Campbell-Washburn Adrienne E, Zhang Hui, Siow Bernard M, Price Anthony N, Lythgoe Mark F, Ordidge Roger J, Thomas David L
Centre for Advanced Biomedical Imaging, Division of Medicine and Institute of Child Health, University College London, UK; Department of Medical Physics and Bioengineering, University College London, UK.
Magn Reson Med. 2013 Oct;70(4):1125-36. doi: 10.1002/mrm.24545. Epub 2012 Nov 20.
Myocardial blood flow (MBF) is an important indicator of cardiac tissue health, which can be measured using arterial spin labeling. This study aimed to develop a new method of MBF quantification with blood pool magnetization measurement ("bpMBF quantification") that allows multislice cardiac arterial spin labeling.
A multislice segmented ECG-gated Look-Locker T1 mapping sequence was validated. Quantification of multislice arterial spin labeling is not straightforward due to the large volume of blood inverted following slice-selective inversion. For bpMBF quantification, a direct measurement of the left-ventricle blood pool magnetization was used to approximate the blood input function into the Bloch equations. Simulations and in vivo measurements in the mouse heart were performed to evaluate the bpMBF method.
Measurements indicated that blood pool magnetization requires ∼3 s to return to equilibrium following slice-selective inversion. Simulation and in vivo results show that bpMBF quantification is robust to variations in slice-selective thickness and therefore applicable to multislice acquisition, whereas traditional methods are likely to underestimate multislice perfusion. In vivo, single and multislice perfusion values matched well when quantified using bpMBF.
The first multislice cardiac arterial spin labeling technique has been presented, which can be used for accurate perfusion measurements in studies of cardiac disease.
心肌血流量（MBF）是心脏组织健康的重要指标，可通过动脉自旋标记进行测量。本研究旨在开发一种利用血池磁化测量进行MBF定量的新方法（“bpMBF定量”），该方法可实现多层心脏动脉自旋标记。
验证了一种多层分段心电图门控Look-Locker T1映射序列。由于切片选择性反转后有大量血液被反转，多层动脉自旋标记的定量并不简单。对于bpMBF定量，直接测量左心室血池磁化以近似布洛赫方程中的血液输入函数。在小鼠心脏中进行了模拟和体内测量，以评估bpMBF方法。
测量表明，切片选择性反转后，血池磁化需要约3秒才能恢复平衡。模拟和体内结果表明，bpMBF定量对切片选择性厚度的变化具有鲁棒性，因此适用于多层采集，而传统方法可能会低估多层灌注。在体内，使用bpMBF进行定量时，单层和多层灌注值匹配良好。
已提出首个多层心脏动脉自旋标记技术，可用于心脏病研究中的准确灌注测量。
