Johnson Kevin M, Velikina Julia, Wu Yijing, Kecskemeti Steve, Wieben Oliver, Mistretta Charles A
Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53792-3252, USA.
Magn Reson Med. 2008 Mar;59(3):456-62. doi: 10.1002/mrm.21505.
The recently introduced HYPR (HighlY constrained backPRojection) method allows reconstruction of serial images from highly undersampled data. In HYPR, individual timeframes are obtained via unfiltered backprojections of normalized sinograms using anatomical constraints provided by a composite image. Here we develop the idea of constraining the backprojected data further to a series of local regions of interest in order to decrease the corruption of local information by distant signals. HYPR LR (local reconstruction) permits the use of a longer temporal window in the formation of the composite image, resulting in increased signal-to-noise ratio and quantitative reconstruction accuracy. Unlike HYPR, the new HYPR LR method can be applied to images acquired with arbitrary k-space trajectories. It is suitable for a broad range of medical imaging applications involving serial changes in image sequence, offering exciting new opportunities in the future.
最近推出的HYPR（高度约束反投影）方法允许从高度欠采样的数据中重建序列图像。在HYPR中，通过使用合成图像提供的解剖学约束对归一化正弦图进行未滤波反投影来获得各个时间帧。在此，我们进一步拓展了将反投影数据约束到一系列局部感兴趣区域的思路，以减少远处信号对局部信息的干扰。HYPR LR（局部重建）允许在合成图像的形成过程中使用更长的时间窗口，从而提高信噪比和定量重建精度。与HYPR不同，新的HYPR LR方法可应用于采用任意k空间轨迹采集的图像。它适用于广泛的涉及图像序列中序列变化的医学成像应用，在未来提供了令人兴奋的新机遇。
