Wang Y, Vidan E, Bergman G W
Department of Radiology, Joan and Sanford I, Weill Medical College, Cornell University, New York, NY 10021, USA.
Radiology. 1999 Dec;213(3):751-8. doi: 10.1148/radiology.213.3.r99dc41751.
To measure the duration of the rest period in the cardiac cycle, a parameter vital to data acquisition in coronary magnetic resonance (MR) angiography.
Motion of coronary arteries was measured in 13 patients by using breath-hold, biplane, conventional angiography, with frontal and lateral projections of the left and right coronary arteries acquired at 30 frames per second. The time courses of the coordinates of bifurcations of proximal parts of the coronary arteries were measured, from which the rest period (motion < 1 mm in orthogonal axes), velocity, displacement range, motion correlation, and reproducibility from heartbeat to heartbeat were estimated.
Both the motion pattern and the amplitude varied substantially from patient to patient. The rest period varied from 66 to 333 msec (mean, 161 msec) for the left coronary artery and from 66 to 200 msec (mean, 120 msec) for the right coronary artery.
The rest period for coronary arteries in the cardiac cycle varies substantially from patient to patient, which may cause quality to be inconsistent in current coronary MR angiography. A cardiac motion image prior to coronary data acquisition (preimage) may be used to estimate the optimal duration and timing in the cardiac cycle for coronary MR angiography.
测量心动周期中静止期的时长，这是冠状动脉磁共振（MR）血管造影数据采集中的一个关键参数。
对13例患者采用屏气双平面传统血管造影术测量冠状动脉运动，每秒30帧采集左、右冠状动脉的正位和侧位投影。测量冠状动脉近端分叉处坐标的时间进程，据此估算静止期（正交轴上运动<1毫米）、速度、位移范围、运动相关性以及心跳间的可重复性。
不同患者的运动模式和幅度差异很大。左冠状动脉的静止期为66至333毫秒（平均161毫秒），右冠状动脉的静止期为66至200毫秒（平均120毫秒）。
心动周期中冠状动脉的静止期在不同患者之间差异很大，这可能导致当前冠状动脉MR血管造影的质量不一致。冠状动脉数据采集前的心脏运动图像（预图像）可用于估算冠状动脉MR血管造影在心动周期中的最佳时长和时机。
