Method of and apparatus for examining a body by radiation such as x or gamma radiation

Apparatus is disclosed for examining a body by means of radiation such as X or γ radiation. The body to be examined is inserted in an aperture in a scanning and locating structure, which structure supports a source of the radiation and detector means therefor on opposite sides of the aperture. The source and detector means are moveable to and fro on the structure so as to scan the radiation laterally across the body in a plane and the structure is rotatable around the body about an axis perpendicular to the plane. Disposed between the source and detector means is an attenuator means which extends laterally in said plane to the full extent of the lateral scanning motion and rotates with the structure