A radiation detection system includes a detector unit and at least one processor. The detector unit is configured to generate signals responsive to radiation. The at least one processor is operably coupled to the detector unit and configured to receive the signals from the detector unit. The at least one processor is configured to obtain, during an imaging process, a first count for at least one of the signals corresponding to a first intrinsic energy window, the first energy window corresponding to values higher than an intrinsic peak value; obtain a second count for the at least one of the signals corresponding to a second intrinsic energy window, the second energy window corresponding to values lower than the intrinsic peak value; and adjust a gain applied to the signals based on at least the first count and the second count.