Diagnostic Significance of the Hepatic Parenchymal Retention Index as Determined by Hepatobiliary Scintigraphy in Liver Transplant Recipients

Abstract

Objectives: The aim of this study was to evaluate the usefulness of the hepatic parenchymal retention index in the early diagnosis of parenchymal complications in liver transplant recipients as determined by hepatobiliary scintigraphy.

Materials and Methods: This retrospective study reviewed 100 liver transplant recipients who had undergone orthotopic liver transplant. In all cases, hepatobiliary scintigraphy images recorded 7 to 10 days posttransplant were quantitatively reinterpreted according to hepatic parenchymal retention index. The hepatocyte extraction fraction value was also calculated. Scintigraphic findings as well as clinical, laboratory, and biopsy results were assessed.

Results: Quantitative analysis showed normal hepatocyte extraction fraction value in all subjects. However, significant differences in hepatic parenchymal retention index were observed. Thus, subjects were divided into 3 groups: group 1 (n=75), normal; group 2 (n=15), severely elevated; group 3 (n=10), mildly-to-moderately elevated hepatic parenchymal retention index. Evaluation of histopathological, clinical, and laboratory findings showed normal grafts in all group 1 recipients, acute rejection in all group 2 recipients, and hepatocyte damage/intrahepatic cholestasis in all group 3 recipients.

Conclusions: Based on these findings, we determined that hepatocyte extraction fraction value was not useful, whereas hepatic parenchymal retention index was beneficial for early and accurate diagnosis of parenchymal complications in liver transplant recipients.