A Study on Reduction of Exposure Dose According to Use of Cone in Radiologic Examination of Paranasal Sinus

Abstract

It aimed to seek the measures to decrease the exposure dose of radiation for the patients as well as the guardians during the paranasal radiography upon the survey on the usage of cone, which is the radiation shielding material in the paranasal radiography in the medical institutions, to measure the exposure dose to the patients depending on the usage of cone. The cone, diagnostic radiator, Ion Chamber, and Skull Phantom were used. The mean value was obtained measuring the points of 5° intervals of 0°, 45°, 90°, 135°, 180°, 225°, and 315° at 15cm from the center of the phantom five times each. In addition, the space dose was measured up to 200cm while increasing the distance with a radius of 50 cm from the center of the phantom. The spatial scattering dose distribution was measured five times at 50cm, 100cm, 150cm, and 200cm intervals in the directions of 0°, 45°, 135°, and 180° based on the phantom.60% of medical institutions did not have the radiation shielding device of a cone and74.4% did not use the cone in paranasal sinus examination. In the comparison of doses between the use and non-use of a cone, the dose decreased by 50.8% at 0°, 47.3% at 45°, 35.7%at 90°,59.2% at 135°, 39.8% at 180°, 27.3% at 225°, and 46.4% at 315° when the cone was used. The spatial dosimetry according to the distance was highest at 11.56mR/h at 0°, 1.08mR/h at 45°, 1.59mR/h at135°, and 0.94mR/h at 180°. In addition, spatial scattering rays were reduced to 92.7% when thecone was used as compared to when no cone was used. Therefore, a cone should be used in the radiologic examinatio of paranasal sinuses, and radiation workers and the family protector should also ensure that they are a safe distance away in order to prevent exposure by secondary radiation.