Campbell Alison M, Beaulieu Christian
Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2V2.
J Magn Reson Imaging. 2006 Mar;23(3):398-403. doi: 10.1002/jmri.20503.
To optimize pulsed arterial spin labeling (PASL) parameters for the elderly to take into account possible perfusion changes that occur in the brain with age.
Healthy young (N = 14, age range = 21-27 years) and elderly (N = 12, age range = 61-67 years) subjects were scanned using Q2TIPS (QUIPSS II with thin-slice TI, periodic saturation) with varying inversion times (TI(2)) at 1.5T. The difference signal (DeltaM), transit time (deltat), and cerebral blood flow (CBF) were calculated in segmented gray matter (GM).
The young displayed more perfusion-weighted signal difference than the elderly at all TI(2)'s. The peak DeltaM occurred at TI(2) approximately 1300 msec and 1500 msec in the young and elderly groups, respectively. Qualitatively, intravascular signal was minimal in the younger group by TI(2) = 1500 msec, whereas a longer TI(2) of 1800 msec was needed to minimize this signal in the elderly. The transit time was approximately 100 msec longer in the elderly, and CBF was in the range of literature values.
For acquiring perfusion-weighted images with minimal intravascular signal and adequate tissue signal for PASL studies of cerebral perfusion in the elderly, a longer inversion time is advantageous.
考虑到随着年龄增长大脑可能发生的灌注变化，优化老年人的脉冲动脉自旋标记（PASL）参数。
对健康的年轻受试者（N = 14，年龄范围 = 21 - 27岁）和老年受试者（N = 12，年龄范围 = 61 - 67岁）在1.5T磁场下使用Q2TIPS（带有薄层TI的QUIPSS II，周期性饱和）进行扫描，采用不同的反转时间（TI(2)）。在分割的灰质（GM）中计算差异信号（DeltaM）、通过时间（deltat）和脑血流量（CBF）。
在所有TI(2)值下，年轻人显示出比老年人更多的灌注加权信号差异。年轻组和老年组的DeltaM峰值分别出现在TI(2)约1300毫秒和1500毫秒处。定性地说，在年轻组中，当TI(2) = 1500毫秒时血管内信号最小，而在老年人中需要更长的TI(2)值1800毫秒才能使该信号最小化。老年人的通过时间大约长100毫秒，CBF在文献值范围内。
对于在老年人脑灌注的PASL研究中获取具有最小血管内信号和足够组织信号的灌注加权图像，较长的反转时间是有利的。
