The development of a new computer program called VISUAL, designed to be applied to a series of cross-sectional ACTA scans of the body, makes possible the three-dimensional visualization of spinal structure without the necessity of surgical exploration. With VISUAL, a molded three-dimensional image of the spine can be displayed on a CT scanner monitor from any of several angles, or from several angles successively, with the direction of illumination determined by the operator. © 1979.