Finite element analysis of bone mechanical properties using MRI-derived bound and pore water concentration maps

Ultrashort echo time (UTE) MRI techniques can be used to image the concentration of water in bones. Particularly, quantitative MRI imaging of collagen-bound water concentration (C_bw) and pore water concentration (C_pw) in cortical bone have been shown as potential biomarkers for bone fracture risk. To investigate the effect of C_bw and C_pw on the evaluation of bone mechanical properties, MRI-based finite element models of cadaver radii were generated with tissue material properties derived from 3 D maps of C_bw and C_pw measurements. Three-point bending tests were simulated by means of the finite element method to predict bending properties of the bone and the results were compared with those from direct mechanical testing. The study results demonstrate that these MRI-derived measures of C_bw and C_pw improve the prediction of bone mechanical properties in cadaver radii and have the potential to be useful in assessing patient-specific bone fragility risk.