ARFI elastography of cystic fibrosis-related liver disease (CFLD)

At present, no gold standard has been defined for the assessment of cystic fibrosis-related liver disease (CFLD). Acoustic radiation force impulse (ARFI) imaging is a non-invasive, radiation-free method to measure stiffness of the liver. To assess ARFI imaging cut-off values for CFLD and identify parameters that could potentially influence ARFI imaging results. Longitudinal changes of a subgroup of CF patients were investigated. ARFI was applied in 86 CF patients with the ultrasound device iU22 (Philips Healthcare) and a C5-1 MHz device in segment VII. The patients were divided into two groups based on the presence or absence of CFLD (n = 29/86 CFLD+), which was determined according to laboratory values, hepatomegaly or splenomegaly, and the Wilson score. After an average of 11 months, 48 CF patients were longitudinally revaluated. Significant differences (p < 0.001) were found regarding ARFI imaging values of patients with and without CFLD. Medians of CFLD+ patients resulted in c = 1.07 +/- 0.12 m/s compared to c = 1.46 +/- 0.33 m/s in the CFLD- group. Significantly higher values were found in males compared to females and in patients with a history of meconium ileus. Age and BMI did not influence results. In the longitudinal assessment after an average of 11 months, only a marginal increase of 1.77 % for the CFLD- and 6.56 % for CFLD+ groups were found. Our results show that ARFI imaging is a valid parameter to assess liver involvement in patients with CF.