Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America.
Phys Med Biol. 2018 Jul 24;63(15):15NT02. doi: 10.1088/1361-6560/aad008.
The goal of this study is to present a framework that allows cine images in orthogonal planes to be reconstructed simultaneously using slice-interleaved acquisitions and k-t GRAPPA. Slice-interleaved acquisitions can be interpreted as an undersampled k-t space in which data are desired at skipped frames. Local spatiotemporal correlations can be exploited to interpolate the skipped data to reconstruct images in orthogonal slice groups simultaneously. An in vivo experiment was performed in which interleaved sagittal and coronal balanced steady-state free-precession data were acquired in the abdomens of volunteers breathing normally. k-t GRAPPA weights were calculated from separate calibration scans and applied to the slice-interleaved data. The images from the interpolated frames have a similar contrast to the acquired frames, and the use of k-t GRAPPA improved the anatomical alignment between the orthogonal images in the presence of motion. The k-t GRAPPA reconstruction of slice-interleaved data is a promising method for obtaining cine images of orthogonal slices simultaneously with arbitrary contrast.
本研究旨在提出一种框架,使用层间采集和 k-t GRAPPA 同时重建正交平面的电影图像。层间采集可以解释为在欠采样的 k-t 空间中,在跳过的帧中需要数据。可以利用局部时空相关性来对跳过的数据进行插值,以同时重建正交切片组中的图像。在一项体内实验中,在正常呼吸的志愿者腹部采集了层间矢状面和冠状面平衡稳态自由进动数据。从单独的校准扫描中计算出 k-t GRAPPA 权重,并将其应用于层间数据。来自插值帧的图像与采集帧具有相似的对比度,并且在存在运动的情况下,使用 k-t GRAPPA 改善了正交图像之间的解剖配准。用 k-t GRAPPA 重建层间数据是一种很有前途的方法,可以同时以任意对比度获得正交切片的电影图像。