QUANTIFICATION OF TRABECULAR STRUCTURE IN THE DISTAL FEMUR USING MAGNETIC-RESONANCE PHASE IMAGING

A new approach for quantifying trabecular bone tissue using the phase images of a simple gradient-echo sequence is presented. The proposed m ethod is based on the hypothesis that the differences in susceptibilit y between bone and bone marrow cause magnetic field (i.e., precession phase) variations between the image voxels. Phase images of the distal femur were obtained in vivo and characterised with the use of the pha se variance. Computer simulations and experimental results indicate th at the distribution of the phases varies with echo time and image reso lution, as expected. Keeping these fixed, however, the phase variance is found to strongly reflect variations in trabecular structure.