Computed tomography or magnetic resonance for evaluating the solitary tumor or tumor-like lesion of bone?

Following an abnormal radiograph, an initial 34 patients had both computed tomography (CT) and magnetic resonance (MR) to further characterize and stage a solitary tumor. This experience determined the choice between CT and MR in evaluating the next 55 solitary tumors. The choice of examination depends on the radiologist's ability to characterize the lesion from the radiograph as to its morphology, matrix, and probable histologic nature. The anatomic location, in turn, frequently influences the ability to characterize the lesion. Lesions in long bones can almost always be successfully characterized by radiography and, in these instances, only the MR examination is required to stage the tumor. Radiographic characterization of tumors in flat bones such as the scapula, certain portions of ribs, vertebrae, and pelvis is often difficult or incomplete. In these cases, CT is the preferred initial examination, and if further staging is required to establish the relationship of the tumor to soft tissues or neurovascular structures, the MR examination is done. Because of MR's superiority in staging the tumor and CT's superiority in characterizing the lesion, the initial choice between the two examinations should depend on the radiologist's ability to characterize the lesion from the radiograph. When radiographic depiction of tumor permits assessment of its morphology, matrix and probable histologic nature, (characterization) MR ought to be the next examination solely for staging purposes. It is the anatomic location of the tumor and the radiologist's ability to characterize it that ought to govern the choice of the next examination. Surgical and histopathological findings were known in all patients in this study.