Background Current terms used to describe the MRI findings for musculoskeletal infections are nonspecific and inconsistent. Purpose To develop and validate an MRI-based musculoskeletal infection classification and scoring system. Materials and Methods In this retrospective cross-sectional internal validation study, a Musculoskeletal Infection Reporting and Data System (MSKI-RADS) was designed. Adult patients with radiographs and MRI scans of suspected extremity infections with a known reference standard obtained between June 2015 and May 2019 were included. The scoring categories were as follows: 0, incomplete imaging; I, negative for infection; II, superficial soft-tissue infection; III, deeper soft-tissue infection; IV, possible osteomyelitis (OM); V, highly suggestive of OM and/or septic arthritis; VI, known OM; and NOS (not otherwise specified), nonspecific bone lesions. Interreader agreement for 20 radiologists from 13 institutions (intraclass correlation coefficient [ICC]) and true-positive rates of MSKI-RADS were calculated and the accuracy of final diagnoses rendered by the readers was compared using generalized estimating equations for clustered data. Results Among paired radiographs and MRI scans from 208 patients (133 male, 75 female; mean age, 55 years ± 13 [SD]), 20 were category I; 34, II; 35, III; 30, IV; 35, V; 18, VI; and 36, NOS. Moderate interreader agreement was observed among the 20 readers (ICC, 0.70; 95% CI: 0.66, 0.75). There was no evidence of correlation between reader experience and overall accuracy (P = .94). The highest true-positive rate was for MSKI-RADS I and NOS at 88.7% (95% CI: 84.6, 91.7). The true-positive rate was 73% (95% CI: 63, 80) for MSKI-RADS V. Overall reader accuracy using MSKI-RADS across all patients was 65% ± 5, higher than final reader diagnoses at 55% ± 7 (P < .001). Conclusion MSKI-RADS is a valid system for standardized terminology and recommended management of imaging findings of peripheral extremity infections across various musculoskeletal-fellowship-trained reader experience levels. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Schweitzer in this issue.

中文翻译：

---

MSKI-RADS：基于 MRI 的肌肉骨骼感染报告和数据系统，用于诊断四肢感染。


背景 目前用于描述肌肉骨骼感染 MRI 结果的术语缺乏特异性且不一致。目的 开发并验证基于 MRI 的肌肉骨骼感染分类和评分系统。材料和方法 在这项回顾性横断面内部验证研究中，设计了肌肉骨骼感染报告和数据系统（MSKI-RADS）。纳入了 2015 年 6 月至 2019 年 5 月期间获得的具有已知参考标准的疑似四肢感染的 X 光照片和 MRI 扫描的成年患者。评分类别如下：0，成像不完整； I，感染阴性； II、浅表软组织感染；三、较深的软组织感染； IV、可能是骨髓炎（OM）； V，高度提示 OM 和/或化脓性关节炎； VI、已知OM；和 NOS（未另有说明），非特异性骨病变。计算了来自 13 个机构的 20 名放射科医生的读者间一致性（组内相关系数 [ICC]）和 MSKI-RADS 的真阳性率，并使用聚类数据的广义估计方程比较了读者最终诊断的准确性。结果 在 208 名患者（133 名男性，75 名女性；平均年龄，55 岁±13 [SD]）的配对 X 光片和 MRI 扫描中，20 名属于 I 类； 34、二； 35、三； 30、四号； 35、V； 18、六；和 36，NOS。 20 名读者之间存在中等程度的读者间一致性（ICC，0.70；95% CI：0.66，0.75）。没有证据表明读者体验与整体准确性之间存在相关性 (P = .94)。 MSKI-RADS I 和 NOS 的真阳性率最高，为 88.7%（95% CI：84.6，91.7）。 MSKI-RADS V 的真阳性率为 73% (95% CI: 63, 80)。 使用 MSKI-RADS 对所有患者的总体读取准确率为 65% ± 5，高于最终读取诊断的 55% ± 7 (P < .001)。结论 MSKI-RADS 是一个有效的系统，可用于标准化术语和推荐管理不同肌肉骨骼研究员经验水平的外周肢体感染的影像学结果。 © RSNA，2024 本文提供补充材料。另请参阅本期 Schweitzer 的社论。