addressing radiation dose and iodine exposure concerns.
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Affiliation(s)
- Anushri Parakh
- Department of Radiology, Abdominal Imaging Division, Massachusetts General Hospital, White 270, 55 Fruit Street, Boston, MA 02114, USA
| | - Francesco Macri
- Department of Radiology, Abdominal Imaging Division, Massachusetts General Hospital, White 270, 55 Fruit Street, Boston, MA 02114, USA; Department of Radiology, University Hospital of Nimes, Place di Pr Debre, Nimes 30029, France
| | - Dushyant Sahani
- Department of Radiology, Abdominal Imaging Division, Massachusetts General Hospital, White 270, 55 Fruit Street, Boston, MA 02114, USA.
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Li W, Li A, Wang B, Niu X, Cao X, Wang X, Shi H. Automatic spectral imaging protocol and iterative reconstruction for radiation dose reduction in typical hepatic hemangioma computed tomography with reduced iodine load: a preliminary study. Br J Radiol 2018; 91:20170978. [PMID: 29714501 DOI: 10.1259/bjr.20170978] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE To evaluate the effect of automatic spectral imaging protocol selection (ASIS) and adaptive statistical iterative reconstruction (ASiR) technique in the reduction of radiation and contrast medium dose in typical hepatic hemangioma (HH) dual energy spectral CT (DEsCT). METHODS 62 patients with suspected HH were randomly divided into two groups equally: Group A, conventional 120-kVp CT with standard iodine load; Group B, DEsCT with ASIS technique and reduced iodine load, two sets of monochromatic spectral images were reconstructed: 69 keV level with 30% ASiR (Group B1) and 52 keV level with 50% ASiR (Group B2). The radiation and total iodine dose, quantitative analysis (standard deviation value, contrast-to-noise and contrast enhancement ratio) and qualitative analysis were evaluated. RESULTS No difference was observed in the standard deviation values, subjective image noise, and the diagnostic acceptability score among the three groups (p > 0.05). Contrast to noise [Group B2 vs A, B1 in arterial phase (AP): 19.51 ± 6.29 vs 15.77 ± 5.93, 11.46 ± 2.84; Group B2 vs A, B1 in portal venous phase (PVP): 9.96 ± 2.18 vs 8.19 ± 3.04, 6.01 ± 1.82], contrast enhancement ratio (Group B2 vs A, B1 in AP: 6.88 ± 2.01 vs 5.47 ± 2.01, 4.15 ± 1.28; Group B2 vs A, B1 in PVP: 5.58 ± 1.02 vs 4.54 ± 1.13, 3.49 ± 0.83), and the lesion conspicuity score (Group B2 vs A, B1 in AP: 3.93 ± 0.26 vs 3.45 ± 0.51, 3.10 ± 0.49; Group B2 vs A, B1 in PVP: 3.90 ± 0.31 vs 3.48 ± 0.57, 3.14 ± 0.44) for Group B2 were higher than those in Group A and B1 (p < 0.05). Compared to Group A, the radiation dose and total iodine dose in Group B were reduced by 30 and 41%, respectively (radiation dose in Group B vs A: 5.53 ± 1.59 vs 7.91± 2.71 mSv; iodine dose in Group B vs A: 18.85 ± 2.88 vs 31.78±3.89 ml; p < 0.05). CONCLUSION DEsCT with ASIS and ASiR technique can reduce the radiation dose without image quality degradation as compared to the conventional 120-kVp CT. The monochromatic spectral images at 52 keV level with 50% ASiR allows the reduction in total iodine dose without deteriorating diagnostic performance. Advances in knowledge: ASIS combined with ASiR technique, by using monochromatic spectral images at 52 keV level, represents a feasible imaging protocol to reduce the radiation and total iodine dose in assessment of typical HH.
