CT density of mesenteric, retroperitoneal, and subcutaneous fat in cirrhotic patients: comparison with control subjects.

We determined the density in Hounsfield units of the mesenteric, retroperitoneal, and subcutaneous fat on CT scans made in 41 patients with biopsy-proved cirrhosis and compared the results with the density of the fat in these locations in 34 control subjects, in an attempt to quantify changes in fat density in patients with cirrhosis. The mean densities of mesenteric, retroperitoneal, and subcutaneous fat in patients with cirrhosis were -56, -107, and -111 H, respectively. The corresponding mean densities in control subjects were -107, -118, and -124 H. The mean density of mesenteric fat in patients with cirrhosis was 50% greater than that of their subcutaneous fat (p less than .0001), 48% greater than that of their retroperitoneal fat (p less than .0001), and 48% greater than that of the mesenteric fat in control subjects (p less than .0001). The mean density of subcutaneous fat in the anterior abdominal wall in patients with cirrhosis was -96 H compared with -119 H for that in their posterior abdominal wall. The corresponding mean densities in control subjects were -109 and -131 H. Density of subcutaneous fat in the anterior abdominal wall for all subjects (patients and controls) was 18% greater than that of subcutaneous fat in the posterior abdominal wall (p less than .05). In all locations, the statistical trend was for patients with cirrhosis to have higher density fat than did control subjects. These changes in density are thought to represent diffuse fat edema, most prominently in the mesentery because of portal hypertension.