Role of 99mTc MDP bone scan in delineation of ischaemic zone in cases of severe frostbite

Frostbite or cold burn is the medical condition in which localized damage is caused to exposed skin and subcutaneous tissue due to freezing. Frostbite most likely involves body parts farthest from the heart and those with large exposed areas. At or below 0 °C (32 °F), blood vessels close to the skin start to constrict, and blood is shunted away from the extremities via the physiological feedback action of glomus bodies. This peripheral vasoconstriction helps to conserve core body temperature. In extreme cold, or when certain parts of the body are exposed to cold conditions for long periods, this protective mechanism can reduce blood flow in some areas of the body to dangerously low levels. This is followed by crystallisation of water in the tissue and subsequent death of tissues in the affected areas. In this case series, we highlight the importance of a 99m technetium methylene diphosphonate ( 99m Tc MDP) triple phase bone scan in cases of severe frostbite to precisely delineate the ischaemic and reperfusion zones, so as to help the surgeons in carefully deciding if amputation is required and the level of amputation in such cases.