Abstract

High Resolution In Vivo Histology: Clinical in vivo Subcellular Imaging using Femtoseceond Laser Multiphoton/CARS Tomography

Karsten König, Professor, Saarland University

We report on a certified, medical, transportable multipurpose nonlinear microscopic imaging system based on a femtosecond excitation source and a photonic crystal fiber with multiple miniaturized time-correlated single-photon counting detectors. The system provides in vivo skin biopsies with superior 300 nm lateral resolution based on the simultaneous acquisition of two-photon autofluorescence, second harmonic generation, and coherent anti-Stokes Raman< scattering. In addition, fluorescence lifetime images (FLIM) can be generated with the multiphoton tomograph in its time resolved single photon counting mode. The flexible scan head permits ex vivo biological imaging such as rapid biopsy examination during surgery as well as imaging of animals. Furthermore, it can be used on volunteers and patients in order to study pathological modifications of the skin (e. g. cancer, dermatitis), anti-aging effects, and the biosafety of nanoparticles in sunscreens. One of the most interesting projects involve the investigation of skin modifications in astronauts as a result of long-term space flights.