Feature selection using factor analysis for Alzheimer's diagnosis using F 18 ‐ FDG PET images

Purpose: This article presents a computer‐aided diagnosis technique for improving the accuracy of the early diagnosis of Alzheimer's disease (AD). Two hundred and ten F18 ‐ FDG PET images from the ADNI initiative [52 normal controls (NC), 114 mild cognitive impairment (MCI), and 53 AD subjects] are studied. Methods: The proposed methodology is based on the selection of voxels of interest using the t‐test and a posterior reduction of the feature dimension using factor analysis. Factor loadings are used as features for three different classifiers: Two multivariate Gaussian mixture model, with linear and quadratic discriminant function, and a support vector machine with linear kernel. Results: An accuracy rate up to 95% when NC and AD are considered and an accuracy rate up to 88% and 86% for NC‐MCI and NC‐MCI, AD, respectively, are obtained using SVM with linear kernel. Conclusions: Results are compared to the voxel‐as‐features and a PCA‐ based approach and the proposed methodology achieves better classification performance.