A Comparison of Deep Learning and Traditional Machine Learning Approaches in Detecting Cognitive Impairment Using MRI Scans

Deep learning has attracted a great amount of interest in recent years and has become a rapidly emerging field in artificial intelligence. In medical image analysis, deep learning methods have produced promising results comparable to and, in some cases, superior to human experts. Nevertheless, researchers have also noted the limitations and challenges of the deep learning approaches, especially in model selection and interpretability. This paper compares the efficacy of deep learning and traditional machine learning techniques in detecting cognitive impairment (CI) associated with Alzheimer's disease (AD) using brain MRI scans. We base our study on 894 brain MRI scans provided by the open access OASIS platform. In particular, we explore two deep learning approaches: 1) a 3D convolutional neural network (3D-CNN) and 2) a hybrid model with a CNN plus LSTM (CNN-LSTM) architecture. We further examine the performance of five traditional machine learning algorithms based on features extracted from the MRI images using the FreeSurfer software. Our experimental results demonstrate that the deep learning models achieve higher Precision and Recall, while the traditional machine learning methods deliver more stability and better performance in Specificity and overall accuracy. Our findings could serve as a case study to highlight the challenges in adopting deep learning-based approaches.