The whole brain CT perfusion imaging findings of symptomatic severe stenosis or occlusion of intracranial internal carotid artery

Objective: To study the hemodynamic patterns demonstrated in whole brain CT perfusion images(CTPI) in patients with symptomatic severe stenosis or occlusion of intracranial internal carotid artery(ICA).Materials and Methods: The CTPI data of 23 patients with symptomatic severe stenosis(70%) or occlusion of ICA were analyzed retrospectively.The 4 dimensional CT angiography(4D-CTA) and the parameter maps of CTPI including cerebral blood volume(CBV),cerebral blood flow(CBF),mean transit time(MTT),time to peak(TTP) and delay maps were generated in the off-line workstation by using specific software.The stenosis degree of ICA,clinical symptoms,location of infarction and features of CTPI and the values of parameter maps were recorded.Paired t-test was used to compare the values of ipsilateral with contralateral normal areas in CTP maps.Results: Fifteen patients had occlusion and 8 patients had severe stenosis of ICA.Thirteen cases had infarction in middle cerebral artery(MCA) or anterior cerebral artery(ACA) areas,6 cases had watershed infarction,2 cases had lacunar infarction and 2 cases had no infarction.The patterns of CTPI abnormalities included the following: ①Normal or slightly increased CBV/CBF and increased MTT/TTP/Delay time(4 csaes).②Normal CBV,slightly decreased in CBF and decreased in MTT/TTP/Delay time(3 cases).③Decreased obviously in CBV/CBF,decreased in regional MTT associated with prolong MTT/ TTP/Delay time(16 cases).CBV,CBF,TTP and Delay values of ipsilateral side brain areas had significant difference when compared with those of contralateral brain areas(P0.05).Conclusions: 320-row CT is a reliable technique in showing intracranial ICA stenosis and perfusion abnormalities.