Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, Pennsylvania.
University of Alberta, Edmonton, Alberta, Canada.
Arthritis Care Res (Hoboken). 2023 Jun;75(6):1220-1227. doi: 10.1002/acr.25014. Epub 2023 Jan 18.
We aimed to determine quantitative sacroiliac (SI) joint magnetic resonance imaging (MRI) cutoffs for active and structural lesions that will be incorporated as imaging domains in classification criteria of axial disease in juvenile spondyloarthritis (SpA).
MRI scans from an international cross-section of juvenile SpA patients were reviewed by 6 musculoskeletal imaging experts blinded to clinical details. Raters globally assessed the presence/absence of lesions typical of axial SpA and performed SI joint quadrant- or joint-based scoring. Sensitivity and specificity of lesion cutoffs were calculated using a rater majority (≥4 of 6 raters) on a global assessment of the presence/absence of active or structural lesions typical of axial SpA with high confidence as the reference standard. Cutoffs were validated in an independent cohort.
Imaging from 243 subjects, 61% male, median age 14.9 years, had sequences available for detailed MRI scoring. Optimal cutoffs for defining lesions typical of axial disease in juvenile SpA were: 1) inflammatory lesion: bone marrow edema in ≥3 SI joint quadrants across all SI joint MRI slices (sensitivity 98.6%, specificity 96.5%); 2) structural lesions: erosion in ≥3 quadrants or sclerosis or fat lesion in ≥2 SI joint quadrants or backfill or ankylosis in ≥2 joint halves across all SI joint MRI slices (sensitivity 98.6%, specificity 95.5%). Sensitivity and specificity of the optimal cutoffs in the validation cohort were excellent.
We propose data-driven cutoffs for active inflammatory and structural lesions on MRI typical of axial disease in juvenile SpA that have high specificity and sensitivity using central imaging global assessment as the reference standard and excellent reliability.
我们旨在确定活跃性和结构性骶髂（SI）关节磁共振成像（MRI）截断值，这些截断值将作为少年特发性脊柱关节炎（SpA）的轴性疾病分类标准的影像学领域纳入。
对来自国际少年 SpA 患者队列的 MRI 扫描进行了回顾，由 6 名肌肉骨骼影像学专家进行评估，他们对临床细节不知情。评估者对典型轴性 SpA 病变的存在/缺失进行了整体评估，并进行了 SI 关节象限或关节为基础的评分。使用对存在/缺失典型轴性 SpA 的活跃性或结构性病变的整体评估中，有 4 位或 4 位以上评估者（共 6 位评估者）达成共识（具有高度置信度）作为参考标准，计算病变截断值的敏感性和特异性。在独立队列中对截断值进行了验证。
243 名受试者（61%为男性，中位年龄 14.9 岁）的影像学资料可用于详细的 MRI 评分，其中有可用序列。用于定义少年 SpA 中轴性疾病典型病变的最佳截断值为：1）炎症性病变：所有 SI 关节 MRI 切片中，≥3 个 SI 关节象限的骨髓水肿（敏感性 98.6%，特异性 96.5%）；2）结构性病变：≥3 个象限的侵蚀或≥2 个 SI 关节象限的硬化或脂肪病变或≥2 个关节半的填充或强直（敏感性 98.6%，特异性 95.5%）。验证队列中最佳截断值的敏感性和特异性均表现出色。
我们提出了基于数据的少年 SpA 中轴性疾病的 MRI 活跃性炎症和结构性病变截断值，这些截断值使用中央影像学整体评估作为参考标准具有高特异性和敏感性，且可靠性极佳。
