John Arun Ravi, Jain Anurag, Kishore Braj, Pandit Aniruddha G
Department of Nuclear Medicine, Army Hospital Research and Referral, New Delhi, India.
Indian J Nucl Med. 2017 Jul-Sep;32(3):203-207. doi: 10.4103/ijnm.IJNM_14_17.
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 technetium methylene diphosphonate (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.
冻伤或冷灼伤是一种医学状况，即由于冷冻导致暴露在外的皮肤和皮下组织受到局部损伤。冻伤最常累及离心脏最远且暴露面积大的身体部位。在0°C（32°F）及以下时，靠近皮肤的血管开始收缩，血液通过球状体的生理反馈作用从四肢分流。这种外周血管收缩有助于维持核心体温。在极端寒冷的情况下，或者当身体某些部位长时间暴露于寒冷环境时，这种保护机制会使身体某些部位的血流减少到危险的低水平。随后组织中的水分结晶，受影响区域的组织继而死亡。在本病例系列中，我们强调了锝亚甲基二膦酸盐（Tc MDP）三相骨扫描在严重冻伤病例中的重要性，以精确描绘缺血和再灌注区域，从而帮助外科医生谨慎决定是否需要截肢以及此类病例的截肢水平。
