Magnetic Resonance Elastography in Trabecular Bone: Preliminary Results

Jun Chen¹, Hugh McGregor¹, Kevin Glaser¹, Yogesh Mariappan¹, Arunark Kolipaka¹, Richard Ehman¹

Osteoporosis is a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue leading to diminished biomechanical competence of the skeleton and low-trauma or atraumatic fractures. Assessing the overall biomechanical properties of the bone, is more valuable than BMD alone for osteoporosis diagnosis. This work demonstrated the feasibility of using MRE to measure the stiffness of trabecular bone (TB). High-frequency mechanical flexural waves were induced in the bone. Spin-echo MRE successfully recorded the submicron mechanical motions in the bone, using the marrow soft tissue as a marker. The beam inversion yielded trabecular bone stiffness values that agree with results in the literature. We speculate that with optimized drivers and sequences these MRE methods can be applied in vivo, to directly measure the stiffness of trabecular bone in extremities.