Compressed sensing for rapid late gadolinium enhanced imaging of the left atrium: A preliminary study.
Compressed sensing for rapid late gadolinium enhanced imaging of the left atrium: A preliminary study.
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DOI：
10.1016/j.mri.2016.03.002
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发表时间：
2016-09
影响因子：
2.5
通讯作者：
DiBella E
中科院分区：
文献类型：
--
作者：
Kamesh Iyer S;Tasdizen T;Burgon N;Kholmovski E;Marrouche N;Adluru G;DiBella E
当前左心房（LA）瘢痕或纤维化的晚期钆增强（LGE）成像相对较慢，需要5-15分钟才能采集欠采样（R=1.7）3D导航数据集。基于并行成像方法的GeneRalized Autocalibration Partially Parallel Acquisitions（GRAPPA）是加速LA 3D LGE成像的当前临床标准，允许加速因子~R=1.7。两种压缩感知（CS）方法已被开发，以实现更高的加速因子：基于补丁的协同过滤技术测试与加速因子R~3，和一种技术，使用3D径向堆叠的星采集模式（R~1.8）与3D总变差约束。这些CS方法的重建时间长，使得它们难以使用，特别是基于补丁的协同过滤技术。此外，尚不清楚CS技术对瘢痕/纤维化百分比定量的影响。我们试图开发一种实用的压缩传感方法，用于在高加速度因子下对LA进行成像。为了开发一种临床上可行的方法，重建时间短，分裂Bregman（SB）重建方法与3D全变差（TV）的限制，开发和实施。该方法在8例房颤患者（4个消融前和4个消融后数据集）上进行了测试。采用模糊度量、归一化均方误差和峰值信噪比作为指标来分析重建图像的质量，对欠采样图像进行量化，并与全采样图像进行比较。消融后数据集的瘢痕量化和消融前数据集的纤维化量化表明，使用3D TV约束和约束SB方法，加速因子高达R~3.5可获得良好的左心房壁3D LGE图像。与目前使用的GRAPPA方法相比，这相当于将扫描时间减少一半。使用SB方法重建3D LGE图像比标准梯度下降方法快20倍以上。
Current late gadolinium enhanced (LGE) imaging of left atrial (LA) scar or fibrosis is relatively slow and requires 5–15 minutes to acquire an undersampled (R=1.7) 3D navigated dataset. The GeneRalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) based parallel imaging method is the current clinical standard for accelerating 3D LGE imaging of the LA and permits an acceleration factor ~R=1.7. Two compressed sensing (CS) methods have been developed to achieve higher acceleration factors: a patch based collaborative filtering technique tested with acceleration factor R~3, and a technique that uses a 3D radial stack-of-stars acquisition pattern (R~1.8) with a 3D total variation constraint. The long reconstruction time of these CS methods makes them unwieldy to use, especially the patch based collaborative filtering technique. In addition, the effect of CS techniques on the quantification of percentage of scar/fibrosis is not known. We sought to develop a practical compressed sensing method for imaging the LA at high acceleration factors. In order to develop a clinically viable method with short reconstruction time, a Split Bregman (SB) reconstruction method with 3D total variation (TV) constraints was developed and implemented. The method was tested on 8 atrial fibrillation patients (4 pre-ablation and 4 post-ablation datasets). Blur metric, normalized mean squared error and peak signal to noise ratio were used as metrics to analyze the quality of the reconstructed images, Quantification was performed on the undersampled images and compared with the fully sampled images. Quantification of scar from post-ablation datasets and quantification of fibrosis from pre-ablation datasets showed that acceleration factors up to R~3.5 gave good 3D LGE images of the LA wall, using a 3D TV constraint and constrained SB methods. This corresponds to reducing the scan time by half, compared to currently used GRAPPA methods. Reconstruction of 3D LGE images using the SB method was over 20 times faster than standard gradient descent methods.