Radiography with detector compensating means

摘要

Radiographic apparatus utilizing a plurality of radiation-sensitive detectors to quantify the radiation emerging from a body along respective paths is provided with means for compensating for differences between the sensitivities of the various detectors. The compensating means includes an arrangement for displacing the source of the radiation relative to the detectors and for utilizing output signals obtained from one detector when the source is in its undisplaced and displaced positions respectively to predict what the output of a second detector, closely adjacent the first, should be if the sensitivities of the two detectors were equal. By comparing the prediction with the actual output signal provided by the second detector, differences in sensitivity are evaluated and allowed for. A technique for convolving difference signals rather than net signals is also disclosed.