Hofman M B, van Rossum A C, Sprenger M, Westerhof N
Department of Clinical Physics & Engineering, ICaR-VU, Free University, Amsterdam, The Netherlands.
Magn Reson Med. 1996 Apr;35(4):521-31. doi: 10.1002/mrm.1910350411.
Flow in the human right coronary artery was determined using magnetic resonance phase contrast velocity quantification. Two methods were applied to reduce respiratory motion: Imaging during breath holding, which is fast, and retrospective respiratory gating, which has a high temporal resolution (32 ms) in the cardiac cycle. Vessel cross-sectional area, through-plane velocity, and volume flow were determined in six healthy subjects. In-plane vessel displacement during the cardiac cycle, caused by cardiac contraction, was about 2-4 mm within a time frame of 32 ms in systole and early diastole. The motion resulted in blurring of images obtained during breath holding caused by the large acquisition time window (126 ms) within the cardiac cycle. Therefore, only with a high temporal resolution correct velocity images over the entire cardiac cycle could be obtained. The time- and cross-sectionally averaged velocity was 7 +/- 2 cm/s, and the volume flow was 30 +/- 10 ml/min.
利用磁共振相位对比速度定量法测定人体右冠状动脉内的血流。应用了两种方法来减少呼吸运动的影响：屏气成像，速度快；回顾性呼吸门控，在心动周期中具有较高的时间分辨率（32毫秒）。在六名健康受试者中测定了血管横截面积、平面内速度和容积流量。在心动周期中，由心脏收缩引起的平面内血管位移，在收缩期和舒张早期的32毫秒时间范围内约为2 - 4毫米。这种运动导致在屏气期间获得的图像模糊，这是由于心动周期内较大的采集时间窗（126毫秒）所致。因此，只有具有高时间分辨率才能在整个心动周期内获得正确的速度图像。时间和横截面平均速度为7±2厘米/秒，容积流量为30±10毫升/分钟。
