Depth-resolved analytical model and correction algorithm for photothermal optical coherence tomography
Photothermal OCT (PT-OCT) is an emerging molecular imaging technique that occupies a spatial imaging regime between microscopy and whole body imaging. PT-OCT has been demonstrated in vitro, ex vivo, and in vivo on multiple contrast agents such as gold nanoparticles and indocyanine green. PT-OCT would benefit from a theoretical model to optimize imaging parameters and test image processing algorithm. Past models have focused on individual components of the PT-OCT signal, but a comprehensive model still had to be assembled. We propose the first PT-OCT model to replicate an A-scan in homogeneous and layered samples. Our predictions were validated experimentally in silicone phantoms. We also propose the PT-CLEAN algorithm to reduce phase-accumulation and shadowing, two artefacts found in PT-OCT images and demonstrate this algorithm on phantom and in vivo images.