title: Predicting progression from mild cognitive impairment to Alzheimer's disease using longitudinal callosal atrophy.
abstract: BACKGROUND
  We investigate whether longitudinal callosal atrophy could predict conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD).
  
  
  METHODS
  Longitudinal (baseline + 1-year follow-up) MRI scans of 132 MCI subjects from the Alzheimer's Disease Neuroimaging Initiative were used. A total of 54 subjects did not convert to AD over an average (±SD) follow-up of 5.46 (±1.63) years, whereas 78 converted to AD with an average conversion time of 2.56 (±1.65) years. Annual change in the corpus callosum thickness profile was calculated from the baseline and 1-year follow-up MRI. A logistic regression model with fused lasso regularization for prediction was applied to the annual changes.
  
  
  RESULTS
  We found a sex difference. The accuracy of prediction was 84% in females and 61% in males. The discriminating regions of corpus callosum differed between sexes. In females, the genu, rostrum, and posterior body had predictive power, whereas the genu and splenium were relevant in males.
  
  
  CONCLUSIONS
  Annual callosal atrophy predicts MCI-to-AD conversion in females more accurately than in males.
authors.affiliation: Center for Biomedical Imaging and Neuromodulation, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA.
authors.forename: Sang Han
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Center for Biomedical Imaging and Neuromodulation, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA.
authors.forename: Alvin H
authors.initials: AH
authors.lastname: Bachman
authors.affiliation: Department of Statistics, Keimyung University, Daegu, South Korea.
authors.forename: Donghyeon
authors.initials: D
authors.lastname: Yu
authors.affiliation: Department of Statistics, Seoul National University, Seoul, South Korea.
authors.forename: Johan
authors.initials: J
authors.lastname: Lim
authors.affiliation: Center for Biomedical Imaging and Neuromodulation, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA; Department of Psychiatry, New York University School of Medicine, New York, NY, USA.
authors.forename: Babak A
authors.initials: BA
authors.lastname: Ardekani
keywords: Alzheimer's disease; Brain; Corpus callosum; Longitudinal analysis; Magnetic resonance imaging; Mild cognitive impairment; Shape analysis