A novel method for scattered radiation compensation in X-ray imaging systems, using partially transparent shields (PTS)

A new method for scattered radiation compensation in 2D projection radiographic imaging is presented. By comparing the detected signal under a small partially transparent shield (e.g. aluminum disk or strip), positioned between the X-ray source and the object being imaged, with the detected signal near the border of the shadow of the shield, the radiation scatter signal in the location of the shield is calculated. For polychromatic X-radiation, calibration with two known basis materials allows accurate calculation of the radiation scatter. Shields are positioned at several locations between object and source. By an interpolation technique, the radiation scatter in every region of interest can be calculated. The radiation scatter image is then subtracted from the original image of the object. The method needs only one exposure of the object. The primary radiation signals at the locations of the shields have undergone an extra drop, but the information about the object under the shields is not lost. One could restore the image by compensating for the effect of the shields on the primary signal. The theory of PTS is presented and results of experiments are given