Learning Deep Convolutional Features for MRI Based Alzheimer's Disease Classification

TL;DR

This paper proposes using deep convolutional neural network features extracted from raw MRI images to classify Alzheimer's disease and mild cognitive impairment, eliminating the need for manual ROI labeling.

Contribution

It introduces a novel approach of leveraging pre-trained CNNs for automatic feature extraction from MRI images for AD classification, bypassing manual ROI annotation.

Findings

Deep features improve classification accuracy.

Pre-trained CNNs effectively capture relevant MRI features.

Method reduces reliance on domain expertise and manual labeling.

Abstract

Effective and accurate diagnosis of Alzheimer's disease (AD) or mild cognitive impairment (MCI) can be critical for early treatment and thus has attracted more and more attention nowadays. Since first introduced, machine learning methods have been gaining increasing popularity for AD related research. Among the various identified biomarkers, magnetic resonance imaging (MRI) are widely used for the prediction of AD or MCI. However, before a machine learning algorithm can be applied, image features need to be extracted to represent the MRI images. While good representations can be pivotal to the classification performance, almost all the previous studies typically rely on human labelling to find the regions of interest (ROI) which may be correlated to AD, such as hippocampus, amygdala, precuneus, etc. This procedure requires domain knowledge and is costly and tedious. Instead of relying on extraction of ROI features, it is more promising to remove manual ROI labelling from the pipeline and directly work on the raw MRI images. In other words, we can let the machine learning methods to figure out these informative and discriminative image structures for AD classification. In this work, we propose to learn deep convolutional image features using unsupervised and supervised learning. Deep learning has emerged as a powerful tool in the machine learning community and has been successfully applied to various tasks. We thus propose to exploit deep features of MRI images based on a pre-trained large convolutional neural network (CNN) for AD and MCI classification, which spares the effort of manual ROI annotation process.