Analysis of the Scattered Radiation and Protection Practice from Mobile X-ray Units

Abstract

         This study aimed to compare the scattered radiation from two portable x-ray machines (SHIMADZU Mobile Art Evolution and FUJI FILM FDR Go Plus) at Nakhon Pathom Hospital. The radiation safety distance of staffs was also analyzed. The scatter radiation was measured by a surve meter at the height of 0.8 meter from the floor, representing the gonad level of a 1.75 meter human height. This level is similar to the height of the gurney. The measurements were collected with varying angles of 0, 45, 90, 135, 180, 225, 270 and 315 degrees at various distances of 0.5, 1.5, 3.0 and 4.0 meters from portable x-ray machines. The exposure technique for chest AP supine radiography was 85 kVp, 1.6 mAs for adult patients and 70 kVp, 0.63 mAs for pediatric patients. The exposure technique for pelvic AP was 85 kVp, 3.2 mAs, at 1 m SID. The 14 × 17˝ DR detector was used for radiographic imaging. The result showed that the amount of scattered radiation was inversely proportion to the distance from the patient, but it did not depend on the direction. In this study, the radiation exposure that the staffs and public received did not exceed the radiation exposure limit of <20 mSv/yr and <1 mSv/yr, respectively. For the safety practice, the staffs should keep the distance more than 4 m, stand at 0 degree from the x-ray tube, and wear lead apron.