CT perfusion is increasingly being performed in the comprehensive work-up of acute stroke [ 1]. Most commonly, a non-enhanced CT scan is performed first to rule-out hemorrhage. Subsequently, CT angiography may be performed to evaluate the site of the thrombembolic occlusion and to moreover assess the supraaortic vessels, e.g. to rule out a relevant carotid artery stenosis [ 2].
If the site of the vessel occlusion suggests a more extensive area of cerebral infarction than expected from the native CT scan, a perfusion analysis can be helpful. To perform CT perfusion, sequential slices are acquired in a cine mode during an intravenous injection of contrast medium. Typically, high flow rates of 5-10 ml/s are used – therefore a large venous access is needed. The scanning time is usually approximately 40 s.