Abstract: Apparatus for scanning a part or all of a patient by X-rays or gamma rays to obtain two or three dimensional information. The apparatus comprises a fan beam source of radiation which is moveable relative to the patient and means fixed or movably relative to the patient, but fixed relative to the source of radiation comprising a scintillation crystal or fluoroscopic screen which may be tilted at an angle, a lens system, a charge coupled device for translating the light photons received from the crystal or screen into a corresponding analog signal which can then be processed either directly by an analog computer or after conversion to digital signals, by a digital computer. The results are then exhibited by a suitable display device such as a cathode ray tube.