CT Features of Primary Graft Nonfunction after Liver Transplantation

Abstract

Purpose To determine computed tomographic (CT) features of primary graft nonfunction (PNF) after liver transplantation in comparison with those of early graft failure or death by identifiable causes. Materials and Methods Institutional review board approval was obtained and informed consent was waived. Among 3947 adult liver transplantations performed in one institution between May 2002 and May 2015, 72 patients died or had graft failure within 10 days, and 38 of them were evaluated with CT. PNF was diagnosed in 21 patients. The other 17 patients who died or had early graft failure were considered the non-PNF control group. On unenhanced CT images, graft attenuation was compared qualitatively. Graft attenuation was measured quantitatively and, if available, the difference between preoperative and postoperative CT (interval change) attenuation was evaluated. Unenhanced CT was evaluated for relative parenchymal enhancement. Statistical analyses included the Fisher exact and χ² tests with Yates correction and the Student t test. Results On unenhanced CT images, grafts with PNF more commonly showed low (eight of 26 [31%]) or extremely low (18 of 26 [69%]) qualitative attenuation compared with grafts in the non-PNF group (three of 21 [14%], one of 21 [5%]; P < .001). The mean attenuation value (30.5 HU ± 10.8) was significantly lower and the mean interval change (24.7 HU ± 12.5) was significantly higher in the PNF group than in the non-PNF group (49.7 HU ± 8.0 and 9.7 HU ± 10.1, respectively; P < .001 and P = .001). There was no significant difference in the proportion of grafts that showed poor enhancement on postcontrast CT images between the PNF group and the non-PNF group (nine of 24 [38%] vs two of 20 [10%], respectively; P = .08). Conclusion Recipients with PNF after liver transplantation tended to show low or extremely low attenuation on unenhanced CT images, and this finding was seen more frequently in patients with PNF than in those who died of identifiable causes and in those with early graft failure. ^© RSNA, 2016 Online supplemental material is available for this article.