Nontumorous decrease in Tc-99m GSA accumulation

Nontumorous decrease in Tc-99m-GSA accumulation has not been well covered i n the literature. Understanding of this phenomenon is, however, essential f or accurate evaluation of regional hepatic function. Scintigrams (transaxia l SPECT) of 269 patients who underwent Tc-99m-GSA liver scintigraphy were r eviewed for the presence of nontumorous decreases in Tc-99m-GSA accumulatio n. Nontumorous decreases in Tc-99m-GSA accumulation were seen in 32 of 269 patients (12%). In 16 of the 32 patients (6%). nontumorous decreases in Tc- 99m-GSA accumulation corresponded to regional decrease in portal venous How . The causes of such decrease in portal venous flow were portal thrombus of hepatocellular carcinomas in eight patients, portal venous stenosis or occ lusion by hilar cholangiocarcinomas in five patients, inter alia. In eight patients (3%), the regions with decreased Tc-99m-GSA accumulation correlate d with massive hepatic necrosis in fulminant hepatitis, scar in hepatitis, or confluent fibrosis in cirrhotic liver. In two patients (0.7%) with hilar cholangiocarcinomas, the possible causes of lobar decrease in Tc-99m-GSA a ccumulation were thought to be lobar decrease in portal venous Flow, lobar biliary stasis, or both. In four patients (1.5%), the exact causes of nontu morous decrease in Tc-99m-GSA accumulation could not be determined.