PURPOSE: To determine prospectively the diagnostic performance of unenhanced computed tomography (CT) in the assessment of macrovesicuiar 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 Methods: 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 macrovesicuiar steatosis was determined. Three liver attenuation indices were derived: liver-to-spleen attenuation ratio (CT//S), difference between hepatic and splenic attenuation (CTL_S), and blood-free hepatic parenchymal attenuation (CT^.). Regression equations were used to quantitatively estimate the degree of macrovesicuiar steatosis. Limits of agreement between estimated macrovesicuiar steatosis and the reference standard were calculated. Receiver operating characteristic analyses were used to determine the performance of each index for qualitative diagnosis of macrovesicuiar 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: Limits of agreement were �14% to 14% for CTL/S and CTL_S and �13% to 13% for CT^,. Performance in diagnosing macrovesicuiar steatosis of 30% or greater was not significantly different among indices (P > .05). Cutoff values of 0.9, �7, and 58 were determined for CT,/S, CT^s, and CTjjj, respectively, and provided a balance between sensitivity and specificity. Cutoff values of 0.8, �9, and 42 were determined for CTt/s, CT,_S, and CT/P, respectively, and yielded 100% specificity for all indices, with corresponding sensitivities of 82%, 82%, and 73% for CTjjsi CTt_s, and CTLP, respectively.
CONCLUSION: Diagnostic performance of unenhanced CT for quantitative assessment of macrovesicuiar steatosis is not clinically acceptable. Unenhanced CT, however, provides high performance in qualitative diagnosis of macrovesicuiar steatosis of 30% or greater.