A PC-based 3D imaging system: algorithms, software, and hardware considerations.

Three-dimensional (3D) imaging in medicine is known to produce easily and quickly derivable medically relevant information, especially in complex situations. We intend to demonstrate in this paper, that with an appropriate choice of approaches and a proper design of algorithms and software, it is possible to develop a low-cost 3D imaging system that can provide a level of performance sufficient to meet the daily case load in an individual or even group-practice situation. We describe hardware considerations of a generic system and give an example of a specific system we used for our implementation. Given a 3D image as a stack of slices, we generate a packed binary cubic voxel array, by combining segmentation (density thresholding), interpolation, and packing in an efficient way. Since threshold-based segmentation is very often not perfect, object-like structures and noise clutter the binary scene. We utilize an effective mechanism to isolate the object from this clutter by tracking a specified, connected surface of the object. The surface description thus obtained is rendered to create a depiction of the surface on a 2D display screen. Efficient implementation of hidden-part removal and image-space shading and a simple and fast antialiasing technique provide a level of performance which otherwise would not have been possible in a PC environment. We outline our software emphasizing some design aspects and present some clinical examples.