Biopsy and quantitative hepatobiliary scintigraphy in the evaluation of liver transplantation

Hepatobiliary scintigraphy with technetium-99m-mebrofenin including a first-pass study of 60 two-sec images and a functional phase of 40 one-min images was performed in 26 patients (42.5 +/- 12.5 yr) in the early postoperative period (9.1 +/- 4.3 days) after liver grafting. Needle biopsy was carried out within a mean of 0.5 +/- 2.2 days of the scintigraphy study. Considering only rejection and cholestasis, biopsy results were used to classify the patients in three groups: control group I (11 patients) with minimal lesions, group II (9 patients) with moderate histologic modifications, and group III (6 patients) with severe dysfunction showing important structural changes. First-pass time-activity curves were used to calculate arterial (alpha-A) and portal (alpha-P) angles as well as a portal perfusion index. Functional time-activity curves were used to define two blood retention indices (BRI1 and BRI2) and two liver uptake indices (LUI1 and LUI2). Excretion was not quantified.

Simple linear regression analysis showed a significant correlation between portal perfusion index and BRI1 (p < 0.05, r = -0.43) and BRI2 (p = 0.01, r = -0.53). The validity of the histologic classification was assessed by the existence of significantly different (p < 0.05) mean values for alpha-P, portal perfusion index and LUI1 in the three groups. All other indices could distinguish significantly between groups I and II. Furthermore, arterial angle alpha-A allowed differentiation of group II from group III but not group I from group II; on the contrary, LUI2 and BRI1 distinguished group I from group II but not group II from group III.

This study demonstrated a close correlation between early biopsy results and perfusion indices in patients with a liver graft as well as uptake parameters determined by hepatobiliary scintigraphy.