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Asmundo L, Rizzetto F, Srinivas Rao S, Sgrazzutti C, Vicentin I, Kambadakone A, Catalano OA, Vanzulli A. Dual-energy CT applications on liver imaging: what radiologists and radiographers should know? A systematic review. Abdom Radiol (NY) 2024:10.1007/s00261-024-04380-y. [PMID: 38811447 DOI: 10.1007/s00261-024-04380-y] [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: 03/05/2024] [Revised: 05/06/2024] [Accepted: 05/11/2024] [Indexed: 05/31/2024]
Abstract
PURPOSE This review aims to provide a comprehensive summary of DECT techniques, acquisition workflows, and post-processing methods. By doing so, we aim to elucidate the advantages and disadvantages of DECT compared to conventional single-energy CT imaging. METHODS A systematic search was conducted on MEDLINE/EMBASE for DECT studies in liver imaging published between 1980 and 2024. Information regarding study design and endpoints, patient characteristics, DECT technical parameters, radiation dose, iodinated contrast agent (ICA) administration and postprocessing methods were extracted. Technical parameters, including DECT phase, field of view, pitch, collimation, rotation time, arterial phase timing (from injection), and venous timing (from injection) from the included studies were reported, along with formal narrative synthesis of main DECT applications for liver imaging. RESULTS Out of the initially identified 234 articles, 153 met the inclusion criteria. Extensive variability in acquisition parameters was observed, except for tube voltage (80/140 kVp combination reported in 50% of articles) and ICA administration (1.5 mL/kg at 3-4 mL/s, reported in 91% of articles). Radiation dose information was provided in only 40% of articles (range: 6-80 mGy), and virtual non-contrast imaging (VNC) emerged as a common strategy to reduce the radiation dose. The primary application of DECT post-processed images was in detecting focal liver lesions (47% of articles), with predominance of study focusing on hepatocellular carcinoma (HCC) (27%). Furthermore, a significant proportion of the articles (16%) focused on enhancing DECT protocols, while 15% explored metastasis detection. CONCLUSION Our review recommends using 80/140 kVp tube voltage with 1.5 mL/kg ICA at 3-4 mL/s flow rate. Post-processing should include low keV-VMI for enhanced lesion detection, IMs for tumor iodine content evaluation, and VNC for dose reduction. However, heterogeneous literature hinders protocol standardization.
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Affiliation(s)
- Luigi Asmundo
- Postgraduate School of Diagnostic and Interventional Radiology, Università degli Studi di Milano, via Festa del Perdono 7, 20122, Milan, Italy
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Francesco Rizzetto
- Postgraduate School of Diagnostic and Interventional Radiology, Università degli Studi di Milano, via Festa del Perdono 7, 20122, Milan, Italy.
- Department of Radiology, ASST Grande Ospedale Metropolitano Niguarda, Piazza Ospedale Maggiore 3, 20162, Milan, Italy.
| | - Shravya Srinivas Rao
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Cristiano Sgrazzutti
- Department of Radiology, ASST Grande Ospedale Metropolitano Niguarda, Piazza Ospedale Maggiore 3, 20162, Milan, Italy
| | - Ilaria Vicentin
- Department of Radiology, ASST Grande Ospedale Metropolitano Niguarda, Piazza Ospedale Maggiore 3, 20162, Milan, Italy
| | - Avinash Kambadakone
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Onofrio Antonio Catalano
- Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Angelo Vanzulli
- Department of Radiology, ASST Grande Ospedale Metropolitano Niguarda, Piazza Ospedale Maggiore 3, 20162, Milan, Italy
- Department of Oncology and Hemato-Oncology, Università degli Studi di Milano, via Festa del Perdono 7, 20122, Milan, Italy
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Borges AP, Antunes C, Caseiro-Alves F. Spectral CT: Current Liver Applications. Diagnostics (Basel) 2023; 13:diagnostics13101673. [PMID: 37238163 DOI: 10.3390/diagnostics13101673] [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: 03/26/2023] [Revised: 05/02/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023] Open
Abstract
Using two different energy levels, dual-energy computed tomography (DECT) allows for material differentiation, improves image quality and iodine conspicuity, and allows researchers the opportunity to determine iodine contrast and radiation dose reduction. Several commercialized platforms with different acquisition techniques are constantly being improved. Furthermore, DECT clinical applications and advantages are continually being reported in a wide range of diseases. We aimed to review the current applications of and challenges in using DECT in the treatment of liver diseases. The greater contrast provided by low-energy reconstructed images and the capability of iodine quantification have been mostly valuable for lesion detection and characterization, accurate staging, treatment response assessment, and thrombi characterization. Material decomposition techniques allow for the non-invasive quantification of fat/iron deposition and fibrosis. Reduced image quality with larger body sizes, cross-vendor and scanner variability, and long reconstruction time are among the limitations of DECT. Promising techniques for improving image quality with lower radiation dose include the deep learning imaging reconstruction method and novel spectral photon-counting computed tomography.
