Characterization of Murine Glioma by Magnetic Resonance Elastography: Preliminary Results

Abstract

Magnetic resonance elastography (MRE) is a non-invasive imaging technique that permits quantitative measurement of the mechanical properties of biological tissue. In MRE, coherent tissue displacements are induced by a mechanical actuator and images are collected in synchrony with these mechanical motions. Components of displacement in any direction can be measured by applying the motion-encoding gradients along that direction. The mechanical properties of tissue are derived by fitting measured displacement data to the equations governing wave propagation. A number of groups have explored the diagnostic value of MRE in the clinical setting, driven largely by the empirically observed relationship between tissue health and stiffness. The investigation of MRI methods as biomarkers of tumor progression and early therapeutic response remains an extremely active and important area of research. In this regard, MRE has considerable potential for staging cancer and monitoring the effects of therapy. We seek to demonstrate the utility of MRE for cancer staging by tracking the viscoelastic properties of brain tumor in a mouse model of high-grade glioma. Brain tissue viscoelasticity cannot be probed in vivo by any other known imaging technique, yet is suspected to contain valuable information about tissue health. Preliminary results indicate elastographic sensitivity to the presence of brain tumors in the living mouse.