Abstract：Objective: To assess the CT findings of sacroiliac joints changes in ankylosing spondylitis(AS), CT scanning were performed in 31 cases with AS proved clinically. Materials and Methods: CT findings of sacroiliac joints who were clinically diagnosed as AS were analysed. Results: Thirty of the 31 cases had abnormal CT findings of the sacroiliac joints. Five cases belonged to grade Ⅰ?(16.1%), 7 cases were grade Ⅱ(22.5%), 16 cases were grade Ⅲ(51.6%), 2 cases were grade Ⅳ(6.5%). In the early stage, sacroiliac joint of most cases had symmetric irregularity of articular surface, subcortical microcysts and mild sclerosis of iliac surface of joint. In advaced stage, sacroiliac articular surfaces were irregular with subcortical cystic destruction, showing serration or brush like deformity, sclerosis or hypertophic changes, and pseudo-widening or narrowing of joint space. Bony ankylosis of the joints with obliteration of joint space and osteoporosis or osteosclerosis were seen in the late or stable stage. Conclusion: CT scanning of sacroiliac joints could be helpful in diagnosis of AS, and helpful in clinical evaluation of the disease.
2006, Vol. 17 
