title: Assessing the performance of atlas-based prefrontal brain parcellation in an aging cohort.
abstract: OBJECTIVE
  It is unclear whether atlas-based parcellation is suitable in aging cohorts because age-related brain changes confound the performance of automatic methods. We assessed atlas-based parcellation of the prefrontal lobe in an aging population using visual assessment and volumetric and spatial concordance.
  
  
  METHODS
  We used an atlas-based approach to parcellate brain MR images of 90 non-demented healthy adults, aged 72.7 ± 0.7 years, and assessed performance.
  
  
  RESULTS
  Volumetric assessment showed that both single-atlas- and multi-atlas-based methods performed acceptably (intraclass correlation coefficient [ICC], 0.74-0.76). Spatial overlap measurements showed that multi-atlas (dice coefficient [DC], 0.84) offered an improvement over the single-atlas (DC, 0.75-0.78) approach. Visual assessment also showed that multi-atlas outperformed single atlas and identified an additional postprocessing step of cerebrospinal fluid removal, enhancing concordance (intraclass correlation coefficient, 0.86; DC, 0.89).
  
  
  CONCLUSIONS
  Atlas-based parcellation performed reasonably well in the aging population. Rigorous performance assessment aided method refinement and emphasizes the importance of age matching and postprocessing. Further work is required in more varied subjects.
authors.affiliation: Brain Research Imaging Centre, Department of Clinical Neurosciences, University of Edinburgh, Western General Hospital, Edinburgh, UK. benjamin.aribisala@ed.ac.uk
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Aribisala
authors.forename: Simon R
authors.initials: SR
authors.lastname: Cox
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Ferguson
authors.forename: Sarah E
authors.initials: SE
authors.lastname: MacPherson
authors.forename: Alasdair M J
authors.initials: AM
authors.lastname: MacLullich
authors.forename: Natalie A
authors.initials: NA
authors.lastname: Royle
authors.forename: Maria C
authors.initials: MC
authors.lastname: Valdés Hernández
authors.forename: Mark E
authors.initials: ME
authors.lastname: Bastin
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Deary
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Wardlaw
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D015331:Cohort Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D017397:Prefrontal Cortex / Q000033:anatomy & histology*; D015203:Reproducibility of Results; D012606:Scotland