Patent Number: 062722077
Section: abstract

An apparatus and method for obtaining a high-resolution digital image of an object or objects irradiated with radiation having a wavelength in the x-ray or gamma ray spectrum generated by a radiation source, or of an object or objects emitting radiation within the x-ray or gamma ray spectrum. The apparatus comprises a detector matrix and a radiation mask. The detector matrix comprises a plurality of detector pixels, each comprising a detection surface having a respective surface area which generates a signal in response to an energy stimulus. The radiation mask has an opaque portion, and a plurality of apertures. The aperture size and position relative to the detector array determines the image resolution not the size of the detector pixels. The mask is positioned between the detector matrix and the radiation source, such that the opaque portion prevents portions of the radiation from passing through the mask, and each of the apertures permits a portion of the radiation which has passed through or has been emitted from a respective portion of the object to propagate onto an area of the detection surface, less than the surface area, of a respective one of the detector pixels. The signal from a large detector pixel or from a group of small detector pixels represent an image of the respective portion of the object. The detector matrix and radiation mask are moved in synchronism in relation to the object to enable the areas of the detection surfaces of the detector pixels to receive portions of the radiation propagating through or emitted from other portions of the object, and to output signals representative of those other portions. These steps of moving the detector pixels and mask and irradiating the object are repeated until digital images of all portions of the object have been obtained. Alternatively, the x-ray source can be moved to image all portions of the object. The images are then arranged into an image representative of the entire object.