[Magnetic resonance imaging for quantifying hepatis steatosis and hepatic fibrosis].

The reference method for detecting and quantifying hepatic steatosis and fibrosis is the histopathological analysis of liver biopsies. Studies performed in animals and humans have shown that magnetic resonance imaging (MRI) is useful for the accurate and non-invasive quantification of these lesions. For fibrosis quantification, functional MRI methods have to be used, including perfusion MRI, diffusion MRI, and more particularly MR elastography. Modifications of the visco-elastic parameters of the liver can also be observed with MR elastography in hepatic diseases without fibrosis, such as the early stages ofnon-alcoholi steatohepatitis. Finally, accurate quantification of liver steatosis can be performed by observing the difference of resonance frequencies between the protons of fat and water at spectroscopy or chemical shift MRI. In conclusion, combined quantification of liver steatosis and fibrosis can be performed with MRI.