Retrospective audit to determine the diagnostic accuracy of Primovist-enhanced MRI in the detection of hepatocellular carcinoma in cirrhosis with explant histopathology correlation

Introduction This study aims to determine the diagnostic accuracy of Primovist-enhanced MRI in the detection of hepatocellular carcinoma (HCC) in cirrhosis, using liver explant histopathology correlation. Methods Thirty patients underwent a Primovist-enhanced MRI prior to liver transplantation for cirrhosis at the Princess Alexandra Hospital from 2006 to June 2012. Pre-contrast T1, T2 and post-Primovist arterial, portal venous and delayed hepatobiliary phase sequences were routinely obtained. A retrospective audit of MRI reports determined whether HCCs was identified on pre-transplantation imaging. Results were correlated to the explant liver histopathology. Specificity and sensitivity of Primovist in HCC identification in cirrhosis was determined. Results The time interval between preoperative MRI and transplantation ranged from the day of transplantation to 112 weeks pre-transplantation. Thirty-nine HCCs were identified histologically in explants. Fifteen HCCs were identified on pre-transplant MRI in 11 patients, ranging from 11 to 43mm, all confirmed on histopathology. Fourteen MRI studies identified no lesion, concordant on histology. Twenty-four either well or moderately differentiated HCCs were identified on histopathology, all of which were less than 17mm, were not depicted on MRI. No poorly differentiated HCCs were present in the explants. Two regenerative nodules were correctly identified on MRI. This correlated to a sensitivity of 42.5%, specificity of 100% and a positive predictive value of 100% and negative predictive value of 39.5%. Conclusion Primovist-enhanced MRI is very accurate in the identification of HCC in cirrhosis, especially if the tumour is greater than 17mm and undifferentiated. However, sensitivity is reduced for well- and moderately differentiated HCC less than 17mm.