Radiation dose reduction on cervical spine radiographic examination by using posteroanterior oblique projection

Abstract

Cervical spine radiographic examination with 450 oblique projection can be performed using anteroposterior (AP) oblique or posteroanterior (PA) oblique. There are radiosensitive organs that are exposed to radiation during the examination. This study aims to determine the radiation dose (Entrance Surface Dose) received by thyroid, eye, and breast on radiographic examination in AP oblique and PA oblique projections. Radiographic phantom with equivalent structure to human body was positioned in AP oblique and PA oblique. A modificated protractor was used to maintain the positioning precision. The optimum exposure factors (confirmed by Exposure Index) were used. Radiation dose on the thyroid, the eye, and the breast were measured 9 times using Termoluminisence Dosemeter for each positioning techniques. Data were analyzed by independent t-test. The average radiation dose received by the thyroid, the breast, and the eye between AP oblique and PA oblique projections were (0.915 and 0.174), (0.059 and 0.025), and (0.234 and 0.079), respectively. There were significant differences in the radiation dose received by the thyroid (p value <0.05), the breast (p value <0.05), and the eye (p value <0.05). The radiation dose were lower (81% on thyroid), (58% on breast), (66% on eye) by using PA oblique projection.