The application of whole brain CT perfusion imaging combined with neck CT angiography with 320-row-detector CT in the evaluation of patients with chronic cerebral ischemia

Objective Using whole brain CT perfusion imaging and neck CT angiography with 320-row-detector dynamic volume CT to investigate the cerebral hemodynamic changes and the relationship between the hemodynamics and cerebral artery stenosis in patients with chronic cerebral ischemia.Methods The data of the dynamic CT angiography(4DCTA),CT brain perfusion and the CTA images of carotid artery were acquired in 88 patients with unilateral MCA and ICA stenosis or occlusion.The narrow rate of the neck and intracranial lesions of vascular and CT perfusion(CTP)parameters,including rCBF,rCBV,rTTP,rMTT,were calculated.Configuration of the CoW was described.The interrelation between the degree of artery stenosis,collateral circulation via the CoW and CTP parameters was analyzed.Results 1)The 88 patients of different intracranial artery and neck vascular stenosis or occlusion included mild stenosis in 12 cases,moderate stenosis in 25,severe stenosis in 24,occlusion in 27.There were 48 cases of unilateral ICA stenosis or occlusion and 40 cases of unilateral MCA stenosis or occlusion(M1-M2);2)There were statistical significances in rCBV,rMTT and rTTP of the middle cerebral region,anterior watershed region,posterior watershed region(P 0.05 for all).No statistically significant difference in rCBF was found among the four stenotic groups(P 0.05 for all);3)There was a weak negative correlation between the stenosis rate and rCBF of the middle cerebral region(r=-0.254,P =0.017),but the stenosis rate and rCBF of anterior watershed and posterior watershed regions was with no correlation(r=-0.131,P =0.13;r=-0.2,P =0.062,respectively).The degree of stenosis and rCBV(r=0.497,r=0.316,r=0.29,respectively;P 0.01 for all),rTTP(r=0.691,r=0.619,r=0.593,respectively;P =0.000 for all),rMTT(r=0.695,r=0.514,r=0.508;P =0.000 for all)was with positive correlation in three regions;4)NO relation was found between the configuration of the CoW and cerebral perfusion parameters.Conclusion The whole brain CT perfusion imaging and neck CT angiography with 320-row-detector dynamic volume CT can fully show position of cerebral ischemia,changes of cerebral blood flow parameters and the degree of stenosis of the corresponding the feeding artery of the head and neck.The narrower of the feeding artery,the bigger the CBV,TTP,MTT are,the ratio of stenosis was highly correlated with the rTTP.