Assessment of dose reduction and influence of gantry rotation time in CT abdomen examinations

Abstract

Background: Worldwide the computed tomography (CT) scanning is recognized as a high radiation dose modality. This article aimed to estimate the radiation dose reduction and radiogenic risks for adult patients undertaking abdominal CT examinations. Materials and Methods: A total of 128 patients were studied using 2, 4, 16 and 64 slice CT scanners. The patients were divided into two categories: the first category as control category (80 patients), and the other as optimisation category (48 patients). The optimisation protocol was based on decreasing the gantry rotation time. Results: In general, the faster gantry rotation times (0.7 s/rot and 0.5 s/rot) resulted in dose reduction while maintaining images noise within the acceptable range. After dose optimization, the overall cancer risk was reduced by 21%, 49%, 29%, and 16%, for the patients undergoing abdominal examinations on 2, 4, 16 and 64 slice CT scanners, respectively. Conclusion: The patient dose optimisation during CT abdomen was investigated. By lowering gantry rotation time, a radiation dose reduction of up to 30 % was achieved without compromising the diagnostic findings. Accordingly, the attention of all technologists necessary to take advantage of the dose reduction methods reported in this study.