Bone structure and mineralization demonstrated using synchrotron radiation computed tomography (SR-CT) in animal models: preliminary findings

We investigated the ability of synchrotron radiation computed tomography (SR-CT) to demonstrate trabecular microstructure, detail of trabecular surfaces, and mineralization of bones. Eight rat vertebrae, six rat tibiae, and eight minipig vertebrae were scanned using SR-CT at the synchrotron radiation facility Super Photon ring-8GeV (SPring-8). Images obtained using conventional micro-CT, scanning electron microscopy (SEM), and contact microradiography (CMR) were compared with the SR-CT images. SR-CT showed high image quality without visible partial volume effect. Three-dimensional SR-CT revealed shallow concavities in the bone surface, which were considered to correspond to osteoclastic resorption areas, as well as the connectivity, anisotropy, and shape (rod- or platelike) of trabeculae. Two-dimensional SR-CT showed different density along the surface of the trabecular bone, indicating the degree of bone mineralization. In conclusion, SR-CT seems to be a useful tool for delineating trabecular surfaces, evaluating bone mineralization, and revealing precise trabecular structure.