Can internal elastic properties of cartilage be measured using MR elastography

Cartilage has internal variations in molecular structure, composition and possibly mechanical properties depending on position within and location of the tissue within the joint. I have examined the possibility of using MR Elastography as a way to measure the internal variations in elastic properties of cartilage. An apparatus was built to compress cartilage and coils were made to obtain the necessary SNR and resolution. Strain data was obtained in homogeneous gel samples. Changes in strain on the order that would be expected for samples differing in Young's modulus by a factor of 2 were measured. Strain was then measured in Young bovine cartilage samples and found to vary both within the sample and between samples. Cartilage proteoglycans were degraded with trypsin, softening the tissue, and the corresponding increase in strain was measured. Strain images and plots representing variations in elastic properties of cartilage were obtained using MR Elastography.