Classification of osteoarthritic and healthy cartilage using deep learning with Raman spectra

Kok, Yong En; Crisford, Anna; Parkes, Andrew; Venkateswaran, Seshasailam; Oreffo, Richard; Mahajan, Sumeet; Pound, Michael

Abstract

Raman spectroscopy is a rapid method for analysing the molecular composition of biological material. However, noise contamination in the spectral data necessitates careful pre-processing prior to analysis. Here we propose an end-to-end Convolutional Neural Network to automatically learn an optimal combination of pre-processing strategies, for the classification of Raman spectra of superficial and deep layers of cartilage harvested from 45 Osteoarthritis and 19 Osteoporosis (Healthy controls) patients. Using 6-fold cross-validation, the Multi-Convolutional Neural Network achieves comparable or improved classification accuracy against the best-performing Convolutional Neural Network applied to either the raw or pre-processed spectra. We utilised Integrated Gradients to identify the contributing features (Raman signatures) in the network decision process, showing they are biologically relevant. Using these features, we compared Artificial Neural Networks, Decision Trees and Support Vector Machines for the feature selection task. Results show that training on fewer than 3 and 300 features, respectively, for the disease classification and layer assignment task provide performance comparable to the best-performing CNN-based network applied to the full dataset. Our approach, incorporating multi-channel input and Integrated Gradients, can potentially facilitate the clinical translation of Raman spectroscopy-based diagnosis without the need for laborious manual pre-processing and feature selection.

Citation

Kok, Y. E., Crisford, A., Parkes, A., Venkateswaran, S., Oreffo, R., Mahajan, S., & Pound, M. (2024). Classification of osteoarthritic and healthy cartilage using deep learning with Raman spectra. Scientific Reports, 14(1), Article 15902. https://doi.org/10.1038/s41598-024-66857-6

• Journal Article Type: Article
• Acceptance Date: Jul 4, 2024
• Online Publication Date: Jul 10, 2024
• Publication Date: Jul 10, 2024
• Deposit Date: Jul 11, 2024
• Publicly Available Date: Jul 11, 2024
• Journal: Scientific Reports
• Electronic ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 14
• Issue: 1
• Article Number: 15902
• DOI: https://doi.org/10.1038/s41598-024-66857-6
• Keywords: Deep learning, Osteoarthritis, Convolutional neural network, Raman spectra, Classification
• Public URL: https://nottingham-repository.worktribe.com/output/37153491
• Publisher URL: https://www.nature.com/articles/s41598-024-66857-6