Department of Electrical Engineering, School of Electrical and Computer Engineering, Cornell University, Ithaca, New York, USA.
Magn Reson Med. 2011 Jan;65(1):184-9. doi: 10.1002/mrm.22584.
Among recent parallel MR imaging reconstruction advances, a Bayesian method called Edge-preserving Parallel Imaging reconstructions with GRAph cuts Minimization (EPIGRAM) has been demonstrated to significantly improve signal-to-noise ratio when compared with conventional regularized sensitivity encoding method. However, EPIGRAM requires a large number of iterations in proportion to the number of intensity labels in the image, making it computationally expensive for high dynamic range images. The objective of this study is to develop a Fast EPIGRAM reconstruction based on the efficient binary jump move algorithm that provides a logarithmic reduction in reconstruction time while maintaining image quality. Preliminary in vivo validation of the proposed algorithm is presented for two-dimensional cardiac cine MR imaging and three-dimensional coronary MR angiography at acceleration factors of 2-4. Fast EPIGRAM was found to provide similar image quality to EPIGRAM and maintain the previously reported signal-to-noise ratio improvement over regularized sensitivity encoding method, while reducing EPIGRAM reconstruction time by 25-50 times.
在最近的并行磁共振成像重建进展中,一种名为基于边缘保持的并行成像重建与图切割最小化(EPIGRAM)的贝叶斯方法已经被证明在与传统正则化敏感编码方法相比时,可以显著提高信噪比。然而,EPIGRAM 需要与图像中的强度标签数量成比例的大量迭代,因此对于高动态范围图像来说计算成本很高。本研究的目的是开发一种基于高效二进制跳跃移动算法的快速 EPIGRAM 重建方法,该方法在保持图像质量的同时,将重建时间缩短到原来的对数级。提出的算法在二维心脏电影磁共振成像和三维冠状动脉磁共振血管造影中进行了初步的体内验证,加速因子为 2-4。结果表明,Fast EPIGRAM 提供了与 EPIGRAM 相似的图像质量,并保持了之前报道的相对于正则化敏感编码方法的信噪比提高,同时将 EPIGRAM 重建时间缩短了 25-50 倍。