Elastographic Assessment of Liver Fibrosis in Children: A Prospective Single Center Experience

Background: The assessment of liver damage in various disease states relies on a combination of clinical findings, biochemical parameters and invasive tests such as liver biopsy. The ultrasound elastography has emerged as a potential alternative test, providing quantifiable information on the elasticity/stiffness of the examined-tissues. We assessed the performance of ultrasound elastography using real-time Acoustic Radiation Force Imaging (ARFI) technology in evaluating the degree of liver fibrosis in children with and without liver disease.

Methods: Children aged 0-18 years, hospitalized in the Emergency Clinical County Hospital Tg. Mures, Romania, between September 15, 2010 and January 15, 2011, were eligible for the study. Four groups were recruited as follow: patients with liver disease in the setting of various malignant disorders, children with non-malignant liver disease, overweight and obese children and healthy controls. The liver tissue elasticity was assessed in each individual using Shear Wave Velocity (SWV). Biochemical tests included transaminase levels. 19 children with chronic liver disease underwent biopsies. SWV was measured globally and separately for the liver-segments 1 and 8. Correlations between the SWV and laboratory test were established using non-parametric Spearman correlation test.

Results: A total of 103 children underwent liver ultrasound elastographic assessments. Of these, 39 had malignancies, 19 had various chronic liver diseases, 13 had nonalcoholic fatty liver disease (NAFLD), and 32 were healthy controls. The transaminase values differed significantly between children with liver diseases and controls. In normal controls SWV values in the 1st segment were significantly lower compared to those in the in 8th segment of the liver (p=0.0216). In the group with hepatic steatosis, the SWV values were statistically higher compared to those in healthy controls. Positive statistical correlations have been established between AST and SWV in the group of children with NAFLD and those with malignancies (p=0.0032, p=0.0045).

Conclusions: Quantification of liver fibrosis by ARFI method correlates with the histological fibrosis stage in children with chronic liver disease and NAFLD. Clinical applications of this method in the diagnosis of pediatric liver disease deserve further study.