MRI & mechanobiology: New science at the intersection of engineering and medicine

Many disease processes such as cancer cause profound changes in the mechanical properties of tissues. This accounts for the efficacy of palpation for detecting abnormalities and provides motivation for developing practical methods to quantitatively image tissue elasticity. Magnetic Resonance Elastography (MRE) is an emerging MRI-based technique that can quantitatively image tissue properties such as stiffness, viscosity, attenuation, and anisotropic behavior-providing access to a new range of previously unexplored tissue imaging biomarkers highly relevant in diagnostic medicine and in the emerging field of mechanobiology. Human studies have demonstrated that it is feasible to apply MRE to quantitatively assess skeletal muscle, brain, thyroid, breast, myocardium, kidney, liver, and skin. The first established clinical application of the technology is for detection of hepatic fibrosis, which is a growing health problem and the most important precedent to primary hepatic malignancy. Growing clinical experience indicates that MRE is at least as accurate as liver biopsy for this diagnosis, while also being safer, more comfortable, and less expensive. Preliminary studies suggest that MRE may be helpful in differentiating between benign and malignant neoplasms. New research has also shown that MRE-assessed estimates of tumor stiffness are helpful in the preoperative assessment of patients with brain tumors such as menigiomas.