Quantitative assessment of skin swelling using optical coherence tomography

Abstract Background Preclinical and clinical studies suggest that optical coherence tomography (OCT) is a useful tool to visualize inflammatory conditions. Objective The objective of this study was to evaluate the usefulness of combining OCT and various image processing techniques for quantitative assessment of histamine-induced tissue swelling. Methods Both time-domain and frequency-domain OCT were used on a mouse ear model. The ear thickness and volume before and after histamine challenge were determined from pixel locations in 2D scans and voxel number counting in 3D scans. Swelling kinetics was analyzed on 3D contour mapping. Microvessel network was visualized using speckle decorrelation analysis. Results OCT images showed that the thickness and volume changes were histamine dose and contact time dependent. The 3D mapping showed that the histamine-induced swelling spread slowly and directionally. OCT data indicated that microvessel opening and vessel dilation occurred prior to tissue swelling. Conclusion OCT is a robust and quantitative non-invasive imaging tool for assessing skin swelling.