US Patent 7865230 Method and system for detecting sentinel lymph nodes

According to one embodiment of the present invention, a method for detecting lymph nodes in a human includes introducing a fluorescent contrast agent into a lymph node system of a body, directing near-infrared time-varying excitation light into the tissue of the body, causing the near-infrared time-varying excitation light to contact a lymph node of the lymphatic system, whereby a redshifted and time-varying emission light is generated, detecting the time-varying emission light at a surface of the body, filtering the time-varying emission light to reject excitation light re-emitted from the lymph node, and imaging the lymph node of the lymphatic system.