Objective:To investigate the clinical and imaging manifestations of SAPHO syndrome patients with axial skele-tal involvement and to improve the recognition rate and diagnostic accuracy.Methods:The clinical data and imaging data of 42 patients (16 males and 26 females) with SAPHO syndrome involving the axial bones were retrospectively analyzed,and the clinical characteristics,lesion range,location,number,and bone changes were summarized.Results:The main clinical mani-festations of patients with axial bone involvement were bone and joint symptoms(42 cases) and skin lesions(40 cases),with 26 cases having axial bone symptoms (pain in the neck,back,lumbosacral region,and mandible).The axial bone involvement in-cluded the spine(28 cases),sacroiliac joints(18 cases),and craniofacial bones(5 cases).The proportion of thoracic vertebrae in-volvement (23 cases) and the number of thoracic vertebrae (47) were the highest,with 23 cases showing multiple vertebral in-volvement(lesion number ≥2).Characteristic imaging signs included the"bull-head sign"on the anterior chest wall on ECT,the "kissing sign"on CT adjacent vertebral bodies (5 cases),the abnormal signal of the round arc shape on MRI vertebral body angle(6 cases),and the unilateral involvement of the sacroiliac joint(12 cases),which manifested as inflammatory lesions of sacroiliitis,partial bone sclerosis,and presence of joint space.The craniofacial bones were mainly affected by unilateral mandibular involvement (4 cases),manifested as bone destruction changes.Conclusion:SAPHO syndrome involving the axial bones is not uncommon,and the clinical and imaging manifestations are highly heterogeneous.Multimodal imaging diagnosis can improve the diagnostic efficiency of this disease.