ABSTRACT
Objective To preliminarily evaluate the value of color power doppler ultrasonography in the diagnosis of sacroiliitis in ankylosing spondylitis(AS). Methods Fifty-seven sacroiliac joints in 31 patients with active AS and 40 sacroiliac joints in 20 volunteers were detected by color power doppler ultrasonography.The color flow signs inside the sacroiliac joints were observed,and the resistance index(RI) was measured. Results In active AS,color flow signs were seen in 55 joints,and the mean RI value was 0.53?0.08 in 45 joints,while the other 10 color flow signs represented reversed phase in diastolic phase on pulse doppler ultrasonography.In the volunteers,color flow signs were seen in 16 joints,and the mean RI value was 0.97?0.01 in 6 joints,while the other 10 color flow signs represented reversed phase in diastolic phase on pulse doppler ultrasonography. Conclusion The abnormal flow signs at the sacroiliac joints can be detected by color power doppler ultrasonography.Low RI values provide diagnosis evidence for active AS.