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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, 3004-504 Coimbra, Portugal
- Academic and Clinical Centre of Coimbra, 3000-370 Coimbra, Portugal
| | - Célia Antunes
- Medical Imaging Department, Coimbra University Hospitals, 3004-561 Coimbra, Portugal
- Academic and Clinical Centre of Coimbra, 3000-370 Coimbra, Portugal
| | - Filipe Caseiro-Alves
- Medical Imaging Department, Coimbra University Hospitals, 3004-561 Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, 3004-504 Coimbra, Portugal
- Academic and Clinical Centre of Coimbra, 3000-370 Coimbra, Portugal
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Morita K, Nishie A, Ushijima Y, Takayama Y, Fujita N, Kubo Y, Ishimatsu K, Yoshizumi T, Maehara J, Ishigami K. Noninvasive assessment of liver fibrosis by dual-layer spectral detector CT. Eur J Radiol 2021; 136:109575. [PMID: 33548853 DOI: 10.1016/j.ejrad.2021.109575] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/08/2021] [Accepted: 01/25/2021] [Indexed: 01/08/2023]
Abstract
PURPOSE To elucidate the diagnostic ability of liver fibrosis using (1) liver parenchymal iodine density on equilibrium computed tomographic imaging and (2) extracellular volume (ECV) measured by dual-layer spectral detector CT. METHODS From April 2018 to June 2019, 68 patients [mean age, 62 years; 39 males, 29 females] underwent dynamic contrast-enhanced CT by a dual-layer spectral detector CT system before liver transplantation or liver resection. The iodine densities of liver parenchyma (I liver) and aorta (I aorta) were independently measured by two radiologists at the equilibrium phase. The iodine-density ratio (I-ratio) (I liver/ I aorta) and the CT-ECV were calculated. Spearman's rank correlation coefficient was used to analyze the relationship between the I-ratio or the CT-ECV and the fibrosis stage. A receiver operating characteristic (ROC) curve analysis was performed to determine the accuracy of the I-ratio and the CT-ECV for discriminating fibrosis stages. RESULTS For both readers, the I-ratio and the CT-ECV increased significantly as the fibrosis stage advanced (I-ratio: rho = 0.380 and 0.443, p < 0.01; CT-ECV: rho = 0.423 and 0.469, p < 0.01). The CT-ECV showed better diagnostic accuracy for staging fibrosis, and the area under the ROC curve values for discriminating F4 stage were 0.884 and 0.925. The two readers' cutoff values of the CT-ECV for diagnosing fibrosis as F4 were 26.2 % and 29.3 %, with 95.0 % and 90.0 % sensitivity and 72.9 % and 85.4 % specificity, respectively. CONCLUSION The liver parenchymal iodine density on the equilibrium phase and the CT-ECV can be useful for predicting a high stage of liver fibrosis.
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Affiliation(s)
- Koichiro Morita
- Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Akihiro Nishie
- Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Yasuhiro Ushijima
- Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Yukihisa Takayama
- Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Nobuhiro Fujita
- Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Yuichiro Kubo
- Departments of Molecular Imaging & Diagnosis, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Keisuke Ishimatsu
- Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Tomoharu Yoshizumi
- Departments of Surgery and Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Junki Maehara
- Departments of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Kousei Ishigami
- Departments of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
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