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IC‐P2‐114: Meta‐analysis ROIs and minimal deformation templates improve PET‐FDG as a candidate biomarker in Alzheimer's disease
Author(s) -
Madison Cindee,
Landau Susan,
Cheung Connie,
Lal Rayhan,
Foster Norman,
Reiman Eric,
Koeppe Robert,
Weiner Michael,
Jagust William
Publication year - 2008
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.2008.05.2569
Subject(s) - posterior cingulate , neuroimaging , alzheimer's disease , fluorodeoxyglucose , positron emission tomography , preprocessor , imaging biomarker , nuclear medicine , cognitive impairment , artificial intelligence , pattern recognition (psychology) , medicine , computer science , magnetic resonance imaging , pathology , psychology , disease , radiology , neuroscience , functional magnetic resonance imaging
Background: Research consistently finds hypometabolism of [18F]Fluorodeoxyglucose (FDG-PET) in patients diagnosed with Alzheimer’s Disease (AD). Identifying abnormalities in metabolism requires precise delineation of affected areas in order to maximize differences between groups, detect change over time and minimize variance. We generated meta-analysis ROIs (MetaROIs) from frequently cited coordinates in existing studies, and compared these regions with standard anatomical ROIs across three image preprocessing streams in order to identify potential bio-marker regions using data from the Alzheimer’s Disease Neuroimaging Initiative (AD 13), (Normal 12). Methods: Six terms relating to FDG-PET, AD, and Mild Cognitive Impairment (MCI) were used to search PubMed, resulting in 18 cross-sectional studies. Study coordinates were used to generate MetaROIs. A minimal deformation template (MDT) was generated for each group (AD, MCI, Normal), using high-resolution MR images, based on the method by Kochonuv et al. (2001). Preprocessing was done with three methods: (1) individual FDG-PET images were spatially normalized to the MNI FDG template, (2) individual MR images were spatially normalized to a group-specific template, then this transformation was applied to individual coregistered FDG-PET images, (3) same as (2) but additionally the FDG-PET image was masked with an individual gray-matter mask. Effect size and percent annual change delineated the most effective processing stream. Results: MetaROIs included frequently cited regions in bilateral posterior cingulate, bilateral angular gyri, and primarily left-sided frontal and temporal regions. MetaROIs exhibited larger mean group difference between AD and Normals compared to corresponding AAL MNI regions (effect size in posterior cingulate increased from 0.48 to 1.82). Normalization to MDT template further improved effect size by 7-15%. MetaROIs also increased twelve month percent change in AD patients (posterior cingulate increased from 8% to 11%). The same region in normals showed little change (MNI ROI 0.4% vs MetaROI 0.3%). Conclusions: The use of research-defined MetaROIs, along with a processing stream that reduced deformation and used individual gray matter masks, greatly improved the viability of FDG-PET as a candidate biomarker in AD.