Magnetic Resonance Elastography at 3 Tesla: Implementation, Validation and Application to a Degenerative Disc Model

The method was applied to quantitatively measure the shear modulus of agar gel samples and bovine intervertebral disc nucleus pulposus tissue. The agar gel measurements compared well with those from traditional compressive mechanical testing. The fitted linear regression lines for the shear modulus from the two methods against agar gel concentration were found to be equivalent. For the bovine tissue, the method was found to effectively determine the change in stiffness of the tissue due to enzymatic degradation using papain. The shear modulus was found to significantly decrease from an average value of 60 kPa before injection to 44 kPa after injection. T2 values were found to increase significantly with degradation, while T1 values remained unchanged.