Purpose: This article presents a computer-aided diagnosis technique for improving the accuracy of the early diagnosis of Alzheimer's disease ͑AD͒. Two hundred and ten 18 F-FDG PET images from the ADNI initiative ͓52 normal controls ͑NC͒, 114 mild cognitive impairment ͑MCI͒, and 53 AD subjects͔ 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.