GastroViT: A Vision Transformer Based Ensemble Learning Approach for Gastrointestinal Disease Classification with Grad CAM & SHAP Visualization

Abstract: The gastrointestinal (GI) tract of humans can have a wide variety of aberrant mucosal abnormality findings, ranging from mild irritations to extremely fatal illnesses. Prompt identification of gastrointestinal disorders greatly contributes to arresting the progression of the illness and improving therapeutic outcomes. This paper presents an ensemble of pre-trained vision transformers (ViTs) for accurately classifying endoscopic images of the GI tract to categorize gastrointestinal problems and illnesses. ViTs, attention-based neural networks, have revolutionized image recognition by leveraging the transformative power of the transformer architecture, achieving state-of-the-art (SOTA) performance across various visual tasks. The proposed model was evaluated on the publicly available HyperKvasir dataset with 10,662 images of 23 different GI diseases for the purpose of identifying GI tract diseases. An ensemble method is proposed utilizing the predictions of two pre-trained models, MobileViT_XS and MobileViT_V2_200, which achieved accuracies of 90.57% and 90.48%, respectively. All the individual models are outperformed by the ensemble model, GastroViT, with an average precision, recall, F1 score, and accuracy of 69%, 63%, 64%, and 91.98%, respectively, in the first testing that involves 23 classes. The model comprises only 20 million (M) parameters, even without data augmentation and despite the highly imbalanced dataset. For the second testing with 16 classes, the scores are even higher, with average precision, recall, F1 score, and accuracy of 87%, 86%, 87%, and 92.70%, respectively. Additionally, the incorporation of explainable AI (XAI) methods such as Grad-CAM (Gradient Weighted Class Activation Mapping) and SHAP (Shapley Additive Explanations) enhances model interpretability, providing valuable insights for reliable GI diagnosis in real-world settings.