Diagnostic Value of Multi‐delay Multi‐parametric 3D pCASL in Early Alzheimer' Disease

Abstract Background Single post‐labeling delay (PLD) pseudo‐continuous arterial spin‐labeling (pCASL) measures cerebral blood Flow (CBF). The altered CBF is associated with cognitive decline in early Alzheimer’s disease (AD). However, multi‐delay pCASL that measures multi‐parametric measurements including CBF, arterial cerebral blood volume (aCBV) and arterial transit time (ATT) has rarely been applied to AD studies and its diagnostic performance to recognize AD in early stage remains unclear. The purpose of this study is to compare the diagnostic value between the CBF measured by single PLD pCASL and the CBF/aCBV/ATT measured by multi‐PLD pCASL for early‐stage AD. Method Both 1 PLD and 7 PLD 3D pCASL protocols on 3T GE scanner were performed within one MR session for 26 cognitively normal (CN), 37 mild cognitive impairment (MCI) and 39 AD subjects who were recruited in Chinese Imaging, Biomarkers, and Lifestyle Study of Ageing Project (CIBL) from April to October 2021. Comparisons on CBF/aCBV/ATT in 10 regions of interest (ROIs), including left and right regions of olfactory, post cingulate, hippocampus, cuneus and precuneus, were performed across different groups. The area under the curve (AUC) were assessed through receiver operating characteristic (ROC) analysis. Result All ROIs showed significant decrease in CBF and increase in ATT of AD groups compared with that of CN and MCI groups (P < 0.05). There was no significant difference in aCBV between groups and CBF/ATT between CN and MCI (P > 0.05). The area under the ROC curve (AUC) of CBF in ROIs for both3D pCASL protocols was similar for discriminating AD against HC (0.949 vs. 0.965 for 1 PLD vs. 7 PLD, respectively), AD against MCI (0.836 vs. 0.830), MCI against HC (0.686 vs. 0.786). However, the combination of CBF/aCBV/ATT in ROIs measured by 7 PLD 3D pCASL could significantly improve diagnostic performance, which AUC was 1.000, 0.967 and 0.918 for identifying AD against HC, AD against MCI and MCI against HC respectively. Conclusion Multi‐parametric perfusion data from multi‐delay pCASL can improve the diagnostic value of AD in early stage, which could be a promising imaging biomarker in AD patients.