[Magnetic resonance elastography of the liver]

Abstract

Clinical/methodical issue: The early detection of liver fibrosis remains a major challenge in medical imaging.

Standard radiological methods: Nowadays staging of liver fibrosis is not a task for radiological examinations and the gold standard is liver puncture.

Methodical innovations: Elastography is sensitive to the mechanical properties of soft tissues and in the liver stiffness is highly correlated to the degree of fibrosis. In magnetic resonance imaging elastography (MRE) time-harmonic vibrations are induced in the liver and encoded by motion-sensitive phase-contrast sequences. Viscoelastic constants are recovered from the obtained wave images and displayed by so-called elastograms.

Performance: The MRE procedure is able to discriminate low grades of fibrosis (F0-F1) from medium and severe fibrosis (F2-F4) with a diagnostic accuracy (AUROC) of 0.92.

Achievements: Currently, MRE is the most sensitive imaging modality for the noninvasive staging of liver fibrosis.

Practical recommendations: Current technical developments of MRE may further improve the accuracy of the method towards a new gold standard for noninvasive staging of fibrosis by radiologists.