Pushing functional MRI spatial and temporal resolution further: High-density receive arrays combined with shot-selective 2D CAIPIRINHA for 3D echo-planar imaging at 7 T
Pushing functional MRI spatial and temporal resolution further: High-density receive arrays combined with shot-selective 2D CAIPIRINHA for 3D echo-planar imaging at 7 T
复制标题
DOI：
10.1002/nbm.4281
复制
发表时间：
2020-03-03
影响因子：
2.9
通讯作者：
Petridou, Natalia
中科院分区：
文献类型：
--
作者：
Hendriks, Arjan D.;D'Agata, Federico;Petridou, Natalia
为了能够检查动态和详细的脑功能，需要提高7 T MRI的空间和时间分辨率。在这项研究中，它被调查是否亚毫米多拍3D EPI功能磁共振成像扫描，获得高密度接收阵列，可以受益于2D CAIPIRINHA采样模式，在噪声放大（g因子），时间SNR和功能磁共振成像灵敏度。高密度接收阵列与7 T多激发3D EPI序列的激发选择性2D CAIPIRINHA实现相结合。在该实施方式中，与传统的包括额外的k（z）梯度点相反，省略了特定的EPI激发以创建CAIPIRINHA移位并减少扫描时间。首先，通过采集亚毫米全脑T-2* 加权解剖图像，使用标准接收设置评价CAIPIRINHA序列的实施。其次，CAIPIRINHA序列与高密度接收阵列相结合，以推动亚毫米级3D EPI功能磁共振成像扫描视觉皮层的时间分辨率。结果表明，与早期报告相比，拍摄选择性2D CAIPIRINHA序列能够将0.5 mm各向同性3D EPI T-2* 加权解剖结构扫描的扫描时间缩短4倍。与传统的SENSE相比，结合高密度接收阵列使用2D CAIPIRINHA实现增强了在高加速度下视觉皮层的亚毫米级3D EPI扫描的图像质量。g因子和时间SNR都得到了改善，从而产生了对fMRI信号更敏感的方法。使用这种方法，有可能在亚秒的时间范围内获得视觉皮层的亚毫米单体积3D EPI扫描。总的来说，高密度接收阵列结合用于3D EPI扫描的拍摄选择性2D CAIPIRINHA被证明对于减少亚毫米MRI采集的扫描时间是有价值的。
To be able to examine dynamic and detailed brain functions, the spatial and temporal resolution of 7 T MRI needs to improve. In this study, it was investigated whether submillimeter multishot 3D EPI fMRI scans, acquired with high-density receive arrays, can benefit from a 2D CAIPIRINHA sampling pattern, in terms of noise amplification (g-factor), temporal SNR and fMRI sensitivity. High-density receive arrays were combined with a shot-selective 2D CAIPIRINHA implementation for multishot 3D EPI sequences at 7 T. In this implementation, in contrast to conventional inclusion of extra k(z) gradient blips, specific EPI shots are left out to create a CAIPIRINHA shift and reduction of scan time. First, the implementation of the CAIPIRINHA sequence was evaluated with a standard receive setup by acquiring submillimeter whole brain T-2*-weighted anatomy images. Second, the CAIPIRINHA sequence was combined with high-density receive arrays to push the temporal resolution of submillimeter 3D EPI fMRI scans of the visual cortex. Results show that the shot-selective 2D CAIPIRINHA sequence enables a reduction in scan time for 0.5 mm isotropic 3D EPI T-2*-weighted anatomy scans by a factor of 4 compared with earlier reports. The use of the 2D CAIPIRINHA implementation in combination with high-density receive arrays, enhances the image quality of submillimeter 3D EPI scans of the visual cortex at high acceleration as compared to conventional SENSE. Both the g-factor and temporal SNR improved, resulting in a method that is more sensitive to the fMRI signal. Using this method, it is possible to acquire submillimeter single volume 3D EPI scans of the visual cortex in a subsecond timeframe. Overall, high-density receive arrays in combination with shot-selective 2D CAIPIRINHA for 3D EPI scans prove to be valuable for reducing the scan time of submillimeter MRI acquisitions.