Comparison of CT methods for determining graft steatosis in living donor liver transplantation

Abstract

Purpose: To evaluate and compare the diagnostic performance of non-enhanced computed tomography (NECT) and contrast-enhanced CT (CECT) attenuation indices in the assessment of hepatic steatosis by using biopsy as the reference standard. Materials and methods: This retrospective study was approved by our Institutional Review Board. 55 Potential donors who underwent both NECT and triphasic CECT and core liver biopsy, were included the study. Average attenuation measurements that were obtained from multiple regions in liver, spleen, and psoas muscle on both unenhanced and CECT were used for analysis. Hepatic attenuation measurements were analyzed with and without normalization with the spleen and psoas muscle. Linear regression and receiver operating characteristic (ROC) curve analysis were used to evaluate the statistical association between CT indices and steatosis at histology. Results: Linear regression analysis confirmed the strongest correlation between steatosis and normalized measurements of hepatic attenuation with splenic attenuations on hepatic venous phase of CECT scan (R 0.821; R2 0.674 and R 0.816; R2 0.665, respectively). The use of ROC curve analysis also demonstrated that normalized measurements of hepatic attenuation with splenic attenuations on hepatic venous phase of CECT showed high diagnostic performance regarding the qualitative distinction of steatosis (AUC values greater than 0.9). Conclusion: Attenuation measurements of liver normalized with spleen on hepatic venous phase may be useful in evaluating steatosis in donor candidates with moderate to severe steatosis who are unacceptable for liver donation. In this manner unnecessary liver biopsy may be avoided in those donor candidates.