Ultrasound directed placement of needles into brains of rhesus monkeys.

Gray scale ultrasound identified the lateral and third ventricles, basal ganglia, columns of the fornix, and the suprasellar optic system of monkeys with craniotomy defects. Needles were placed in these structures under ultrasound guidance. Radiographs and formalin fixed brain sections confirmed the expected position of the needle tracts.