Transient Versus Two-Dimensional Shear-Wave Elastography in a Multistep Strategy to Detect Advanced Fibrosis in NAFLD

Background and aims: The combination of laboratory and elastography tests allows the accurate diagnosis of advanced liver fibrosis in patients with NAFLD. In this study, we compared the diagnostic performances of a two-step strategy (laboratory tests and vibration-controlled transient elastography [VCTE] or two-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).

Approach and results: 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 = not significant). Conversely, more patients required liver biopsy after 2D-SWE-SSI (24.6% versus 15.3%, P < 0.001). Performing a second elastography technique in patients with unreliable or gray zone (between 8 and 10 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% versus 81.3%, 69.7%, and 89.5%, respectively; all P = not significant).

Conclusions: Using the same cutoff 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.