Imaging bone tumors in the 1990s. Progress in bone tumor management has occurred as a result of cooperation among surgeons, oncologists, pathologists, and radiologists. During the 1990s radiologists will contribute to care of patients with bone tumors in major ways. Tumor detection and preliminary diagnosis will be accomplished by radiography. Tumor local extent will be assessed by magnetic resonance imaging (MRI) and to a lesser degree by computed tomography (CT). Distant spread of malignancy will be documented by radionuclide scintigraphy (skeleton) and by CT (lungs). The combined estimate of local extent and distant spread will assure adequate staging before definitive management decisions. Preoperative closed percutaneous biopsy for histologic diagnosis will be accomplished on an outpatient basis under fluoroscopic or CT guidance. Arteriography will be employed for delivery of local chemotherapy. Some combination of arteriography, MRI, and MR spectroscopy will be used to evaluate tumor response. After limb-salvage surgery, MRI will sequentially assess the tumor bed; bone scintigraphy and CT will detect skeletal and pulmonary metastases. The radiologist's role will undergo continuous redefinition. 