Cerebrovascular changes in rats during ischemia and reperfusion: a comparison of BOLD and first pass bolus tracking techniques.

Both first pass bolus tracking of a susceptibility contrast agent and blood oxygenation level dependent (BOLD) sequences provide information on the tissue perfusion and the cerebral blood volume, but each sequence has its own particular limitations. In this article, both techniques were used to assess the cerebrovascular changes occurring in a rat model of focal cerebral ischemia with reperfusion after 2 h of ischemia. The blood oxygenation level dependent studies were performed before, during, and after 60 s of anoxia to observe the response of the tissue to a respiratory challenge. Both techniques were able to detect ischemia and reperfusion; however, first pass bolus tracking provided better sensitivity and was easier to interpret. Because the blood oxygenation level dependent sequence did not provide any additional information, bolus tracking would appear to be the method of choice for studies of cerebral ischemia with reperfusion.