Assessment of Scattered Radiation Dose to the Eye Lens of Staff during Portable Chest X-Rays

Abstract

            This study aimed to evaluate the scattered radiation dose to the lens of the eye of radiologic personnel during chest radiography using a mobile X-ray unit. A human torso tissue-equivalent phantom (Kyoto Kagaku model PHU-60) and a mobile X-ray machine (FUJI NANO DR-XD 1000) at Somdech Phra Pinklao Hospital were utilized. The exposure parameters were set at 85 kVp, 1.6 mAs, and a source-to-image distance (SID) of 100 cm. Chest radiographs were obtained in three patient positions: AP supine, AP semi-upright, and AP upright. The scattered radiation dose was measured at a height of 160 cm. using an optically stimulated luminescence dosimeter (OSLD) nanoDot (Landauer). Measurements were taken at seven angular positions around the mobile X-ray unit: 0°, 30°, 60°, 90°, 120°, 150° and 180°. The results showed that the scatter radiation distribution patterns were similar in all positions; however, the AP supine position produced the widest scatter distribution. The minimum scattered dose was 4.640 ± 0.45 µSv at 0°, and the maximum was 6.467 ± 0.60 µSv at 90°, which exceeded the lens dose limit byapproximately 1.3 - 1.9 times. In conclusion, radiologic technologists should stand behind the mobile X-ray unit during exposures to minimize scatter radiation exposure. Additionally, the use of personal protective equipment, including lead aprons, thyroid shields, and lead glasses, is strongly recommended to ensure long-term radiation safety.