This application responds to the cooperative agreement of RFA 90-CA-05 of the National Collaborative Diagnostic Imaging Trial Project. The focus of the investigation is the development of specific decision algorithms for the appropriate, sequential use of state-of-the-art magnetic resonance (MR), computed tomography (CT) and scintigraphy for diagnostic staging and evaluation of musculoskeletal tumors. Data gathered from the three imaging procedures will be compared with resected tumor specimen or with multiple biopsies obtained from the tumor. Both gross and histologic correlation will be made. Sensitivity, specificity, and accuracy for location, size, and specific regions of anatomic involvement will be made for each of the three imaging modalities. Direct comparative study of the imaging modality with the pathologic specimen as well as ROC analysis of specific parameters will be made.