Tc-99m
galactosyl-neoglycoalbumin (Tc-NGA) is a new liver-imaging agent which binds to
hepatic binding protein (an hepatocyte-specific membrane receptor). This study evaluated the sensitivity of Tc-NGA kinetics and imaging anatomy to pathologic states that are encountered after
liver transplantation. Studies were performed in adolescent pigs under control conditions (18 studies), and after orthotopic
liver transplantation (nine studies), common bile duct
ligation (three studies), hepatic artery
ligation (one study), and hepatic resection (two studies). Anatomic and kinetic data were analyzed. Excellent liver images and minimal kinetic changes were noted after common bile duct
ligation. Marked imaging defects and major kinetic alterations were observed after hepatic artery
ligation and in the presence of preservation injury. Marked depression in hepatic Tc-NGA uptake was observed during acute rejection. Minor alterations in Tc-NGA kinetics were noted after a 25%
hepatectomy. These studies indicate that minimal changes in Tc-NGA uptake occur after common bile duct
ligation; Tc-NGA uptake is markedly sensitive to hepatic
ischemia; decreased Tc-NGA uptake occurs during acute rejection; and
hepatic infarcts are demonstrated promptly after preservation injury. Thus Tc-NGA imaging provides a novel means of evaluating hepatic
ischemia, hepatic preservation, and hepatic allograft rejection. Tc-NGA imaging may also provide a means of evaluating hepatic regeneration and hepatocyte retrodifferentiation during regeneration.