通过非相干采样和低秩矩阵补全加速动态螺旋化学位移成像
Speeding up dynamic spiral chemical shift imaging with incoherent sampling and low-rank matrix completion.
作者信息
DeVience Stephen J, Mayer Dirk
机构信息
Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA.
出版信息
Magn Reson Med. 2017 Mar;77(3):951-960. doi: 10.1002/mrm.26170. Epub 2016 Feb 24.
PURPOSE
To improve the temporal and spatial resolution of dynamic C spiral chemical shift imaging via incoherent sampling and low-rank matrix completion (LRMC).
METHODS
Spiral CSI data were both simulated and acquired in rats, and undersampling was implemented retrospectively and prospectively by pseudorandomly omitting a fraction of the spiral interleaves. Undersampled data were reconstructed with both LRMC and a conventional inverse nonuniform fast Fourier transform (iNUFFT) and compared with fully sampled data.
RESULTS
Two-fold undersampling with LRMC reconstruction enabled a two-fold improvement in temporal or spatial resolution without significant artifacts or spatiotemporal distortion. Conversely, undersampling with iNUFFT reconstruction created strong artifacts that obscured the image. LRMC performed better at time points with strong metabolite signal.
CONCLUSION
Incoherent undersampling and LRMC provides a way to increase the spatiotemporal resolution of spiral CSI without degrading data integrity. Magn Reson Med 77:951-960, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
目的
通过非相干采样和低秩矩阵补全（LRMC）提高动态C螺旋化学位移成像的时间和空间分辨率。
方法
在大鼠中模拟并采集螺旋CSI数据，通过伪随机省略一部分螺旋交错采样进行回顾性和前瞻性欠采样。用LRMC和传统的逆非均匀快速傅里叶变换（iNUFFT）对欠采样数据进行重建，并与全采样数据进行比较。
结果
采用LRMC重建进行两倍欠采样可使时间或空间分辨率提高两倍，且无明显伪影或时空失真。相反，采用iNUFFT重建进行欠采样会产生强烈伪影，模糊图像。在代谢物信号较强的时间点，LRMC表现更好。
结论
非相干欠采样和LRMC提供了一种在不降低数据完整性的情况下提高螺旋CSI时空分辨率的方法。《磁共振医学》77:951 - 960，2017年。©2016国际磁共振医学学会。
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