Our specific aims are to a) Evaluate differences in MicroMRI parameters of trabecular microstructure (bone volume fraction, trabecular thickness, surface/curve ratio and erosion index) between age-, race- and BMD-matched postmenopausal women with and without fracture; b.) Correlate T2* relaxation time (a rapid indirect MRI measure of trabecular density and microstructure) with BMD measured by DXA, and microstructural parameters measured by MicroMRI. As an exploratory aim we will investigate HR-MRI parameters of trabecular microstructure obtained using a newly developed, rapid MRI sequence referred to as IDEAL-FSE with parameters obtained using the currently available MicroMRI, Inc. sequence.