Three-dimensional (3D) imaging on a CT or magnetic resonance scanner by the use of software that runs on the scanner's computer is one of a number of approaches to 3D imaging that have become available in recent years. It is shown that this particular approach can be made very inexpensive, provided that it is used in an appropriate manner in the clinical environment. The proposed methodology for the clinical use of 3D imaging on the scanner is illustrated by a discussion of the use of 3D98 (software designed for the GE CT/T 9800 scanner) for the 3D imaging of craniofacial surgical cases.