Deshpande V S, Shea S M, Laub G, Simonetti O P, Finn J P, Li D
Department of Radiology, Northwestern University, Chicago, Illinois, USA.
Magn Reson Med. 2001 Sep;46(3):494-502. doi: 10.1002/mrm.1219.
The purpose of this work was to develop an ECG-triggered, segmented 3D true-FISP (fast imaging with steady-state precession) technique to improve the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of breath-hold coronary artery imaging. The major task was to optimize an appropriate magnetization preparation scheme to permit saturation of the epicardial fat signal. An alpha/2 preparation pulse was used to speed up the approach to steady-state following a frequency-selective fat-saturation pulse in each heartbeat. The application of dummy cycles was found to reduce the oscillation of the magnetization during data acquisition. The fat saturation and magnetization preparation scheme was validated with simulations and phantom studies. Volunteer studies demonstrated substantially increased SNR (55%) and CNR (178%) for coronary arteries compared to FLASH (fast low-angle shot) with the same imaging time. In conclusion, true-FISP is a promising technique for coronary artery imaging.
这项工作的目的是开发一种心电图触发的分段三维稳态进动快速成像（true-FISP）技术，以提高屏气冠状动脉成像的信噪比（SNR）和对比噪声比（CNR）。主要任务是优化合适的磁化准备方案，以使心外膜脂肪信号饱和。在每个心动周期中，使用一个α/2准备脉冲，在频率选择性脂肪饱和脉冲之后加速达到稳态。发现应用虚拟周期可减少数据采集期间磁化的振荡。通过模拟和体模研究验证了脂肪饱和和磁化准备方案。志愿者研究表明，与相同成像时间的快速低角度激发（FLASH）相比，冠状动脉的SNR大幅提高（55%），CNR提高（178%）。总之，true-FISP是一种很有前景的冠状动脉成像技术。
