The application of the whole brain CT perfusion combined with CT angiography techniques in the evaluation of transient ischemic attack patients

Objective Explore the value of the inspection techniques which the 320-row volume CT low dose the CT perfusion imaging combined with CT angiography in the assessment of changes in brain tissue of patients with transient ischemic attack microcirculation. Methods Application of the 320-slice dynamic volume CT,low-dose whole brain CTP imaging of 26 patients with unilateral middle cerebral artery (MCA) stenosis or occlusion in patients with TIA,obtaining MCA area of responsibility of cerebral flow (CBF),cerebral volume (CBV),mean transit time (MTT),time to peak (TTP) and delay time (DLY) perfusion parameters and dynamic 4D-CTA images.Take the mirror measurement technique to measured MCA area of responsibility of the affected brain tissue and the contralateral corresponding parts of the brain tissue's perfusion indicators specific quantitative values,as well as varying degrees of MCA stenosis or occlusion of the ratio of ipsilateral and contralateral semiquantitative values;Dynamic 4D-CTA images observed the site of vascular stenosis,the degree of stenosis and the collateral circulation status,t test was used for the statistic analysis in between mild to moderate stenosis group and severe stenosis or occlusion group. Results Twenty six patients successfully completed the whole brain CTP and CTA images.Twenty six patients of MCA stenosis or occlusion in patients with TIA,MCA mild to moderate stenosis are 17 patients (1 patient of ipsilateral anterior cerebral artery with mild stenosis,two patients of ipsilateral posterior cerebral artery with mild stenosis),MCA severe stenosis or occlusion of 9 patients (2 patients of ipsilateral posterior cerebral artery with mild stenosis,1 patient of ipsilateral anterior cerebral artery with mild stenosis and posterior cerebral artery with mild stenosis).The posterior circulation of willis opened 14 patients,16 patients of leptomeningeal anastomotic branch formation.The ipsilateral CBF,CBV were significantly lower than the contralateral,contralateral MTT,TTP,DLY significantly lower than the affected side.The ratio of the MCA with mild to moderate stenosis group of MTT,TTP,DLY were (1.06±0.06),(1.05±0.07),(1.42±0.66) ;The ratio of the MCA with severe stenosis or occlusion group of MTT,TTP,DLY were (1.12±0.09),(1.10±0.04),(1.98±1.21).The ratios of the MCA with mild to moderate stenosis group of MTT,TTP,DLY in ipsilateral and contralateral were significantly lower than the MCA severe stenosis or occlusion group (t=-1.798,-1.583,-1.536,P<0.01). Conclusions The technology of one-stop CTP combined with CTA imaging reflects brain tissue microcirculation which based on visualize the positional relationship of the vascular lesions with abnormal perfusion,assessment of unilateral MCA stenosis or occlusion of cerebral oxygen supply and cerebral blood flow mechanics in patients with TIA. Key words: Tomography,X-ray computed; Perfusion; Middle cerebral artery; Ischemicattack,transient