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Affiliation(s)
- Wei Li
- 1 Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University , Jinan, Shandong , China
| | - Aiyin Li
- 1 Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University , Jinan, Shandong , China
| | - Bin Wang
- 2 Department of Medical Imaging, ZhangQiu district hospital of TCM , Jinan, Shandong , China
| | - Xiuyuan Niu
- 2 Department of Medical Imaging, ZhangQiu district hospital of TCM , Jinan, Shandong , China
| | - Xin Cao
- 1 Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University , Jinan, Shandong , China
| | - Xinyi Wang
- 1 Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University , Jinan, Shandong , China
| | - Hao Shi
- 1 Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University , Jinan, Shandong , China
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van Hamersvelt RW, Eijsvoogel NG, Mihl C, de Jong PA, Schilham AMR, Buls N, Das M, Leiner T, Willemink MJ. Contrast agent concentration optimization in CTA using low tube voltage and dual-energy CT in multiple vendors: a phantom study. Int J Cardiovasc Imaging 2018. [PMID: 29516228 DOI: 10.1007/s10554-018-1329-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We investigated the feasibility and extent to which iodine concentration can be reduced in computed tomography angiography imaging of the aorta and coronary arteries using low tube voltage and virtual monochromatic imaging of 3 major dual-energy CT (DECT) vendors. A circulation phantom was imaged with dual source CT (DSCT), gemstone spectral imaging (GSI) and dual-layer spectral detector CT (SDCT). For each scanner, a reference scan was acquired at 120 kVp using routine iodine concentration (300 mg I/ml). Subsequently, scans were acquired at lowest possible tube potential (70, 80, 80 kVp, respectively), and DECT-mode (80/150Sn, 80/140 and 120 kVp, respectively) in arterial phase after administration of iodine (300, 240, 180, 120, 60, 30 mg I/ml). Objective image quality was evaluated using attenuation, CNR and dose corrected CNR (DCCNR) measured in the aorta and left main coronary artery. Average DCCNR at reference was 227.0, 39.7 and 60.2 for DSCT, GSI and SDCT. Maximum iodine concentration reduction without loss of DCCNR was feasible down to 180 mg I/ml (40% reduced) for DSCT (DCCNR 467.1) and GSI (DCCNR 46.1) using conventional CT low kVp, and 120 mg I/ml (60% reduced) for SDCT (DCCNR 171.5) using DECT mode. Low kVp scanning and DECT allows for 40-60% iodine reduction without loss in image quality compared to reference. Optimal scan protocol and to which extent varies per vendor. Further patient studies are needed to extend and translate our findings to clinical practice.
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Affiliation(s)
- Robbert W van Hamersvelt
- Department of Radiology, University Medical Center Utrecht, Utrecht University, P. O. Box 85500, 3508 GA, Utrecht, The Netherlands.
| | - Nienke G Eijsvoogel
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Casper Mihl
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Pim A de Jong
- Department of Radiology, University Medical Center Utrecht, Utrecht University, P. O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Arnold M R Schilham
- Department of Radiology, University Medical Center Utrecht, Utrecht University, P. O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Nico Buls
- Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Marco Das
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Tim Leiner
- Department of Radiology, University Medical Center Utrecht, Utrecht University, P. O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Martin J Willemink
- Department of Radiology, University Medical Center Utrecht, Utrecht University, P. O. Box 85500, 3508 GA, Utrecht, The Netherlands
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Saito H, Noda K, Ogasawara K, Atsuji S, Takaoka H, Kajihara H, Nasu J, Kitaoka M, Morishita S, Matsushita I, Katahira K. Reduced iodinated contrast media for abdominal imaging by dual-layer spectral detector computed tomography for patients with kidney disease. Radiol Case Rep 2018; 13:437-443. [PMID: 29904492 PMCID: PMC6000079 DOI: 10.1016/j.radcr.2018.01.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 01/26/2018] [Indexed: 01/17/2023] Open
Abstract
Contrast-enhanced computed tomography using iodinated contrast media is useful for diagnosis of gastrointestinal diseases. However, contrast-induced nephropathy remains problematic for kidney diseases patients. Although current guidelines recommended the use of a minimal dose of contrast media necessary to obtain adequate images for diagnosis, obtaining adequate images with sufficient contrast enhancement is difficult with conventional computed tomography using reduced contrast media. Dual-layer spectral detector computed tomography enables the simultaneous acquisition of low- and high-energy data and the reconstruction of virtual monochromatic images ranging from 40 to 200 keV, retrospectively. Low-energy virtual monochromatic images can enhance the contrast of images, thereby facilitating reduced contrast media. In case 1, abdominal computed tomography angiography at 50 keV using 40% of the conventional dose of contrast media revealed the artery that was the source of diverticular bleeding in the ascending colon. In case 2, ischemia of the transverse colon was diagnosed by contrast-enhanced computed tomography and iodine-selective imaging using 40% of the conventional dose of contrast media. In case 3, advanced esophagogastric junctional cancer was staged and preoperative abdominal computed tomography angiography could be obtained with 30% of the conventional dose of contrast media. However, the texture of virtual monochromatic images may be a limitation at low energy.
