Quantification of trabecular bone structure from three-dimensional μMR images

Magnetic resonance imaging (MRI) has recently been applied to the study of osteoporosis. Accurate acquisition techniques and image analysis protocols for the determination of trabecular bone structure are yet to be defined. Two different approaches for three-dimensional acquisition and reconstruction are exploited to derive the structural parameters of trabecular bone explants. In particular, MR microscopy (μMRI) is used to obtain conventional (FT) and projection reconstruction (PR) spin-echo images (41×41×41 μm³ /voxel). Segmentation of the high-resolution images into bone and bone marrow is obtained by using a suitable threshold. The main bone structural parameters are then derived by using a 3D version of the directed secant algorithm applied to a series of contiguous sections. The efficiency of the two methods in the assessment of trabecular bone architecture is discussed