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P2‐252: Cerebral blood flow changes in early Alzheimer's disease: A high‐field arterial spin labeling perfusion MRI study
Author(s) -
Song Xiaowei,
Wei Chen,
D'Arcy Ryan,
Beyea Steven,
Liu Careesa,
Major Alma,
Darvesh Sultan,
Rockwood Kenneth
Publication year - 2012
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2012.05.960
Subject(s) - perfusion , cerebral blood flow , arterial spin labeling , perfusion scanning , medicine , posterior cingulate , cerebral perfusion pressure , cardiology , temporal cortex , nuclear medicine , neuroscience , psychology , radiology , functional magnetic resonance imaging
Background: Recent research has suggested that Alzheimer’s disease (AD) is associated with significant cerebral circulation abnormalities, in addition to the hallmark neurodegenerative changes. While decline in cerebral perfusion in localized brain regions has been well documented in established AD, hyperperfusion has also been observed at the early stages, which has not been well studied. We investigated both hypoperfusion and hyperperfusion perfusion changes in early AD, using arterial spin labeling perfusion MRI at high-field. Methods: Twelve patients with early AD (72.3 6 7.9 years old; 5 women) and 12 cognitively normal older adults (CN, 73.7 6 5.5 years old, 9 women) were scanned using 4 Tesla MRI (Varian-Oxford human imaging system). Flow-sensitive alternating inversion recovery imaging (FAIR) was acquired using the arterial spin labeling (ASL) perfusion weighted imaging method (seven interleaved axial slices, thickness 1⁄4 5mm, gap 1⁄4 2mm, TR/TE/TI 1⁄4 2800/3/1400ms). Subjects were asked to remain relaxed with their eyes open during a seven-minute scan. High-resolution whole brain structural images were acquired using MP-FLASH (TR/TE 1⁄4 10.1/5ms, thickness 1⁄4 1.2mm). Data processing included motion correction, spatial smoothing, registration of non-selective and selective slices, and brain segmentation (using FSL and SPM5). Analysis outcomes were adjusted for age, sex, education level, structural brain changes, and cognitive performance. Results: Compared to CN, early AD patients showed significant hypoperfusion chiefly in the left precuenus, the right superior temporal cortex, and the posterior cingulate cortex. Meanwhile, relative to CN, in AD, significant hyperperfusion was found in the right dorsolateral prefrontal cortex (DLPFC) and the left anterior cingulate cortex, as well as in the left DLPFC and the ventrolateral prefrontal cortex (VLPFC). Conclusions: Early AD appears to be characterized by both hypoperfusion and hyperperfusion in well-defined brain regions, correlating with the underlying neuropathological processes. The increased resting-state cerebral blood flow in the DLPFC and in the VLPFC suggests a possible compensatory mechanism to maintain important neural networks, such as the attentional neural network, in early stages of AD.