Comparison and repeatable study in magnetic resonance 3D arterial spin labeling imaging of different post labeling delay time

HU Jianbin; DAI Zhenyu; CHEN Fei; GAN Min; YAO Lizheng; YUAN Zhenzhou

Abstract：Objective To explore the difference of magnetic resonance (MR) 3D arterial spin labeling (3D-ASL) perfusion imaging in analysis of cerebral blood flow using different post labeling delay time (PLD) and to observe its repeatability.MethodsWe recruited 24 normal volunteers to do regular head MR scan and 3D-ASL examination with PLD=1.5 s and PLD=2.5 s twice in one week from August 2014 to July 2016.We imported ASL images to post-processing workstation to get the total cerebral blood flow (CBF) images, and selected regions of interesting (ROI) at bilateral symmetrical frontal, parietal, temporal and occipital lobe of cortex and white matter, cerebellum and brain stem on the CBF map, and recorded the CBF value of each ROI.We did intraclass correlation coefficient analysis of each regional cerebral CBF in two examinations and compared the difference of them.The difference of each regional cerebral CBF between PLD=1.5 s and PLD=2.5 s was compared at the same examination.Results There is no statistic difference of each regional cerebral CBF, and all ICC of CBF values of the frontal and temporal lobe of cortex and white matter are >0.75 and that of parietal and occipital lobe of cortex and white matter are between 0.4 to 0.75 in two 3D-ASL examination with PLD=1.5 s and PLD=2.5 s separately.ICC of most regional cerebral CBF are higher in examination with PLD=2.5 s.Each regional cerebral CBF in examination with PLD=2.5 s is lower than that in examination with PLD=1.5 s, however, there are statistic differences only in frontal, parietal, temporal and temporal lobe of cortex (all P<0.05).Conclusion 3D-ASL can quantitatively measure the CBF values of various brain regions with a high repeatability and clinical application value.The longer PLD has a higher repeatability and a lower estimated CBF value of cerebral cortex.