Elastography

Many diseases are known to be associated with changes in the mechanical properties of tissue. Palpation of the breast and thyroid, for example, continues to be a part of routine clinical exams, because many neoplasms can be detected by touch as they have different properties than a healthy tissue. Magnetic resonance elastography (MRE) is a noninvasive technique for imaging the mechanical properties of tissue in vivo. In MRE, the tissue is stressed quasi-statically or dynamically, and the internal displacement of the tissue is imaged using various MRI techniques. The displacement images can be used to indicate qualitative changes in the tissue (e.g., strain) and to quantitatively determine tissue mechanical properties (e.g., the shear modulus). MRE techniques have been developed for studying many tissues, including liver, breast, muscle, heel pad, brain, and kidney. Information provided by MRE can help to characterize both healthy and diseased tissues to improve the diagnosis of various diseases.