Kasalak Ömer, Overbosch Jelle, Adams Hugo Ja, Dammann Amelie, Dierckx Rudi Ajo, Jutte Paul C, Kwee Thomas C
1 Department of Radiology, Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
2 Department of Radiology and Nuclear Imaging, Deventer Hospital, Deventer, The Netherlands.
Acta Radiol. 2019 Feb;60(2):204-212. doi: 10.1177/0284185118774953. Epub 2018 May 9.
The value of magnetic resonance imaging (MRI) signs in differentiating Ewing sarcoma from osteomyelitis has not be thoroughly investigated.
To investigate the value of various MRI signs in differentiating Ewing sarcoma from osteomyelitis.
Forty-one patients who underwent MRI because of a bone lesion of unknown nature with a differential diagnosis that included both Ewing sarcoma and osteomyelitis were included. Two observers assessed several MRI signs, including the transition zone of the bone lesion, the presence of a soft-tissue mass, intramedullary and extramedullary fat globules, and the penumbra sign.
Diagnostic accuracies for discriminating Ewing sarcoma from osteomyelitis were 82.4% and 79.4% for the presence of a soft-tissue mass, and 64.7% and 58.8% for a sharp transition zone of the bone lesion, for readers 1 and 2 respectively. Inter-observer agreement with regard to the presence of a soft-tissue mass and the transition zone of the bone lesion were moderate (κ = 0.470) and fair (κ = 0.307), respectively. Areas under the receiver operating characteristic curve of the diameter of the soft-tissue mass (if present) were 0.829 and 0.833, for readers 1 and 2 respectively. Mean inter-observer difference in soft-tissue mass diameter measurement ± limits of agreement was 35.0 ± 75.0 mm. Diagnostic accuracies of all other MRI signs were all < 50%.
Presence and size of a soft-tissue mass, and sharpness of the transition zone, are useful MRI signs to differentiate Ewing sarcoma from osteomyelitis, but inter-observer agreement is relatively low. Other MRI signs are of no value in this setting.
磁共振成像（MRI）征象在鉴别尤因肉瘤与骨髓炎方面的价值尚未得到充分研究。
探讨各种MRI征象在鉴别尤因肉瘤与骨髓炎中的价值。
纳入41例因性质不明的骨病变接受MRI检查的患者，鉴别诊断包括尤因肉瘤和骨髓炎。两名观察者评估了多个MRI征象，包括骨病变的过渡区、软组织肿块的存在、髓内和髓外脂肪球以及半影征。
对于鉴别尤因肉瘤与骨髓炎，观察者1和观察者2判断软组织肿块存在的诊断准确率分别为82.4%和79.4%，骨病变锐利过渡区的诊断准确率分别为64.7%和58.8%。观察者间关于软组织肿块存在和骨病变过渡区的一致性分别为中等（κ = 0.470）和一般（κ = 0.307）。软组织肿块（若存在）直径的受试者操作特征曲线下面积，观察者1和观察者2分别为0.829和0.833。观察者间软组织肿块直径测量的平均差异±一致性界限为35.0±75.0 mm。所有其他MRI征象的诊断准确率均<50%。
软组织肿块的存在和大小以及过渡区的锐利程度是鉴别尤因肉瘤与骨髓炎有用的MRI征象，但观察者间一致性相对较低。在此情况下，其他MRI征象无价值。
