Chapter 19 - Applications of Multiphoton Microscopy in Dermatology

Abstract

Multiphoton microscopy is an important imaging method for noninvasive visualization of dermal physiology and pathology. Multiphoton technology has certain advantages over other visualization techniques. Compared with ultrasound and optical coherence tomography, multiphoton microscopy offers submicron-level spatial resolution. Compared with optical wide-field imaging, multiphoton microscopy offers inherent three-dimensional resolved optical sectioning. Compared with confocal microscopy, multiphoton microscopy offers improved penetration depths in skin imaging of tissue endogenous and exogenous fluorophores. Advances in developing multiphoton microscopes with novel contrast mechanisms, such as second harmonic generation and stimulated Raman scattering, further allow visualization of skin morphology and function based on molecular-level signatures of biological molecules. Therefore multiphoton microscopy has found increasing usage in dermatology that will be reviewed in this chapter. This review covers the basic spectroscopic and imaging principles underlying multiphoton microscopy. Skin photophysics and photochemistry important for multiphoton imaging will be examined. We will review several classes of multiphoton microscope designs that are useful for dermal imaging. Finally, the application of multiphoton microscopy in imaging skin cancers and various other diseases will be covered. The uses of multiphoton imaging to study skin immuno-response, aging, and regeneration phenomena will be presented. Finally, the uses of multiphoton microscopy for analyzing the transdermal transport of drugs, cosmetics and other agents are summarized.