Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK.
Magn Reson Med. 2010 Jun;63(6):1627-36. doi: 10.1002/mrm.22387.
Flow-sensitive alternating inversion recovery arterial spin labeling with parallel imaging acquisition is used to acquire single-shot, multislice perfusion maps of the kidney. A considerable problem for arterial spin labeling methods, which are based on sequential subtraction, is the movement of the kidneys due to respiratory motion between acquisitions. The effects of breathing strategy (free, respiratory-triggered and breath hold) are studied and the use of background suppression is investigated. The application of movement correction by image registration is assessed and perfusion rates are measured. Postacquisition image realignment is shown to improve visual quality and subsequent perfusion quantification. Using such correction, data can be collected from free breathing alone, without the need for a good respiratory trace and in the shortest overall acquisition time, advantageous for patient comfort. The addition of background suppression to arterial spin labeling data is shown to reduce the perfusion signal-to-noise ratio and underestimate perfusion.
采用带并行采集的流敏感交替反转恢复动脉自旋标记技术可单次采集肾脏多层面灌注图。基于序列减影的动脉自旋标记方法存在一个突出问题，即在采集过程中肾脏会因呼吸运动而移动。本研究探讨了呼吸策略（自由呼吸、呼吸触发和屏气）的影响，并研究了背景抑制的应用。评估了图像配准运动校正的应用，并测量了灌注率。图像后配准校正可提高视觉质量，有助于后续的灌注定量分析。采用这种校正方法，仅需自由呼吸即可采集数据，无需良好的呼吸轨迹，并且总的采集时间最短，有利于提高患者舒适度。动脉自旋标记数据中添加背景抑制会降低灌注信号噪声比并低估灌注。
