Deshpande Vibhas S, Li Debiao
Department of Radiology, Northwestern University, Chicago, Illinois 60611, USA.
Magn Reson Med. 2003 Sep;50(3):570-7. doi: 10.1002/mrm.10554.
An ECG-triggered, segmented, magnetization-prepared, 3D, trueFISP sequence was recently developed for coronary artery imaging. Fat saturation was achieved by a chemically selective fat saturation pulse, which is susceptible to field inhomogeneities. In addition, the blood-myocardial contrast was compromised because data were acquired during signal transience to steady state. The goals of this work were to investigate the potential benefits of T(1)-shortening agents in improving blood-myocardial contrast, and to develop a technique to make fat suppression robust to resonance offsets for coronary artery imaging using trueFISP. A magnetization-preparation scheme using saturation and inversion pulses was developed for simultaneous suppression of tissues over a wide range of T(1)'s, including myocardium and fat. An additional advantage of this method is that it is insensitive to heart rate variations. Computer simulations were used to design the magnetization preparation, and volunteer studies were performed to compare precontrast imaging to contrast-enhanced (CE) imaging. Results showed consistent fat suppression and a 78% increase in the blood-myocardial contrast-to-noise ratio (CNR) for postcontrast imaging over precontrast imaging. In conclusion, contrast agents are useful for trueFISP coronary artery imaging.
最近开发了一种心电图触发、分段、磁化准备的三维真实快速成像稳态进动序列用于冠状动脉成像。通过化学选择性脂肪饱和脉冲实现脂肪饱和，该脉冲易受场不均匀性影响。此外，由于数据是在信号从瞬态到稳态的过程中采集的，血液与心肌的对比度受到影响。这项工作的目标是研究T(1)缩短剂在改善血液与心肌对比度方面的潜在益处，并开发一种技术，使脂肪抑制对共振偏移具有鲁棒性，用于使用真实快速成像稳态进动序列的冠状动脉成像。开发了一种使用饱和和反转脉冲的磁化准备方案，用于同时抑制包括心肌和脂肪在内的广泛T(1)值范围内的组织。该方法的另一个优点是对心率变化不敏感。使用计算机模拟来设计磁化准备，并进行志愿者研究以比较对比剂注射前成像与对比增强（CE）成像。结果显示脂肪抑制一致，对比剂注射后成像的血液与心肌对比度噪声比（CNR）比注射前成像增加了78%。总之，对比剂对真实快速成像稳态进动序列冠状动脉成像很有用。
