Zhao Ying-Hua, Cao Yan-Yan, Zhang Qun, Mei Ying-Jie, Xiao Ji-Jie, Hu Shao-Yong, Li Wei, Li Shao-Lin
Department of Radiology, Third Affiliated Hospital of Southern Medical University, Orthopaedic Hospital of Guangdong Province, Guangzhou, Guangdong 510630, China.
Department of Rheumatology, Hospital of Integrated Traditional Chinese Medicine and Western Medicine of Southern Medical University, Guangzhou, Guangdong 510315, China.
Chin Med J (Engl). 2017 Jun 5;130(11):1303-1308. doi: 10.4103/0366-6999.206359.
Previous studies showed that combining apparent diffusion coefficient (ADC) value with the Spondyloarthritis Research Consortium of Canada (SPARCC) index value might provide a reliable evaluation of the activity of ankylosing spondylitis (AS), and that contrast-enhanced (CE) magnetic resonance imaging (MRI) is unnecessary. However, the results were based on confirming only a small random sample. This study aimed to assess the role of CE-MRI in differentiating the disease activity of AS by comparing ADC value with a large sample.
A total of 115 patients with AS were enrolled in accordance with Bath AS Disease Activity Index and laboratory indices, and 115 patients were divided into two groups, including active group (n = 69) and inactive group (n = 46). SPARCC, ΔSI, and ADC values were obtained from the short tau inversion recovery (STIR), diffusion-weighted imaging (DWI), and CE-MRI, respectively. One-way analysis of variance and receiver operating characteristic analysis were performed for all parameters.
The optimal cutoff values (with sensitivity, specificity, respective area under the curve, positive likelihood ratio, and negative likelihood ratio) for the differentiation between active and inactive groups are as follows: SPARCC = 6 (72.06%, 82.61%, 0.836, 4.14, 0.34); ΔSI (%) = 153 (80.6%, 84.78%, 0.819, 5.3, 0.23); ADC value = 1.15 × 10-3 mm2/s (72.73%, 81.82%, 0.786, 4, 0.33). No statistical differences were found among the predictive values of SPARCC, ΔSI, and ADC. Multivariate analysis showed no significant difference between the combination of SPARCC and ADC values with and without ΔSI.
Using large sample, we concluded that the combination of STIR and DWI would play significant roles in assessing the disease activity, and CE-MRI sequence is not routinely used in imaging of AS to avoid renal fibrosis and aggravation of kidney disease.
既往研究表明，将表观扩散系数（ADC）值与加拿大脊柱关节炎研究联盟（SPARCC）指数值相结合，可能为强直性脊柱炎（AS）的疾病活动度提供可靠评估，且无需对比增强（CE）磁共振成像（MRI）。然而，这些结果仅基于对一小部分随机样本的验证。本研究旨在通过对大量样本进行比较，评估CE-MRI在区分AS疾病活动度方面的作用。
根据巴斯强直性脊柱炎疾病活动指数和实验室指标，共纳入115例AS患者，并将其分为两组，即活动组（n = 69）和非活动组（n = 46）。分别从短tau反转恢复（STIR）、扩散加权成像（DWI）和CE-MRI中获取SPARCC、ΔSI和ADC值。对所有参数进行单因素方差分析和受试者工作特征分析。
活动组与非活动组区分的最佳截断值（包括敏感性、特异性、曲线下面积、阳性似然比和阴性似然比）如下：SPARCC = 6（72.06%，82.61%，0.836，4.14，0.34）；ΔSI（%） = 153（80.6%，84.78%，0.819，5.3，0.23）；ADC值 = 1.15×10⁻³mm²/s（72.73%，81.82%，0.786，4，0.33）。SPARCC、ΔSI和ADC的预测值之间未发现统计学差异。多因素分析显示，有或无ΔSI时，SPARCC和ADC值的组合之间无显著差异。
通过大量样本研究，我们得出结论，STIR和DWI的联合应用在评估疾病活动度方面将发挥重要作用，且CE-MRI序列在AS成像中非常规使用，以避免肾纤维化和肾脏疾病加重。
