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

We performed positron emission tomography with O-15 water ((H2O)-O-15) to measure hepatic arterial and portal blood flow. In addition, portal haemodynamics and hepatic functional reserve were measured by per-rectal portal scintigraphy and scintigraphy with galactosyl human serum albumin, respectively. We studied 15 patients who had cirrhosis of the liver with underlying viral infection. After the intravenous injection of (H2O)-O-15, positron emission tomography was performed. Blood samples were obtained after beginning the emission scan. The blood samples and positron emission tomographic images were analysed to calculate the radioactivity in the blood and liver. One-compartment model analysis was used to estimate hepatic arterial and portal blood flow. Computer acquisition of gamma-camera data was started just before the injection of Tc-99(m)-galactosyl human serum albumin. A receptor index and an index of blood clearance were calculated on the basis of the radioactivity of the liver and heart. A Tc-99(m)-pertechnetate solution was instilled into the rectum; serial scintigrams were performed and radioactivity 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 portal blood flow and the Child-Turcotte classification score, portal shunt index and receptor index were all significant. Our results show that hepatic arterial and portal blood flow can be measured by positron emission tomography with (H2O)-O-15 non-invasively and physiologically. This technique may be useful in pathophysiological studies of liver disease. ((C) 2000 Lippincott Williams & Wilkins).