Basic study on evaluation of X-ray dose distribution using plastic scintillator plate and digital CMOS camera

Abstract

Evaluation of dose distribution in a phantom is effective for quality control of radiation diagnostic equipment and evaluation of exposure. However, measurements at multiple points using a dosimeter is complicated. An alternative is to combine a plastic scintillator (PS) plate and digital camera to obtain the dose distribution of the entire phantom. In this study, the basic characteristics of this system were examined. A PS was sandwiched between Polymethyl Methacrylate (PMMA) disk phantoms, and irradiation was performed while the tube current was changed from one direction. The tube voltage was set to two values, specifically 60 and 120 kV. During irradiation, the entire phantom was recorded at 0.1 s intervals using a digital Complementary Metal Oxide Semiconductor (CMOS) camera. The lowest dose rate where luminescence could be detected was approximately 1 mGy per 0.1 s. The amount of luminescence increased linearly with the dose rate. The proportional relationship that was confirmed between dose rate and luminescence suggests the possibility of using the system for dose estimation. This proposed dose-evaluation method can enable the dose distribution to be evaluated with a time resolution of 0.1 s and a high spatial resolution.