title: Boosting diagnosis accuracy of Alzheimer's disease using high dimensional recognition of longitudinal brain atrophy patterns.
abstract: OBJECTIVE
  Boosting accuracy in automatically discriminating patients with Alzheimer's disease (AD) and normal controls (NC), based on multidimensional classification of longitudinal whole brain atrophy rates and their intermediate counterparts in analyzing magnetic resonance images (MRI).
  
  
  METHODS
  Longitudinal percentage of brain volume changes (PBVC) in two-year follow up and its intermediate counterparts in early 6-month and late 18-month are used as features in supervised and unsupervised classification procedures based on K-mean, fuzzy clustering method (FCM) and support vector machine (SVM). The most relevant features for classification are selected using discriminative analysis (DA) of features and their principal components (PC). Accuracy of the proposed method is evaluated in a group of 30 patients with AD (16 males, 14 females, age±standard-deviation (SD)=75±1.36 years) and 30 normal controls (15 males, 15 females, age±SD=77±0.88 years) using leave-one-out cross-validation.
  
  
  RESULTS
  Results indicate superiority of supervised machine learning techniques over unsupervised ones in diagnosing AD and withal, predominance of RBF kernel over lineal one. Accuracies of 83.3%, 83.3%, 90% and 91.7% are achieved in classification by K-mean, FCM, linear SVM and SVM with radial based function (RBF) respectively.
  
  
  CONCLUSIONS
  Evidence that SVM classification of longitudinal atrophy rates may results in high accuracy is given. Additionally, it is realized that use of intermediate atrophy rates and their principal components improves diagnostic accuracy.
authors.affiliation: Faculty of Computer Engineering, IAU, Shabestar Branch, Iran. Electronic address: alifarzanam@gmail.com.
authors.forename: Ali
authors.initials: A
authors.lastname: Farzan
authors.affiliation: Department of Computer & Communication Systems, Faculty of Engineering, University of Putra Malaysia, 43400 Serdang, Selangor, Malaysia; Institute of Advanced Technology, UPM, Malaysia.
authors.forename: Syansiah
authors.initials: S
authors.lastname: Mashohor
authors.affiliation: Department of Computer & Communication Systems, Faculty of Engineering, University of Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
authors.forename: Abd Rahman
authors.initials: AR
authors.lastname: Ramli
authors.affiliation: Faculty of Radiology, University Putra Malaysia (UPM), 43400 Serdang, Selangor D.E., Malaysia.
authors.forename: Rozi
authors.initials: R
authors.lastname: Mahmud
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis*; D001284:Atrophy / Q000473:pathology; D001921:Brain / Q000473:pathology*; D016000:Cluster Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D025341:Principal Component Analysis / Q000379:methods*; D060388:Support Vector Machine
keywords: Alzheimer's disease; Diagnostic; FCM; Longitudinal atrophy; MRI; SVM