Analysis Towards Classification of Infection and Ischaemia of Diabetic Foot Ulcers

This paper introduces the Diabetic Foot Ulcers dataset (DFUC2021) for analysis of pathology, focusing on infection and ischaemia. We describe the data preparation of DFUC2021 for ground truth annotation, data curation and data analysis. The final release of DFUC2021 consists of 15,683 DFU patches, with 5,955 training, 5,734 for testing and 3,994 unlabeled DFU patches. The ground truth labels are four classes, i.e. control, infection, ischaemia and both conditions. We curate the dataset using image hashing techniques and analyse the separability using UMAP projection. We benchmark the performance of five key backbones of deep learning, i.e. VGG16, ResNet101, InceptionV3, DenseNet121 and EfficientNet on DFUC2021. We report the optimised results of these key backbones with different strategies. Based on our observations, we conclude that EfficientNetB0 with data augmentation and transfer learning provided the best results for multi-class (4-class) classification with macro-average Precision, Recall and F1-score of 0.57, 0.62 and 0.55, respectively. In ischaemia and infection recognition, when trained on one-versus-all, EfficientNetB0 achieved comparable results with the state of the art. Finally, we interpret the results with statistical analysis and Grad-CAM visualisation.

Recognition of Ischaemia and Infection in Diabetic Foot Ulcers: Dataset and Techniques

Diabetic Foot Ulcers (DFU) detection using computerized methods is an emerging research area with the evolution of machine learning algorithms. However, existing research focuses on detecting and segmenting the ulcers. According to DFU medical classification systems, i.e. University of Texas Classification and SINBAD Classification, the presence of infection (bacteria in the wound) and ischaemia (inadequate blood supply) has important clinical implication for DFU assessment, which were used to predict the risk of amputation. In this work, we propose a new dataset and novel techniques to identify the presence of infection and ischaemia. We introduce a very comprehensive DFU dataset with ground truth labels of ischaemia and infection cases. For hand-crafted machine learning approach, we propose new feature descriptor, namely Superpixel Color Descriptor. Then, we propose a technique using Ensemble Convolutional Neural Network (CNN) model for ischaemia and infection recognition. The novelty lies in our proposed natural data-augmentation method, which clearly identifies the region of interest on foot images and focuses on finding the salient features existing in this area. Finally, we evaluate the performance of our proposed techniques on binary classification, i.e. ischaemia versus non-ischaemia and infection versus non-infection. Overall, our proposed method performs better in the classification of ischaemia than infection. We found that our proposed Ensemble CNN deep learning algorithms performed better for both classification tasks than hand-crafted machine learning algorithms, with 90% accuracy in ischaemia classification and 73% in infection classification.