MRI of subacute hemorrhagic transformation in the rat suture occlusion model

In this study we investigated the utility of different MRI techniques for the detection and predictability of hemorrhagic transformation (HT) in a rat model of transient focal cerebral ischemia. Hemorrhagic infarction was reliably identified with gradient-echo sequences and developed between 2 and 7 days following the insult. None of the investigated early MRI features of the ischemic lesions (including the apparent diffusion coefficient and post-reperfusion blood–brain barrier damage) was a good predictor of HT severity at 7 days. This indicates that subacute HT at 2–7 days occurs independently of the severity of acute tissue and BBB damage.