title: Mild cognitive impairment: differential atrophy in the hippocampal subfields.
abstract: OBJECTIVE
  Hippocampus volumetry is a useful surrogate marker for the diagnosis of Alzheimer disease, but it seems insufficiently sensitive for the aMCI stage. We postulated that some hippocampus subfields are specifically atrophic in aMCI and that measuring hippocampus subfield volumes will improve sensitivity of MR imaging to detect aMCI.
  
  
  METHODS
  We evaluated episodic memory and hippocampus subfield volume in 15 patients with aMCI and 15 matched controls. After segmentation of the whole hippocampus from clinical MR imaging, we applied a new computational method allowing fully automated segmentation of the hippocampus subfields. This method used a Bayesian modeling approach to infer segmentations from the imaging data.
  
  
  RESULTS
  In comparison with controls, subiculum and CA2-3 were significantly atrophic in patients with aMCI, whereas total hippocampus volume and other subfields were not. Total hippocampus volume in controls was age-related, whereas episodic memory was the main explanatory variable for both the total hippocampus volume and the subfields that were atrophic in patients with aMCI. Segmenting subfields increases sensitivity to diagnose aMCI from 40% to 73%.
  
  
  CONCLUSIONS
  Measuring CA2-3 and subiculum volumes allows a better detection of aMCI.
authors.affiliation: Department of Neurology, Saint-Luc University Hospital, Brussels, Belgium. bernard.hanseeuw@uclouvain.be
authors.forename: B J
authors.initials: BJ
authors.lastname: Hanseeuw
authors.forename: K
authors.initials: K
authors.lastname: Van Leemput
authors.forename: M
authors.initials: M
authors.lastname: Kavec
authors.forename: C
authors.initials: C
authors.lastname: Grandin
authors.forename: X
authors.initials: X
authors.lastname: Seron
authors.forename: A
authors.initials: A
authors.lastname: Ivanoiu
mesh_terms: D000544:Alzheimer Disease / Q000473:pathology; D001284:Atrophy / Q000473:pathology; D001499:Bayes Theorem; D056651:CA2 Region, Hippocampal / Q000473:pathology*; D056654:CA3 Region, Hippocampal / Q000473:pathology*; D060825:Cognitive Dysfunction / Q000473:pathology* / Q000503:physiopathology; D018891:Dentate Gyrus / Q000473:pathology; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D061212:Memory, Episodic; D008959:Models, Neurological; D009483:Neuropsychological Tests; D012680:Sensitivity and Specificity