Intraoperative sonography in the nonstereotaxic biopsy and aspiration of subcortical brain lesions.

Deep-seated brain lesions, especially small ones, present a neurosurgical challenge to achieve tissue diagnosis with minimal damage to intervening normal brain. Needle biopsy is often indicated but has been a relatively arduous procedure using stereotaxic frame methods. Tissue sampling is greatly simplified by the use of intraoperative real-time sonography for needle guidance. The technique is also applicable to cyst or abscess drainage and ventricular decompression. Of 37 cases in which intraoperative brain sonography was used, 19 included sonographic guidance of a needle, probe, or wire-stiffened catheter into the lesion. Sonography is an easy and accurate substitute for stereotaxic guidance procedures. It is also useful for reexamination of the brain after interventions such as biopsy, resection, and drainage.