De Smet A A, Ilahi O A, Graf B K
Department of Radiology E3/311, University of Wisconsin Hospital, Madison 53792, USA.
Skeletal Radiol. 1996 Feb;25(2):159-63. doi: 10.1007/s002560050054.
T2-weighted MR images has been reported to be an accurate method for assessing osteochondritis dissecans. We reviewed our MR experience to confirm the accuracy of the published criteria of instability. We also assessed the value of each of four MR signs of instability.
We reviewed the original MR interpretations, arthroscopic reports, and MR examinations of 40 patients with osteochondritis dissecans of the talar dome or femoral condyles. Arthroscopy was used as the gold standard for stability. The MR examinations were reviewed retrospectively for a high-signal-intensity line or cystic area beneath the lesion, a high-signal-intensity line through the articular cartilage, or a focal articular defect.
All patients who had undergone MR imaging for osteochondritis dissecans from 1990 to 1993 were reviewed. Forty patients were identified who had arthroscopy after the MR examination. There were 30 male and 10 female patients with an average age of 25.7 years. Thirty-one lesions were in femoral condyle and nine were in the talar dome.
The original MR interpretations correctly identified 35 of the 36 unstable lesions and all 4 stable lesions, giving a sensitivity of 0.97 and specificity of 1.0. There was a 98% agreement between the original and retrospective diagnoses. A high-signal-intensity line was seen beneath 72% of the 36 unstable lesions. The other three signs were noted in 22-31% of the unstable lesions. Fifty-six percent of the unstable lesions showed only one sign of instability. MR imaging is a highly sensitive method for detection of unstable osteochondritis dissecans. The presence of any one sign indicates instability, the most frequent sign being an underlying high-signal-intensity line. Because we examined only four stable lesions, our 95% confidence interval of 0.40-1.0 for a specificity of 1.0 gives only a limited estimate of the specificity of MR.
据报道，T2加权磁共振成像（MR）是评估剥脱性骨软骨炎的一种准确方法。我们回顾了我们的MR经验，以确认已发表的不稳定标准的准确性。我们还评估了四种不稳定MR征象各自的价值。
我们回顾了40例距骨穹窿或股骨髁剥脱性骨软骨炎患者的原始MR解读、关节镜报告和MR检查。关节镜检查被用作稳定性的金标准。对MR检查进行回顾性分析，观察病变下方的高信号强度线或囊性区域、穿过关节软骨的高信号强度线或局灶性关节缺损。
对1990年至1993年因剥脱性骨软骨炎接受MR成像检查的所有患者进行回顾。确定了40例在MR检查后接受关节镜检查的患者。其中男性30例，女性10例，平均年龄25.7岁。31处病变位于股骨髁，9处位于距骨穹窿。
原始MR解读正确识别出36处不稳定病变中的35处以及所有4处稳定病变，敏感性为0.97，特异性为1.0。原始诊断与回顾性诊断之间的一致性为98%。在36处不稳定病变中的72%下方可见高信号强度线。其他三种征象在22% - 31%的不稳定病变中可见。56%的不稳定病变仅显示一种不稳定征象。MR成像对于检测不稳定的剥脱性骨软骨炎是一种高度敏感的方法。任何一种征象的出现都表明不稳定，最常见的征象是下方的高信号强度线。由于我们仅检查了4处稳定病变，我们对于特异性为1.0的95%置信区间为0.40 - 1.0，这仅对MR的特异性给出了有限的估计。
