The elastometry method is proved to be efficient for the evaluation of liver fibrosis in adults. But the inter-costal space is too thin in children, and the adult probe could not be used. Recently a special probe adapted to the children have been TECHNICATED. We want to test this specific probe in children. Five French Paediatrics centres will participate to the study. We need 200 children inclusions in 2 years to have a statistically power analysis. Inclusion of each child will be in order to the need of a liver biopsy. Each children included will have an elastometry measure in the same time than the liver biopsy. The fibrosis will be staged by a trained pathologist and scored by METAVIR score witch is the reference. The elastometry measure will be realised by physician with 3 sequential measures in each child. The statistical analysis will be performed by statistician. If elastometry is proved to be an efficient method to evaluate the liver fibrosis in children, a numerous of liver biopsy could be avoided. Because elastometry is a non invasive method it could also be used as follow-up in different categories of children who needs sequential liver biopsy.
