The Role of 99mTc-Annexin V Apoptosis Scintigraphy in Visualizing Early Stage Glucocorticoid-Induced Femoral Head Osteonecrosis in the Rabbit

摘要

Objective. To validate the ability of ^99mTc-Annexin V to visualize early stage of glucocorticoid-induced femoral head necrosis by comparing with ^99mTc-MDP bone scanning. Methods. Femoral head necrosis was induced in adult New Zealand white rabbits by intramuscular injection of methylprednisolone. ^99mTc-Annexin scintigraphy and ^99mTc-MDP scans were performed before and 5, 6, and 8 weeks after methylprednisolone administration. Rabbits were sacrificed at various time points and conducted for TUNEL and H&E staining. Results. All methylprednisolone treated animals developed femoral head necrosis; at 8 weeks postinjection, destruction of bone structure was evident in H&E staining, and apoptosis was confirmed by the TUNEL assay. This was matched by ^99mTc-Annexin V images, which showed a significant increase in signal over baseline. Serial ^99mTc-Annexin V scans revealed that increased ^99mTc-Annexin V uptake could be observed in 5 weeks. In contrast, there was no effect on ^99mTc-MDP signal until 8 weeks. The TUNEL assay revealed that bone cell apoptosis occurred at 5 weeks. Conclusion. ^99mTc-Annexin V is superior to ^99mTc-MDP for the early detection of glucocorticoid-induced femoral head necrosis in the rabbit and may be a better strategy for the early detection of glucocorticoid-induced femoral head necrosis in patients.