Highly k-t-Space-Accelerated Phase-Contrast MRI
Highly k-t-Space-Accelerated Phase-Contrast MRI
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DOI：
10.1002/mrm.21764
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发表时间：
2008-11-01
影响因子：
3.3
通讯作者：
Markl, Michael
中科院分区：
文献类型：
--
作者：
Jung, Bernd;Honal, Matthias;Markl, Michael
本研究的目的是将最近引入的一种时空并行成像技术--峰值-GRAPPA(具有扩展和平均的广义自校准部分并行采集的并行MRI)与二维(213)电影相对比速度图相结合。应用相位对比MRI测量胸主动脉血流量和左心室心肌运动。为了评价不同重建方法的性能，使用完全获取的k空间数据集，比较了压缩因子R=2-6的GRAPPA和峰-GRAPPA的常规并行成像以及压缩因子R=2-12(净加速因子高达5.2)的滑动窗口重建。峰值图重建改善了图像质量，大大减少了伪影，这也得到了误差分析的支持。为了分析时空峰值图的潜在模糊或低通滤波效果，评估了主动脉血流和心肌组织运动的速度时程，并与常规图像重建进行了比较。血流速度的定量比较和速度的像素相关分析突出了峰-梯度在高速加速动态相衬速度图中的潜力。《医学评论》60：1169-1177,2008。(C)2008年Wiley-Liss，Inc.
The purpose of this study was to combine a recently introduced spatiotemporal parallel imaging technique, PEAK-GRAPPA (parallel MRI with extended and averaged generalized autocalibrating partially parallel acquisition), with two-dimensional (213) cine phase-contrast velocity mapping. Phase-contrast MRI was applied to measure the blood flow in the thoracic aorta and the myocardial motion of the left ventricle. To evaluate the performance of different reconstruction methods, fully acquired k-space data sets were used to compare conventional parallel imaging using GRAPPA with reduction factors of R = 2-6 and PEAK-GRAPPA as well as sliding window reconstruction with reduction factors R = 2-12 (net acceleration factors up to 5.2). PEAK-GRAPPA reconstruction resulted in improved image quality with considerably reduced artifacts, which was also supported by error analysis. To analyze potential blurring or low-pass filtering effects of spatiotemporal PEAK-GRAPPA, the velocity time courses of aortic flow and myocardial tissue motion were evaluated and compared with conventional image reconstructions. Quantitative comparisons of blood flow velocities and pixel-wise correlation analysis of velocities highlight the potential of PEAK-GRAPPA for highly accelerated dynamic phase-contrast velocity mapping. Magn Reson Med 60: 1169-1177, 2008. (C) 2008 Wiley-Liss, Inc.