Brain CT Perfusion in Stroke in Progression

acute CT brain scan revealed subtle hypodensity of the left MCA territory with narrowing of the proximal MCA on CT angiography ( fig. 1 a). Due to symptom regression during the next 30 min and the unknown time of symptom onset, aspirin was given but not thrombolysis. The next morning she had minimal dysphasia and central facial paresis only (NIHSS score 2). However, her symptoms were fluctuating and on day 3 she again progressed to global aphasia. Brain CT with angiography was unchanged ( fig. 1 a). Brain CTP was performed, consisting of a 50-second series using cinemode scanning and nonionic contrast medium, which is believed to have no brain damaging effects during acute stroke [9] . A significant decrease of relative cerebral blood flow (rCBF) to approximately 30 ml/100 g brain tissue/min in the left MCA territory was seen ( fig. 1 b). Conventional angiography with angioplasty of the occluded M1 segment was performed. Due to immediate normalization of the blood flow we renounced stenting. After the procedure our patient again exhibited minimal dysphasia only. Brain CTP 2 days and angiography 8 days later showed complete restoration of rCBF to approximately 70 ml/100 g/min ( fig. 2 a and b). Magnetic resonance imaging on day 5 revealed minor infarcts in the left insular lobe and internal capsule. Despite extensive cardiovascular workup an embolic source was not found. Having made Dear Sir, Brain CT perfusion imaging (CTP) has been used to study cerebral blood flow (CBF) in acute ischemic [1] and hemorrhagic [2] stroke, vasospasm secondary to subarachnoidal hemorrhage [3] and in brain trauma [4] . CTP using new generation multislice scanners is a relatively recent technique with the potential of becoming a widely used tool of standard stroke assessment due to its better access in general medical emergency departments compared to magnetic resonance perfusion [5] . In patients with suspected acute stroke the site of vascular occlusion, infarct core, salvageable brain tissue and collateral circulation is best assessed by a combination of CTP and CT angiography [6, 7] . CTP may help decision-making for thrombolysis when there is no clear time of symptom debut [8] . Moreover, as shown below, CTP may assist decision-making for endovascular neuroradiologic treatment in patients with stroke in progression. To our knowledge, this is the first report of brain CTP in stroke in progression due to middle cerebral artery (MCA) occlusion.