Learning Brain Connectivity of Alzheimer's Disease from Neuroimaging Data
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Transcript of Learning Brain Connectivity of Alzheimer's Disease from Neuroimaging Data
Learning Brain Connectivity of Alzheimer's Disease from Neuroimaging Data Shui Huang1, Jing Li1, Liang Sun1, Jun Liu1, Teresa Wu1, Kewei Chen2, Adam Fleisher2, Eric Reiman2, Jieping Ye1
1: Arizona State University, 2: Banner Alzheimer’s Institute
This work was sponsored by the
NSF.
• Literature suggests functional brain connectivity difference between AD and normal aging.• Existing functional connectivity studies have limitations: -Correlation-based methods capture only pair-wise info. -Most approaches are confirmative, not exploratory. -A small number of brain regions are focused on. -Thorough comparison between AD, MCI, and normal aging with statistical significant assessment is lacking. -fMRI data are mostly used, not PET
Introduction
Sparse Inverse Covariance Estimation (SICE)
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)( 1kC )( 2kC
kX 1 2 21 )()( 21 kk CC
Objective
• Build functional brain connectivity models of AD, MCI, and normal controls using a machine learning technique, called inverse covariance, based on ADNI-PET data.• Assess statistical significance of the connectivity difference and summarize the results.
Approach & Monotone Property
Monotone PropertyLet and be the sets of all the connectivity components of with and respectively. If , then .Intuitively, if two regions are connected (either directly or indirectly) at one level of sparseness, they will be connected at all lower levels of sparseness.
Results
Small λLarge λ λ3 λ2 λ1Small λLarge λ
AD MCI NC
• AD: between-lobe connectivity weaker than within-lobe con.• AD: left-right same region connectivity much weaker.• MCI: patterns not as distinct from normal controls as AD.
Observations:
AD MCI NC AD MCI NC AD MCI NC
Strong Connectivity Mild Connectivity Weak Connectivity
•Temporal: decreased connectivity in AD, decrease not significant in MCI.• Frontal: increased connectivity in AD (compensation), increase not significant in MCI.• Parietal, occipital: no significant difference.• Parietal-occipital: increased weak/mild con. in AD.• Frontal-occipital: decreased weak/mild con. in MCI.• Left-right: decreased strong con. in AD, not MCI.
Observations: