Intraoperative ultrasonography through a burr-hole.

Intraoperative ultrasound diagnosis through a burr-hole was performed in 22 cases using a 5 MHz electronic sector-scanning transducer. The pathology along with the landmarks, such as ventricles and the interhemispheric fissure, were visualized. In two cases, a second burr-hole was placed nearby, and aspiration of the fluid was accomplished under real-time ultrasonic monitoring using the first hole as an acoustic window. Our results suggest a possibility of ultrasound-guided stereotactic surgery of the brain through twin burr-holes.