Hyperacute cerebral enhancement: The earliest predictor of hemorrhage by MR imaging?

A test to detect very early hemorrhage in acute cerebral infarct could offe r a substantial increase in the safety and success of advanced stroke thera pies, particularly when the use of thrombolytic therapies is contemplated. Currently, computed tomography is the standard test for the detection of ce rebral hemorrhage but is not a valid predictor of potential areas of hemorr hagic transformation. A technique to evaluate the risk of hemorrhagic trans formation in infarcted cerebral tissue has been conducted with contrast-enh anced magnetic resonance imaging in various animal stroke models. Knight de monstrated Gadolinium-DTPA enhancement in the territory of occluded vessels immediately in rats after reperfusion. Gadolinium enhancement was thought to predict areas of hemorrhagic transformation. Yenari and associates demon strated in rabbit models that contrast-enhanced T1-weighted scans can revea l regions of blood-brain barrier disruption, characterized as hemorrhagic t ransformation in ischemic tissue. The authors report a clinical example in which hyperacute contrast-enhanced magnetic resonance imaging was the first indication of hemorrhagic transformation within 24 hours of onset of an ac ute cerebral infarct.