Study on the intensity of radiation attenuated by protective barriers in diagnostic X-ray installations


The main objective of the present study is to find out the intensity of radiation attenuated by different types of patient entrance doors (PED) as well as control panel (CP) protective barriers in diagnostic X-ray installations. To measure the intensity of ionizing radiation, ion chamber survey meter was used; all measurements were performed in freeze mode. In setting maximum accelerating potential, minimum tube current and fixed exposure time, a water phantom was exposed through maximum field size. Radiation exposure rates were measured at CPs as well as PEDs with and without barriers. In chest mission, radiation rates with PED ranged from 0.3 µSv/h to 0.7 mSv/h and without PED 0.2 mSv/h to 1.2 mSv/h. At the same time, in couch mission, radiation rates measured behind PED ranged from 0.3 µSv/h to 2.2 mSv/h and 0.03 mSv/h to 2.25 mSv/h in front of PED. All institutions showed higher exposure rates without PED; all types of doors considerably attenuated radiation. Among different types of door, lead-lined door attenuated 99.53% in chest mission and 97.44% in couch mission. While plywood doors attenuated approximately 40% of the incident radiation, it is more or less similar as air does in every half meter away from the phantom. Radiation rates in chest missions with CP barriers ranged from 2 µSv/h to 0.38 mSv/h, while 0.4 mSv/h to 2.35 mSv/h without CP barriers. In couch missions, radiation rates measured with CP barriers varied from 4 µSv/h to 0.6 mSv/h whereas without CP barriers from 0.7 mSv/h to 5 mSv/h. There was a significant difference between radiation measured behind and in front of the CP barriers. Among them, the percentage of attenuation was high in lead and concrete barriers.

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