Increased liver stiffness by transient elastography and acoustic radiation force impulse imaging in patients with extrahepatic cholestasis

BACKGROUND: Transient elastography and acoustic radiation force impulse (ARFI) imaging are noninvasive tools for liver stiffness measurement (LSM), which may be influenced by cholestasis. AIM: The aim of the study was to evaluate the performance of transient elastography and ARFI in extrahepatic cholestasis and correlate changes in LSM with biochemical activity. MATERIALS AND METHODS: A total of 38 patients with extrahepatic cholestasis prospectively underwent transient elastography and ARFI. Changes in LSM by transient elastography/ARFI were evaluated after 1 week of ERCP and correlated with biochemical parameters. The optimal ARFI cutoffs according to stages of clinical interest were analyzed. RESULTS: Biliary obstruction was calcular in 21 (55.3%) and noncalcular in 17 (44.7%) (benign n = 15, malignant n = 2). After 1 week, adequate biliary drainage reduced total bilirubin from 7.7 to 2.2 mg/dL (P < 0.001) which significantly correlated with reduction of LSM by transient elastography from 12.38 ± 6.68 kPa to 8.08 ± 3.21 kPa (P < 0.001), and by ARFI from 1.73 ± 0.51 m/s to 1.56 ± 0.70 m/s (P = 0.014). The LSM percentage change showed a decrease (nonsignificant, P = 0.843) by 25.83% using transient elastography and a significant decrease (P < 0.001) by 18.42% using ARFI in the improved patients. At initial visit, transient elastography positively correlated with ARFI, bilirubin and platelets, also, transient elastography had a positive correlation with ARFI, bilirubin, alkaline phosphatase (ALP), γ-glutamyl transpeptidase (GGT) in follow-up visit. LSM by ARFI (visit 1) negatively correlated with ALT, while in (visit 2), ARFI positively correlated with bilirubin, ALP, GGT and negatively correlated with albumin. CONCLUSION: The increased LSM in patients with extrahepatic cholestasis is reduced after adequate biliary drainage, implying that increased values are not solely due to liver fibrosis, but due to biliary congestion leading temporarily to increased elasticity.