Evaluation and Comparison of Entrance Skin Dose in the Imaging of Hip Region Using Computed Tomography (CT) Scan and Stereoradiography

Extensive use of computed tomography (CT)-scan imaging is associated with an increase in cumulative dose. Stereoradiography by electro-optical system (EOS) is an X-ray imaging technology that can reduce patient absorption dose, and increase image quality by removing scattered radiation. The aim of this study was to quantify the dose of radiation in CT-scan and stereoradiography imaging, and to compare the dose values between the two methods. This descriptive-analytical study was carried out in the Shahid Sadoughi hospital of Yazd City, Iran, with two different types of imaging apparatus, stereoradiography and CT-scan. Fifteen patients were selected randomly for each imaging method. Prior to irradiation, nine thermoluminescence dosimeters (TLDs) were installed on the target area in anterior-posterior (AP), right transverse (RT), and left transverse (LT) views. 85-110 and 120 kilovoltage peaks (kVp) were used for stereoradiography and CT-scan, respectively. The TLDs were read, and the mean dose of radiation was calculated. Finally, the statistical analysis was performed using one-way ANOVA method via SPSS software. The mean dose of radiation in stereoradiography imaging from the lower regions with AP, RT, and LT views were 0.75, 0.26, and 1.14 mGy, respectively. These values with similar views in CT-scan images were 18.08, 10.87, and 10.37 mGy, respectively. According to the results of statistical analysis, radiation dose in the all views of stereoradiography imaging was significantly lower than CT-scan. Using stereoradiography imaging instead of CT-scan impose a lower dose to the patient in detecting lower limb malformations, and thus reducing the risk of cancer and side effects.