Breath-hold three-dimensional true-FISP imaging of coronary arteries using asymmetric sampling
Breath-hold three-dimensional true-FISP imaging of coronary arteries using asymmetric sampling
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DOI：
10.1002/jmri.10087
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发表时间：
2002-04-01
影响因子：
4.4
通讯作者：
Li, DB
中科院分区：
文献类型：
--
作者：
Deshpande, VS;Shea, SM;Li, DB
目的：评价在三维、磁化准备、分段的TRUE-FISP序列中使用非对称采样的可行性，以降低对共振偏移量的敏感性，同时提高成像速度。材料和方法：非对称采样减少重复时间，从而在固定的成像时间内减少共振偏移量，提高分辨率。然而，由于血液流动，它引入了额外的相位项，这可能会导致图像伪影。用计算机模拟的方法研究了TRUE-FISP中非对称采样的非共振和流动效应。对健康志愿者进行了冠状动脉成像。结果：模拟和志愿者研究表明，在低速情况下，由于流动诱导的相位变化而产生的图像伪影是可以接受的。志愿者研究表明，利用读出方向的数据不对称，分段三维True-FISP成像可以在一次屏气内获得相对高分辨率的冠状动脉图像。结论：非对称采样是True-FISP的一种有用的改进，可以减少非共振伪影，提高流速较小时的成像速度。
Purpose: To evaluate the feasibility of using asymmetric sampling in a three-dimensional, magnetization-prepared, segmented true-FISP (fast imaging with steady-state precession) sequence in order to reduce the sensitivity to resonance offsets, while simultaneously improving imaging speed.Materials and Methods: Asymmetric sampling reduces the repetition time, leading to reduced resonance offset effects and improved resolution in a fixed imaging time. However, it introduces additional phase terms due to blood flow, which can cause image artifacts. Computer simulations were performed to study the off-resonance and flow effects of asymmetric sampling in true-FISP. Coronary artery imaging was performed in healthy volunteers.Results: Simulations and volunteer studies show that image artifacts due to flow-induced phase variations may be acceptable at low velocities. Volunteer studies demonstrate that relatively high-resolution coronary artery images can then be acquired within a single breath-hold with segmented three-dimensional true-FISP imaging using data asymmetry in the readout direction.Conclusion: Asymmetric sampling is a useful modification to true-FISP for reducing the off-resonance artifacts and improving imaging speed when the flow velocities are small.