Yun Peng1, Jing Ye1, Chang Liu1, Hongru Jia1, Jun Sun1, Jun Ling1, Martin Prince2, Chang Li3, Xianfu Luo1. 1. Department of Radiology, Northern Jiangsu People's Hospital, Clinical Medical College, Yangzhou University, Yangzhou, China. 2. Department of Radiology, Weill Medical College of Cornell University, New York, NY, USA. 3. Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
Abstract
BACKGROUND: Liver iron and fat are often co-deposited, synergistically aggravating the progression of chronic liver disease. Accurate determination of liver iron and fat content is helpful for patient management. To assess the accuracy of hepatic iron/fat decomposition using dual-energy computed tomography (DECT) for simultaneously quantifying hepatic iron and fat when both are present. METHODS: Sixty-eight New Zealand rabbits on a high-fat/cholesterol diet plus iron injections were used to establish a model of coexisting hepatic iron/fat. Abdominal imaging was performed using dual-source DECT. The iron and fat fractions (Iron-CT and Fat-CT, respectively) were calculated using a 3-material decomposition algorithm. The spectroscopic liver iron concentration (LIC) grading (normal, mild, moderate, severe, and massive iron overload) and the histopathological fat fraction (Fat-ref) grading (normal, mild, moderate, severe steatosis) were used as references. Correlations between the DECT parameters and the references were analyzed. Hepatic iron/fat quantification equations were established and validated. Analysis of covariance was used to assess the influence of fat on iron measurements and vice versa. RESULTS: Iron-CT highly correlated with LIC (r=0.94, P<0.001), and Fat-CT highly correlated with Fat-ref (r=0.88, P<0.001). Both the Iron-CT- and Fat-CT-derived LIC and fat fraction showed good agreement with spectroscopy/histology. The linear relationship between Iron-CT and spectroscopic LIC was not affected by the grade of hepatic fat (F=1.93, P=0.16). The linear relationship between Fat-CT and Fat-ref was unaffected by hepatic iron grades from normal to severe (F=0.18, P=0.91). However, with massive iron overload [>15.0 mg Fe/g (270 µmol/g)] the regression began to deviate, causing fat underestimation (F=5.50, P=0.04). CONCLUSIONS: Our DECT-based iron/fat decomposition algorithm accurately measured hepatic iron and fat when both were present in a rabbit model. Hepatic fat may be underestimated when there is massive iron overload. 2021 Quantitative Imaging in Medicine and Surgery. All rights reserved.
BACKGROUND: Liver iron and fat are often co-deposited, synergistically aggravating the progression of chronic liver disease. Accurate determination of liver iron and fat content is helpful for patient management. To assess the accuracy of hepatic iron/fat decomposition using dual-energy computed tomography (DECT) for simultaneously quantifying hepatic iron and fat when both are present. METHODS: Sixty-eight New Zealand rabbits on a high-fat/cholesterol diet plus iron injections were used to establish a model of coexisting hepatic iron/fat. Abdominal imaging was performed using dual-source DECT. The iron and fat fractions (Iron-CT and Fat-CT, respectively) were calculated using a 3-material decomposition algorithm. The spectroscopic liver iron concentration (LIC) grading (normal, mild, moderate, severe, and massive iron overload) and the histopathological fat fraction (Fat-ref) grading (normal, mild, moderate, severe steatosis) were used as references. Correlations between the DECT parameters and the references were analyzed. Hepatic iron/fat quantification equations were established and validated. Analysis of covariance was used to assess the influence of fat on iron measurements and vice versa. RESULTS: Iron-CT highly correlated with LIC (r=0.94, P<0.001), and Fat-CT highly correlated with Fat-ref (r=0.88, P<0.001). Both the Iron-CT- and Fat-CT-derived LIC and fat fraction showed good agreement with spectroscopy/histology. The linear relationship between Iron-CT and spectroscopic LIC was not affected by the grade of hepatic fat (F=1.93, P=0.16). The linear relationship between Fat-CT and Fat-ref was unaffected by hepatic iron grades from normal to severe (F=0.18, P=0.91). However, with massive iron overload [>15.0 mg Fe/g (270 µmol/g)] the regression began to deviate, causing fat underestimation (F=5.50, P=0.04). CONCLUSIONS: Our DECT-based iron/fat decomposition algorithm accurately measured hepatic iron and fat when both were present in a rabbit model. Hepatic fat may be underestimated when there is massive iron overload. 2021 Quantitative Imaging in Medicine and Surgery. All rights reserved.
Authors: Xian Fu Luo; Xue Qian Xie; Shu Cheng; Yi Yang; Jing Yan; Huan Zhang; Wei Min Chai; Bernhard Schmidt; Fu Hua Yan Journal: Radiology Date: 2015-04-16 Impact factor: 11.105
Authors: Elmar Aigner; Igor Theurl; Milan Theurl; Dieter Lederer; Heike Haufe; Otto Dietze; Michael Strasser; Christian Datz; Guenter Weiss Journal: Am J Clin Nutr Date: 2008-05 Impact factor: 7.045