Abstract:Objective: To investigate the value of 99Tcm-MDP triple phase bone imaging for the differential diagnosis of prosthesis loosening and joint infection after arthroplasty. Methods: 14 patients with joint pain after joint arthroplasty underwent triphase SPECT/CT bone imaging. By visual analysis, the bone imaging results were validated with the findings of germiculture, serum C reative protein(CRP), erythrocyte sedimentation rate(ESR) and biopsy. Results: The final clinical diagnosis was taken as gold standard. If diffuse radioactivity in the bone and prosthesis simply by delayed phase was considered joint infection, the diagnostic sensitivity, specificity and accuracy were 80%, 77.78% and 78.6%, respectively. When increased uptake of isotopes in the blood flow or pool phase as well as positive findings in the delayed phase as the criterion of joint infection, the diagnostic sensitivity, specificity and accuracy were 100%, 88.89% and 92.9%, respectively. Conclusion: Delayed SPECT/CT hybrid imaging may precisely indicate the position of prosthesis loosening and joint infection. By combination of 99Tcm-MDP blood flow and pool imaging, it showed higher clinical value in differentiating joint infection from prosthesis loosening after arthroplasty.