이동형 방사선 차폐장치의 성능평가에 관한 연구

A Study on the Performance Evaluation of Portable Radiation Shielding Apparatus

When using a mobile X-ray unit, primary radiation creates medical images and secondary radiation scatters in many directions, which reduces image quality and causes exposure to patients, care givers and medical personnel. The purpose of this study was to develop a radiation shielding system for effectively shielding secondary radiation and evaluate its effectiveness. Using a mobile X-ray unit, spatial dose according to presence of human equivalent phantom and spatial dose using the developed shielding device were measured, and the phantom at 80 cm equidistance from center of X-ray was compared with spatial dose according to use of a shield. Measurements were taken at intervals of 10 cm every 30° from the head direction(-90°) to the body direction(+90°). In the spatial dose measurement with and without the phantom, when the human equivalent Phantom was used, the spatial dose was increased by 40% in all directions from 40 cm to 100 cm from the central X-ray, and about 88% of the space dose was reduced when using the developed shields with the phantom. The equidistance dose at 80 cm from the central X-ray was increased by 39% from 5.1±0.26 μ Gy to 7.1±0.15 μGy when the human equivalent phantom was used, and when phantom was used and shielding was used, the spatial dose was reduced by about 90% from 7.1±0.15 μGy to 0.7±0.07 μGy. The spatial dose of natural radiation was measured to be about 0.2±0.04 μGy when using the developed shielding with Phantom at a distance of 1 m or more. It is expected that by using the developed shielding system, it will be possible to effectively reduce secondary radiation dose received in all directions and to ensure safe imaging.