A quantitative model of technetium-99m-DTPA-galactosyl-HSA for the assessment of hepatic blood flow and hepatic binding receptor.

Technetium-99m-diethylenetriaminepentaacetic acid-galactosyl-human serum albumin (99mTc-GSA) was studied in normal volunteers and in patients with impaired liver function. The extrapolation approach originated the absolute dose of 99mTc-GSA in blood and the hepatic blood volume. The heart and liver regression curves were simultaneously fractionated into the three compartments (extrahepatic blood, hepatic blood and hepatocytes). Four differential equations were integrated with the six parameters as variables, and the smallest residual sum of squares was obtained by the damping Gauss-Newton method. The result of hepatic blood flow was 1603 +/- 144 (ml/min) in normal controls, which was compatible with previously reported values. Maximal removal rate (mg/min) showed statistically significant differences between the normal volunteers and patients with chronic hepatitis or liver cirrhosis. Our kinetic model of 99mTc-GSA can be used in the evaluation of liver function.