Value of SPECT/CT bone imaging in the diagnosis of SAPHO syndrome

Objectives To discuss the clinical value of SPECT/CT bone imaging in the diagnosis of synovitis, acne, pustulosis, hyperostosis, and osteomyelitis (SAPHO) syndrome. Methods The clinical data and SPECT and SPECT/CT imaging results of 11 patients with suspected SAPHO syndrome were retrospectively analyzed. All patients underwent 99Tcm-MDP full-body bone imaging, local fault imaging, and CT scanning with the same or different machines. The accuracy, sensitivity, and specificity of the diagnosis of SAPHO syndrome through SPECT and SPECT/CT imaging were analyzed and compared. Data were analyzed through χ2 test. Results Among 11 patients with suspected SAPHO syndrome, 9 underwent puncture pathology or follow-up for the definite diagnosis of their conditions. Two patients were diagnosed with metastatic tumors. In 6 patients with SPECT, 41 lesions exhibited radioactive concentration. Furthermore, 44 lesions were observed in 9 patients who were diagnosed through SPECT/CT. The sensitivity, specificity, and accuracy of SPECT and SPECT/CT imaging were 66.7%(6/9) and 100% (9/9), 50.0%(1/2) and 50.0%(1/2), 63.6%(7/11) and 90.9%(10/11), respectively. The diagnostic accuracy of SPECT/CT imaging for SAPHO syndrome was higher than that for pure SPECT. Moreover, the diagnostic accuracies of the two methods were significantly different(χ2=11.82, P<0.05). Conclusions The combined application of SPECT/CT may improve the accuracy of identifying the anatomical orientations of lesions and the specificity of bone imaging. This method can be used for the precise localization of lesions, the identification and diagnosis of SAPHO in its early stages, the implicit detection of lesions, and the characterization of lesion metabolic activity. Therefore, the combined application of SPECT/CT diagnosis has high clinical value in the diagnosis of SAPHO syndrome. Key words: Acquired hyperostosis syndrome; Tomography, emission-computed, single-photon; Tomography, X-ray computed; Bone imaging