Admire与Safire：CT重建算法及其噪声特性的客观比较
Admire vs. Safire: Objective comparison of CT reconstruction algorithms and their noise properties
摘要：
目的：Siemens在其CT扫描仪上开发了几种迭代重建（IR）算法。大多数CT扫描仪上都有SAFIRE。最新的算法ADMIRE可用于其最新的高端CT扫描仪。我们的研究的目的是使用客观的方法来比较两种IR算法的降噪性能。方法和材料：Catphan体模的均质模块在Siemens AS+和Siemens Flash CT扫描仪上使用轴向腹部协议进行扫描，固定管电流为两个剂量水平。使用滤波反投影（FBP）和低、中、高水平SAFIRE或ADMIRE，使用腹部滤波器（B30）重建图像。使用这些图像计算噪声功率谱（SNR）曲线。然后，使用相同的设置和曝光参数扫描拟人腹部体模（Kyoto Kagaku PH-5）。使用相同切片位置处的50个轴向图像来计算图像间标准差图。结果：在全剂量下，两种扫描仪在所有IR水平下的MRI曲线的中值相似。在低剂量下，辐射曲线的中值通常向较低的空间频率偏移，通常导致图像纹理更有斑点。对于所有IR水平，ADMIRE的这种变化比SAFIRE更显著。基于拟人体模的图像间标准差图，ADMIRE比SAFIRE更有效地去除边缘附近的噪声。结论：ADMIRE算法在保持噪声结构方面没有显着改善。基于图像间的标准差映射，ADMIRE比SAFIRE更有效地去除边缘附近的噪声。
英文摘要：
Purpose: Siemens has developed several iterative reconstruction (IR) algorithms on their CT scanners. SAFIRE is available on most of their CT scanners. The latest algorithm, ADMIRE, is available on their newest high-end CT scanners. The aim of our study was to compare the noise reduction properties of the two IR algorithms using objective methods. Methods and Materials: The homogeneous module of the Catphan phantom was scanned on a Siemens AS+ and a Siemens Flash CT scanner using an axial abdomen protocol with fixed tube current at two dose levels. The images were reconstructed with an abdomen filter (B30) using filtered back projection (FBP) and a low, medium, and high level of SAFIRE or ADMIRE. Noise Power Spectrum (NPS) curves were calculated using these images. Then, an anthropomorphic abdomen phantom (Kyoto Kagaku PH-5) was scanned using the same setup and exposure parameters. Fifty axial images at the same slice location were used to calculate inter-image standard deviation maps. Results: At full dose, the median values of the NPS curves were similar for both scanners at all IR levels. At low dose the median values of the NPS curves were generally shifted towards lower spatial frequencies, usually resulting in a more blotchy image texture. This shift was more prominent for ADMIRE compared to SAFIRE for all IR levels. Based on the inter-image standard deviation maps of the anthropomorphic phantom, ADMIRE removed noise near edges more efficiently than SAFIRE. Conclusion: No significant improvement in maintaining noise structure were found for the ADMIRE algorithm. Based on the inter-image standard deviation maps, ADMIRE removed noise near edges more efficiently than SAFIRE.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
