计算机与现代化

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基于复合正则化的高效压缩感知磁共振成像研究

  

  1. 四川工程职业技术学院车辆工程系,四川德阳618000
  • 收稿日期:2015-11-03 出版日期:2016-05-24 发布日期:2016-05-25
  • 作者简介:申慧君(1987-),女,四川绵阳人,四川工程职业技术学院车辆工程系助教,硕士,研究方向:图像处理。

Efficient Compressed Sensing Magnetic Resonance Imaging #br# Based on Compound Regularization

  1. Department of Vehicle Engineering, Sichuan Engineering Technical College, Deyang 618000, China
  • Received:2015-11-03 Online:2016-05-24 Published:2016-05-25

摘要:

压缩感知磁共振成像可以在实现数据扫描加速的同时不降低成像质量。在压缩感知磁共振成像方法中,当前的复合正则化重建模型极少根据信号包含的各种各样的结构特征个性化选取不同的正则
化方法,使得当前成像方法需要较高的采样率以获得具有医学诊断价值的图像。基于此,本文提出一种新的复合正则化成像模型,该模型根据曲波变换域高低频子带系数的不同结构特征全变分正则化图
像灰度值和低频系数,l1范数正则化高频系数并采用k空间观测值约束成像保真度。采用变量分裂与交替方向乘子法求解该成像模型。针对活体数据的实验仿真结果表明,在相同采样率下,本文所
提方法重构性能远优于当前基于小波与全变分的正则化模型。

关键词: 压缩感知, 磁共振成像, 均匀离散曲波变换, 变量分裂, 交替方向乘子法

Abstract:

Compressed sensing(CS) is well utilized to accelerate magnetic resonance imaging(MRI) without degrading images quality. The present compound regularization imaging
models seldom select different regularization tools according to the different structural features of images. The imaging methods thus require high sampling rates to obtain
images with diagnostic value. In this paper, a novel compound regularization CS MRI model integrating two regularization tools: uniform discrete curvelet transform and total
variation, is introduced. It includes spatial image and lowpass subband coefficients total variation regularization, highpass subbands coefficients l1
regularization and kspace data fidelity constraint. Then this CS MRI model formulation is solved via variable splitting and alternating direction method of multipliers.
Simulated results on in vivo data are evaluated by objective indices and visual perception, which indicates that the proposed method outperforms the existing regularization
models established on the total variation and wavelets under the same sampling rate.

Key words: compressed sensing, magnetic resonance imaging, uniform discrete curvelet transform, variable splitting, alternating direction method of multipliers

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