Comparison of Non-invasive Measurement Methods of Hepatic Fibrosis in Cystic Fibrosis

Inclusion Criteria: * Children with cystic fibrosis aged 6-18 years. The diagnosis of cystic fibrosis will be based on testing the abnormal sweat (\> 60 mEq / L of chloride sweat) and / or on the presence of two pathogen mutations of CFTR. * Written consent of parents or holders of parental rights. * Affiliated or benefiting from a national social insurance Exclusion Criteria: * Presence of another disease associated with cystic fibrosis that may be responsible for a chronic hepatic disease such as deficiency of alpha-1antitrypsine ZZ genotype or chronic infection by virus B or C. * Child grafted * Actual febrile pulmonary infection that can change the value of Fibrotest * Important peri-hepatic ascites preventing the elasticity measurements by Fibroscan® * Severe respiratory insufficient preventing attainment of Magnetic Resonance Imagery