Macrovesicular hepatic steatosis in living liver donors: Use of CT for quantitative and qualitative assessment

Purpose: To determine prospectively the diagnostic performance of unenhanced computed tomography (CT) in the assessment. of macrovesicular steatosis in potential donors for living donor liver transplantation by using same-day biopsy as a reference standard. Materials and Methods: Institutional review board approval and informed consent were obtained. A total of 154 candidates, including 104 men (mean age, 30.2 years +/- 10.3 [standard deviation]) and 50 women (mean age, 31.8 years +/- 11.2), underwent same-day unenhanced CT and ultrasonography-guided liver biopsy. Histologic degree of macrovesicular steatosis was determined. Three liver attenuation indices were derived: liver-to-spleen attenuation ratio (CT,), difference between hepatic and splenic attenuation (CTL-S), and blood-free hepatic parenchymal attenuation (CTLP). Regression equations were used to quantitatively estimate the degree of macrovesicular, steatosis. Limits of agreement between estimated macrovesicular steatosis and the reference standard were calculated. Receiver operating characteristic analyses were used to determine the performance of each index for qualitative diagnosis of macrovesicular steatosis of 30% or greater. The cutoff value that provided a balance between sensitivity and specificity and the highest cutoff value that yielded 100% specificity were determined. Results: Units or agreement were -14% to 14% for CTL/S and CTL-S and -13% to 13% for CTLP. Performance in diagnosing macrovesicular steatosis or 30% or greater was not significantly different among indices (P > .05). Cutoff values of 0.9, -7, and 58 were determined for CTL/S, CTL-S, and CTLP, respectively, and provided a balance between sensitivity and specificity. Cutoff values of 0.8, -9, and 42 were determined for CTL/S, CTL-S, and CTLP, respectively, and yielded 100% specificity for all indices, with corresponding sensitivities of 82%, 82%, and 73% for CTL/S, CTL-S, and CTLP, respectively. Conclusion: Diagnostic performance of unenhanced CT for quantitative assessment of macrovesicular steatosis is not clinically acceptable. Unenhanced CT, however, provides high performance in qualitative diagnosis of macrovesicular steatosis or 30% or greater. (c) RSNA, 2006.