 The QCT-image analysis method investigated in our study is original, as there are no commercially available tools for measuring proximal femur BMD on QCT images. This original method grew out of 6 years of work conducted jointly at the Medical Physics Institute of the Erlangen University and the Experimental Radiology Laboratory of the LARIBOISIERE-St-Louis Research and Training Unit. Advantages of our method include 3D evaluation of the hip with measurement of the true volumetric density, evaluation of both BMD and bone geometry, and separate evaluations of cortical and trabecular bone. DXA produces 2D images of the hip, spine, or wrist that neither provide geometric data except projected neck length nor allow separate analysis of cortical and trabecular bone. 