Variable portal circulation from inferior mesenteric vein assessed by per-rectal radionuclide administration

The intrahepatic distribution of radioactivity after the per-rectal administration of 201T-chloride and/or 99Tcm-pertechnetate was investigated in 177 studies in 149 patients with no liver disease or diffuse liver disease and compared with that of 99Tcm-stannous (99Tcm-Sn) colloid scintigrams. The patients were classified into two groups: distribution of intrahepatic radioactivity of 201Tl and/or 99Tcm-pertechnetate scintigrams similar to (homogeneous) or different from (heterogeneous) that of 99Tcm-Sn-colloid scintigrams. The heterogeneous group was divided into three subgroups: increased radioactivity of the right lobe (right dominant pattern), increased radioactivity of the left lobe (left dominant pattern) and uneven distribution of radioactivity in both lobes (uneven pattern). Of the 80 patients in whom the studies were performed in the supine position at rest, 14 (17.5%) showed a heterogeneous pattern (8 right dominant, 4 left dominant, 2 uneven) and 66 (82.5%) a homogeneous pattern. In the 97 patients allowed free body movement, 6 (6.2%) showed a heterogeneous (1 right dominant, 5 left dominant) and 91 (93.8%) a homogeneous pattern. A significant difference in the incidence of heterogeneous distribution between the resting and free body movement groups was found (P < 0.05). One patient with a left dominant pattern after free body movement with 201Tl showed a right dominant pattern at rest in the 99Tcm-pertechnetate study. It is concluded that a heterogeneous intrahepatic distribution of inferior mesenteric vein blood is sometimes observed and that the distribution of portal vein blood flow seems to be affected by the patient's positioning and free body movement.