Accelerated Multi-Shot Diffusion Imaging

作者：Madore Bruno^*; Chiou Jr yuan George; Chu Renxin; Chao Tzu Cheng; Maier Stephan E

来源：Magnetic Resonance in Medicine, 2014, 72(2): 324-336.

DOI：10.1002/mrm.24919

• diffusion imaging
• accelerated imaging
• navigator echoes
• multi-shot EPI

Purpose: To reduce image distortion in MR diffusion imaging using an accelerated multi-shot method. %26lt;br%26gt;Methods: The proposed method exploits the fact that diffusion-encoded data tend to be sparse when represented in the k(b)-k(d) space, where k(b) and k(d) are the Fourier transform duals of b and d, the b-factor and the diffusion direction, respectively. Aliasing artifacts are displaced toward under-used regions of the k(b)-k(d) plane, allowing nonaliased signals to be recovered. A main characteristic of the proposed approach is how thoroughly the navigator information gets used during reconstruction: The phase of navigator images is used for motion correction, while the magnitude of the navigator signal in k(b)-k(d) space is used for regularization purposes. As opposed to most acceleration methods based on compressed sensing, the proposed method reduces the number of k(y) lines needed for each diffusion-encoded image, but not the total number of images required. Consequently, it tends to be most effective at reducing image distortion rather than reducing total scan time. %26lt;br%26gt;Results: Results are presented for three volunteers with acceleration factors ranging from 4 to 8, with and without the inclusion of parallel imaging. %26lt;br%26gt;Conclusion: An accelerated motion-corrected diffusion imaging method was introduced that achieves good image quality at relatively high acceleration factors.

• 出版日期2014-8
• 单位河北医科大学