A method for assessing tissue perfusion in a living subject comprises identifying a target tissue using autofluorescence detection with a fiber optic probe-based fluorescence detection system; administering a dose of a contrast agent to the living subject, wherein the dose is about 0.6 mg; detecting fluorescence emitted from the contrast agent in the target tissue using the fiber optic probe-based fluorescence detection system, without acquiring an image of the target tissue; quantifying the detected fluorescence to obtain a detection level and/or detection ratio; and determining a degree of perfusion of the target tissue based on the detection level and/or detection ratio.

A local positioning system (LPS) is provided. The LPS includes at least three local position tracking devices, each further including one or more of: a clock synchronized to the clock in each of the other devices; a transmitter transmitting signals over time synchronized to the clock; and a receiver receiving the signals over time from the other devices. The LPS further includes a processor operatively coupled to at least one of the devices and that is configured to: obtain for each of the signals a location of the device that transmitted that signal; produce one or more representations of at least a part of a living body based on at least one of one or more of the locations and one or more further representations of the at least the part of the living body, each of the representations including one or more temporal frames; and to provide output.

A combined auto-fluorescence imaging and laser speckle contrast imaging (LSCI) system to enable intra-operative parathyroid identification and viability assessment with the same tool. The system includes a light source for emitting a beam of light to illuminate a target of interest, and an imaging head positioned over the target of interest for individually acquiring auto-fluorescence images and LSCI images of light from the illuminated target of interest responsive to the illumination. Auto-fluorescence imaging helps identify the parathyroid, while LSCI helps assess its viability.