title: Metabolic connectivity by interregional correlation analysis using statistical parametric mapping (SPM) and FDG brain PET; methodological development and patterns of metabolic connectivity in adults.
abstract: OBJECTIVE
  Regionally connected areas of the resting brain can be detected by fluorodeoxyglucose-positron emission tomography (FDG-PET). Voxel-wise metabolic connectivity was examined, and normative data were established by performing interregional correlation analysis on statistical parametric mapping of FDG-PET data.
  
  
  METHODS
  Characteristics of seed volumes of interest (VOIs) as functional brain units were represented by their locations, sizes, and the independent methods of their determination. Seed brain areas were identified as population-based gyral VOIs (n = 70) or as population-based cytoarchitectonic Brodmann areas (BA; n = 28). FDG uptakes in these areas were used as independent variables in a general linear model to search for voxels correlated with average seed VOI counts. Positive correlations were searched in entire brain areas.
  
  
  RESULTS
  In normal adults, one third of gyral VOIs yielded correlations that were confined to themselves, but in the others, correlated voxels extended to adjacent areas and/or contralateral homologous regions. In tens of these latter areas with extensive connectivity, correlated voxels were found across midline, and asymmetry was observed in the patterns of connectivity of left and right homologous seed VOIs. Most of the available BAs yielded correlations reaching contralateral homologous regions and/or neighboring areas. Extents of metabolic connectivity were not found to be related to seed VOI size or to the methods used to define seed VOIs.
  
  
  CONCLUSIONS
  These findings indicate that patterns of metabolic connectivity of functional brain units depend on their regional locations. We propose that interregional correlation analysis of FDG-PET data offers a means of examining voxel-wise regional metabolic connectivity of the resting human brain.
authors.affiliation: Department of Nuclear Medicine, Seoul National University, College of Medicine, 28 Yeongeon-dong, Jongno-gu, Seoul, Korea. dsl@plaza.snu.ac.kr
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Lee
authors.forename: Hyejin
authors.initials: H
authors.lastname: Kang
authors.forename: Heejung
authors.initials: H
authors.lastname: Kim
authors.forename: Hyojin
authors.initials: H
authors.lastname: Park
authors.forename: Jungsu S
authors.initials: JS
authors.lastname: Oh
authors.forename: Jae Sung
authors.initials: JS
authors.lastname: Lee
authors.forename: Myung Chul
authors.initials: MC
authors.lastname: Lee
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods* / Q000706:statistics & numerical data*
chemical_list: D019788:Fluorodeoxyglucose F18