Masses at the craniovertebral junction generally have serious prognostic implications. However, the authors studied three patients who had chronic atlantoaxial subluxation from either degenerative disease or congenital dysplasia of the dens and who also had benign fibrous masses in this region, confirmed at surgery. The association of masses of the craniovertebral junction with chronic atlantoaxial subluxation raises the possibility that the underlying cause of the masses is chronic mechanical irritation. All patients were imaged with metrizamide myelography and adjunctive computed tomography (CT), then by magnetic resonance (MR) imaging. MR images were not only superior to myelograms and CT scans in delineating the exact extent of the lesions, they also indicated the benign, fibrous nature of the masses.

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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.

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We report a case of extradural spinal meningioma with pathologically proven features of malignant transformation. The MRI findings of extradural spinal meningioma and differences in the findings from intradural meningiomas are discussed.

In cases of severe dural AV fistula in the cavernous sinus, the pituitary gland is enlarged, which should not be misdiagnosed as pathologic.

Enhancement characteristics of the normally developing spinal column were examined in magnetic resonance (MR) images obtained in 58 children aged 7 days to 9 years. With a 1.5-T imager, short-repetition-time spin-echo images were obtained before and after the administration of 0.1 mmol/kg gadopentetate dimeglumine. Enhancement of normal bone marrow was seen in all patients aged less than 7 years; it was marked only in patients aged less than 2 years. Enhancement of normal cartilage, seen in all patients aged less than 1 1/2 years, may be the most striking feature of enhanced MR images of the infant spine. Enhancement of both bone marrow and cartilage in children appears to be due to the unusual prominence of vasculature, associated with permeability of the capillary endothelium and a plentiful extravascular space. Although marked and diffuse enhancement of vertebral bodies in adults is often thought to indicate a pathologic marrow state, caution must be used before the same criteria are applied to children.

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