Discriminative Power of Arterial Spin Labelling Magnetic Resonance Imaging and F-18-Fluorodeoxyglucose Positron Emission Tomography Changes for Amyloid-beta-Positive Subjects in the Alzheimer%26apos;s Disease Continuum

作者：Tosun Duygu; Schuff Norbert; Jagust William; Weiner Michael W

来源：Neurodegenerative Diseases, 2016, 16(1-2): 87-94.

DOI：10.1159/000439257

• Alzheimer's disease
• Amyloid
• Amyloid-beta protein
• Brain
• Cerebral cortex
• Magnetic resonance imaging
• Neurodegeneration

Background: Recent studies have demonstrated that arterial spin labeling magnetic resonance imaging (ASL-MRI) and fluorodeoxyglucose positron emission tomography (FDG-PET) identify similar regional abnormalities and have comparable diagnostic accuracy in Alzheimer's disease (AD). The agreement between these modalities in the AD continuum, which is an important concept for early detection and disease monitoring, is yet unclear. Objective: We aimed to assess the ability of the cerebral blood flow (CBF) measures from ASL-MRI and cerebral metabolic rate for glucose (CMRgI) measures from FDG-PET to distinguish amyloid-Ppositive (A beta+) subjects in the AD continuum from healthy controls. Methods: The study included asymptomatic, cognitively normal (CN) controls and patients with early mild cognitive impairment (MCI), late MCI, and AD, all with sig-nificant levels of cortical AP based on their florbetapir PET scans to restrict the study to patients truly in the AD continuum. The discrimination power of each modality was based on the whole-brain patterns of CBF and CMRgI changes identified by partial least squares logistic regression, a multivariate analysis technique. Results: While CBF changes in the posterior inferior aspects of the brain and a pattern of CMRgI changes in the superior aspects of the brain including frontal and parietal regions best discriminated the A beta+ subjects in the early disease stages from the AP CN subjects, there was a greater agreement in the whole-brain patterns of CBF and CMRgI changes that best discriminated the A beta+ subjects from the AP CN subjects in the later disease stages. Despite the differences in the whole-brain patterns of CBF and CMRgI changes, the discriminative powers of both modalities were similar with statistically nonsignificant performance differences in sensitivity and specificity. Conclusion: The results comparing measurements of CBF to CMRgI add to previous reports that MRI-measured CBF has a similar diagnostic ability to detect AD as has FDG-PET. Our findings that CBF and CMRgI changes occur in different brain regions in A beta+ subjects across the AD continuum compared with A beta CN subjects may be the result of methodological differences. Alternatively, these findings may signal alterations in neurovascular coupling which alter relationships between brain perfusion and glucose metabolism in the AD continuum.

• 出版日期2016