Evaluation of hepatic function using 99mTc-galactosyl human serum albumin (GSA) scintigraphy: comparison with antipyrine plasma clearance

^99mTc-galactosyl human serum albumin (GSA) is a new scintigraphy agent which binds specifically to asialoglycoprotein receptors on hepatocytes, and can be used to evaluate hepatic function. Indocyanine green (ICG) is hepatic blood flow-dependent, while antipyrine plasma clearance is independent of blood flow and thus antipyrine plasma clearance is an excellent parameter with which to assess liver function. In this study, we investigated the relationship between GSA examination and antipyrine plasma clearance to assess the usefulness of GSA in evaluating metabolic function of the liver. Studies were performed on 22 patients with liver diseases. Antipyrine plasma clearance measurement, ICG testing and biochemical analysis of blood were performed at the same time as GSA examination. GSA HH15 and antipyrine plasma clearance showed a good correlation (r = −0.702, P < 0.0005). On the other hand, ICGR15 showed a poor correlation with antipyrine plasma clearance (r = 0.449, P < 0.05). The results of this study suggest, that hepatic function determined using GSA is more closely related to the metabolic capacity of hepatocytes than to hepatic blood flow.