T_(1)灰阶反转图评估中轴型脊柱关节炎骶髂关节结构性病变的价值

Grey-scale Reversed T_(1)-weighted MRI for Detecting Structural Lesions of the Sacroiliac Joint in Patients with Axial Spondyloarthritis

【目的】探讨T_(1)灰阶反转(rT_(1))图对中轴型脊柱关节炎(ax-SpA)骶髂关节结构性病变的诊断价值。【方法】回顾性搜集我院2020年2月至2022年12月在1周内行骶髂关节MRI及CT检查并符合ax-SpA诊断标准的患者52例,共计104个骶髂关节。两名放射科医师基于常规T_(1)WI、rT_(1)、T_(1)WI+rT_(1)三组图像,分别评估ax-SpA骶髂关节结构病变:骨侵蚀、骨质硬化、关节间隙改变,在斜冠状位图像上将骶髂关节分为前、中、后3部分,每部分分骶面、髂面,共6个区域,并按拟定评分规则对上述3种结构性病变进行评分,其中1名医师间隔1月后再次进行评分。由第3名肌骨影像专科医师同样使用上述方法评估CT图像作为参考标准。使用组内相关系数(ICC)分析医师间及医师内分别评估各病变评分一致性;采用Friedman M检验比较三组图像对各病变评分与CT评分的差异;以CT为参考标准,采用诊断性试验分析计算三组图像诊断骨侵蚀、骨质硬化及关节间隙改变的准确率、灵敏度、特异度,并采用McNemar检验比较rT_(1)、T_(1)WI+rT_(1)与T_(1)WI的差异。【结果】三组图像评分各类结构病变医师间、医师内一致性好,其中以T_(1)WI+rT_(1)的一致性最优,评估各类病变ICC≥0.85695%CI(0.794,0.900),优于rT_(1)及T_(1)WI[rT_(1):ICC≥0.81995%CI(0.745,0.874),T_(1)WI:ICC≥0.75495%CI(0.656,0.827)];T_(1)WI+rT_(1)对各病变的评分结果与CT评分结果相当,rT_(1)对骨侵蚀、关节间隙改变评分与CT相当(P>0.05)。相较T_(1)WI,T_(1)WI+rT_(1)诊断各病变均有更高的准确率及灵敏度(准确率骨侵蚀:90.3%vs 76.9%;灵敏度骨侵蚀:91.6%vs 76.1%;准确率骨质硬化:89.4%vs 80.8%;灵敏度骨质硬化:84.6%vs 73.9%;准确率关节间隙改变:86.5%vs 73.1%;灵敏度关节间隙改变:84.9%vs 60.4%;P<0.05);rT_(1)提高了对骨侵蚀、关节间隙改变诊断的准确性和灵敏度(准确率骨侵蚀:87.5%vs 76.9%;灵敏度骨侵蚀:88.7%vs 76.1%;准确率关节间隙改变:85.6%vs 73.1%;灵敏度关节间隙改变:83.0%vs 60.4%;P<0.05)。【结论】rT_(1)能提高ax-SpA骶髂关节结构性病变的诊断效能,T_(1)WI+rT_(1)效能更优。

【Objective】To analyze the value of grey-scale reversed T_(1)-weighted(rT_(1))MRI in the detection of structur-al lesions of the sacroiliac joint(SIJ)in patients with axial spondyloarthritis(ax-SpA).【Methods】Fifty-two ax-SpA pa-tients who underwent both MRI and CT in our hospital within a week from February 2020 to December 2022 were retrospec-tively included.Both sacral and iliac side of each SIJ on oblique coronal images were divided into anterior,middle and pos-terior portion.Two radiologists reviewed independently three groups of MRI including T_(1)-weighted imaging(T_(1)WI),rT_(1)and T_(1)WI+rT_(1)images to evaluate the structural lesions like erosions,sclerosis and joint space changes in each of the 6 re-gions of the SIJ.One of the radiologist did the evaluation again one month later.CT images were scored for lesions by a third radiologist and served as the reference standard.Intra-class correlation coefficients(ICC)were calculated to test the inter-and intra-reader agreement for the assessment of SIJ lesions.A Friedman test was performed to compare the lesion results of MRI and CT image findings.We examined the diagnostic performance[accuracy,sensitivity(SE)and specifici-ty]of different groups of MRI in the detection of lesions by using diagnostic test.A McNemar test was used to compare the differences of three groups of MRI findings.【Results】CT showed erosions in 71 joints,sclerosis in 65 and joint space changes in 53.Good inter-and intra-reader agreements were found in three groups of MRI images for the assessment of le-sions,with the best agreement in T_(1)WI+rT_(1).There were no difference between T_(1)WI+rT_(1)and CT for the assessment of all lesions,nor between rT_(1)and CT for the assessment of erosions and joint space changes(P>0.05).T_(1)WI+rT_(1)yielded better accuracy and SE than T_(1)WI in detection of all lesions(Accuracy erosions:90.3%vs 76.9%;SE erosions:91.6%vs 76.1%;Accu-racy sclerosis:89.4%vs 80.8%;SE sclerosis:84.6%vs 73.9%;Accuracy jointspacechanges:86.5%vs 73.1%;SE jointspacechanges:84.9%vs 60.4%;P<0.05).rT_(1)yielded better accuracy and SE than T_(1)WI in detection of erosions and joint space changes(Accuracy erosions:87.5%vs 76.9%;SE erosions:88.7%vs 76.1%;Accuracy jointspacechanges:85.6%vs 73.1%;SE jointspacechanges:83.0%vs 60.4%;P<0.05).【Conclusions】In the detection of SIJ structural lesions in ax-SpA,rT_(1)improves the diagnostic perfor-mance and T_(1)WI+rT_(1)is more superior to others.