High-resolution magnetic resonance imaging of trabecular bone in the wrist at 3 tesla: initial results

PURPOSE: To evaluate the feasibility of high-resolution magnetic resonance imaging (MRI) of trabecular bone of the wrist at 3 Tesla (3T) in vivo and to assess the potential benefit of the increased resolution for clinical assessment of structural changes in spongy bone. MATERIAL AND METHODS: High-resolution MRI of the wrist was performed with a whole-body 3T MR scanner using a dedicated circularly polarized transmit-receive wrist-coil. Two 3D-FISP sequences with a spatial resolution of 300 x 300 x 300 microm3 in a measuring time of TA = 7:51 min, and 200 x 200 x 200 microm3 in TA = 9:33 min were applied. Seven young healthy volunteers and three elderly subjects with suspected osteoporosis were examined. The signal-to-noise ratio (SNR) in the optimized setup at 3T was compared to measurements at 1.5T. RESULTS: The images at 3T allow microscopic analysis of the bone structure at an isotropic spatial resolution of 200 microm in examination times of <10 min. Differences in the structure of the spongy bone between normal and markedly osteoporotic subjects are well depicted. The SNR at 3T was found up to 16 times higher than at 1.5T applying unchanged imaging parameters. CONCLUSION: The proposed high-resolution MRI technique offers high potential in the diagnosis and follow-up of diseases with impaired bone structure of hand and/or wrist in clinical applications.