Scattered Radiation Dose and Safety Assessment from Mobile X-Ray Radiography Radiation Assessment from Mobile X-ray Units

Abstract

OBJECTIVE: This study aimed to measure the scattered radiation levels that surround a mobile X-ray machine during chest radiography using adult and pediatric phantoms and to estimate the radiation exposure experienced by nearby individuals in simulated clinical ward settings.
METHODS: Scattered radiation was measured using a solid-state scatter probe at distances of 1.0, 1.5, and 2.0 meter (m), and at nine angular positions around the X-ray tube. Chest X-ray (CXR) exposures were performed using two parameter sets: 80 kilovoltage peak (kVp) and 2 milliampere-seconds (mAs) for the adult phantom, and 55 kVp and 1.6 mAs for the pediatric phantom. The data obtained regarding the dose were used to simulate and calculate the potential scattered radiation exposure in hospital wards under three different scenarios: (1) without walls or shielding, (2) using measured distances based on the experimental setup, and (3) with shielding barriers, incorporating attenuation coefficients for common building materials.
RESULTS: For the adult phantom, the highest scattered dose was 0.26 microgray (μGy) at 1.0 m and the lowest was 0.03 μGy at 2.0 m. For the pediatric phantom, values ranged from 0.107 μGy to 0.002 μGy. The calculations of radiation dose using ward layouts showed that the annual exposure to adjacent patients and health care workers, based on 730 imaging sessions per year, did not exceed the International Commission on Radiological Protection annual public dose limit of 1 millisievert.
CONCLUSION: Scattered radiation levels during mobile CXR procedures decrease with distance and remain within safe limits. However, the cumulative low-dose exposure may contribute to long-term stochastic risks. Measures to protect against radiation, such as maintaining a minimum 2-m distance and wearing lead aprons, are recommended for safety.