Liver and spleen stiffness measured by acoustic radiation force impulse elastography for noninvasive assessment of liver fibrosis and esophageal varices in patients with chronic hepatitis B.

OBJECTIVES: To evaluate the performance of liver and spleen stiffness measured by acoustic radiation force impulse (ARFI) elastography for noninvasive assessment of liver fibrosis and esophageal varices in patients with chronic hepatitis B virus. METHODS: Two hundred sixty-four participants, of whom 60 were healthy volunteers (classified as stage 0), 66 were patients with chronic hepatitis B who had undergone liver biopsy, and 138 were patients with hepatitis B-related cirrhosis, were enrolled in this study. Median liver and spleen stiffness values (meters per second) from 10 successful measurements per participant were obtained. Patients with cirrhosis were examined by upper endoscopy. RESULTS: Significant linear correlations were found between liver (Spearman ρ = 0.87; P < .001) and spleen (Spearman ρ = 0.76; P < .001) stiffness and the fibrosis stage. Liver and spleen stiffness values increased as fibrosis progressed; however, overlaps in liver stiffness were detected in stages 0 and 1 and 1 and 2, and overlaps in spleen stiffness were observed in stages 0 and 1, 1 and 2, and 2 and 3. Liver stiffness cutoff values were 1.69 m/s for predicting stage 3 or greater (area under the receiver operating characteristic curve [AUROC] = 0.99) and 1.88 m/s for stage 4 (AUROC = 0.97). The spleen stiffness cutoff value was 2.72 m/s for stage 4 (AUROC = 0.96). Liver stiffness was not correlated with the varix grade, whereas a significant linear correlation (Spearman ρ = 0.65; P < .001) between spleen stiffness and the varix grade was found. The optimal spleen stiffness cutoff value for predicting varices was 3.16 m/s (AUROC = 0.83). CONCLUSIONS: Liver and spleen stiffness values measured by ARFI elastography are reliable predictors of liver fibrosis. Spleen stiffness measured by ARFI can be used as a non-invasive method for determining the presence and severity of esophageal varices; however, evidence to support a similar role for liver stiffness is lacking.