Department of Diagnostic Radiology & Nuclear Medicine, University of Maryland School of Medicine, HSF III Room 1173, 670 W Baltimore St, Baltimore, MD, 21201, USA.
Brain Imaging Behav. 2023 Jun;17(3):306-319. doi: 10.1007/s11682-023-00764-8. Epub 2023 Mar 27.
Arterial spin labeling (ASL) perfusion MRI has been increasingly used in Alzheimer's Disease (AD) research. However, ASL MRI sequences differ greatly in terms of arterial blood signal preparations and data acquisition strategies, both leading to a large difference of signal-to-noise ratio (SNR). It is of great translational importance to compare the several widely used ASL MRI sequences regarding sensitivity of ASL measured cerebral blood flow (CBF) for detecting the between-group difference across the AD continuum. To this end, this study compared three ASL MRI sequences in AD research, including the 2D Pulsed ASL (PASL), 3D Background Suppressed (BS) PASL, and 3D BS Pseudo-Continuous ASL (PCASL). We used data from 100 healthy and cognitively normal elderly control (NC) subjects, 75 patients with mild cognitive impairment (MCI), and 57 Alzheimer's disease (AD) subjects from the AD neuroimaging initiative (ADNI). Both cross-sectional perfusion difference and perfusion versus clinical assessment correlations were examined. The major findings included: 3D PCASL sequence identified stronger patient versus control CBF/rCBF differences than 2D PASL and 3D PASL; MCI showed reduced CBF and CBF redistribution; CBF in orbito-frontal cortex presents a new U-shape change pattern from normal aging to MCI and to AD; 3D PCASL identified a negative rCBF to memory correlation while 2D PASL showed a positive correlation.
动脉自旋标记（ASL）灌注 MRI 已越来越多地用于阿尔茨海默病（AD）的研究。然而，ASL MRI 序列在动脉血信号准备和数据采集策略方面存在很大差异，这两者都导致了信噪比（SNR）的很大差异。比较几种广泛使用的 ASL MRI 序列对于测量 ASL 测量的脑血流（CBF）的敏感性以检测 AD 连续体中的组间差异具有重要的转化意义。为此，本研究比较了 AD 研究中的三种 ASL MRI 序列，包括 2D 脉冲 ASL（PASL）、3D 背景抑制（BS）PASL 和 3D BS 伪连续 ASL（PCASL）。我们使用了来自 AD 神经影像学倡议（ADNI）的 100 名健康和认知正常的老年对照组（NC）受试者、75 名轻度认知障碍（MCI）患者和 57 名 AD 患者的数据。我们检查了横断面灌注差异和灌注与临床评估的相关性。主要发现包括：3D PCASL 序列比 2D PASL 和 3D PASL 更能识别患者与对照组之间的 CBF/rCBF 差异；MCI 表现出 CBF 减少和 CBF 再分布；眶额皮层的 CBF 呈现出从正常衰老到 MCI 再到 AD 的新 U 形变化模式；3D PCASL 确定了 rCBF 与记忆的负相关，而 2D PASL 则显示出正相关。
