Li Zhiqiang, Schär Michael, Wang Dinghui, Zwart Nicholas R, Madhuranthakam Ananth J, Karis John P, Pipe James G
Imaging Research, Barrow Neurological Institute, Phoenix, Arizona, USA.
Philips Healthcare, Cleveland, Ohio, USA.
Magn Reson Med. 2016 Jan;75(1):266-73. doi: 10.1002/mrm.25645. Epub 2015 Mar 5.
The three-dimensional (3D) spiral turbo spin echo (TSE) sequence is one of the preferred readout methods for arterial spin labeled (ASL) perfusion imaging. Conventional spiral TSE collects the data using a spiral-out readout on a stack of spirals trajectory. However, it may result in suboptimal image quality and is not flexible in protocol design. The goal of this study is to provide a more robust readout technique without such limitation.
The proposed technique incorporates a spiral-in/out readout into 3D TSE, and collects the data on a distributed spirals trajectory. The data set is split into the spiral-in and -out subsets that are reconstructed separately and combined after image deblurring.
The volunteer results acquired with the proposed technique show no geometric distortion or signal pileup, as is present with GRASE, and no signal loss, as is seen with conventional spiral TSE. Examples also demonstrate the flexibility in changing the imaging parameters to satisfy various criteria.
The 3D TSE with a distributed spiral-in/out trajectory provides a robust readout technique and allows for easy protocol design, thus is a promising alternative to GRASE or conventional spiral TSE for ASL perfusion imaging.
三维（3D）螺旋涡轮自旋回波（TSE）序列是动脉自旋标记（ASL）灌注成像的首选读出方法之一。传统的螺旋TSE在一堆螺旋轨迹上使用螺旋向外读出方式采集数据。然而，这可能导致图像质量欠佳，并且在协议设计上缺乏灵活性。本研究的目的是提供一种没有此类限制的更稳健的读出技术。
所提出的技术将螺旋向内/向外读出方式纳入3D TSE，并在分布式螺旋轨迹上采集数据。数据集被分割为螺旋向内和向外子集，分别进行重建，并在图像去模糊后合并。
用所提出的技术获得的志愿者结果显示，没有像梯度回波采集单次激发快速自旋回波（GRASE）那样的几何失真或信号堆积，也没有像传统螺旋TSE那样的信号丢失。示例还展示了在改变成像参数以满足各种标准方面的灵活性。
具有分布式螺旋向内/向外轨迹的3D TSE提供了一种稳健的读出技术，并允许轻松进行协议设计，因此对于ASL灌注成像而言，是GRASE或传统螺旋TSE的一个有前景的替代方法。
