Abbeyquaye D, Inkoom S, Hammond N B, Fletcher J J, Botwe B O
Department of Medical Physics, School of Nuclear and Allied Sciences, University of Ghana, Atomic Energy Campus, P.O. Box AE 1, Atomic Energy-Accra, Ghana.
Department of Biomedical Engineering Technology, Faculty of Health and Allied Sciences, Koforidua Technical University, P.O. Box KF-981, Koforidua, Ghana.
Radiat Prot Dosimetry. 2021 Aug 14;195(1):41-49. doi: 10.1093/rpd/ncab111.
Digital radiography systems can reduce radiation dose, this capability was harnessed to explore dose and image quality (IQ) optimisation strategies. Entrance surface dose (ESD), effective dose (ED) and organ doses were determined by the indirect method for patients undergoing pelvic anteroposterior X-ray examinations with computed radiography systems. The IQ of patients' radiographs was assessed in terms of signal-to-noise ratio (SNR). An anthropomorphic phantom was exposed with varying tube potential (kVp), tube current-time product (mAs), and focus-to-detector distance (FDD) to determine phantom-entrance dose for the optimisation studies. SNR of each phantom radiograph was determined. Patients' mean ESD of 2.38 ± 0.60 mGy, ED of 0.25 ± 0.07 mSv and SNR of 8.5 ± 2.2 were obtained. After optimisation, entrance dose was reduced by 29.2% with 5 cm increment in FDD, and 5 kVp reduction in tube potential. kVp and/or mAs reduction with an increment in FDD reduced entrance dose without adversely compromising radiographic-IQ.
数字放射成像系统能够降低辐射剂量，利用这一特性探索了剂量与图像质量（IQ）的优化策略。对于使用计算机X线摄影系统进行骨盆前后位X线检查的患者，采用间接方法测定其体表入射剂量（ESD）、有效剂量（ED）和器官剂量。根据信噪比（SNR）评估患者X线片的图像质量。为了进行优化研究，使用不同的管电压（kVp）、管电流-时间乘积（mAs）和焦点-探测器距离（FDD）对一个仿真人体模型进行照射，以确定模型体表入射剂量。测定每个模型X线片的SNR。患者的平均ESD为2.38±0.60 mGy，ED为0.25±0.07 mSv，SNR为8.5±2.2。优化后，将FDD增加5 cm并将管电压降低5 kVp，体表入射剂量降低了29.2%。在增加FDD的同时降低kVp和/或mAs可降低体表入射剂量，且不会对射线照相IQ产生不利影响。
