OBJECTIVE To compare the diagnostic performance and inter-reader agreement of an abbreviated (5 min) MR protocol compared to a complete (25 min) protocol, for evaluation of suspected tibial bone stress injury. MATERIALS AND METHODS This IRB-approved retrospective study consisted of 95 consecutive MR examinations in 88 patients with suspected tibial bone stress injury. Three musculoskeletal radiologists independently classified all examinations utilizing both an abbreviated protocol consisting only of axial T2-weighted images with fat suppression, and after a washout period again classified the complete examinations. Accuracy was calculated as proportion of cases classified exactly, within 1 grade, within 2 grades, and also utilizing a simplified "clinically relevant" classification combining grades 2, 3, and 4A into a single group. Significance testing was performed with the chi-test, and a post-hoc power analysis was performed. Inter-reader agreement was calculated with Kendall's coefficient of concordance, with significance testing performed utilizing the z-test after bootstrapping to obtain the standard error. RESULTS AND CONCLUSIONS There was no significant difference in accuracy of grading tibial bone stress injuries between complete and abbreviated examinations. For complete exams, pooled exact accuracy was 47.8%; accuracy within 1 grade was 82.8%; and accuracy within 2 grades was 96.1%. For the abbreviated protocol, corresponding accuracies were 50.2, 82.0, and 93.9%. With the "clinically relevant" simplified classification, accuracy was 58.6% for complete exams and 64.2% for abbreviated exams. There was no significant difference in inter-reader agreement, with substantial agreement demonstrated for both complete (Kendall coefficient of concordance 0.805) and abbreviated examinations (coefficient of 0.767).

中文翻译：

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胫骨应力损伤：简短的5分钟磁共振方案的诊断性能和阅读器间一致性。

目的比较简略（5分钟）MR方案与完整（25分钟）方案的诊断性能和阅读器间一致性，以评估可疑的胫骨骨应力损伤。材料与方法这项经IRB批准的回顾性研究由88例怀疑胫骨骨应力性损伤的患者连续95次MR检查组成。三位肌肉骨骼放射科医生使用简化的方案（仅包括轴向T2加权图像和抑制脂肪的缩写方案）对所有检查进行了独立分类，并且在清除期后再次对完整检查进行了分类。准确度的计算方法是：准确分类为1级，2级以内的病例比例，并且还使用简化的“临床相关”分类，将2、3和4A级合并为一组。用卡方检验进行显着性检验，并进行事后功效分析。阅读者之间的一致性是使用肯德尔的一致性系数计算得出的，而自举后使用z检验执行显着性检验以获得标准误差。结果与结论在完整和简短的检查之间，胫骨骨应力损伤分级的准确性没有显着差异。对于完整的考试，合并的准确率是47.8％；1年级以内的准确度为82.8％; 2个等级内的准确率为96.1％。对于缩写协议，相应的准确度分别为50.2％，82.0和93.9％。使用“临床相关”简化分类，完整检查的准确性为58.6％，简短检查的准确性为64.2％。