A three-dimensional display for medical images from slices

A number of new medical imaging modalities, e.g. computed tomography and B-scan ultrasonography, produce 3-D data as a stack of parallel cross-sectional slices. The interpretation of such data is made difficult by the inherent 2-D nature of current viewing devices-each slice has to be viewed individually and imagined to be part of a stack of such images. We are currently developing a family of display systems for observing these and other distributions of data in 3-space. The devices are based on an acoustically vibrated ('varifocal') mirror surface reflecting a screen on which different images are presented in synchrony with the mirror positions. The resulting images, each seen at different depth from the mirror surface, appear as a stack of transparencies and can be viewed by a number of observers who may move about the mirror. All familiar depth cues such as head-motion parallax and stereopsis are present