Moore S C, Judy P F
Med Phys. 1987 Mar-Apr;14(2):193-6. doi: 10.1118/1.596134.
A fourth-generation, computed tomographic (CT) scanner, equipped for prospectively gated cardiac imaging, was modified to control the scan data acquisition by using knowledge of the location of redundant rays in the sinogram. In conventional prospective gating, a computer monitors the electrocardiogram (ECG) and calculates when to initiate the next scan in a gated series in order to acquire all 360 degrees of projection data for a desired phase of the cardiac cycle. However, in each scan of a series, every projection ray is measured twice (when the positions of the source and detector are reversed). Redundant-ray prospective gating takes advantage of this information to improve the efficiency of data acquisition. Using a heart phantom "beating" at 90 min-1, images of all phases of the cardiac cycle with 100-ms temporal resolution were obtained in four scans with redundant-ray gating; whereas a four-scan series with conventional prospective gating yielded worse images of 170-ms resolution.
一台配备前瞻性门控心脏成像功能的第四代计算机断层扫描（CT）扫描仪，通过利用正弦图中冗余射线位置的信息来控制扫描数据采集，从而进行了改进。在传统的前瞻性门控中，计算机监测心电图（ECG）并计算何时启动门控系列中的下一次扫描，以便获取心动周期所需相位的所有360度投影数据。然而，在系列扫描的每次扫描中，每条投影射线都要测量两次（当源和探测器的位置互换时）。冗余射线前瞻性门控利用这一信息来提高数据采集效率。使用以90次/分钟“跳动”的心脏模型，通过冗余射线门控在四次扫描中获得了具有100毫秒时间分辨率的心动周期所有相位的图像；而采用传统前瞻性门控的四次扫描系列产生的图像分辨率为170毫秒，质量较差。
