The development of breath-held imaging in CT and MR is the third development that has driven 3D imaging and virtual reality. This development has eliminated misregistration artifacts and respiratory artifacts, thereby achieving true volumetric imaging. Imaging has moved from the flat picture of a 2D display to the perspective revealed by a 3D display. This is an imaging renaissance. However, the ability to look at a single view and see the entire picture of the carinii and the bifurcation has clear diagnostic value as opposed to scrolling through 150 axial images.
Volume rendering is one of the most important software techniques.
It will continue to aid in the display of this volumetric data well into the future. Rather than editing a single scan, volume rendering interpolates the entire data set. Volume rendering is interactive, and it allows quick scans through data sets. This ability to shine a light into a data set is extremely important to virtual colonoscopy, virtual bronchoscopy, and virtual angioscopy. To highlight the importance of perspective in perspective volume rendering, imagine shining a light from any point on earth and looking at the constellation in figure 3 .