The value of magnetic resonance imaging dynamic enhancement technique in evaluating the activity of hip joint lesions in ankylosing spondylitis / 中华风湿病学杂志

ABSTRACT

Objective To evaluate the value of 3.0 T dynamic contrast-enhanced magnetic resonance imaging(MRI) in the diagnosis of hip joint lesions in patients with ankylosing spondylitis (AS).Methods Fifty-two AS patients with hip involvement were diagnosed in Department of Rheumatology in our hospital from January 2013 to December 2016.All patients underwent AS disease activity ankylosing spondylitis disease activity score (ASDAS)-C-reactive protein (CRP) score evaluation of hip joint acti-vity and hip joint disease activity was evaluated by doctors.According to ASDAS-CRP score,patients were divided into active disease 34 cases and remission for 18 cases.All patients underwent double hip MRI plain scan,dynamic enhanced scan and post-processing analysis after the diagnosis.Six regions of interest were selected in the abnormal synovial area around the hip joint.The time signal TIC curve was generated automatically,the shape of the curve was described and the early intensification rate of the third,fourth phase was measured.The early intensification rates of the active disease group and the remission group were analyzed statistically.Two independent samples t test was used for analysis,and P＜0.05 was regarded as statistically significant.The early intensification rate of the third,fourth phase were compared with the ASDAS-CRP score,the evaluation of hip joint activity in patients and the evaluation of hip joint activity were carried out by doctors taking care of the patients.Results The TIC curve of the active group was rising fast,followed by platform or fast rising.The curve of the remission group was slow rising.The inten-sification rate of the third,fourth phase [(116±9)％,(146±12)％ respectively] in the active phase group was higher than that of the remission group [(23±5)％,(43±14)％],and the difference was statistically significant (t=2.447,3.054;P＜0.05).The rate of synovial enhancement of the third,fourth phases was positively correlated with the ASDAS-CRP score (r=0.802,0.836,P=0.01),and the correlation was poor with evaluation of hip joint activity by patients (r=0.352,0.458;the P=0.02,0.01respectively),and the correlation was goodwith the evaluation of hip joint activity by doctors (r=0.652,0.717;P=0.01).Conclusion The shape and early enhancement rate of magnetic reson-ance dynamic enhanced TIC curve is valuable in assessing the disease activity of hip joint lesions in AS patients.