Clinical feasibility of liver elastography by acoustic radiation force impulse imaging (ARFI)

Background: Transient elastography is increasingly used for assessment of liver fibrosis. Acoustic radiation force impulse imaging (ARFI) is a new technology to perform liver elastography. Aims: We evaluated the clinical feasibility, validity and accuracy of the ARFI method and compared it to Fibroscan (R) and liver histology. Methods: Ultrasonographic elastography of the liver using ARFI was performed in 29 patients with liver cirrhosis, 70 patients with liver disease and 23 healthy controls. Results: ARFI was feasible in all patients providing a mean propagation velocity of 1.65 +/- 0.93 m/s. ARFI results of the right and left liver lobes were comparable (p < 0.001). In cirrhotic patients, ARFI gave significantly higher values than in the other patients (p < 0.001). Rate of invalid measurements was lower in ARFI than in Fibroscan (R) (p < 0.04). Both elastography methods were highly correlated to each other (p < 0.001). Furthermore, ARFI correlated to histological grading of liver fibrosis (p < 0.001) and to inflammatory activity (p < 0.05). Liver steatosis had no statistical influence on ARFI results (p = 0.2) in contrast to Fibroscan (R) (p < 0.05). Conclusions: The new ultrasonographic method of ARFI elastography allows valid, accurate and flexible evaluation of liver stiffness. It seems more feasible in patients with liver cirrhosis than Fibroscan (R). ARFI elastography of the left liver lobe is also possible. Liver steatosis does not seem to influence ARFI elastography. (C) 2011 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.