Post-operative assessment in patients after liver transplantation: imaging parameters associated with 1-year graft failure

Purpose To identify post-liver transplant CT findings which predict graft failure within 1 year. Materials and methods We evaluated the CT scans of 202 adult liver transplants performed in our institution who underwent CT within 3 months after transplantation. We recorded CT findings of liver perfusion defect (LPD), parenchymal homogeneity, and the diameters and attenuations of the hepatic vessels. Findings were correlated to 1-year graft failure, and interobserver variability was assessed. Results Forty-one (20.3%) of the 202 liver grafts failed within 1 year. Graft failure was highly associated with LPD (n= 18/25, or 67%, versus 15/98, or 15%,p< 0.001), parenchymal hypoattenuation (n= 20/41, or 48.8% versus 17/161, or 10.6%,p< 0.001), and smaller diameter of portal veins (right portal vein [RPV], 10.7 +/- 2.7 mm versus 14.7 +/- 2.2 mm, and left portal vein [LPV], 9.8 +/- 3.0 mm versus 12.4 +/- 2.2 mm,p< 0.001, respectively). Of these findings, LPD (hazard ratio [HR], 5.43,p< 0.001) and small portal vein diameters (HR, RPV, 3.33,p< 0.001, and LPV, 3.13,p< 0.05) independently predicted graft failure. All the measurements showed fair to moderate interobserver agreement (0.233 similar to 0.597). Conclusion For patients who have CT scan within the first 3 months of liver transplantation, findings of LPD and small portal vein diameters predict 1-year graft failure.