Teaching neuroimages: "subarachnoid hemorrhage" from decreased contrast elimination after therapeutic hypothermia.

DISCUSSION Cerebrocirculatory arrest and reperfusion causes injury that breaks down the blood–brain barrier. In patients undergoing contrast imaging, there may be active extravasation of contrast into the subarachnoid space. Hypothermia alters contrast viscosity, decreases glomerular filtration, and subsequently decreases elimination of the contrast. It is important to recognize such mimickers of subarachnoid hemorrhage in the era of hypothermia.