Evaluation of the liver function by 99mTc-N-pyridoxyl-5-methyltryptophan (PMT) scintigraphy. In patients with chronic viral liver diseases and in perfused rat livers

99mTc-N-pyridoxyl-5-methyltryptophan (PMT) scintigraphy was performed in 64 cases of chronic viral liver diseases, and in 6 normal controls. The mean hepatic transit time (MTT) calculated from the time-activity curves of 99mTc-PMT scintigraphy in the patients with chronic hepatitis (CH2a) and liver cirrhosis showed significant delay as compared with that of control, although the hepatic extraction (LVT 1/2) was disturbed only in the patients with liver cirrhosis. In the rats with hepatic fibrosis caused by thioacetamide, when the livers were perfused with 99mTc-PMT, the biliary excretory peak was delayed and the cumulative excretion rates were significantly less with the development of liver fibrosis. However, the effluent rates and extraction rates were not significantly different. These results suggest that MTT was useful parameter to evaluate the minor liver dysfunction. (author)