High-resolution Optical Tissue Imaging for Biology and Medicine

Abstract

High-resolution optical tissue imaging techniques are to provide information of tissues at the molecular, cellular, and physiological levels, and have been developed for in vivo studies in biology and for diagnostic or surgical guides in several medical fields. We have been working on two high-resolution optical tissue imaging techniques, multi-photon microscopy (MPM) and optical coherence tomography (OCT). MPM is a 3D fluorescence microscopy technique based on multiphoton excitation of fluorophores, and it has been used for in vivo deep tissue imaging in the molecular, cellular levels by using long excitation wavelengths compared to single-photon microscopy techniques. OCT is a 3D imaging technique based on light back-reflection from the tissue, and has been used as a non-invasive diagnostic imaging method for clinical applications. We used MPM for the in vivo imaging of various tissues such as the cornea, skin, brain, and intestine, targeting either basic biological studies or potential clinical applications. A clinically compatible cell contrast agent has been tested for clinical applications of MPM. A combined two-photon and coherent anti-Stokes Raman scattering (CARS) microscopy has been developed for brain tumor delineation. Several techniques based on multi-functional OCT providing information of tissue structure, birefringence, and vasculature has been developed and utilized. Dark-field multi-functional OCT and its combination with dermoscopy have been developed for potential dermatological applications. Studies of these optical tissue imaging techniques will be presented and discussed in detail.