We investigated the performances of two computed tomography (CT) systems produced by the same manufacturers (Somatom Flash and Edge Siemens) with different detector technologies (Ultrafast Ceramic and Stellar) and different generation of iterative reconstruction (IR) algorithms (SAFIRE and ADMIRE). A homemade phantom was scanned and the images were reconstructed with filtered back-projection (FBP) and IR algorithms. In terms of image quality, the performances of the systems were checked using the low-contrast detectability, evaluated by a Channelized Hotelling Observer (CHO), and the noise power spectrum (NPS). The analysis with CHO showed the best performance of Edge respect to Flash system for both FBP and IR algorithms. This better behavior, which reaches 20%, has been ascribed to the Stellar detector. From the NPS analysis, the noise reduction due to Stellar detector was 57%, moreover ADMIRE algorithm preserves a more traditional CT image texture appearance versus SAFIRE due to a lower NPS peak shift.

中文翻译：

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使用通道化酒店观察器和 NPS 指标对两个 CT 系统进行表征。

我们研究了由相同制造商（Somatom Flash 和 Edge Siemens）生产的两个计算机断层扫描 (CT) 系统的性能，这些系统具有不同的探测器技术（超快陶瓷和恒星）和不同代的迭代重建 (IR) 算法（SAFIRE 和 ADMIRE）。扫描自制的体模，并使用滤波反投影 (FBP) 和 IR 算法重建图像。在图像质量方面，系统的性能使用低对比度可检测性（由通道化酒店观察员 (CHO) 评估）和噪声功率谱 (NPS) 进行检查。使用 CHO 的分析表明，对于 FBP 和 IR 算法，Edge 相对于 Flash 系统的性能最佳。这种达到 20% 的更好行为归功于恒星探测器。从 NPS 分析来看，