骨肉腫のＭＲＩについて

Abstract

The accurate assessment of extent of tumor is necessary to evaluate the propriety of limb sparing surgery, amputation level or resection width when we consider surgical treatment of the patients with osteosarcoma of an extremity. Therefore, we investigated the clinical utilities and problems of the magnetic resonance imaging (MRI) in the diagnosis of the patient with osteosarcoma as compared with plane radiography, computed tomography (CT). Seven patients were examined with a Signa 1.5-Tesla superconducting magnet. The results were as follows. 1) Intramedullary extent and extraosseous extent were clearly demonstrated on T1 and T2 weighted image, respectively. 2) Destructions of growth plate were actually displayed in all patients whose tumor had extended to the growth plate. 3) Cortical invasions by tumor could be seen on MRI as well as on CT. 4) Reactive zone was demonstrated in five of seven patients, and could be descriminated from the tumor except one patient. 5) The periosteal reaction was poorly identified with MRI. 6) In one case, skip metastasis was suspected on MRI, but it was excluded because of no evidence of malignancy in the pathological specimen and no reccurrence at the amputated femur postoperatively. We should be careful in making a diagnosis upon the skip metastasis.