Image Processing Techniques for ROI Identification in Rheumatoid Arthritis Patients from Thermal Images

Rheumatoid arthritis (RA) is a systemic autoimmune disease that manifests itself by joint inflammation, swelling, pain, tenderness and may involve extra-articular organs in severe cases. Joint inflammatory lesions are associated with higher temperature due to increased vascularity in the area of inflamed tissues. This papers aimed to identify heat patterns from ROIs to interpret the presence of inflammation in rheumatoid arthritis patients. The thermovisual image sequences were collected from 65 patients with Rheumatoid Arthritis (RA). Infrared images were generated by a thermal scanning camera (FLIR E60bx Systems Inc., USA). Separate recordings of left and right foot temperature changes were performed for 3 minute periods. The temperature measurement was performed at the moment right after cold water immersion (post-cooling temperature) and at the moment after thermal recovery (post-recovery temperature). The recording of 3-minute foot thermal recovery was used for analysis. Automatically identified ROI corresponds to the area of the soft tissues covering cuboid and navicular bone.