Targeted partial reconstruction for real‐time fMRI with arbitrary trajectories
Targeted partial reconstruction for real‐time fMRI with arbitrary trajectories
复制标题
任意轨迹实时功能磁共振成像的靶向部分重建
DOI：
10.1002/mrm.27478
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发表时间：
2019
影响因子：
3.3
通讯作者：
J. Hennig
中科院分区：
文献类型：
--
作者：
B.Riemenschneider;P. Levan;J. Hennig
目的当实时全图像重建对计算要求过高时，引入部分图像重建形式，用于从任意轨迹有针对性地提取实时反馈。方法通过空间坐标的不完全基变化对重建矩阵的线的线性组合进行显式计算和存储，导致昂贵的完全重建从帧式应用程序转换为感兴趣区域（ROI）式应用程序。该步骤与信号数据无关，可以在实验前执行。随后，可以直接评估完全重建体素的总和结果。高速功能磁共振成像采集的数据用于研究功能性 ROI 图集的目标部分重建，并结合体积内相移校正。使用相同的数据和 ROI 将获得的时间序列与现有的分区重建方法获得的时间序列进行比较。为了检查实时可行性，实施了重建并测试了在线重建性能。结果重建产生的结果实际上与标准重建（即 ROI 上的幅度总和）相同，即使在可行的迭代次数下终止共轭梯度算法后，差异也可以忽略不计。值得注意的是，现有的隔室重建会出现更多差异。在线实时实现在高度并行 3D 全脑采集的情况下在 2.8 毫秒内评估了 1 个 ROI。结论高重建保真度和速度满足使用高度并行 3D 全脑采集的实时功能反馈的示例性应用。
PurposeA partial image reconstruction formalism is introduced for the targeted extraction of real‐time feedback from arbitrary trajectories when full image reconstruction in real time is computationally too demanding.MethodsExplicit calculation and storage of linear combinations of lines of the reconstruction matrix by an incomplete basis change in spatial coordinates lead to translation of the expensive full reconstruction from a frame‐wise application to a region of interest (ROI)‐wise application. This step is independent from signal data and can be executed before the experiment. Subsequently, the results of the sum over fully reconstructed voxels can be evaluated directly. Data from a high‐speed fMRI acquisition was used to investigate the targeted partial reconstruction of a functional ROI atlas, incorporating an intravolume dephasing correction. The same data and ROIs were used for a comparison of the time series obtained with those obtained from already existing methods for compartment‐wise reconstruction. To examine real‐time feasibility, the reconstruction was implemented and tested for online reconstruction performance.ResultsThe reconstruction yields results that are virtually identical to the standard reconstruction (i.e., the magnitude sums over the ROIs), with negligible discrepancies even after termination of the conjugate gradient algorithm at a feasible number of iterations. Notably, more discrepancies arise with existing compartment‐wise reconstructions. The online real‐time implementation evaluated 1 ROI within 2.8 ms in the case of a highly parallel 3D whole brain acquisition.ConclusionThe high reconstruction fidelity and speed are satisfying for the exemplary application of real‐time functional feedback using a highly parallel 3D whole brain acquisition.
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影响因子：
3.3
作者：
Uecker, Martin;Lai, Peng;Murphy, Mark J.;Virtue, Patrick;Elad, Michael;Pauly, John M.;Vasanawala, Shreyas S.;Lustig, Michael
通讯作者：
Lustig, Michael
影响因子：
5.7
作者：
Posse, Stefan;Ackley, Elena;Mutihac, Radu;Rick, Jochen;Shane, Matthew;Murray-Krezan, Cristina;Zaitsev, Maxim;Speck, Oliver
通讯作者：
Speck, Oliver
影响因子：
4.8
作者：
Akin, Burak;Lee, Hsu-Lei;LeVan, Pierre
通讯作者：
LeVan, Pierre
影响因子：
3.7
作者：
Shirer, W. R.;Ryali, S.;Greicius, M. D.
通讯作者：
Greicius, M. D.
DOI：
10.1073/pnas.0505210102
发表时间：
2005-12-20
影响因子：
11.1
作者：
deCharms, RC;Maeda, F;Mackey, SC
通讯作者：
Mackey, SC