title: Semi-automated hippocampal segmentation in people with cognitive impairment using an age appropriate template for registration.
abstract: BACKGROUND
  To evaluate a new semi-automated segmentation method for calculating hippocampal volumes and to compare results with standard software tools in a cohort of people with subjective memory complaints (SMC) and mild cognitive impairment (MCI).
  
  
  METHODS
  Data from 58 participants, 39 with SMC (17 male, 22 female, mean age 72.6) and 19 with MCI (6 male, 13 female, mean age 74.3), were analyzed. For each participant, T1-weighted images were acquired using an MPRAGE sequence on a 3 Tesla MRI system. Hippocampal volumes (left, right, and total) were calculated with a new, age appropriate registration template, based on older people and using the advanced software tool ANTs (Advanced Normalization Tools). The results were compared with manual tracing (seen as the reference standard) and two widely accepted automated software tools (FSL, FreeSurfer).
  
  
  RESULTS
  The hippocampal volumes, calculated by using the age appropriate registration template were significantly (P < 0.05) more accurate (mean volume accuracy more than 90%) than those obtained with FreeSurfer and FSL (both less than 70%). Dice coefficients for the hippocampal segmentations with the new template method (75.3%) were slightly, but significantly (P < 0.05) higher than those from FreeSurfer (72.4%).
  
  
  CONCLUSIONS
  These results suggest that an age appropriate registration template might be a more accurate alternative to calculate hippocampal volumes when manual segmentation is not feasible.
authors.affiliation: Department of Radiology, The University of Melbourne, Melbourne, Victoria.|Department of Radiology, The Royal Melbourne Hospital, Melbourne, Victoria.
authors.forename: Bernd
authors.initials: B
authors.lastname: Merkel
authors.affiliation: Department of Radiology, The University of Melbourne, Melbourne, Victoria.|Department of Radiology, The Royal Melbourne Hospital, Melbourne, Victoria.
authors.forename: Christopher
authors.initials: C
authors.lastname: Steward
authors.affiliation: Department of Medicine, The University of Melbourne, Melbourne, Victoria.
authors.forename: Lucy
authors.initials: L
authors.lastname: Vivash
authors.affiliation: Melbourne School of Psychological Sciences, The University of Melbourne, Melbourne, Victoria.
authors.forename: Charles B
authors.initials: CB
authors.lastname: Malpas
authors.affiliation: Department of Radiology, The University of Melbourne, Melbourne, Victoria.|Department of Radiology, The Royal Melbourne Hospital, Melbourne, Victoria.
authors.forename: Pramit
authors.initials: P
authors.lastname: Phal
authors.affiliation: Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria.
authors.forename: Bradford A
authors.initials: BA
authors.lastname: Moffat
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia.
authors.forename: Kay L
authors.initials: KL
authors.lastname: Cox
authors.affiliation: Academic Unit for Psychiatry of Old Age, Department of Psychiatry, St. Vincent's Health, The University of Melbourne, Kew, Victoria.
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Ellis
authors.affiliation: Academic Unit for Psychiatry of Old Age, Department of Psychiatry, St. Vincent's Health, The University of Melbourne, Kew, Victoria.|National Ageing Research Institute, Parkville, Victoria.
authors.forename: David J
authors.initials: DJ
authors.lastname: Ames
authors.affiliation: National Ageing Research Institute, Parkville, Victoria.
authors.forename: Elizabeth V
authors.initials: EV
authors.lastname: Cyarto
authors.affiliation: National Ageing Research Institute, Parkville, Victoria.
authors.forename: Michelle M Y
authors.initials: MM
authors.lastname: Lai
authors.affiliation: School of Health Sciences, University of Tasmania, Hobart, Tasmania.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Sharman
authors.affiliation: Department of Medicine, The University of Melbourne, Melbourne, Victoria.
authors.forename: Cassandra
authors.initials: C
authors.lastname: Szoeke
authors.affiliation: The Florey Institute, The University of Melbourne, Melbourne, Victoria.
authors.forename: Colin L
authors.initials: CL
authors.lastname: Masters
authors.affiliation: Academic Unit for Psychiatry of Old Age, Department of Psychiatry, St. Vincent's Health, The University of Melbourne, Kew, Victoria.|School of Psychiatry and Clinical Neurosciences & WA Centre for Health and Ageing, The University of Western Australia, Perth, Western Australia.
authors.forename: Nicola T
authors.initials: NT
authors.lastname: Lautenschlager
authors.affiliation: Department of Radiology, The University of Melbourne, Melbourne, Victoria.|Department of Radiology, The Royal Melbourne Hospital, Melbourne, Victoria.
authors.forename: Patricia
authors.initials: P
authors.lastname: Desmond
mesh_terms: D000368:Aged; D000375:Aging / Q000473:pathology*; D060825:Cognitive Dysfunction / Q000150:complications / Q000473:pathology*; D005260:Female; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008569:Memory Disorders / Q000150:complications / Q000473:pathology*; D010363:Pattern Recognition, Automated / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software; D013382:Subtraction Technique
keywords: Alzheimer's disease; hippocampus; magnetic resonance imaging; mild cognitive impairment; segmentation; subjective memory complaints