Classification of Alzheimer’s Disease from MRI Data Using a Lightweight Deep Convolutional Model

Abstract

Alzheimer’s disease (AD) is a progressive brain disorder affecting millions of people worldwide. An accurate diagnosis of AD plays a significant role in identifying the progression of the disease at its prodromal stage, i.e., mild cognitive impairment (MCI). In this paper, we propose a lightweight deep model to classify the patients into diagnostic groups, AD vs. normal control (NC) or progressive MCI (pMCI)vs. stable MCI (sMCI), with high accuracy, using MRI data. The proposed model uses separable and attention-based convolution operations. The separable convolution can reduce the complexity of the model by splitting a kernel into two separate kernels that do depth-wise and pointwise convolution operations, respectively. Moreover, integrating an attention-based convolution, which concatenates the convolutional and attentional feature maps, can capture the most relevant features for improved classification with fewer filters. From the experimental results on the Alzheimer’s disease neuroimaging initiative (ADNI) database, compared to the state-of-the-art methods, it is observed that the proposed method shows significant improvement in the classification performance in terms of accuracy, specificity, sensitivity, and AUC. In addition, the proposed method drastically reduces the number of parameters without affecting the performance.