In vivo assessment of the trabecular bone microstructure of the distal radius using a compact MRI system.

We repeatedly measured the trabecular bone (TB) microstructure of the distal radius in 5 healthy volunteers using a compact magnetic resonance (MR) imaging system to evaluate the reproducibility of the TB structural parameters. The compact system was specially developed with a 1.0-tesla permanent magnet for the distal radius in a previous study. We measured the distal radius using a 3-dimensional (3D), driven-equilibrium, spin-echo sequence (repetition time/echo time=80 ms/10 ms, number of excitations=1, field of view=76.8 mm x 57.6 mm x 16.0 mm, acquisition time=17 min, matrix size=512 x 384 x 32, voxel size=150 microm x 150 microm x 500 microm) and analyzed the acquired image datasets using the virtual bone biopsy system developed by the University of Pennsylvania. Root mean squares of the coefficients of variance expressed as percentages ranged from 2.9% to 14% for the TB structural parameters. Therefore, we concluded that this compact MR imaging system could be used to assess TB microstructure of the distal radius and provide results consistent with those using a whole-body MR imaging system and showing the promise of this system for evaluating bone quality in clinical settings.