Assessment of hepatic blood flow by PET with O-15 water: Correlation between per-rectal portal scintigraphy with Tc-99(m)-pertechnetate and scintigraphy with Tc-99(m)-GSA

We performed positron emission tomography with O-15 water ((H2O)-O-15) to m easure hepatic arterial and portal blood flow. In addition, portal haemodyn amics and hepatic functional reserve were measured by per-rectal portal sci ntigraphy and scintigraphy with galactosyl human serum albumin, respectivel y. We studied 15 patients who had cirrhosis of the liver with underlying vi ral infection. After the intravenous injection of (H2O)-O-15, positron emis sion tomography was performed. Blood samples were obtained after beginning the emission scan. The blood samples and positron emission tomographic imag es were analysed to calculate the radioactivity in the blood and liver. One -compartment model analysis was used to estimate hepatic arterial and porta l blood flow. Computer acquisition of gamma-camera data was started just be fore the injection of Tc-99(m)-galactosyl human serum albumin. A receptor i ndex and an index of blood clearance were calculated on the basis of the ra dioactivity of the liver and heart. A Tc-99(m)-pertechnetate solution was i nstilled into the rectum; serial scintigrams were performed and radioactivi ty curves for the Liver and heart were recorded sequentially. A per-rectal portal shunt index was calculated from the curves. Median portal blood flow was 80 ml . 100 g(-1) . min(-1), median hepatic arterial blood flow was 56 ml . 100 g(-1) . min(-1), and median total hepatic blood flow was 138 ml . 100 g(-1) . min(-1) in patients with cirrhosis. The correlations between p ortal blood flow and the Child-Turcotte classification score, portal shunt index and receptor index were all significant. Our results show that hepati c arterial and portal blood flow can be measured by positron emission tomog raphy with (H2O)-O-15 non-invasively and physiologically. This technique ma y be useful in pathophysiological studies of liver disease. ((C) 2000 Lippi ncott Williams & Wilkins).