A simple system for image directed stereotaxis.

A simple system for CT directed stereotaxis has been developed. This technique represents a true three-dimensional solution to the problems of CT stereotaxis and is therefore free of positional constraints relating to the orientation of the patient/stereotactic instrument/CT scan plane, but is not dependent on the relatively complicated mathematical methods required by existing techniques. The preliminary series of 17 procedures are presented, 13 of these were designed to obtain tissue diagnosis. One patient had effective stereotactic aspiration of a colloid cyst of the third ventricle. The stereotactic instrument itself is lightweight and easy to use, a wide range of target trajectories including low sites are possible. The design of this instrument would be particularly well suited for MR directed stereotaxis.