An apparatus and method for radiation detection is herein described. The apparatus consists of two radiation-detection arrays: A primary radiation-detection array, based on scintillator-CMOS design, and a secondary radiation-detection array, mounted on the back of said primary array. A method of controlling the detection operation is described, where output of the secondary array is exploited for controlling the acquisition-start and acquisition-stop of the primary array. Further, the apparatus is equipped with fast memory for storage of correction tables, and with a processor for fast computation of the correction. A method of calibration is also describes with tables for: offset correction, gain correction, and for defect-pixel correction. These tables are evaluated by the fast processor and stored on the fast memory. A method of real-time evaluation of the signal corrections is described, which depends on the acquisition-start and acquisition-stop timings and which results a clean, artifact-free image.
