[Indirect method of measuring the scatter X-ray fraction using collimators in the diagnostic domain]

The lead disc method is conventionally applied to measure the scatter fraction directly in the energy range of diagnostic X-rays. There are numerous reports of use of this method, but it is difficult to make lead discs with sufficient fabrication accuracy. In this paper, we newly propose an indirect measurement method using collimators instead. In our method, we measure the following two experimental values: the sum of the intensities of the direct X-rays and scattered X-rays, and the intensity of direct X-rays using lead collimators. The ratio of these two values shows the fraction of the direct X-ray that is the complementary value of the scatter fraction. To verify this method experimentally, we carried out experiments using a computed radiography system at tube voltages of 40 kV to 100 kV, and phantom thicknesses of 10 mm to 100 mm. The results confirmed the validity of our method.