Ullman Gustaf, Sandborg Michael, Dance David R, Hunt Roger, Alm Carlsson Gudrun
Department of Radiation Physics, Linköping University, SE-581 85 Linköping, Sweden.
Radiat Prot Dosimetry. 2005;114(1-3):294-7. doi: 10.1093/rpd/nch542.
The aim of this work was to study the influence of patient thickness, tube voltage and image detector on patient dose, contrast and ideal observer signal-to-noise ratio (SNR(I)), for pathological details positioned at different regions in the image in posterior-anterior (PA) chest radiology. A Monte Carlo computational model was used to compute measures of physical image quality (contrast, SNR(I)) and patient effective dose, E. Two metastasis-like details positioned in the central right lung and right lung near the spine, respectively, were studied. The tube voltage was varied between 100 and 150 kV and the patient thickness between 20 and 28 cm. Both, a computed radiography (CR) system and a direct radiography (DR) system, were investigated. The DR system provides both lower doses and better image quality compared with the CR system. The SNR(I)2/E is approximately 2.9 times higher for the DR system compared with the CR system.
这项工作的目的是研究在前后位（PA）胸部放射成像中，患者厚度、管电压和图像探测器对位于图像不同区域的病理细节的患者剂量、对比度和理想观察者信噪比（SNR(I)）的影响。使用蒙特卡罗计算模型来计算物理图像质量（对比度、SNR(I)）和患者有效剂量E的测量值。分别研究了位于右肺中央和脊柱附近右肺的两个类似转移灶的细节。管电压在100至150 kV之间变化，患者厚度在20至28 cm之间变化。研究了计算机X线摄影（CR）系统和直接X线摄影（DR）系统。与CR系统相比，DR系统提供更低的剂量和更好的图像质量。与CR系统相比，DR系统的SNR(I)2/E大约高2.9倍。
