MR imaging of spinal intramedullary tumors.

The MR examinations in 25 patients with intramedullary tumors were analyzed. Seven patients were diagnosed with astrocytoma, 6 ependymoma, 2 unspecified glioma, 3 medulloblastoma, 2 metastasis, one neurinoma, and one teratoma. In 3 patients the diagnosis was uncertain. The tumors frequently involved a large portion of the cord and were often accompanied by intratumor necrosis, cystic degeneration, and edema, which was well demonstrated on MR. Gd-DTPA was used in 6 patients and was helpful in separating solid tumor components from cysts and edema. It was difficult to separate different kind of tumors based on morphologic and signal characteristics on MR. Some prominent features could, however, be distinguished. Complete cystic degeneration was more common in astrocytomas than in other tumors, and ependymomas frequently had a heterogeneous signal pattern on both T1- and T2-weighted sequences. The single teratoma had a characteristic content of fat and calcification, and the melanoma had a signal pattern consistent with blood. CSF pathway spread in cases of medulloblastoma was demonstrated by ill-defined contour of the cord and CSF or tumor nodules on the surface of cord and nerve roots.