This document discusses a novel approach using thermography to identify vulnerable plaques. It hypothesizes that vascular inflammation and plaque vulnerability can be identified by the heat released from activated macrophages in plaques. Studies in animal models and humans found significant temperature heterogeneity over atherosclerotic arteries that correlated with macrophage density and markers of inflammation. A thermography catheter was developed and initial studies suggest it may help identify high-risk plaques by detecting areas of increased heat from macrophage activity. Larger clinical studies are still needed but thermography shows promise as a new technique for detecting vulnerable plaques when combined with other imaging methods.