The role of magnetic resonance imaging in the evaluation of Ewing sarcoma

The experience with magnetic resonance imaging (MRI) in 27 patients with Ewing sarcoma is reported and compared with computed tomography (CT) and plain films. Plain radiography proved to be the best imaging method to assess probable histological diagnosis in all cases (n=6). For the evaluation of chemotherapeutic response (n=4), CT and MRI gave the same information about the variation in size of the tumor. It was not possible with MRI to differentiate active tumor from reactive change, even after Gd-DTPA infusion. At present MRI is of little value in diagnosis, and is no better than CT in evaluating the effectiveness of chemotherapy. It has, however, proved to be the best single examination for preoperative evaluation of the extent of neoplastic involvement and follow-up of patients with Ewing sarcoma. (orig./GDG)