A method and apparatus for processing signals output from an array of X-ray radiation detectors which receive X-ray radiation emanating from an object irradiated by a source beam of X-ray radiation, to thereby produce an visual image of internal object features, utilizes repetitive sampling P times and digital accumulation of signals output from each detector to increase signal-to-noise ratio of the images by the factor 1/ P. In a basic embodiment, each of the N detectors in a linear detector array is sampled P times. In another embodiment, artifacts resulting from decay of detector pre-amplifier output voltages on capacitors of low-pass filter circuits, referred to as pseudo-integrators, are reduced by sequentially sampling and accumulating each of N detector amplifier output voltages P times in turn, and repeating the sampling and accumulating sequence Q times, thereby reducing variations in the P.times.Q accumulated values between the first and last detector channels of an N detector array.