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

Abstract

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(®) 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(®) (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(®) (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(®). ARFI elastography of the left liver lobe is also possible. Liver steatosis does not seem to influence ARFI elastography.