Radiography apparatus and method

Radiography apparatus includes radiation sources for substantially simultaneously generating first and second radiation beams. Collimators are interposed between the radiation source and an object to be exposed to radiation in order to convert the first and second radiation beams into parallel fan-shaped beams. Radiation detectors convert the radiation passing through the object being examined into an electrical signal containing image information. The radiation detector may have at least one scintillator to convert radiation which is passed through an object into light and at least one self-scanning array of photodiodes to convert the light into an electrical signal containing image information. Fiber optic coupling may be provided between the scintillator and the self-scanning array of photodiodes. Means for effecting subtraction of image information resulting from the first beam from image information resulting from the second beam will serve to permit elimination of obstructions to effective visualization of portions of the objects desired to be visualized such as, for example, coronary arteries in a human being. Apparatus may be provided for receiving the signal to store, process or display the image as by a visual display system. The method of effecting such radiographic imaging including subtraction of undesirable portions of the image information.