Reducing data acquisition times in phase-encoded velocity imaging using compressed sensing
Reducing data acquisition times in phase-encoded velocity imaging using compressed sensing
复制标题
DOI：
10.1016/j.jmr.2010.01.001
复制
发表时间：
2010-04-01
影响因子：
2.2
通讯作者：
Gladden, L. F.
中科院分区：
文献类型：
--
作者：
Holland, D. J.;Malioutov, D. M.;Gladden, L. F.
我们提出了一种方法，用于加速相位编码的速度图像的采集，通过使用压缩传感（CS），一种技术，利用观察到的欠采样信号可以准确地重建利用先验知识，它是稀疏或可压缩的。我们目前的模拟和实验测量的液体流动通过球形玻璃珠填充床的结果。对于这个系统，最好的图像重建使用空间有限差分变换。通过利用图像内液体分布的先验知识，进一步改进了重建。使用这种方法，我们证明，对于类似于30%的全k空间数据集的采样分数，速度可以恢复与11%的相对误差。其低于视觉可检测极限。此外，使用CS重建测量的总流量的误差为= 30%。因此，在使用常规成像所需采集时间的三分之一内获得定量速度图像。数据采集时间的减少也可以用于以更高的空间分辨率采集图像，这通过减少由部分体积效应引起的误差来提高测量的准确性。为了说明这一点，CS算法被用来重建气相速度图像的空间分辨率为230 μ m × 230 μ m。使用全k空间采样技术获取此空间分辨率的图像非常耗时。(C)2010年爱思唯尔公司All rights reserved.
We present a method for accelerating the acquisition of phase-encoded velocity images by the use of compressed sensing (CS), a technique that exploits the observation that an under-sampled signal can be accurately reconstructed by utilising the prior knowledge that it is sparse or compressible. We present results of both simulated and experimental measurements of liquid flow through a packed bed of spherical glass beads. For this system, the best image reconstruction used a spatial finite-differences transform. The reconstruction was further improved by utilising prior knowledge of the liquid distribution within the image. Using this approach, we demonstrate that for a sampling fraction of similar to 30% of the full k-space data set, the velocity can be recovered with a relative error of 11%. which is below the visually detectable limit. Furthermore, the error in the total flow measured using the CS reconstruction is = 30%. Thus, quantitative velocity images were obtained in a third of the acquisition time required using conventional imaging. The reduction in data acquisition time can also be exploited in acquiring images at a higher spatial resolution, which increases the accuracy of the measurements by reducing errors arising from partial volume effects. To illustrate this, the CS algorithm was used to reconstruct gas-phase velocity images at a spatial resolution of 230 mu m x 230 mu m. Images at this spatial resolution are prohibitively time-consuming to acquire using full k-space sampling techniques. (C) 2010 Elsevier Inc. All rights reserved.