RESUMEN
PURPOSE: The aim of this study was to define liver shear stiffness by magnetic resonance elastography (MRE) that distinguishes normal from abnormal liver biopsy, especially when steatosis ≥20%, among potential live liver donors. METHODS: Baseline clinical, laboratory, imaging, MRE, and liver biopsy results were recorded. Using MRE, hepatic shear stiffness in kilopascals (kPa) was measured and compared to liver biopsy. Comparison between groups was done using χ(2) or Fisher's exact test for categorical variables and Wilcoxon test for continuous variables. Receiver operating characteristic (ROC) curve was calculated to assess diagnostic accuracy. Statistical significance was set at p < 0.05. RESULTS: 38 healthy adults were included. Liver biopsy was normal in 27 and abnormal in 11. ROC curve for MRE defined optimal cutoff at 2.6 kPa (sensitivity 0.72, specificity 0.85, AUC 0.81) to distinguish these 2 groups. Hepatic steatosis ≥20% on biopsy is a contraindication for liver donation in our center. We evaluated the ability of MRE to distinguish this degree of steatosis: 8 persons had steatosis ≥20% and were excluded from donation. ROC curve for MRE defined optimal cutoff at 2.82 kPa (sensitivity 0.88, specificity 1, AUC 0.98) to identify this group. CONCLUSIONS: Liver stiffness measured by MRE, even in the absence of liver fibrosis, can be useful in differentiating normal from abnormal liver histology, and most importantly in patients under evaluation for live liver donation, can very accurately distinguish those with complicated hepatic steatosis ≥20%, our cutoff for donation. In the future, MRE might provide supplementary information to make liver biopsy unnecessary in the donor evaluation process.