Magnetic resonance imaging of severe frostbite injuries.

Frostbite injury causes damage by direct ice crystal formation at the cellular level with cellular dehydration and microvascular occlusion. Acute treatment is well defined with rapid tissue rewarming. Definitive surgical therapy is usually delayed until a clear level of demarcation is seen. Technium (Tc)-99 bone scanning has become the standard imaging study employed within the first several days to assess tissue perfusion and viability. We present 2 patients with severe frostbite injury in which magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) were compared to Tc-99 bone scans. MRI/MRA appears to be superior to bone scanning by allowing direct visualization of occluded vessels, imaging of surrounding tissues, and by showing a more clear-cut line of demarcation of ischemic tissue. MRI/MRA may also allow early intervention in cases of severe frostbite, thus preventing secondary infection and increased cost.