Morehouse C C, Brody W R, Guthaner D F, Breiman R S, Harell G S
Radiology. 1980 Jan;134(1):213-7. doi: 10.1148/radiology.134.1.7350608.
CT images of the heart are significantly degraded by the effects of motion during the scanning interval. The use of electrocardiographic (ECG) gating to provide "stop-action" cardiac images remains limited by artifacts. A motion phantom has been constructed to allow systematic study of the artifact structure of ECG-gated images and to isolate the origins of these artifacts. "Stop-action" reconstructed images are presented demonstrating two classes of artifacts: (a) pinwheel artifacts that appear at the edges of high-contrast moving objects; and (b) linear streaks occurring in relation to missing views when an incomplete angular set of projections is used for image reconstruction with the convolution back-projection algorithm. These results underscore the use of the motion phantom for the analysis of image artifacts and stress the need for new CT reconstruction algorithms which are optmized for "stop-action" scanning.
在扫描期间，心脏的CT图像会因运动影响而显著退化。使用心电图（ECG）门控来提供“定格”心脏图像仍受伪影限制。现已构建了一个运动模型，以便系统研究ECG门控图像的伪影结构并确定这些伪影的来源。展示了“定格”重建图像，其显示出两类伪影：（a）出现在高对比度移动物体边缘的风车状伪影；（b）当使用不完整的角度投影集通过卷积反投影算法进行图像重建时，与缺失视图相关出现的线性条纹。这些结果强调了运动模型在图像伪影分析中的用途，并强调需要针对“定格”扫描进行优化的新型CT重建算法。
