Hepatobiliary scintigraphy in a pediatric population: determination of hepatic extraction fraction by deconvolution analysis.
A study was performed to assess the feasibility of measuring the hepatic extraction fraction (HEF) and hepatic half clearance time (HCT) in pediatric patients with a variety of hepatobiliary diseases. There were 45 children categorized into four groups: normal 12; obstruction 9; hepatocellular disease (HCD) 16 and miscellaneous 8. In the normal patients, the mean HEF was 99% +/- 3.6% and the HCT was 23.6 +/- 7.7 min. In the two disease categories, hepatocellular disease and obstruction, there was a wide range of HEF 15%-84% and 25%-100%, respectively. This reflected the varying degrees of liver dysfunction and/or cholestasis. The average results of HEF for the HCD group was significantly lower than controls, and the greatest difference of the HCD group and other disease groups was with the miscellaneous group. This was not, however, different from the obstructive group. There was, however, a large overlap of results, and differentiation between the disease groups was not possible. HCT from the disease groups also showed a prolonged average clearance when compared to normals, although this was not significant when the p value was adjusted for multiple comparisons. The normal HCT was 23.6 +/- 7.7 min, whereas the hepatobiliary disease groups ranged from 20 to 714 min. Again, there was considerable overlap of results in the disease groups. These functional parameters are feasible and applicable in the pediatric population.