Abstract
The combination of laboratory and elastography tests allows the accurate diagnosis of advanced liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). In this study, we compared the diagnostic performances of a two-step strategy (laboratory tests and vibration-controlled transient elastography [VCTE] or 2-dimensional shear-wave elastography with SuperSonic Imagine [2D-SWE-SSI]) and the added value of a three-step strategy (laboratory tests and two elastography methods). From a prospective registry, we retrospectively selected 577 consecutive patients with suspicion of NAFLD who underwent laboratory tests to calculate the Fibrosis-4 (FIB-4) score, liver stiffness evaluation by VCTE (M and XL probes) and 2D-SWE-SSI, and liver biopsy. The diagnostic performances and need for liver biopsy in unclassified patients for the diagnosis of advanced fibrosis (F ≥3) in multistep strategies were compared. The area under the curve of FIB-4, VCTE, and 2D-SWE-SSI was 0.74, 0.82, and 0.88, respectively. Using the same thresholds, the FIB-4/2D-SWE-SSI and FIB-4/VCTE diagnostic performances were comparable (sensitivity: 71.4% and 66%; specificity: 91.4% and 91.5%; and accuracy: 83.7% and 81.4%; all P = NS). Conversely, more patients required liver biopsy after 2D-SWE-SSI (24.6% vs. 15.3%; P < 0.001). Performing a second elastography technique in patients with unreliable or grey zone (between 8 and10 kPa) results greatly decreased the need for liver biopsy (42/577; 7.3%). The diagnostic performances (accuracy, sensitivity, and specificity) of FIB-4/2D-SWE-SSI/VCTE and FIB-4/VCTE/2D-SWE-SSI were comparable (81.1%, 71.5%, and 87.9% vs. 81.3%, 69.7%, and 89.5%, respectively [all P = NS]). Conclusion: Using the same cut-off values, 2D-SWE-SSI is as accurate as VCTE for advanced liver fibrosis diagnosis in NAFLD. The three-step strategy in selected patients strongly decreased the need for liver biopsy while maintaining excellent accuracy.