Intraoperative ultrasonography of the brain and spine.

Intraoperative ultrasonography can play a particularly useful role in facilitating surgery or guiding biopsies in the brain and spinal canal. Given the limited access that is frequently afforded to the operating surgeon, coupled with lesions that may be located in deep or seemingly inaccessible locations, sonography performed through tiny burr holes is useful for confirming location of lesions, guiding biopsy, and confirming extent of resection. In the spine, sonography is most helpful for confirming the precise location of intradural or extradural masses and guiding biopsies. In this review, we describe the technical requirements necessary for scanning the brain and spinal cord and suggest scanning techniques. The spectrum of pathological entities are illustrated along with potential pitfalls that the inexperienced operator is likely to encounter.