A new method for evaluating portal systemic circulation was presented. Following transrectal administration of 99mTc - MIBI it was feasible to detect the presence of portasy-atemic shunting in both animal and patient studies. The heart -liver ratio （H/L ratio） and the portosystemic shunt index （SI） in normal controls were 0. 21±0.08 and 0. 17 ± 0. 06. Whereas in patients of liver cirrhosis with portal hypertension were 1. 12 ± 0. 18

and 0. 54 ± 0. 07 respectively. And showed a significant difference （p<0. 01） between normal and cirrhosis group. A good correlation between the H/L

SI and the portal pressure measurement during operation （r = 0. 93） was also found. Thereby it seems that portasystemic shunting can be quantified with this radionuclide noninvasive method .