Department of Medical Physics, University Hospital of Parma, Italy.
Department of Medicine, University of Parma, Italy.
Radiat Prot Dosimetry. 2020 Jul 13;189(2):224-233. doi: 10.1093/rpd/ncaa034.
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.
我们研究了由同一家制造商（Siemens Somatom Flash 和 Edge）生产的两种 CT 系统的性能，这两种系统采用了不同的探测器技术（Ultrafast Ceramic 和 Stellar）和不同代的迭代重建（IR）算法（SAFIRE 和 ADMIRE）。我们使用自制的体模对其进行了扫描，并使用滤波反投影（FBP）和 IR 算法进行了图像重建。在图像质量方面，我们使用 Channelized Hotelling Observer（CHO）评估了低对比度检测性能，并分析了噪声功率谱（NPS）。分析结果表明，Edge 系统在 FBP 和 IR 算法下的性能均优于 Flash 系统，这种性能的提升幅度达到了 20%，这归因于 Stellar 探测器。从 NPS 分析的结果来看，Stellar 探测器的降噪效果达到了 57%，此外，ADMIRE 算法由于 NPS 峰值偏移较小，因此与 SAFIRE 相比，其 CT 图像纹理的外观更接近传统的 CT 图像。
