System, method and apparatus wherein a probe employing non-imagining optics is utilized in conjunction with a fluorescing (e.g., nanocrystal) tracer at the body of a patient. Excitation components within the probe working end are utilized to excite the nanocrystals to fluoresce at wavelengths in the near infrared region, such fluorescent energy is homogenized by interacting with involved tissue to provide a uniform fluorescing intensity over the surface of a photo-detector. Initialization and background determination procedures are described along with a technique for determining statistically significant levels of fluorescing activity.