Trabecular bone structure and anisotropy studies via diffusion-based MR
Sigmund E, Chen P, Brown T, Guo E, Byrnes S, Cho H, Song Y
We present MR diffusion characterizations of trabecular bone providing geometrical information (projected surface-to-volume ratio S/V) without high resolution imaging. The first technique employs magnetization decay due to diffusion in internal fields (DDIF), while the second measures time-dependent diffusion coefficients via applied field gradients. We found that both methods probe the projected S/V ratio for the full range of the samples. Two regimes of strength-geometry relationship were found: a weak regime with constant anisotropy, and a strong regime with increasing anisotropy. These geometrical parameters from the diffusion techniques are likely to be useful for clinical bone evaluation.