Chordomas: MR imaging.

Twenty histologically verified intracranial and upper cervical chordomas were retrospectively studied with both magnetic resonance (MR) imaging and computed tomography (CT), and the advantages of each modality were compared with regard to three criteria: detection of tumor, delineation of extent of tumor, and characterization of tumor. MR imaging and CT were equivalent in permitting the detection of chordomas. MR imaging was considerably better in delineating the full extent of the tumor, which would influence establishment of treatment. MR imaging also provided a degree of histologic specificity that would be useful in prognosis.