The Shear Modulus of the Nucleus Pulposus Measured Using MR Elastography: A Potential Biomarker for Intervertebral Disc Degeneration

Daniel H. Cortes¹, Jeremy F. Magland², Alexander C. Wright², Dawn M. Elliott¹

Intervertebral disc degeneration is characterized by a progressive cascade of biochemical and mechanical changes that affect its function. The structural changes characteristic of advanced degeneration are considered permanent due to the slow matrix turnover performed by disc cells. Therefore, early diagnosis of disc degeneration is critical for the success of any molecular or biological treatment. It is known that the shear modulus of the tissues in the disc changes significantly even for mild degeneration, and therefore it has potential for the diagnosis of early changes in the degeneration cascade. The objectives of the this study are: 1) to develop MRE methods to measure the shear modulus of the NP of intervertebral disc segments, 2) to quantify the effect of disc degeneration on the shear modulus measured using MRE, and 3) to compare the shear modulus to other MR-based biomarkers of disc degeneration.