Acoustic radiation force impulse (ARFI) imaging with Virtual Touch Tissue Quantification in liver disease associated with cystic fibrosis in children

PURPOSE: Cystic-fibrosis-associated liver disease (CFLD) may lead to portal hypertension (PHT) and cirrhosis. Clinical signs and biochemistry of liver involvement are not discriminating. The aim of the study was to evaluate the performance of acoustic radiation force impulse (ARFI) with virtual tissue quantification in comparison with clinical signs, biochemistry and standard hepatic ultrasound (US) patterns. MATERIALS AND METHODS: Virtual Touch Tissue Quantification, an implementation of US ARFI with shear-wave velocity (SWV) measurements was used in 75 children with cystic fibrosis (CF) and suspected CFLD to quantify hepatic stiffness. In each patient, ten measurements of SWV were performed on the right hepatic lobe. Patients were also evaluated by standard diagnostic tools (standard US, liver- and lung function tests, oesophagogastroscopy). RESULTS: Among CF patients, median SWV was significantly higher in patients with clinical, biochemical and US signs of hepatic involvement than in patients without US evidence of liver disease 1.08 m/s [(95% confidence interval (CI), 1.02-1.14]. Median SWV values in patients with portal hypertension, splenomegaly and oesophageal varices were 1.30 (95% CI, 1.17-1.43), 1.54 (95% CI, 1.32-1.75) and 1.63 (95% CI, 1.26-1.99), respectively. Differences were significant (p<0.001). CONCLUSIONS: ARFI is an innovative screening technique able to help identify CFLD in children.