Tissue transition projection (TTP) of the intestines

Tissue transition projection (TTP) represents a three-dimensional reconstru ction technique for volumetric image data sets. To demonstrate the principl e characteristics of TTP, a simple phantom consisting of two pipes with a s imulated, wall-adherent polyp was scanned with spiral CT, and images were r econstructed by means of volume rendering for both opaque surface reconstru ctions and TT. Tissue transition projection was used in 7 patients for reco nstruction of the small intestine or the colon. Unlike three-dimensional re constructions with opaque, surfaces, TTP enhances surface transitions while suppressing homogeneous areas, allowing delineation of bowel wall similar to conventional double-contrast studies.