GLIOSARCOMA - MR FEATURES

Purpose: Our goal was to characterize the MR features of pathologicall y documented gliosarcoma and to determine if these features help diffe rentiate gliosarcoma from other intracranial neoplasms. Method: MR stu dies of six patients with pathologically documented gliosarcoma were r etrospectively analyzed. Results: The tumors tended to be well defined lesions demonstrating either an inhomogeneous or cystic appearance wi th surrounding vasogenic edema. All tumors were characterized as prima rily intraaxial but abutting a dural surface. On T2-weighted images, a ll tumors were of intermediate signal intensity with surrounding edema . The signal intensity of the tumor was similar to gray matter but was hypointense relative to other glial neoplasms. Postcontrast TI-weight ed images showed intense tumor enhancement, often with a ring-like app earance. The isointense component on the T2-weighted images correspond ed to this area of intense enhancement. Conclusion: Gliosarcoma exhibi ts some characteristic MR features. It should be included in the diffe rential diagnosis of any tumor that appears to be intraaxial but abuts a dural surface and is much less hypointense on T2-weighted images th an other glial neoplasms.