Relation between image-based assessment of distal radius trabecular structure and compressive strength

Objective: To investigate the degree to which an image-based assessment of trabecular bone structure can predict bone strength. Methods: Transaxial hi gh-resolution magnetic resonance imaging (MRI) images and peripheral quanti tative computed tomography (pQCT) images were obtained for a set of 9 isola ted radii. Trabecular bone was segmented from fat, and indices relating to the connectivity of the bone network and the size of the marrow space were derived. Bane mineral density was also assessed in each radius by means of dual-energy x-ray absorptiometry and pQCT. Each bone was subjected to a mec hanical load consistent with a fall from a standing height, and measures of density and trabecular structure were compared to the compressive load. Re sults: Bn the 9 bones tested, measures of bone mineral density explained ap proximately 50% of the variability with load (0.52 < r(2) < 0.57, p < 0.03) , and indices relating to the size of the marrow spaces explained an additi onal 25% to 30% of the variance. This held true whether the indices quantif ying the marrow space were derived from the MRI images (r(2) = 0.70, p = 0. 03) or the pQCT images (r(2) = 0.82, p = 0.006). Conclusion: Our findings s uggest that image-based assessments of trabecular bone structure relate to bone strength in vitro.