Validation of intimate correlation between visceral fat and hepatic steatosis: Quantitative measurement techniques using CT for area of fat and MR for hepatic steatosis

Abstract

Background & aim: The relationship between obesity and hepatic steatosis is well known, and there are many methods to measure obesity and severity of hepatic steatosis. Because of advances in radiologic techniques, the areas of certain body components can be measured on computed tomography (CT) while the severity of hepatic steatosis can be measured by magnetic resonance spectroscopy (MRS) with high accuracy. The aim of this study is to investigate the relationship between degree of fatty infiltration of the liver measured by MRS and body composition measured from CT images.

Materials and methods: We evaluated 95 potential liver donors who underwent abdomen CT and liver MRI (including MRS) between February 2014 and September 2015 in a tertiary university hospital. Body composition analysis was performed on CT images using commercial software. The areas of subcutaneous fat, visceral fat and abdominal circumference were measured automatically and the area of muscle was measured semi-automatically. The degree of hepatic steatosis was measured by MRS.

Results: The degree of hepatic steatosis showed a significant correlation with total fat area, visceral fat area, subcutaneous fat area, muscle area, abdominal circumference, BMI, and ratio of visceral fat to total fat. The strongest correlation was between hepatic steatosis and the area of visceral fat in all subjects (r=0.569). Multivariate regression analysis showed that male gender and visceral fat area were significantly associated with hepatic steatosis (P = 0.031, <0.001, respectively).

Conclusions: The area of visceral fat has the most intimate correlation to the severity of hepatic steatosis among all significantly correlated parameters associated with body habitus. Accurate and quantitative body composition measurement and degree of hepatic steatosis can be noninvasively performed using advanced radiological techniques.

Keywords: Computed tomography; Hepatic steatosis; Magnetic resonance spectroscopy; Obesity.