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Affiliation(s)
- Hirokazu Saito
- Department of Gastroenterology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Minami-ku, Kumamoto City, Kumamoto, 862-0965, Japan
| | - Kana Noda
- Department of Gastroenterology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Minami-ku, Kumamoto City, Kumamoto, 862-0965, Japan
| | - Koji Ogasawara
- Department of Radiology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Minami-ku, Kumamoto City, Kumamoto, 862-0965, Japan
| | - Shutaro Atsuji
- Department of Radiology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Minami-ku, Kumamoto City, Kumamoto, 862-0965, Japan
| | - Hiroko Takaoka
- Department of Radiology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Minami-ku, Kumamoto City, Kumamoto, 862-0965, Japan
| | - Hiroo Kajihara
- Department of Radiology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Minami-ku, Kumamoto City, Kumamoto, 862-0965, Japan
| | - Jiro Nasu
- Department of Gastroenterological Surgery Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Minami-ku, Kumamoto City, Kumamoto, 862-0965, Japan
| | - Mitsuhiko Kitaoka
- Department of Diagnostic Pathology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Minami-ku, Kumamoto City, Kumamoto, 862-0965, Japan
| | - Shoji Morishita
- Department of Radiology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Minami-ku, Kumamoto City, Kumamoto, 862-0965, Japan
| | - Ikuo Matsushita
- Department of Gastroenterology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Minami-ku, Kumamoto City, Kumamoto, 862-0965, Japan
| | - Kazuhiro Katahira
- Department of Radiology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Minami-ku, Kumamoto City, Kumamoto, 862-0965, Japan
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Nagayama Y, Nakaura T, Oda S, Utsunomiya D, Funama Y, Iyama Y, Taguchi N, Namimoto T, Yuki H, Kidoh M, Hirata K, Nakagawa M, Yamashita Y. Dual-layer DECT for multiphasic hepatic CT with 50 percent iodine load: a matched-pair comparison with a 120 kVp protocol. Eur Radiol 2017; 28:1719-1730. [PMID: 29063254 DOI: 10.1007/s00330-017-5114-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/15/2017] [Accepted: 10/02/2017] [Indexed: 01/17/2023]
Abstract
OBJECTIVES To evaluate the image quality and lesion conspicuity of virtual-monochromatic-imaging (VMI) with dual-layer DECT (DL-DECT) for reduced-iodine-load multiphasic-hepatic CT. METHODS Forty-five adults with renal dysfunction who had undergone hepatic DL-DECT with 300-mgI/kg were included. VMI (40-70-keV, DL-DECT-VMI) was generated at each enhancement phase. As controls, 45 matched patients undergoing standard 120-kVp protocol (120-kVp, 600-mgI/kg, and iterative reconstruction) were included. We compared the size-specific dose estimate (SSDE), image noise, CT attenuation, and contrast-to-noise ratio (CNR) between protocols. Two radiologists scored the image quality and lesion conspicuity. RESULTS SSDE was significantly lower in DL-DECT group (p < 0.01). Image noise of DL-DECT-VMI was almost constant at each keV (differences of ≤15%) and equivalent to or lower than of 120-kVp. As the energy decreased, CT attenuation and CNR gradually increased; the values of 55-60 keV images were almost equivalent to those of standard 120-kVp. The highest scores for overall quality and lesion conspicuity were assigned at 40-keV followed by 45 to 55-keV, all of which were similar to or better than of 120-kVp. CONCLUSIONS For multiphasic-hepatic CT with 50% iodine-load, DL-DECT-VMI at 40- to 55-keV provides equivalent or better image quality and lesion conspicuity without increasing radiation dose compared with standard 120-kVp protocol. KEY POINTS • 40-55-keV yields optimal image quality for half-iodine-load multiphasic-hepatic CT with DL-DECT. • DL-DECT protocol decreases radiation exposure compared with 120-kVp scans with iterative reconstruction. • 40-keV images maximise conspicuity of hepatocellular carcinoma especially at hepatic-arterial phase.
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Affiliation(s)
- Yasunori Nagayama
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
| | - Takeshi Nakaura
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Seitaro Oda
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Daisuke Utsunomiya
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Yoshinori Funama
- Department of Medical Physics, Faculty of Life Sciences, Kumamoto University, 4-24-1 Kuhonji, Chuo-ku, Kumamoto, 862-0976, Japan
| | - Yuji Iyama
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Narumi Taguchi
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Tomohiro Namimoto
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Hideaki Yuki
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Masafumi Kidoh
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Kenichiro Hirata
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Masataka Nakagawa
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Yasuyuki Yamashita
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
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