A Spectral Demixing Model for Triplex In Vivo Imaging of Optical Coherence Tomography Contrast Agents

The ability to detect multiple contrast agents simultaneously would greatly enhance optical coherence tomography (OCT) images, providing nuanced biological context to physiological structures. However, previous OCT contrast agent work has been limited to scenarios where only a single contrast agent could be robustly detected within each voxel. We present a novel spectroscopic technique for demixing the spectral signal from multiple OCT contrast agents within a single voxel. We validate our technique in vitro and also demonstrate in vivo imaging of three spectrally distinct gold nanobipyramids, trafficking within the lymphatic system of a live mouse.