摘要目的 探讨骶髂关节MRI在慢性腰背痛患者确诊中轴脊柱关节炎(SpA)的特异性及局限性.方法 回顾性分析解放军总医院风湿科2013年1月—2015年12月门诊及住院收治的慢性腰背痛患者390例,分析患者的临床表现、实验室检查及骶髂关节MRI影像学资料.结果 390例患者中326例诊断为中轴SpA,男性216例,女性110例,年龄(27.10 ±8.64)岁,病程(7.64 ±3.50)个月,243例(74.5％)患者HLA-B27阳性.64例非SpA患者,男性22例,女性42例,年龄(31.29±7.76)岁,病程(5.75±2.90)个月,10例(15.6％)患者HLA-B27阳性.中轴SpA患者骶髂关节MRI中68.1％(222/326)有骨髓水肿,65.0％(212/326)有骨侵蚀.尽管非SpA患者髂关节MRI中也有25.0％(16/64)骨髓水肿,7.8％ (5/64)骨侵蚀,但骨髓水肿评分[0.00(0.00,0.75)分]、骨侵蚀评分[0.00(0.00,0.00)分]均较中轴SpA患者[骨髓水肿评分2.00(0.00,4.00)分,骨侵蚀评分1.00(0.00,3.00)分]低,差异有统计学意义(P=0.000).中轴SpA患者与非SpA患者脂肪浸润评分[1.00(0.00,4.25)分,1.00(0.00,4.00)分]、骨硬化评分[0.00(0.00,1.00)分,0.00(0.00,1.75)分]比较差异无统计学意义.骨髓水肿和骨侵蚀对中轴SpA的敏感度(56.4％,64.1％)和特异度(93.8％,92.2％)均较高,阳性预测值为9.09和8.21,阴性预测值为0.46和0.38;骨硬化和脂肪浸润对中轴SpA的敏感度(29.1％,57.7％)和特异度(64.1％,46.9％)均较低,阳性预测值为0.81和1.08,阴性预测值为1.10和0.90.logistic回归分析显示,慢性腰背痛患者HLA-B27阳性、伴有外周关节炎、对非甾体消炎药治疗反应好、骨髓水肿评分、骨侵蚀评分与中轴SpA诊断相关性大.结论 骶髂关节MRI对慢性腰背痛患者确诊中轴SpA具有重要意义,但仍具有局限性,部分患者还需结合临床及脊柱MRI表现明确诊断.

abstractsObjective To evaluate the specificity and limitations of sacroiliac joint magnetic resonance imaging (MRI) in the diagnosis of axial spondyloarthritis (SpA)in patients with chronic low back pain.Methods We retrospectively analyzed clinical data of 390 patients with chronic low back pain in Department of Rheumatology,the PLA General Hospital from January 2013 to December 2015,including clinical manifestations,laboratory examinations and MRI data of sacroiliac joints.Results There were 238 men and 152 women recruited.A total of 326 cases were diagnosed as axial SpA,including 216 men and 110 women with mean age (27.10 ± 8.64) years and mean duration (7.64 ± 3.50) months.Among these 326 patients,243 (74.5％) were HLA-B27 positive.The other 64 patients were considered as diagnoses rather than SpA (non-SpA),consisting of 22 men and 42 women with mean age (31.29 ± 7.76) years and mean duration (5.75 ±2.90)months.Non-SpA group had 10 (15.6％) patients with HLA-B27 positive.There were 68.1％ and 65.0％ SpA patients showing bone marrow edema and bone erosion of sacroiliac joint in MRI imaging respectively.Although there were 25.0％ non-SpA patients with bone marrow edema and 7.8 ％ with bone erosion in MRI of sacroiliac joint,the scores of bone marrow edema 0.00 (0.00,0.75) and bone erosion [0.00(0.00,0.00)] were significantly lower compared with those in axial SpA group [bone marrow edema scores 2.00 (0.00,4.00),bone erosion scores 1.00 (0.00,3.00);P ＜ 0.05].The scores of fat infiltration [1.00 (0.00,4.25),1.00 (0.00,4.00)] and bone sclerosis [0.00 (0.00,1.00),0.00(0.00,1.75)] were not statistically different between two groups.Diagnostic sensitivity of bone marrow edema and bone erosion for axial SpA were 56.4％ and 64.1％ respectively,specificity were 93.8％ and 92.2％ respectively.The positive predictive value of bone marrow edema and bone erosion for axial SpA were 9.09 and 8.21,negative predictive value were 0.46 and 0.38.Diagnositic sensitivity of fatty infiltration and bone sclerosis for axial SpA group were 29.1％ and 57.7％,specificity were 64.1％ and 46.9％.The positive predictive value of fatty infiltration and bone sclerosis for axial SpA were 0.81 and 1.08,negative predictive valne were 1.10 and 0.90.Conclusion Sacroiliac joint MRI is a valuable method to diagnose axial SpA in patients with chronic low back pain.Yet it still has some limitations.Clinical presentations and spinal MRI would be helpful in some patients.