Abstract：
BACKGROUND: Unilateral presentation of sacroiliitis is a diagnostic dilemma, especially between infection and inflammatory sacroiliitis associated with spondyloarthritis, requiring an early and accurate diagnosis.
OBJECTIVE: To assess the utility of magnetic resonance imaging (MRI) in differentiating infective versus inflammatory etiology in unilateral sacroiliitis.
METHODS: Retrospective review of the MRI of 90 patients with unilateral sacroiliitis, having an established final diagnosis. MR images were evaluated for various bone and soft tissue changes using predefined criteria and analyzed using univariate and multivariate regression analysis.
RESULTS: Among the 90 patients, infective etiology was diagnosed in 66 (73.3%) and inflammatory etiology in 24 (26.7%). Large erosions, both iliac and sacral-sided edema, joint space involvement with effusion or synovitis, soft tissue edema, elevated ESR/CRP, and absence of capsulitis and enthesitis were associated with infection (p < .001). The independently differentiating variables favoring infection on multivariate analysis were-both iliac and sacral-sided edema (OR 4.79, 95% CI: 0.96-23.81, p = .05), large erosions (OR 17.96, 95% CI: 2.66-121.02, p = .003), and joint space involvement (OR 9.9, 95% CI: 1.36-72.06, p = .02). Exclusive features of infection were osteomyelitis, sequestra, abscesses, sinus tracts, large erosions, and multifocality. All infective cases had soft tissue edema, joint space involvement, elevated ESR, and no capsulitis.
CONCLUSIONS: MRI evaluation for the presence and pattern of bone and joint space involvement, soft tissue involvement, and careful attention to certain exclusive features will aid in differentiating infectious sacroiliitis from inflammatory sacroiliitis.
OBJECTIVE: To assess the utility of magnetic resonance imaging (MRI) in differentiating infective versus inflammatory etiology in unilateral sacroiliitis.
METHODS: Retrospective review of the MRI of 90 patients with unilateral sacroiliitis, having an established final diagnosis. MR images were evaluated for various bone and soft tissue changes using predefined criteria and analyzed using univariate and multivariate regression analysis.
RESULTS: Among the 90 patients, infective etiology was diagnosed in 66 (73.3%) and inflammatory etiology in 24 (26.7%). Large erosions, both iliac and sacral-sided edema, joint space involvement with effusion or synovitis, soft tissue edema, elevated ESR/CRP, and absence of capsulitis and enthesitis were associated with infection (p < .001). The independently differentiating variables favoring infection on multivariate analysis were-both iliac and sacral-sided edema (OR 4.79, 95% CI: 0.96-23.81, p = .05), large erosions (OR 17.96, 95% CI: 2.66-121.02, p = .003), and joint space involvement (OR 9.9, 95% CI: 1.36-72.06, p = .02). Exclusive features of infection were osteomyelitis, sequestra, abscesses, sinus tracts, large erosions, and multifocality. All infective cases had soft tissue edema, joint space involvement, elevated ESR, and no capsulitis.
CONCLUSIONS: MRI evaluation for the presence and pattern of bone and joint space involvement, soft tissue involvement, and careful attention to certain exclusive features will aid in differentiating infectious sacroiliitis from inflammatory sacroiliitis.
摘要：
背景：骶髂关节炎的单侧表现是一个诊断难题，尤其是感染和与脊柱关节炎相关的炎性骶髂关节炎，需要早期和准确的诊断。
目的：评估磁共振成像（MRI）在区分单侧骶髂关节炎的感染性和炎性病因中的应用。
方法：回顾90例单侧骶髂关节炎患者的MRI，有一个确定的最终诊断。使用预定义标准评估MR图像的各种骨骼和软组织变化，并使用单变量和多变量回归分析进行分析。
结果：在90例患者中，感染性病因诊断为66例（73.3％），炎症病因诊断为24例（26.7％）。大侵蚀,髂和骶骨侧水肿，关节间隙累及积液或滑膜炎，软组织水肿，ESR/CRP升高，无包膜炎和附着点炎与感染相关(p<.001)。在多变量分析中，有利于感染的独立区分变量是髂侧和骶侧水肿（OR4.79，95％CI：0.96-23.81，p=0.05），大的侵蚀（OR17.96，95%CI：2.66-121.02，p=0.003），和关节间隙受累（OR9.9，95%CI：1.36-72.06，p=.02）。感染的唯一特征是骨髓炎，sequestra,脓肿,窦道,大的侵蚀,和多焦点。所有感染病例均有软组织水肿，联合空间参与，ESR升高,也没有囊炎.
结论：MRI评估骨和关节间隙受累的存在和模式，软组织受累，仔细注意某些独特的特征将有助于区分感染性骶髂关节炎和炎性骶髂关节炎。
目的：评估磁共振成像（MRI）在区分单侧骶髂关节炎的感染性和炎性病因中的应用。
方法：回顾90例单侧骶髂关节炎患者的MRI，有一个确定的最终诊断。使用预定义标准评估MR图像的各种骨骼和软组织变化，并使用单变量和多变量回归分析进行分析。
结果：在90例患者中，感染性病因诊断为66例（73.3％），炎症病因诊断为24例（26.7％）。大侵蚀,髂和骶骨侧水肿，关节间隙累及积液或滑膜炎，软组织水肿，ESR/CRP升高，无包膜炎和附着点炎与感染相关(p<.001)。在多变量分析中，有利于感染的独立区分变量是髂侧和骶侧水肿（OR4.79，95％CI：0.96-23.81，p=0.05），大的侵蚀（OR17.96，95%CI：2.66-121.02，p=0.003），和关节间隙受累（OR9.9，95%CI：1.36-72.06，p=.02）。感染的唯一特征是骨髓炎，sequestra,脓肿,窦道,大的侵蚀,和多焦点。所有感染病例均有软组织水肿，联合空间参与，ESR升高,也没有囊炎.
结论：MRI评估骨和关节间隙受累的存在和模式，软组织受累，仔细注意某些独特的特征将有助于区分感染性骶髂关节炎和炎性骶髂关节炎。
