Murakami Rie, Katsuragawa Shigehiko
Department of Radiological Sciences, Graduate School of Health Sciences, Teikyo University, 6-22 Misakimachi, Omuta, Fukuoka, 836-8505, Japan.
Radiol Phys Technol. 2020 Mar;13(1):111-118. doi: 10.1007/s12194-020-00555-6. Epub 2020 Feb 5.
The present study aimed to develop a simple computer simulation method of low-dose radiographs based on a radiograph acquired at a clinical-dose level. A chest phantom was used for the development of this method. In this method, a simulated low-dose image was obtained from a clinical-dose image using an input-output characteristic curve of a flat panel detector and noise metrics of the standard deviation (SD) and noise power spectrum. We applied this method for low-dose images of a chest phantom to evaluate the simulation accuracy. The noise SDs were compared between the simulated and real images corresponding to 1/2, 1/4, and 1/8 of clinical doses. The relative error of noise SDs in the chest phantom images was less than 3%. Therefore, we believe that the proposed simulation method has the potential to be useful for determination of the optimal exposure condition in chest radiography to reduce patients' exposure dose.
本研究旨在基于临床剂量水平获取的X光片开发一种简单的低剂量X光片计算机模拟方法。为此采用了胸部体模。在该方法中，利用平板探测器的输入-输出特性曲线以及标准差（SD）和噪声功率谱的噪声指标，从临床剂量图像中获得模拟低剂量图像。我们将此方法应用于胸部体模的低剂量图像，以评估模拟精度。比较了模拟图像和真实图像中对应临床剂量1/2、1/4和1/8时的噪声标准差。胸部体模图像中噪声标准差的相对误差小于3%。因此，我们认为所提出的模拟方法有可能用于确定胸部X光摄影的最佳曝光条件，以降低患者的照射剂量。
