X-ray ct system with means to expand detector signals by interpolation

Abstract

In an X-ray CT apparatus including an X-ray source for irradiating X-rays to an object to be tested; a radiant ray detector for detecting the amount of X-rays transmitted through said object to be tested; a device for rotating the X-ray source and the detector about an axis to produce detection signals corresponding to the amount of transmitted X-rays; a filter for filter processing the detection signal; circuitry for back-projecting the filtering resultant to thereby reproduce a distribution image of X-ray absorption in a cross-section of the object to be tested, and a device for interpolating interpolation values into the detection signals to form expanded signals having an elongated length so that the expanded signals are used for the filter processing.