Ren Cui, Zhu Qiao, Chen Wen, Lang Ning, Yuan Hui Shu
Department of Radiology,Peking University Third Hospital,Beijing 100191,China.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2018 Dec 20;40(6):723-729. doi: 10.3881/j.issn.1000-503X.10602.
Objective To investigate the clinical value of diffusion-weighted imaging (DWI) for evaluating the activity of sacroiliitis in ankylosing spondylitis (AS).Methods Totally 73 AS patients were prospectively enrolled and divided into active group (n=43) and chronic group (n=30) according to Bath ankylosing spondylitis disease activity index (BASDAI) scores and laboratory findings. Conventional magnetic resonance imaging (MRI) and DWI were performed in all subjects. Apparent diffusion coefficient (ADC) values of subchondral lesions in sacroiliac joint were independently measured by two radiologists,and the relative ADC (rADC) values were calculated. ADC and rADC values were compared between active and chronic groups. The efficiencies of ADC and rADC values for differentiating the activity of sacroiliitis were analyzed. In addition,the correlation coefficients of ADC values,rADC values,and BASDAI scores were calculated.Results The ADC and rADC values in the active group were (0.667±0.122)×10 mm /s and (1.715±0.343)×10 mm /s,respectively,which were significantly higher than those of the chronic group [(0.492±0.0651)×10 mm /s and (1.289±0.209)×10 mm /s,respectively)] (P<0.0001). The agreement of measurement results between two radiologists was good,and all the interclass correlation coefficients were >0.81. The correlation coefficients of ADC value and rADC value with BASDAI scores were 0.82 and 0.80,respectively (P<0.0001). The optimal cutoff values of ADC value and rADC value for differentiating AS activity were 0.545×10 mm /s and 1.467×10 mm /s,respectively,The specificity was 81.8% for both indicators,and the sensitivity was 92.0% and 88.0%,respectively.Conclusion DWI is helpful in the quantitative assessment of the activity of sacroiliitis in AS patients.
目的 探讨扩散加权成像（DWI）在评估强直性脊柱炎（AS）骶髂关节炎活动度中的临床价值。方法 前瞻性纳入73例AS患者，根据巴斯强直性脊柱炎疾病活动指数（BASDAI）评分及实验室检查结果分为活动组（n = 43）和慢性组（n = 30）。所有受试者均行常规磁共振成像（MRI）及DWI检查。由两名放射科医师独立测量骶髂关节软骨下病变的表观扩散系数（ADC）值，并计算相对ADC（rADC）值。比较活动组与慢性组的ADC值及rADC值。分析ADC值及rADC值鉴别骶髂关节炎活动度的效能。此外，计算ADC值、rADC值与BASDAI评分的相关系数。结果 活动组的ADC值及rADC值分别为（0.667±0.122）×10⁻³mm²/s和（1.715±0.343）×10⁻³mm²/s，显著高于慢性组[分别为（0.492±0.0651）×10⁻³mm²/s和（1.289±0.209）×10⁻³mm²/s]（P < 0.0001）。两名放射科医师测量结果的一致性良好，组内相关系数均>0.81。ADC值及rADC值与BASDAI评分的相关系数分别为0.82和0.80（P < 0.0001）。鉴别AS活动度的ADC值及rADC值的最佳截断值分别为0.545×10⁻³mm²/s和1.467×10⁻³mm²/s，两种指标的特异性均为81.8%，敏感性分别为92.0%和88.0%。结论 DWI有助于对AS患者骶髂关节炎的活动度进行定量评估。
