Brain gliomas: sonographic characterization.

To determine the ability of ultrasound (US) to help characterize brain lesions and determine the best site for biopsy, intraoperative sonographic examination of nine intracerebral gliomas was performed and correlated with the preoperative computed tomographic (CT), gross intraoperative, and histopathologic findings. Real-time US provided a precise and rapid method for intraoperative localization of intracerebral neoplasms in all cases. While the sonographic appearance of gliomas is nonspecific, US added information on tumor characterization to that provided by CT. All gliomas were sonographically echogenic compared with surrounding brain. US permitted good characterization of the cystic components of tumors; portions of the operation therefore involved surgical drainage rather than resection. Autopsy specimens from five anaplastic cerebral gliomas were examined with US and found to be echogenic. The central portions of all five tumors were echogenic and corresponded to areas of tumor necrosis; thus they were poor sites for biopsy. Alternatively, the best site for biopsy was the inner portion of the echogenic margin of the mass, which usually represented areas of active tumor growth. The information obtained from both preoperative CT and intraoperative US is beneficial in characterizing lesions and predicting the best site for biopsy.