The physical characteristics of two computed radiography (CR) systems, Carestream EHR-M3 and Carestream GP-2 (used in mammography and general radiography, respectively), were assessed at the standard beam conditions RQA-M2 and RQA-5, in the ranges of 9.5–800 μGy and 2.5–70 μGy, respectively. Objective criteria such as response function, modulation transfer function (MTF), normalized noise power spectrum (NNPS) and detective quantum efficiency (DQE) were employed for this evaluation. A careful image system noise analysis through component decomposition was performed in order to determine the quantum limited exposure range for each system. Both CR systems showed a logarithmic response in the tested air kerma range (R² > 0.99). Spatial frequencies for 50% and 10% MTF were 2.0 mm⁻¹ and 4.9 mm⁻¹ for EHR-M3 mammography system and 1.1 mm⁻¹ and 3.5 mm⁻¹ for general radiography system GP-2. The mammography system EHR-M3 was quantum limited for the entire air kerma range evaluated, while GP-2 general radiography system was quantum noise limited for a range of 2.5–30 μGy. NNPS increased as kerma decreased for both systems. DQE increased with decreasing kerma for both systems. A quantitative technical characterization of digital systems was achieved for a variety of air kerma values, in the mammography and general radiography energy ranges.

在标准射束条件 RQA-M2 和 RQA-5 下评估了两个计算机 X 射线照相 (CR) 系统 Carestream EHR-M3 和 Carestream GP-2（分别用于乳房 X 线照相术和普通 X 射线照相术）的物理特性，范围为分别为 9.5–800 μGy 和 2.5–70 μGy。客观标准，如响应函数、调制传递函数 (MTF)、归一化噪声功率谱 (NNPS) 和检测量子效率 (DQE) 用于该评估。通过分量分解进行了仔细的图像系统噪声分析，以确定每个系统的量子限制曝光范围。^{两种 CR 系统在测试的空气比释动能范围 (R 2}  > 0.99)中都显示出对数响应。50% 和 10% MTF 的空间频率为 2.0 mm ^-14.9 mm ^-1用于 EHR-M3 乳腺摄影系统，1.1 mm ^-1和 3.5 mm ^-1用于一般 X 射线摄影系统 GP-2。乳腺 X 线摄影系统 EHR-M3 在评估的整个空气比释动能范围内受到量子限制，而 GP-2 通用 X 射线摄影系统在 2.5-30 μGy 范围内受到量子噪声限制。NNPS 随着两个系统的比释动能下降而增加。两个系统的 DQE 随着 kerma 的减小而增加。在乳房 X 线摄影和一般 X 射线摄影能量范围内，针对各种空气比释动能值实现了数字系统的定量技术表征。