The principles of tomographic positioning with particular reference to skull tomography

Because the principles of tomography relating to positioning have not been clearly understood it has generally been the practice to employ only basic positions when undertaking tomographic studies. The purpose of this paper is to outline tomographic positioning principles, and to integrate them in a simple positioning system for common usage. This has given rise to the need for a completely new set of technical terms which pertain to positioning for skull tomography. It is hoped to establish an understanding which will enable the radiographer to devise methods of demonstrating structures for which there are no text book references to act as a guide, and to assist the radiologist in the recognition of pseudo-shadows.