Bernard and Irene Schwartz Center for Biomedical Imaging, NYU School of Medicine, New York, New York.
Siemens Healthcare GmbH, Erlangen, Germany.
Magn Reson Med. 2019 May;81(5):2947-2958. doi: 10.1002/mrm.27609. Epub 2019 Jan 7.
To develop a flexible method for tracking respiratory and cardiac motions throughout MR and PET-MR body examinations that requires no additional hardware and minimal sequence modification.
The incorporation of a contrast-neutral rosette navigator module following the RF excitation allows for robust cardiorespiratory motion tracking with minimal impact on the host sequence. Spatial encoding gradients are applied to the FID signal and the desired motion signals are extracted with a blind source separation technique. This approach is validated with an anthropomorphic, PET-MR-compatible motion phantom as well as in 13 human subjects.
Both respiratory and cardiac motions were reliably extracted from the proposed rosette navigator in phantom and patient studies. In the phantom study, the MR-derived motion signals were additionally validated against the ground truth measurement of diaphragm displacement and left ventricle model triggering pulse.
The proposed method yields accurate respiratory and cardiac motion-state tracking, requiring only a short (1.76 ms) additional navigator module, which is self-refocusing and imposes minimal constraints on sequence design.
开发一种灵活的方法，用于在 MR 和 PET-MR 全身检查中跟踪呼吸和心脏运动，该方法不需要额外的硬件，并且对原始序列的修改最小。
在 RF 激发后加入一个对比度中性的梅花形导航模块，允许进行稳健的心肺运动跟踪，对主序列的影响最小。对 FID 信号施加空间编码梯度，并使用盲源分离技术提取所需的运动信号。该方法在人体运动模拟体模以及 13 名志愿者中进行了验证。
在体模和患者研究中，均可靠地从所提出的梅花形导航器中提取出呼吸和心脏运动。在体模研究中，MR 衍生的运动信号还通过对膈肌位移和左心室模型触发脉冲的地面真实测量进行了验证。
所提出的方法可实现准确的呼吸和心脏运动状态跟踪，仅需要一个短的（1.76ms）附加导航模块，该模块具有自聚焦功能，并且对序列设计的限制最小。
