INTRODUCTIONAlzheimer's disease (AD) typically involves both neurodegenerative and vascular pathologies, each associated with reductions in cerebral blood flow (CBF). However, it remains unclear whether vascular and neural contributions to regional CBF can be differentiated.METHODSUsing 3D background‐suppressed arterial spin labeled perfusion magnetic resonance imaging, we evaluated regional CBF in a cohort of 257 participants across the AD continuum and assessed the impact of risk factors for both AD and small vessel disease (SVD) on regional CBF.RESULTSVascular risk factors (VRFs) were associated with reduced CBF in normal‐appearing periventricular white matter, while amyloid positivity was associated with reduced CBF in the posterior cingulate cortex and precuneus. Putative SVD‐sensitive regions in white matter exhibited diagnosis‐related CBF changes comparable to those in typical AD cortical regions.DISCUSSIONSpatial patterns of hypoperfusion may differentiate AD and VRF‐related effects on regional CBF. Our findings also support the contribution of SVD in AD pathogenesis.Highlights We used 3D background‐suppressed pCASL MRI to evaluate CBF across the AD continuum. Putative SVD‐sensitive regions in white matter exhibited diagnosis‐related CBF changes. AD and/or SVD risk correlated with reduced CBF in AD and/or SVD‐related regions. VRFs were associated with more widespread CBF reductions than amyloid positivity. Spatial patterns of hypoperfusion may differentiate AD and VRF‐related effects.

中文翻译：

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区域脑血流反映了阿尔茨海默病连续体中的神经退行性和微血管完整性


引言阿尔茨海默病 （AD） 通常涉及神经退行性和血管病变，每一种都与脑血流量 （CBF） 的减少有关。然而，目前尚不清楚血管和神经对区域 CBF 的贡献是否可以区分。方法利用 3D 背景抑制的动脉自旋标记灌注磁共振成像，我们评估了 AD 连续体中 257 名参与者的队列中的区域 CBF，并评估了 AD 和小血管病 （SVD） 危险因素对区域 CBF 的影响。结果血管危险因素 （VRFs） 与外观正常的脑室周围白质 CBF 降低相关，而淀粉样蛋白阳性与后扣带皮层和楔前叶 CBF 降低相关。白质中推定的 SVD 敏感区域表现出与诊断相关的 CBF 变化，与典型的 AD 皮质区域相当。讨论低灌注的空间模式可能区分 AD 和 VRF 相关对区域 CBF 的影响。我们的研究结果还支持 SVD 在 AD 发病机制中的作用。亮点 我们使用 3D 背景抑制的 pCASL MRI 来评估整个 AD 连续体的 CBF。白质中推定的 SVD 敏感区域表现出与诊断相关的 CBF 变化。AD 和/或 SVD 风险与 AD 和/或 SVD 相关区域的 CBF 降低相关。VRFs 与淀粉样蛋白阳性更广泛的 CBF 降低相关。灌注不足的空间模式可以区分 AD 和 VRF 相关效应。