Computed Tomography Measurements of Hepatic Steatosis in Cholelitihiasis and Cholecystectomy Cases Using Unenhanced Images

Introduction: Computed tomography (CT) measurements of hepatic steatosis can be performed using unenhanced CT images. The purpose of this study was to assess the occurrence of hepatic steatosis using unenhanced CT images for patients undergoing cholecystectomy or having cholelithiasis. Methods: A total of 143 unenhanced CT cases from a single centre were retrospectively examined. The CT number of liver, ratio of CT number of liver to spleen, and CT number of liver minus CT number of spleen were measured in three groups: (1) patients undergoing cholecystectomy, (2) patients having cholelithiasis, and (3) control group. Abdominal circumference, anterior subcutaneous fat tissue thickness, and body mass index were obtained. Results: Mean CT number of liver was significantly different between the group of patients with cholecystectomy and cholelithiasis and the control group (P < .001) and also between cases of cholecystectomy and cholelithiasis (P = .041), with the lowest CT number of liver in the cholecystectomy group. The mean CT number of liver minus CT number of spleen and mean CT number (liver/spleen) ratios, evaluated separately for both lobes, were not different comparing the cholelithiasis and cholecystectomy groups. The mean CT number of liver minus CT number of spleen and mean CT number (liver/spleen) ratios differed significantly between the control group and both patient groups (P < .001). Positive correlations were identified between abdominal circumference, subcutaneous fat depth, body mass index, and liver size and hepatic steatosis. Conclusion: There was an increased occurrence of hepatic steatosis in patients who have undergone a cholecystectomy compared with patients treated for cholelithiasis and the control group.