[Focus on peroperative ultrasonography]

Based on a personal experience of more than 70 intraoperative ultrasound examinations performed in the last 3 years, the authors discuss the present status of this technique in its various indications: insertion of ventricular catheters, intracranial surgery, neuroendoscopy, and spinal surgery. The material and techniques currently used are presented. Because of its simplicity, non-invasive character, and relative low-cost, intra-operative ultrasound is a technique easily incorporated in general neurosurgical practice, providing an alternative to stereotactic procedures in some cases.