DWI诊断儿童附着点炎症相关关节炎的早期骶髂关节炎性病变

目的 探讨DWI检测儿童附着点炎症相关关节炎（ERA）早期骶髂关节炎性病变的价值。方法 回顾性分析20例经临床确诊的ERA患儿（ERA组）及20例非骶髂关节炎儿童（对照组）的资料，年龄均为6~16岁。所有受试者均接受双侧骶髂关节MR检查，主要为精确频率反转恢复（SPAIR）脂肪抑制序列扫描及DWI（b值为0、400 s/mm²），观察骶髂关节骶骨缘及髂骨缘骨质，测量并比较2组骶髂关节ADC值差异，绘制ROC曲线，评价ADC值对ERA的诊断效能。结果 ERA组中，17例SPAIR序列可见骶髂关节面缘片状高信号或斑片状稍高信号，3例SPAIR序列图像未见异常；16例DWI可见骶髂关节面缘片状高信号或斑片状稍高信号，4例DWI未见异常。对照组中，12例SPAIR序列图像骶髂关节面缘未见异常，8例SPAIR序列图像可见斑片状稍高信号；15例DWI骶髂关节面缘未见异常，5例DWI可见斑片状稍高信号。ERA组骶髂关节ADC值为（1.24±0.32）×10^-3 mm²/s，对照组为（0.69±0.24）×10^-3 mm²/s，差异有统计学意义（t=14.466，P=0.001）。以ADC=0.87×10^-3 mm²/s为阈值，诊断ERA的ROC曲线AUC为0.834（P=0.023），敏感度为87.50%，特异度为77.50%，诊断准确率为82.50%。结论 DWI是显示儿童ERA骶髂关节炎性病变的敏感方法，ADC值定量分析对诊断早期骶髂关节炎性病变具有较高临床价值。

DWI in detecting early stage sacroiliac joint lesions in children with enthesitis-related arthritis

Objective To investigate the value of DWI in detecting early inflammation of sacroiliac joints in children with enthesitis-related arthritis (ERA). Methods Data of 20 children with clinical diagnosed ERA (ERA group) and 20 children without ERA (control group) were retrospectively analyzed. All of children aged 6-16 years old. MR images were obtained, mainly included spectral attenuated inversion recovery (SPAIR) sequence and DWI (b value was 0 and 400 s/mm², respectively). MRI features of sacroiliac joints were observed. ADC values of all sacroiliac joints were measured and compared between the two groups. ROC curve was used to evaluate the diagnostic efficacy of ADC value on ERA. Results In ERA group, 17 patients showed high signal intensity at sacroiliac joints on SPAIR images and 3 were normal, 16 patients showed high signal intensity on DWI and 4 were normal. In control group, 12 children were normal on SPAIR images and 8 showed high signal intensity at sacroiliac joints, while 15 children were normal on DWI images and 5 showed high signal intensity. ADC value in ERA group and control group was (1.24±0.32)×10^-3 mm²/s and (0.69±0.24)×10^-3 mm²/s, respectively (t=14.466, P=0.001). Taking ADC=0.87×10^-3 mm²/s as the threshold, AUC of ROC curve in diagnosis of ERA was 0.834 (P=0.023), with the sensitivity, specificity and diagnostic accuracy was 87.50%, 77.50% and 82.50%, respectively. Conclusion DWI is a sensitive method for displaying inflammation of the sacroiliac joint in patients with ERA. Quantitative analysis of ADC value shows high value in detecting early inflammation of sacroiliac joints.