FOCAL SPARING OF LIVER PARENCHYMA IN STEATOSIS - ROLE OF THE GALLBLADDER AND ITS VESSELS

The purpose of this study was to determine the prevalence and localiza tion of focal areas of sparing in a population of patients with fatty infiltration (steatosis) of the liver. We also sought to determine if the blood supply of the gallbladder has an effect on fatty infiltratio n of the liver adjacent to it. We studied 290 patients with sonographi c signs of fatty infiltration of liver with gray scale sonography. In 58 of the patients, the gallbladder had been removed previously. A zon e of focal sparing was found in 67% of patients with liver steatosis ( 78% in patients with an intact gallbladder versus 33% in patients with previous cholecystectomy). In patients with an intact gallbladder, se gments 4 and 5 were spared most often. These segments were rarely spar ed in patients with previous cholecystectomy. Other sites of focal spa ring were observed with the same frequency in the two groups. We concl ude that focal sparing occurs frequently in patients with liver steato sis, especially in segments 4 and 5. When the gallbladder is absent, a reas of focal sparing are less frequent, and they rarely involve segme nts 4 and 5. This suggests that the blood supply of the gallbladder pl ays a role in the distribution of the fat in the adjacent liver. Focal sparing might serve as an additional sign in the diagnosis of steatos is of the liver, especially in patients with an intact gallbladder.