Neuroimaging of Ischemic Stroke With CT and MRI. Ischemic Stroke Classification and Outcomes. Major or Minor stroke based on whether a proximal cerebral artery is occluded .
ECASS-II-up to 6 h after onset, the incidence of CT hypoattenuation (47%) was higher than in the NINDS tPA trial, and the PPV for brain infarction was 96%
In the first few hours after onset of ischemia, CT hypoattenuation is most difficult to detect when it occurs in the posterior fossa, or when the patient has chronic ischemic changes or areas of leukomalacia
this drug had a clear statistically significant benefit only in patients presenting with NIHSS scores of 6-10.These are patients with moderate neurological deficits, and generally result from occlusions of smaller arterial branches.
intravenous tPA administration resulted in recanalization of approximately 10% of distal internal carotid artery occlusions and approximately 25% of M1 occlusions. Occlusions at the level of M2 were recanalized at a rate of less than 40%.
Patients without a significant penumbra are unlikely to benefit from therapy designed to restore blood flow, even if the patient is within the time window for such therapy.