Abstract: In a computerized tomographic apparatus in which the requisite absorption data are derived by rotating a source of fanned radiation around a body to be examined and detecting radiation emergent from a cross-sectional slice of the body at many times during the rotation the data, when assembled into sets relating to parallel beam paths through the slice, tends to relate to beam paths which are non-uniformly spaced across the slice. Some techniques for processing such data to produce a representation of the variation of absorption of said radiation over the slice should preferably have said data presented thereto in the form of sets relating to substantially uniformly spaced, parallel beam paths. The application of this invention provides considerably more data then is actually required for the processing so that data relating to beam paths of the required numbers and dispositions can be derived therefrom.

Abstract: The invention relates to a flat plate X-ray detector. In one example a back plate of a flat xenon detector has coaxial cables in a conducting solid matrix connected to the power supply. Each cable center conductor is a small capacitor which charges in response to ion collection. The signals are derived via a commutator.In another embodiment the back plate is an anisotropic plate discharged in a spiral pattern similar to a gramophone record groove.

Abstract: In order to monitor the progress of a deflected electron beam across the target of an X-ray tube, the emitted X-radiation is monitored, by allowing radiation to impinge, via a common aperture, upon two or more radiation sensitive detectors, to produce a progress signal which is compared with an ideal progress signal to generate error signals in the event of departure of the monitored progress from the ideal progress.

Abstract: In a computerized tomographic CT scanner, a lateral scan of a pencil beam of radiation is effected by causing an apertured, annular collar to rotate around a source of a fan-shaped spread of radiation. The motion of the collimator causes a pencil like beam to sweep angularly across the body. Successive sweeps, caused by successive apertures, are in the same direction.