MR imaging of intradural extramedullary tumors of the cervical spine.

Magnetic resonance imaging was performed in eight patients with extramedullary cervical tumors; two were studied with a 0.15 T resistive system and six with a 0.5 superconductive unit. All tumors were verified surgically: Five meningiomas and three schwannomas were found. Magnetic resonance demonstrated the location and size of the tumors as well as their relationship with and mass effect on the adjacent spinal cord. Meningiomas showed a tendency to have relaxation times close to those of the normal parenchyma; in multiple echo sequences their signal tends to decay in a way similar to that of the spinal cord. The different signal from the surrounding cerebrospinal fluid sometimes provides a visual cleavage to define the extramedullary location of the neoplasm. Schwannomas and neurofibromas have a less constant behavior; their T2 relaxation time may be slightly longer than that of the spinal cord and the tumor may display a more intense signal in the T2 weighted images. Usually, however, the signal intensity of the extramedullary tumors is lower than that of the intramedullary.