Three-dimensional display: stereo and beyond

With the advent of large, high-quality stereo display monitors and high-volume 3-D image acquisition sources, it is time to revisit the use of 3-D display for diagnostic radiology. Stereo displays may be goggled, or goggleless. Goggleless displays are called autostereographic displays. We concentrate on autostereographic technologies. Commercial LCD flat-screen 3-D autostereographic monitors typically rely on one of two techniques: blocked perspective and integral display. On the acquisition modality side: MRI, CT and 3-D ultrasound provide 3-D data sets. However, helical/spiral CT with multi-row detectors and multiple x-ray sources provides a monsoon of data. Presenting and analyzing this large amount of potentially dynamic data will require advanced presentation techniques. We begin with a very brief review the two stereo-display technologies. These displays are evolving beyond presentation of the traditional pair of views directed to fixed positions of the eyes to multi-perspective displays; at differing head positions, the eyes are presented with the proper perspective pairs corresponding to viewing a 3-D object from that position. In addition, we will look at some of the recent developments in computer-generated holograms or CGH's. CGH technology differs from the other two technologies in that it provides a wave-optically correct reproduction of the object. We then move to examples of stereo-displayed medical images and examine some of the potential strengths and weaknesses of the displays. We have installed a commercial stereo-display in our laboratory and are in the process of generating stereo-pairs of CT data. We are examining, in particular, preprocessing of the perspective data.