Hypo- and Hyper-perfusion in MCI and AD Identified by Different ASL MRI Sequences

Abstract

Abstract Arterial spin labeling (ASL) perfusion MRI has been increasingly used in Alzheimer's Disease (AD) research. Because ASL implementations differ greatly in signal preparations and data acquisition strategies, both resulting in a large difference of signal-to-noise ratio (SNR), a comparison of different sequences that are widely available in major MR vendors is vital. The purpose of this study was to compare three types of commercial ASL MRI methods in Siemens and GE scanners: 2D Pulsed ASL (PASL), 3D Background Suppressed (BS) PASL, and 3D BS Pseudo-Continuous ASL (PCASL). We used data from 100 healthy control (NC), 75 mild cognitive impairment (MCI), and 57 Alzheimer’s disease (AD) subjects from the AD neuroimaging initiative (ADNI). Both cross-sectional perfusion difference and perfusion vs clinical assessment correlations were compared across the three types of data. Different perfusions change patterns were observed, being 3D + BS ASL more sensitive than 2D ASL and 3D PASL the most sensitive. Significant lower CBF were found in MCI compared with NC subjects in the left and right middle temporal gyrus, right cerebellum, and left postcentral gyrus; and significantly higher CBF in MCI compared to NC in the left and right precuneus, left middle temporal gyrus, and right calcarine gyrus. Significant lower CBF were found in AD compared with MCI in left and right cerebellum and right MCC, and significantly higher CBF in AD compared with MCI in left and right insula lobe, right thalamus, right calcarine gyrus, left and right thalamus, and right and left cerebellum.