Intraoperative sonography through a burr hole: guide for brain biopsy.

Sonographic imaging of the brain was accomplished through a burr hole using a small, real-time, 5 MHz transducer in five patients. Brain tumors were accurately imaged, corresponding closely in morphology to the computed tomographic scan. Intraoperative sonography through a burr hole allows flexibility in technique and greatly facilitates brain biopsy procedures.