Virtual Touch Quantification using Acoustic Radiation Force Impulse Imaging Technology versus Transient Elastography for the Noninvasive Assessment of Liver Fibrosis in Patients with Chronic Hepatitis B or C using Liver Biopsy as the Gold Standard.

AIMS: Our aim was to assess the diagnostic performance of transient elastography (TE) and Virtual Touch Quantification (VTQ), a point Shear Wave Elastography (pSWE) technique, using Acoustic Radiation Force Impulse (ARFI) technology, for liver fibrosis assessment, as compared to percutaneous liver biopsy (LB), in patients with chronic hepatitis B or C.

METHODS: We analyzed 157 patients (80 with chronic hepatitis B and 77 with chronic hepatitis C) with reliable liver stiffness (LS) measurements, in whom we compared TE and VTQ to the LB performed during the same session (evaluated according to the Metavir scoring system: F0-F4). LS was assessed by TE (FibroScan, EchoSens, Paris, France) and VTQ using the Siemens Acuson S2000TM ultrasound system (Siemens AG, Erlangen, Germany). We defined reliable LS measurements as the median value of 10 measurements with an IQR/M <30% for both TE (obtained using the M probe) and VTQ. The areas under receiver operating characteristic curves (AUROCs) were used to assess the diagnostic performance of TE and VTQ. Correlation analysis determined the relationship between LSM values and liver histology.

RESULTS: On LB 31 (19.7%) patients had no fibrosis, 35 (22.3%) had F1, 43 (27.4%) had F2, 28 (17.8%) had F3 and 20 (12.7%) had cirrhosis. The mean size of the liver specimen in LB was 27 mm. A strong, linear correlation (Spearman ρ=0.826; p<0.001) with 95% confidence interval for rho (0.769- 0.870), was found between the TE and VTQ measurements. By comparing the AUROC curves, TE and VTQ had similar predictive values for the presence of F≥1 Metavir: AUROC TE=0.876, AUROC VTQ=0.832, p=0.358, for F≥2 Metavir: AUROC TE=0.826, AUROC VTQ=0.862, p=0.313, for F≥3 Metavir: AUROC TE=0.907, AUROC VTQ=0.880, p=0.434 and for F=4 Metavir: AUROC TE=0.981, AUROC VTQ=0.974, p= 0.423.

CONCLUSIONS: Both methods, TE and VTQ (pSWE) offer excellent diagnostic accuracy for liver fibrosis assessment in patients with chronic hepatitis B or C with similar performance.