The MR Imaging of Intramedullary Astrocytomas

Purpose To study the MRI findings of intramedullary astrocytomas. Methods MR images of fifty patients with intramedullary astrocytomas proved by operation and pathology were reviewed retrospectively. Results The tumor showed mainly isointensity or hypo intensity on T1WI and hyper intensity on T2WI. Intratumoral cysts were seen in 25 tumors, rostral or caudal cysts were seen in 22 tumors. On contrast enhanced studies, the margins were considered ill defined in 33 and well defined in 17 tumors. The tumors exhibited gentle enhancement (30/50), intense enhancement (14/50) and no enhancement (6/50). 44 tumors had uniform enhancement, 22/44 were scattered patch enhancement, 15/44 were nodulous or mass enhancement, 7/44 were large piece enhancement. Conclusion Contrast MRI is very important in diagnosing intramedullary astrocytomas. There are some characteristics: Astrocytomas located most frequently in cervical and thoracic region, often eccentrically located, usually in the posterior aspect of the cord. Astrocytomas often had gentle scattered patch enhancement with ill defined margins.