Nonlinear optical endomicroscopy for label-free functional histology in vivo

A compact, flexible probe based on nonlinear optics offers doctors and researchers a noninvasive way to directly image internal organs. Histology using optical microscopy has been widely employed for diagnosing disease, but it typically takes a few days to obtain results and it does not provide functional information. Now, Xingde Li at Johns Hopkins University and coworkers have developed a 2-millimeter-diameter probe that uses two-photon imaging to obtain images of organs inside the body that are comparable in quality to those obtained by a laser scanning microscope. They realized this through innovations in double-clad fiber optics, a miniature objective lens and short pulse management. The team demonstrated the potential of their probe by using it to obtain metabolic imaging of a functioning mouse kidney model. The probe is promising for both diagnosing disease and basic research.