k-t GRAPPA:: A k-space implementation for dynamic MRI with high reduction factor
k-t GRAPPA:: A k-space implementation for dynamic MRI with high reduction factor
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DOI：
10.1002/mrm.20641
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发表时间：
2005-11-01
影响因子：
3.3
通讯作者：
Limkeman, M
中科院分区：
文献类型：
--
作者：
Huang, F;Akao, J;Limkeman, M
引入了一种称为“ K-T Grappa”的新技术，以加速动态磁共振成像。动态磁共振图像在K空间和时间维度中具有显着的信号相关性。因此，仅获取减少数据并恢复缺失部分是可行的。广义自动校准部分并行采集（Grappa）是一种重要的并行成像技术，将k空间中缺失的数据线性插值。在这项工作中，结果表明，Grappa的想法也可以在K-T空间中应用，以利用相关性并插入K-T空间中缺失的数据。对于此方法，不需要训练数据，过滤器，其他参数或灵敏度图，并且适用于单个或多个接收器线圈。信号相关性是从获得的数据局部得出的。在这项工作中，将K-T Grappa技术与我们对Grappa，Tgrappa和滑动窗口重建的实现进行了比较，如方法中所述。实验结果表明，当还原因子高达4时，K-T Grappa会产生较高的空间分辨率重建而不会显着丢失时间分辨率。当还原因子变得更高时，可能会引起时间分辨率的明显损失，因为K-T Grappa使用时间插值， 。与滑动窗口重建的图像相比，使用K-T Grappa重建的残留/折叠伪像的图像要比通过Grappa重建的噪声少得多，而更宽的时间带宽要比用残留K空间重建的噪声更宽。 K-T Grappa适用于广泛的动态成像应用，并且不限于具有准周期运动的成像零件。由于仅将本地信息用于重建，因此对于需要实时重建的应用，例如监视介入的MRI，K-T Grappa也是首选的。 Magn Reson Med 54：1172-1184，2005。（C）2005 Wiley-Liss，Inc。
A novel technique called "k-t GRAPPA" is introduced for the acceleration of dynamic magnetic resonance imaging. Dynamic magnetic resonance images have significant signal correlations in k-space and time dimension. Hence, it is feasible to acquire only a reduced amount of data and recover the missing portion afterward. Generalized autocalibrating partially parallel acquisitions (GRAPPA), as an important parallel imaging technique, linearly interpolates the missing data in k-space. In this work, it is shown that the idea of GRAPPA can also be applied in k-t space to take advantage of the correlations and interpolate the missing data in k-t space. For this method, no training data, filters, additional parameters, or sensitivity maps are necessary, and it is applicable for either single or multiple receiver coils. The signal correlation is locally derived from the acquired data. In this work, the k-t GRAPPA technique is compared with our implementation of GRAPPA, TGRAPPA, and sliding window reconstructions, as described in Methods. The experimental results manifest that k-t GRAPPA generates high spatial resolution reconstruction without significant loss of temporal resolution when the reduction factor is as high as 4. When the reduction factor becomes higher, there might be a noticeable loss of temporal resolution since k-t GRAPPA uses temporal interpolation. Images reconstructed using k-t GRAPPA have less residue/folding artifacts than those reconstructed by sliding window, much less noise than those reconstructed by GRAPPA, and wider temporal bandwidth than those reconstructed by GRAPPA with residual k-space. k-t GRAPPA is applicable to a wide range of dynamic imaging applications and is not limited to imaging parts with quasi-periodic motion. Since only local information is used for reconstruction, k-t GRAPPA is also preferred for applications requiring real time reconstruction, such as monitoring interventional MRI. Magn Reson Med 54:1172-1184, 2005. (c) 2005 Wiley-Liss, Inc.