Computer generated 3-D display of x-ray computed tomographic volume image data: Visualisation numérique 3-D d’“images-volume” acquises par tomographie rayons x

The use of two computer-based, multi-dimensional display methods to efficiently convey three-dimensional (3-D) anatomic information contained within computed tomographic (CT) volume images is described. The term volume image refers to a stack of discrete 2-D CT images and is therefore a 3-D array of volume picture elements (voxels). The first display method is referred to as a direct display approach because it directly represents the 3-D volume image array as a 3-D distribution of brightnesses, i.e., each voxel is a brightened point in space. The second display method is referred to as a transformed display approach meaning that before display, the volume image data is transformed resulting in a new image data set which then forms the basis of the display process. An example of transformed display is shaded surface display, where the transformation is the detection and subsequent representation of the “surface” as a 3-D distribution of reflectors. These display approaches facilitate the direct visualization of 3-D shapes and spatial relationships thereby obviating the necessity of mentally reconstructing shapes from the series of cross sections.