Determination and comparison of thyroid gland and orbital surface doses that exposed to radiation in patients undergoing thorax computed tomography in TWO different devices by dosimetric methods

In this study, thyroid gland, right eye and left eye surface dose measurements were taken, in two different computed tomography devices, 50 patients in each device, in total 100 patients. TLD-100 dosimeters were used for dosimetric measurements. According to the measurement results obtained from three different points on the patients who underwent thorax tomography scanning, the measured surface doses in the 128-section CT device were found to be significantly higher than the surface doses measured in the 16-section CT device. At the same time, the measurement parameters such as CTDIvol, DLP, total DLP, kV, mAs, scan time, slice thickness, pitch and number of slices, which are obtained during scanning and used in the evaluation of radiation dose, were added to the study. The distribution of CTDIvol, DLP, total DLP, number of slices, age, weight and height variables was similar in both devices. However, kV, mAs, scan time, slice thickness and pitch values differ. CTDIvol, DLP and total DLP values were higher in the 16-section CT device, but the measured surface doses were higher in the 128-section CT device. Keywords: Computed tomography, CTDIvol, DLP, TLD-100 dosimetry, surface dose