Noumeir R, Mailloux G E, Lemieux R
Department of Electrical Engineering, Ecole de Technologie Supérieure, Montréal, Canada.
Comput Biomed Res. 1996 Feb;29(1):1-15. doi: 10.1006/cbmr.1996.0001.
An automatic procedure to detect and quantify patient motion during the acquisition of the tomographic views in single photon emission computerized tomography (SPECT) is proposed. This method first computes the optical flow vector field which assigns to each pixel of a tomographic view the two-dimensional displacement vector that describes its motion between two successive views. The average optical flow in a region of interest is then computed to measure its inter-view global motion. This algorithm is tested on a point source, on a cardiac phantom (with and without induced motion), and on a patient. The proposed method can accurately detect the presence of motion, localize the camera angle at which motion occurred, and measure the distance of motion. The optical flow method can be used to control the quality of the tomographic acquisition and to alert the user to the potential of reconstruction artifacts due to patient motion. It can also be used to correct for the translational motion in the direction of the axis of rotation of the camera.
提出了一种在单光子发射计算机断层扫描（SPECT）的断层图像采集过程中检测和量化患者运动的自动程序。该方法首先计算光流矢量场，该矢量场为断层图像的每个像素分配二维位移矢量，以描述其在两个连续视图之间的运动。然后计算感兴趣区域内的平均光流，以测量其视图间的整体运动。该算法在点源、心脏模型（有和没有诱导运动）以及患者身上进行了测试。所提出的方法可以准确地检测运动的存在，定位运动发生时的相机角度，并测量运动距离。光流方法可用于控制断层图像采集的质量，并提醒用户注意由于患者运动导致重建伪影的可能性。它还可用于校正相机旋转轴方向上的平移运动。
