title: Manual segmentation qualification platform for the EADC-ADNI harmonized protocol for hippocampal segmentation project.
abstract: BACKGROUND
  The use of hippocampal volumetry as a biomarker for Alzheimer's disease (AD) requires that tracers from different laboratories comply with the same segmentation method. Here we present a platform for training and qualifying new tracers to perform the manual segmentation of the hippocampus on magnetic resonance images (MRI) following the European Alzheimer's Disease Consortium and Alzheimer's Disease Neuroimaging Initiative (EADC-ADNI) Harmonized Protocol (HarP). Our objective was to demonstrate that the training process embedded in the platform leads to increased compliance and qualification with the HarP.
  
  
  METHODS
  Thirteen new tracers' segmentations were compared with benchmark images with respect to: (a) absolute segmentation volume; (b) spatial overlap of contour with the reference using the Jaccard similarity index; and (c) spatial distance of contour with the reference. Point by point visual feedback was provided through three training phases on 10 MRI. Tracers were then tested on 10 different MRIs in the qualification phase.
  
  
  RESULTS
  Statistical testing of training over three phases showed a significant increase of Jaccard (i.e. mean Jaccard overlap P < .001) between phases on average for all raters, demonstrating that training positively increased compliance with the HarP. Based on these results we defined qualification thresholds which all tracers were able to meet.
  
  
  CONCLUSIONS
  This platform is an adequate infrastructure allowing standardized training and evaluation of tracers' compliance with the HarP. This is a necessary step allowing the use of hippocampal volumetry as a biomarker for AD in clinical and research centers.
authors.affiliation: Department of Radiology, Université Laval and Centre de Recherche de l'Institut universitaire en santé mentale de Québec, Quebec City, Canada. Electronic address: simon.duchesne@crulrg.ulaval.ca.
authors.forename: Simon
authors.initials: S
authors.lastname: Duchesne
authors.affiliation: Department of Radiology, Université Laval and Centre de Recherche de l'Institut universitaire en santé mentale de Québec, Quebec City, Canada.
authors.forename: Fernando
authors.initials: F
authors.lastname: Valdivia
authors.affiliation: Department of Radiology, Université Laval and Centre de Recherche de l'Institut universitaire en santé mentale de Québec, Quebec City, Canada.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Robitaille
authors.affiliation: Department of Radiology, Université Laval and Centre de Recherche de l'Institut universitaire en santé mentale de Québec, Quebec City, Canada.
authors.forename: Abderazzak
authors.initials: A
authors.lastname: Mouiha
authors.affiliation: Department of Radiology, Université Laval and Centre de Recherche de l'Institut universitaire en santé mentale de Québec, Quebec City, Canada.
authors.forename: F Abiel
authors.initials: FA
authors.lastname: Valdivia
authors.affiliation: LENITEM (Laboratory of Epidemiology, Neuroimaging and Telemedicine) IRCCS - S. Giovanni di Dio - Fatebenefratelli, Brescia, Italy; Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy.
authors.forename: Martina
authors.initials: M
authors.lastname: Bocchetta
authors.affiliation: Mary S. Easton Center for Alzheimer's Disease Research and Laboratory of NeuroImaging, David Geffen School of Medicine, University of California, Los Angeles, USA.
authors.forename: Liana G
authors.initials: LG
authors.lastname: Apostolova
authors.affiliation: Department of Radiology, Université Laval and Centre de Recherche de l'Institut universitaire en santé mentale de Québec, Quebec City, Canada.
authors.forename: Rossana
authors.initials: R
authors.lastname: Ganzola
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic and Foundation, Rochester, MN, USA.
authors.forename: Greg
authors.initials: G
authors.lastname: Preboske
authors.affiliation: Klinik für Psychiatrie und Psychotherapie, Johannes Gutenberg-Universität, Mainz, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: Wolf
authors.affiliation: LENITEM (Laboratory of Epidemiology, Neuroimaging and Telemedicine) IRCCS - S. Giovanni di Dio - Fatebenefratelli, Brescia, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Boccardi
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic and Foundation, Rochester, MN, USA.
authors.forename: Clifford R
authors.initials: CR
authors.lastname: Jack
authors.affiliation: LENITEM (Laboratory of Epidemiology, Neuroimaging and Telemedicine) IRCCS - S. Giovanni di Dio - Fatebenefratelli, Brescia, Italy; University Hospitals and University of Geneva, Geneva, Switzerland.
authors.forename: Giovanni B
authors.initials: GB
authors.lastname: Frisoni
mesh_terms: D000544:Alzheimer Disease / Q000473:pathology; D060825:Cognitive Dysfunction / Q000473:pathology; D006624:Hippocampus / Q000033:anatomy & histology / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D007318:Inservice Training / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009929:Organ Size; D015203:Reproducibility of Results
keywords: Alzheimer's disease; Area; Harmonized protocol; Hippocampal segmentation; Magnetic resonance imaging; Qualification platform; Qualitative criteria; Quantitative criteria; Spatial distance; Spatial overlap