Zhao Jiaoshi, Lin Churong, Liu Dong, Liu Budian, Chen Qilong, Gu Jieruo
Department of Rheumatology and Immunology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
Department of Radiology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
Front Med (Lausanne). 2023 Aug 23;10:1218834. doi: 10.3389/fmed.2023.1218834. eCollection 2023.
Findings of fatty lesions in the context of other imaging manifestations, especially bone marrow edema and erosions can effectively assist in the diagnosis of axSpA. Chemical shift-encoded MRI is a sequence which allows for the quantification of fat signal and has been applied in the imaging evaluation of the SIJ in axSpA. The objective of this study was to investigate the diagnostic performance of morphological features of fatty lesions visualized by CSE-MRI in the imaging evaluation of SIJ in axSpA.
Fatty lesions with morphological features (subchondral, homogeneity and distinct border) were assessed and recorded as a binary variable in each quadrant of the SIJ. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for different morphological features as well as the anatomical distribution in patients with nr-axSpA and r-axSpA. T1-weighted images and CSE-MRI fat fraction maps were directly compared in the recognition of different morphological features.
Eighty-two patients [non-SpA ( = 21), nr-axSpA ( = 23), r-axSpA ( = 38)] with lower back pain (LBP) were enrolled. Presence of the three morphological features of fatty lesions had a specificity of 90.48% in axSpA. The sensitivities of being subchondral, homogeneity and distinct border were 52.17, 39.13 and 39.13% in nr-axSpA on T1-weighted images. For patients with r-axSpA, the sensitivities reached 86.84, 76.32 and 57.89%. No significant difference was found in the distribution of fatty lesions between T1-weighted images and CSE-MRI. However, CSE-MRI fat fraction maps could detect significantly more fatty lesions with homogeneity ( = 0.0412) and distinct border ( = 0.0159) than T1-weighted images in the sacroiliac joint, but not subchondral lesions ( = 0.6831).
The homogeneity and distinct border are more relevant for the diagnosis of axSpA. Moreover, CSE-MRI could detect more typical morphological features of fatty lesions than T1-weighted images in showing these two features. The presence of all three features was more likely to be indicative of axSpA.
在其他影像学表现（尤其是骨髓水肿和侵蚀）的背景下发现脂肪性病变，可有效辅助诊断轴向性脊柱关节炎（axSpA）。化学位移编码磁共振成像（CSE-MRI）是一种能够对脂肪信号进行量化的序列，已应用于axSpA中骶髂关节（SIJ）的影像学评估。本研究的目的是探讨CSE-MRI显示的脂肪性病变形态学特征在axSpA的SIJ影像学评估中的诊断效能。
评估并记录SIJ每个象限中具有形态学特征（软骨下、均匀性和清晰边界）的脂肪性病变，并将其记录为二元变量。计算nr-axSpA和r-axSpA患者不同形态学特征以及解剖分布的敏感性、特异性、阳性预测值（PPV）和阴性预测值（NPV）。直接比较T1加权图像和CSE-MRI脂肪分数图对不同形态学特征的识别情况。
纳入82例下背痛（LBP）患者[非脊柱关节炎（=21）、nr-axSpA（=23）、r-axSpA（=38）]。脂肪性病变的三种形态学特征在axSpA中的特异性为90.48%。在T1加权图像上，nr-axSpA中软骨下、均匀性和清晰边界的敏感性分别为52.17%、39.13%和39.13%。对于r-axSpA患者，敏感性分别达到86.84%、76.32%和57.89%。T1加权图像和CSE-MRI之间脂肪性病变的分布无显著差异。然而，CSE-MRI脂肪分数图在骶髂关节中能够检测到比T1加权图像更多具有均匀性（=0.0412）和清晰边界（=0.0159）的脂肪性病变，但软骨下病变除外（=0.6831）。
均匀性和清晰边界对axSpA的诊断更具相关性。此外，在显示这两个特征方面，CSE-MRI比T1加权图像能检测到更多脂肪性病变的典型形态学特征。所有三个特征的存在更有可能提示axSpA。
