Comparative Study Of Two Methods For Assessing Leakage Radiation Dose In Digital X-Ray Machine: Regulatory Compliance

Abstract

This study aims to evaluate leakage radiation in Digital x-ray equipment through two dosimetry methods: ion chamber and Semiconductor diode dosimeter. The research investigates the feasibility and advantages of employing these methods for the precise assessment of leakage radiation dose in digital x-ray machines. Leakage radiation poses significant risks to patients and healthcare professionals, necessitating accurate assessment techniques. The research is conducted in accordance with established guidelines and standards, with a specific focus on compliance with regulations set forth by the Atomic Energy Regulatory Board (AERB). [1], [2], [3]. Method-1 involves ion chamber dosimetry, while Method-2 employs Semiconductor diode dosimeters. By conducting controlled experiments and comparisons, we assess the precision, reliability, and practicality of each approach. The study's findings elucidate the benefits and challenges associated with these dosimetry methods, contributing to enhanced radiation safety protocols and quality assurance in Digital x-ray imaging. Method-1, employing ion chamber dosimetry, is a conventional approach widely used in radiation measurement applications. It involves the use of a calibrated ion chamber to measure radiation dose accurately. Method-2, utilizing Semiconductor diode dosimeters, represents a newer technology offering advantages such as compactness, portability, and potential for real-time data acquisition. The study involves meticulous experimental setup and data collection procedures. Measurements are conducted under controlled conditions. The permissible limit for radiation leakage from the protective tube housing and collimator in digital x-ray machine is 1.0 mGy (about 114 mR) in one hour at 1.0 meter from the x-ray tube focus point. The measurement of radiation leakage involves employing an ionization chamber and a semiconductor-based radiation survey meter, with the radiation being averaged over a specified area not exceeding 100 cm². Throughout the leakage measurement process, the x-ray machine remains operational with the radiation activated. The collimator of the tube housing is fully closed, and the tube is energized at the maximum rated tube potential and tube current corresponding to that kilovolt peak (kVp). The exposure rate at one meter from the focal spot is measured at various positions, including the anode side, cathode side, front, back, and top of the tube housing and collimator, as illustrated in Figure-1. The study determines the maximum leakage rates for both the tube housing and collimator, accounting for a workload of 180 mA-min per hour for a diagnostic machine (radiography and fluoroscopy). The recorded highest equivalent dose rate is also documented. The measurements values from test method-1 and test method-2 are within the specified limits (114 mR in one hour) of AERB requirement and deviation is within 10%.