T1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OA北大核心CSTPCD

[Objective]To analyze the value of grey-scale reversed T1-weighted(rT1)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 T1-weighted imaging(T1WI),rT1 and T1WI+rT1 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 T1WI+rT1.There were no difference between T1WI+rT1 and CT for the assessment of all lesions,nor between rT1 and CT for the assessment of erosions and joint space changes(P>0.05).T1WI+rT1 yielded better accuracy and SE than T1WI 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 joint space changes:86.5%vs 73.1%;SE joint space changes:84.9%vs 60.4%;P<0.05).rT1 yielded better accuracy and SE than T1WI in detection of erosions and joint space changes(Accuracy erosions:87.5%vs 76.9%;SE erosions:88.7%vs 76.1%;Accuracy joint space changes:85.6%vs 73.1%;SE joint space changes:83.0%vs 60.4%;P<0.05).[Conclusions]In the detection of SIJ structural lesions in ax-SpA,rT1 improves the diagnostic perfor-mance and T1WI+rT1 is more superior to others.