MRI of the sacroiliac joints is increasingly acknowledged as being indispensable in the early diagnosis of axial spondyloarthritis (axSpA) and as having a prominent role in the prognosis and classification of axSpA. Technological advances include improvements in the resolution of structural lesions and in methodologies for the quantification of lesions. Limited access and expertise in interpretation of MRI have led to a resurgence of interest in CT, especially the development of low radiation protocols for assessing the sacroiliac joints. Trials of TNF inhibitors in patients with non-radiographic axSpA have led to greater understanding of the role of MRI in selecting which patients might respond well to this therapy. The role of MRI features as target end points in treat-to-target strategies remains unclear because the effect of such targeting on structural damage parameters has only recently been explored. The relative importance of active and structural lesions for prognostic risk assessment and selection of appropriate treatment is also an area of current research. Given the increased capacity to visualize a broad array of lesions in both the sacroiliac joints and the spine using MRI and CT, these modalities will probably be increasingly employed for assessment of the disease-modifying activity of new therapies.

中文翻译：

---

影像学在中轴型脊柱关节炎诊断和治疗中的作用。

骶髂关节 MRI 越来越被认为在轴型脊柱关节炎 (axSpA) 的早期诊断中必不可少，并且在 axSpA 的预后和分类中具有重要作用。技术进步包括改善结构性病变的分辨率和量化病变的方法。对 MRI 解释的有限访问和专业知识导致人们对 CT 重新产生兴趣，特别是开发用于评估骶髂关节的低辐射方案。在非放射影像学 axSpA 患者中进行的 TNF 抑制剂试验使人们更深入地了解 MRI 在选择哪些患者可能对这种治疗反应良好方面的作用。MRI 特征作为靶向治疗策略中的目标终点的作用仍不清楚，因为这种靶向对结构损伤参数的影响最近才被探索。活动性和结构性病变对预后风险评估和选择适当治疗的相对重要性也是当前研究的一个领域。鉴于使用 MRI 和 CT 可视化骶髂关节和脊柱中广泛病变的能力增加，这些方式可能会越来越多地用于评估新疗法的疾病缓解活性。