【正文】
ys after stroke to compare final infarct volume to initial DWI lesion,1 Thijs VN et al. Neurology 2001,Example of PWI/DWI mismatch and final infarct,This study demonstrated that patients with an increased mean transit time the DWI lesion expanded into what was expected on PWI A second study by Tong et al.1 showed that the initial NIHSS at admission correlated more strongly with PWI and final infarct volume on day 7 as opposed to initial DWI lesion,1 Tong DC et al. Neurology 1998,Cerebral Blood Flow changes in Acute Ischemic Stroke,Tissue outcome following arterial occlusion is determined by cerebral blood flow thresholds below which neuronal integrity and function is differentially affected 1,1 Baron JC, Cerebrovasc Dis 2001,CBF thresholds in human cerebral ischemia,ISCHEMIC PENUMBRA,Tissue that is functionally impaired but structurally intact CBF range 1220 mL/100g/min Salvaging this tissue by restoring its flow to nonischemic levels is the aim of reperfusion therapy Penumbra converts to ischemic core with hyperglycemia, acidosis, reduced local perfusion pressure 1 Baron et. al, Cerebrovasc Dis 2001, 2 Heiss et al. 2001,Cerebral Blood Flow changes in Acute Ischemic Stroke,tissue irreversibly damaged beyond a certain time limit it corresponds to CBF values of less than 12 ml/100g/min 4, 5 thrombolytic therapy administered to patients with large amounts of core is associated with an increased risk of symptomatic hemorrhage and malignant cerebral edema 6, 7, 8, 9, 10 4 Baron et. al, Cerebrovasc Dis 2001 , 5 Heiss et al, Stroke 2000, 6 Goldstein et al., Stroke 2000, 7 Ueda et al., J Cereb Blood Flow Metab 1999 , 8 Larue et al., Stroke 2001, 9 Firlik et al., J Neurosurg 1998, Jovin et al., Neurology 2002,ISCHEMIC CORE,Cerebral Blood Flow Changes in Acute Ischemic Stroke,23 patient with MCA occlusion 6 hour symptom onset and imaged with Xen