Combination of MR dynamic contrast-enhanced imaging with T2-corrected intra-voxel incoherent motion imaging at 3.0T to assess liver fibrosis
Résumé
Liver fibrosis is an important cause of mortality and morbidity in patients with chronic liver diseases and cirrhosis, end-stage of fibrosis, involve 15,000 and 40,000 deaths per year in France and in USA respectively (1,2). Reversible aspect of liver fibrosis has been recognized, and more effective treatment strategies have emerged. Nevertheless these latter require an early detection and a clinical follow-up of liver fibrosis. While liver biopsy is the gold standard for the diagnosis of chronic liver diseases, inherent risk, interobserver variability and sampling errors makes liver biopsy unusable for the clinical follow up. Thus, there is a real clinical need in the development of non-invasive methods for liver fibrosis assessment. At 1.5 T, human in-vivo studies have demonstrated that liver perfusion imaging using a MR dynamic contrast enhanced method (MR-DCE) has the potential to detect and assess vascular modifications associated to liver fibrosis (3,4). On another hand, intra-voxel incoherent motion imaging (IVIM) has been proposed to asses liver fibrosis (5). This technique was able to separate two kind of diffusion: the pure molecular diffusion and the perfusion-related diffusion. Our objective was to combine IVIM with perfusion imaging using a MR-DCE technique at 3.0 T and evaluate this protocol for fibrosis severity assessment on a prospective study including patients with chronic liver diseases. Through this study, perfusion-related diffusion parameters given by IVIM and quantitative perfusion parameters given by MR-DCE imaging were compared.