Department of Radiology, Queen Mary Hospital, Pokfulam, Hong Kong.
Department of Radiology, Queen Mary Hospital, Pokfulam, Hong Kong.
Clin Radiol. 2022 Oct;77(10):e783-e788. doi: 10.1016/j.crad.2022.06.017. Epub 2022 Aug 5.
To evaluate the effect of subchondral oedema in T2-weighted Dixon magnetic resonance imaging (MRI) sequence evaluation of sacroiliac joint erosion in patients with axial spondyloarthropathy.
Twenty patients diagnosed with axial spondyloarthritis underwent MRI at a tertiary referral centre from December 2019 to March 2021 were included. In-phase, opposed-phase and fat-only images were scored by two musculoskeletal radiologists independently for the presence of erosions in eight sacroiliac joint quadrants. Sensitivity, specificity and areas under the curve (AUC) of the receiver operating characteristic curve were determined using T1W sequence as reference standard. Intra-observer and interobserver reliability were calculated using Cohen's kappa coefficient.
The diagnostic performance of fat-only and in-phase images were similar (AUC 0.857-0.902 and 0.828-0.868) and better than opposed-phase images (AUC 0.613-0.658). The interobserver reliability of fat-only and in-phase images were substantial (k = 0.747 and 0.712), and moderate for opposed-phase images (k = 0.417). Intra-observer reliability was almost perfect for all the images. In the subgroup analysis, the specificity and AUC for oedema-positive group were lower than oedema-negative group in all image sets. Interobserver reliability was substantial for fat-only and in-phase images in both groups, but slight and moderate for the opposed-phase oedema-positive and negative groups, respectively.
The presence of subchondral oedema in active sacroiliitis decreased the diagnostic accuracy of sacroiliac joint erosion detection on T2W Dixon MRI images.
评估 T2 加权 Dixon 磁共振成像（MRI）序列中软骨下水肿对轴性脊柱关节炎患者骶髂关节侵蚀的评估效果。
纳入 2019 年 12 月至 2021 年 3 月在一家三级转诊中心接受 MRI 检查的 20 例诊断为轴性脊柱关节炎的患者。两名肌肉骨骼放射科医生独立对八个骶髂关节象限的侵蚀情况进行同相位、反相位和仅脂肪图像评分。使用 T1W 序列作为参考标准，确定受检者工作特征曲线的灵敏度、特异性和曲线下面积（AUC）。使用 Cohen's kappa 系数计算观察者内和观察者间的可靠性。
仅脂肪和同相位图像的诊断性能相似（AUC 0.857-0.902 和 0.828-0.868），优于反相位图像（AUC 0.613-0.658）。仅脂肪和同相位图像的观察者间可靠性为中等（k 值分别为 0.747 和 0.712），反相位图像为中度（k 值为 0.417）。所有图像的观察者内可靠性几乎都是完美的。在亚组分析中，在所有图像组中，水肿阳性组的特异性和 AUC 均低于水肿阴性组。在两组中，仅脂肪和同相位图像的观察者间可靠性均为中等，而反相位水肿阳性和阴性组的观察者间可靠性分别为轻度和中度。
在活动性骶髂关节炎中存在软骨下水肿会降低 T2W Dixon MRI 图像检测骶髂关节侵蚀的诊断准确性。
