幼年特发性关节炎骶髂关节ADC定量诊断价值探讨

Quantitative diagnosis of MRI apparent diffusion coefficient of sacroiliac joint in juvenile idiopathic arthritis

目的探讨幼年特发性关节炎(juvenile idiopathic arthritis,JIA)骶髂关节磁共振表观扩散系数(apparent diffusion coefficient,ADC)诊断价值,以实现定量影像诊断的临床应用。方法选取骶髂关节JIA 95例和正常对照组50例,分析JIA骶髂关节MR影像特征,对骶髂关节间隙区域和关节面下异常信号区与对照组相应部位行ADC值测量,对相关数据行统计学分析。根据cut-off值分为两组,绘制Kaplan-Meier曲线比较两组不同时间点症状复发的情况。结果骶髂关节JIA常规MR表现为滑膜增厚、关节面下骨质异常、关节积液。骶髂关节ADC值和各指标分析:关节间隙区域正常组与JIA组ADC值比较,差异无统计学意义(P>0.05);关节面下区域正常组与JIA组ADC值比较,差异无统计学意义(P>0.05),JIA组ADC值高于正常组,两组类风湿因子(rheumatoid factor,RF)比较,差异无统计学意义(P>0.05),两组红细胞沉降率(erythrocytesedimentation,ESR)、C反应蛋白(c-reactionprotein,CRP)、MR评分比较,差异无统计学意义(P>0.05)。两组关节积液发生率比较,差异无统计学意义(P>0.05),滑膜增厚发生率、关节面下骨质异常发生率比较,差异有统计学意义(P<0.05)。骶髂关节面下ADC值在诊断JIA中获得较高的(area under ROC curve,AUC)值(0.959),cut-off值为0.7095×10-3。骶髂关节面下区域ADC值与MR评分呈中等程度的正相关(r=0.633,P<0.001),与其他临床因素指标[类风湿因子(rheumatoid factor,RF)、红细胞沉降率(erythrocytesedimentation,ESR)、C反应蛋白(c-reactionprotein,CRP)]均无明显相关性(P>0.05)。多因素Logistic回归分析中发现骶髂关节面下区域ADC值及CRP是影响JIA的独立影响因素。两组症状复发情况比较,差异有统计学意义(P<0.05),ADC>0.7095×10-3组随着时间推移症状复发率明显增加。结论MRI检查能够较全面地评价JIA骶髂关节滑膜、关节面下骨质受累及水肿情况,骶髂关节面下区域ADC值在JIA的诊断中具有重要价值。

Objective To explore the diagnostic value of MRI apparent diffusion coefficient(ADC)of sacroiliac joint in juvenile idiopathic arthritis(JIA),so as to realize the application of quantitative image diagnosis in clinic.Methods A total of 95 cases of sacroiliac joint JIA and 50 cases of normal control group were selected for this study.In this study,the MR imaging characteristics of JIA sacroiliac joint were analyzed,and the ADC values of the sacroiliac joint space area and subarticular abnormal signal area and the corresponding parts of the control group were measured,and the related data were statistically analyzed.All the patients were divided into two groups based on cut off values,a Kaplan–Meier curve was plotted to compare the recurrence of symptoms at different time points in the two groups.Results JIA conventional MR findings of sacroiliac joint showed synovial thickening,subarticular bone abnormality and joint effusion.ADC value and indexes of sacroiliac joint were analyzed.In the area of joint space,there was no significant difference in ADC value between normal group and JIA group(P>0.05).In the area under the articular surface,there was no significant difference in ADC value between the normal group and the JIA group(P>0.05),and the ADC value in the JIA group was higher than that in the normal group.There was no significant difference in rheumatoid factor between the two groups(P>0.05),but there was significant difference in(erythrocytesedimentation, ESR), (c-reactionprotein, CRP) and MR scores between the two groups (P<0.05). There was no difference in the incidence of joint effusion (P>0.05), but there was significant difference in the incidence of synovial thickening and abnormal bone under the articular surface (P<0.05). The ADC value under the sacroiliac joint surface obtained a higher area under (receiver operating characteristic curve, ROC) curve (AUC) value (0.959) in the diagnosis of JIA, and the Cut-off value was 0.7095×10-3. The ADC value of sacroiliac joint subsurface was moderately positively correlated with MR score (r=0.633, P<0.001), but not with other clinical factors (RF, ESR, CRP). ADC value in the infrafacial region of sacroiliac joint and CRP were independent factors affecting Jia. There was a significant statistical difference in symptom recurrence between the two groups (P<0.05);ADC greater-0.7095×103 group of symptoms increased significantly than Less-0.7095×103 group. Conclusion MRI can comprehensively evaluate the synovium and subarticular bone involvement and edema of JIA sacroiliac joint, the ADC value of sacroiliac joint subsurface plays an important role in the diagnosis of JIA.