Magnetic Resonance Elastography: Combining Magnetic Resonance and Acoustics*

Many disease processes cause marked changes in the mechanical properties of tissues.  For instance, cancers of the thyroid, breast, and prostate, are often first detected by simple touch.  While conventional medical imaging technologies such as computed tomography, ultrasonography, and magnetic resonance imaging (MRI) can be used to measure many physical properties of tissue, they are not capable of assessing mechanical properties.  Magnetic resonance elastography (MRE) is an emerging technology that addresses this need.

 

Magnetic Resonance Elastography (MRE) employs a unique phase-contrast MRI technique to visualize propagating mechanical waves generated by surface drivers, inertial effects, acoustic radiation pressure, or endogenous mechanisms.  MRE acquisition sequences are capable of visualizing waves of less a micron in amplitude in vivo.  Inversion algorithms are used to process the wave data to generate maps of properties such as stiffness, viscosity, attenuation, and anisotropic behavior, providing access to a new range of previously unexplored tissue imaging biomarkers.

 

This presentation will discuss the physical basis of MRE and survey the existing and emerging applications of the technology in clinical medical practice and in fields of science such as mechanobiology.  Like most other advances in medical imaging technology, MRE was developed through convergence science: bringing the disciplines of physics, mathematics, and engineering together with biological science. The presentation will discuss challenges and opportunities where convergence science promises to further advance MRE and its applications.