ABSTRACT
BACKGROUND: With a clear distinction from traditional computed tomography (CT) imaging with information absorption, phase-contrast CT with synchronous radiation has implemented the microstructure imaging of soft tissues in organisms with an unprecedented imaging mechanism. OBJECTIVE: To explore the synchrotron radiation phase-contrast CT imaging technology in the bone regeneration imaging after bone grafting. METHODS: Four New Zealand white rabbits were used to make a metaphyseal defect model. Then, model rabbits were randomized into a group with calcium phosphate bone grafting and a group with Bio-Oss bone grafting in the defects. The specimens were imaged by the synchrotron radiation phase-contrast CT and stained with hematoxylin-eosin and sirius red 2 weeks after bone grafting. RESULTS AND CONCLUSION: (1) Bio-Oss bone graft material group: Osteoid was observed not only around the graft material but also in the area far from the graft bone material as reticulate structure by the synchrotron radiation phase-contrast CT. Hematoxylin-eosin staining showed a large amount of red osteoid tissues arranged as trabecular bone, and a large amount of osteoblasts with obvious osteogensis. Sirius red-stained pathological sections were largely stained yellow, and there were round or oval osteoblasts with strongly expressed type I collagen. (2) Calcium phosphate bone graft material group: There was no reticulate structure shown by the synchrotron radiation phase-contrast CT, and the creep of osteoid tissues was only around the bone graft. Hematoxylin-eosin staining showed a large amount of red osteoid tissues, and sirius red-stained pathological sections were stained yellow and red. To conclude, the synchronous radiation phase-contrast CT can clearly display the regenerated structure of bone grafts.