Abstract: An axial tomography system is disclosed which includes an assembly rotatable about an axis extending along a central opening defined therein, and means for positioning the body portion to be examined within the central opening so that the axis of assembly rotation is perpendicular to a plane passing through the bodily structures to be examined. A source of penetrating radiation is mounted on the assembly toward one side thereof and via a first collimating means provides radiation in the form of a fan beam. The first collimating means is mounted proximate to the radiation source, and includes an adjustable slit, which can be opened completely to enable a conventional x-ray exposure. Means are provided for rotating the assembly so that the fan beam impinges upon said body portion at a plurality of incident directions.