[Value and limits of CT in the preoperative assessment of primary malignant tumors of bone. Observations in 138 cases].

To estimate the capabilities and limitations of CT in the preoperative evaluation of malignant primary bone neoplasms, 138 patients were examined with high resolution CT and subsequently underwent surgery. In all cases a pathologic examination of the surgical specimen was performed, whose results were compared to CT findings. CT appears to yield important diagnostic contribution to preoperative staging. As a matter of fact, CT shows the tumor extension and its relationship to the adjacent anatomical structures, particularly, it shows the involvement of the muscular and vascular bundles, and that of the articular cavity and medullary canal. These data are of primary importance for planning therapy. The commonest CT limitations are: overestimation of the tumor extension, false positives and false negatives when searching "skip" metastases, and, sometimes, inaccurate definition of the relationship between tumor and vascular bundles and/or articular cavities. These limitations may be overcome by using, when necessary, other techniques--i.e. angiography, bone scan and, above all, MR imaging.