Diagnostic value of MRI signs in differentiating Ewing sarcoma from osteomyelitis. (February 2019)

• Record Type: Journal Article
• Authors: Kasalak, Ömer; Overbosch, Jelle; Adams, Hugo JA; Dammann, Amelie; Dierckx, Rudi AJO; Jutte, Paul C; Kwee, Thomas C
• Is Part Of: Acta radiologica. Volume 60:Number 2(2019)
• Page Start: 204
• Page End: 212
• Publication Date: 2019-02
• Subjects: Ewing -- magnetic resonance imaging -- MRI -- osteomyelitis; Radiology, Medical -- Periodicals; Radiography, Medical -- Periodicals; Radiotherapy -- Periodicals; 616.0757
• DOI: 10.1177/0284185118774953
• Languages: English
• ISSNs: 0284-1851

Abstract

Background: The value of magnetic resonance imaging (MRI) signs in differentiating Ewing sarcoma from osteomyelitis has not be thoroughly investigated. Purpose: To investigate the value of various MRI signs in differentiating Ewing sarcoma from osteomyelitis. Material and Methods: 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. Results: 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%. Conclusion: 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.