Kang Yusuhn, Hong Sung Hwan, Kim Ji Young, Yoo Hye Jin, Choi Ja-Young, Yi Minkyung, Kang Heung Sik
1 All authors: Department of Radiology, Seoul National University College of Medicine, 101 Daehak-ro Jongno-gu, Seoul 110-744, Korea.
AJR Am J Roentgenol. 2015 Nov;205(5):1048-55. doi: 10.2214/AJR.14.14217.
The purpose of this study was to identify the MRI features that aid in the differentiation between infectious sacroiliitis and unilateral sacroiliitis associated with spondyloarthritis.
The MR images of 54 patients who received a diagnosis unilateral sacroiliitis between August 2001 and August 2013 were reviewed. MR images were evaluated for bone lesions (extent and distribution of bone marrow edema and presence and size of bone erosions), soft-tissue lesions (capsulitis, extracapsular fluid collections, and periarticular muscle edema), and joint space enhancement. The Fisher exact test was used for comparison of categoric data, and multivariate stepwise logistic regression analysis was performed.
Thick capsulitis, extracapsular fluid collection, and periarticular muscle edema were all more frequently observed in infectious sacroiliitis (p < 0.001). Iliac-dominant bone marrow edema and joint space enhancement were statistically significantly more common in spondyloarthritis (p < 0.001 and p = 0.014, respectively). The presence of periarticular muscle edema was the only independently differentiating variable on multivariate stepwise logistic regression analysis. When periarticular muscle edema was the sole predictor, unilateral sacroiliitis in spondyloarthritis was correctly identified in 77.3% of cases, and infectious sacroiliitis was correctly identified in 90.6% of cases. The overall accuracy was 85.2%.
MRI features of the bone lesions, soft-tissue lesions, and joint space enhancement in unilateral sacroiliitis aid in the differential diagnosis between infection and spondyloarthritis. Among various findings, periarticular muscle edema was the single most important predictor of infectious sacroiliitis.
本研究旨在确定有助于区分感染性骶髂关节炎和与脊柱关节炎相关的单侧骶髂关节炎的MRI特征。
回顾了2001年8月至2013年8月期间被诊断为单侧骶髂关节炎的54例患者的MR图像。对MR图像进行骨病变（骨髓水肿的范围和分布以及骨侵蚀的存在和大小）、软组织病变（囊炎、囊外积液和关节周围肌肉水肿）以及关节间隙强化评估。采用Fisher精确检验比较分类数据，并进行多因素逐步逻辑回归分析。
厚囊炎、囊外积液和关节周围肌肉水肿在感染性骶髂关节炎中更常见（p < 0.001）。以髂骨为主的骨髓水肿和关节间隙强化在脊柱关节炎中在统计学上更常见（分别为p < 0.001和p = 0.014）。在多因素逐步逻辑回归分析中，关节周围肌肉水肿的存在是唯一独立的鉴别变量。当关节周围肌肉水肿是唯一预测因素时，脊柱关节炎所致单侧骶髂关节炎在77.3%的病例中被正确识别，感染性骶髂关节炎在90.6%的病例中被正确识别。总体准确率为85.2%。
单侧骶髂关节炎的骨病变、软组织病变和关节间隙强化的MRI特征有助于感染与脊柱关节炎之间的鉴别诊断。在各种发现中，关节周围肌肉水肿是感染性骶髂关节炎最重要的单一预测因素。
