System for detecting emissions from a radiopharmaceutical injected within a lymph duct wherein a hand-held probe is utilized. When employed to locate sentinel lymph nodes, supplementary features are provided including a function for treating validated photon event pulses to determine count rate level...http://www.google.co.uk/patents/US5928150?utm_source=gb-gplus-sharePatent US5928150 - System for locating and detecting a source of photon emissions
