Reliability and Accuracy of Clinical Assessment and Digital Image Analysis for Steatosis Evaluation in Discarded Human Livers

Abstract Background Accurate assessment of steatosis in procured livers is crucial to reduce the poor outcome associated with high-grade steatosis and to optimize the utilization of donor grafts. Clinical examination and digital image analysis (DIA) have been used for steatosis evaluation, but the validity of these methods is debated. This study aimed to compare these methods with standard histology for assessment of steatosis severity in human livers and to evaluate a revised classification system for automated fat measurement. Methods Clinical assessment of liver steatosis at time of retrieval and automated measurement were compared with standard histology in paraffinized and hematoxylin and eosin–stained slides, using a 4-grade scale for ordinal data and percentages for numerical values. Results Analysis of 42 human livers that were retrieved but not transplanted showed that clinical examination was not reliable for assigning steatosis grades (κ w , 0.12; 95% CI, −0.06 to 0.30), overestimated steatosis severity, and had an accuracy of 67% for discriminating low- and high-grade steatosis. Digital image analysis had a substantial agreement on absolute fat percentage (intraclass correlation coefficient, 0.76; 95% CI, 0.63–0.84) and steatosis grades (κ w , 0.70; 95% CI, 0.57–0.82), with 88% accuracy using the revised classification system. Conclusions Clinical assessment of steatosis is inaccurate, and relying on this method alone could result in unnecessary discard of livers. Digital image analysis is feasible with higher accuracy and reliability, but further clinical studies are required to evaluate its clinical validity.