Evaluation on Heterogeneity of Fatty Liver in Rats: A Multiparameter Quantitative Analysis by Dual Energy CT

Abstract

To investigate the value of using rapid kVp switching dual energy computed tomography (rsDECT) for the multi-parameter analysis of the heterogeneity of fatty liver in rat. Twenty-four male rats were randomly divided into experimental (n = 16) and control (n = 8) groups. Four rats in the experimental group and two in the control group were examined by rsDECT every 3 weeks starting from week 8. The liver fat contents (LFC) of the left and right liver lobes were measured on the fat(water)-based material decomposition images to calculate fat content and CT value of liver and spleen were measured on the 70keV monochromatic images to calculate the liver-to-spleen CT value ratio [(L/S)70 keV] and difference at 70keV[(L-S)70 keV], and the spectral curve slopes of the left and right liver lobes (Slope-L, Slope-R). Measurements were evaluated statistically. The statistical analysis showed that the (L/S)70 keV, (L-S)70 keV, Slope and LFC in the different fatty liver groups were all significantly different (p < 0.05). Pearson correlation analysis results showed that the rsDECT results of the left and right liver lobes correlated with the fat percentage from pathological analysis (p < 0.05), with the left liver lobe having better correlation. Paired t-tests showed that the fat percentage of the left liver lobe was significantly higher than that of the right one, while (L/S)70 keV, and (L-S)70 keV were significantly lower. Diagnostic analysis using ROC curve showed that the areas under the curves with parameters of the left liver lobe were also greater than those of the right liver lobe. rsDECT multi-parameter imaging could quantitatively evaluate the heterogeneity of fat deposition in the liver, providing valuable information for the accurate and effective assessment of the heterogeneity of fatty liver.