Evaluation Of Cerebrovascular Blood Flow Reserve Capacity In Unilateral Carotid Artery Patients With Moderate And Severe Stenosis By Using ASL Technique Multiple Delay Time

Objective:Evaluation of cerebrovascular blood flow reserve capacity in unilateral carotid artery patients with moderate and severe stenosis by using ASL technique multiple delay time Materials and Methods:By ultrasound or high resolution magnetic resonance(High-resolution Magnetic Resonance Imaging,HR-MRI)and severe check clear side carotid artery stenosis(70%~99%),contralateral carotid artery stenosis was less than 50% 29 patients.According to clinical symptoms and brain MRI were divided into TIA group(ASL patients have a history of TIA and four weeks ago no clear intracranial ischemic lesions,16 cases,mean age 68±6.24 years)and the infarction group(patients with MRI scan showed intracranial lesions there,13 patients with ischemic stroke,71±4.93 years).The other included in the control group(bilateral carotid artery stenosis was less than 50% and no patients with cerebral ischemic disease in 15 cases,the average age of 65 ± 5.62 years).Using a 3.0TMRI scanner on patients with craniocerebral three-dimensional false continuous arterial spin labeling(Threedimentional pulsed continuous ASL,3D-pCASL)under two different delay time(Post labeling delay marker time,PLD(T1=1525ms,T2=2525ms)of the cerebral blood perfusion imaging,obtained under different time and narrow side of middle cerebral artery(middle cerebral,artery,MCA)supply area,the cerebral blood flow after the watershed,watershed and the basal ganglia putamen and thalamus(CBF1 and CBF2),according to the formula of CBF=CBF2-CBF1,calculated state of cerebral vascular blood flow under resting reserve capacity estimates of ?CBF,compared three groups of resting cerebrovascular reserve capacity.The clinical data of patients in each group by chi square test;in the TIA group compared with the narrow side and contralateral brain areas CBF independent sample t test;TIA group,CBF group and control group three groups of cerebral infarction area compared with single factor analysis of variance(one-way ANOVA).All the statistical analysis by P<0.05 said the difference was statistically significant.The CBF group and TIA group of patients with cerebral infarction area were all receiveroperating characteristic(receiver operating,characteristic,ROC)curve analysis,calculation of the area under the curve(area under,curve,AUC),the threshold,the sensitivity and specificity.Result:1.TIA group comparison:There was no significant difference between the TIA and the contralateral brain regions in the MCA group compared with the control group.The other regions of the stenosis were significantly lower than the contralateral side,the difference was statistically significant(P < 0.05)2.TIA group compared with the control group:(1)TIA patients with narrow side compared with the control group,there was no significant difference between MCA and ?CBF supply area before the watershed(P > 0.05);TIA group than the control group after the narrow side of the watershed,CBF was significantly reduced in the thalamus and lentiform nucleus,the difference is positive.(2)patients in the TIA group compared with the control group on the narrow side MCA territory,lentiform nucleus was not statistically significant difference(P > 0.05);TIA group of narrow side front outside the watershed than in the control group CBF was significantly increased in TIA group;stenosis on the lateral outer watershed of ?CBF was significantly lower than the control group.3.Comparison between TIA group and infarction group:(1)compared two groups of patients with narrow side,there was no significant difference before the watershed cerebral vascular CBF(P > 0.05);patients in group TIA MCA territory.After the watershed,?CBF putamen and thalamus infarction group was significantly increased and the most positive,the corresponding region of ?CBF infarction group Ming and most significantly negative.TIA group CBF increased significantly compared with the infarction group.(2)two groups of patients with narrow side ?CBF of the ROC curve analysis: area under the curve of a substantially small blood supply area were MCA(0.95),putamen(0.94),thalamus(0.88),the watershed(0.53)?CBF.MCA regions in 4.10 is the best value of sensitivity to ischemia degree will progress corresponding to infarction diagnosis was 1,the specificity was CBF 0.93.lenticula to 4.55 is the best value of sensitivity to diagnose whether the ischemic degree will progress corresponding to infarction was 0.88,the specificity was CBF 1.00.of the thalamus to 3.95 is the best value of sensitivity to diagnose whether the extent of myocardial ischemia in corresponding infarction was 0.75,the specificity was CBF outside the watershed 0.92.by 5.05 as the best field sensitivity value for diagnosis of ischemic degree will progress corresponding to infarction was 0.88,the specificity was 0.62.because the area before the watershed under the curve was 0.53,diagnostic value is very low.conclusion1.Using 3D-pCASL technology to set two PLD check method can fully reflect the brain tissue of patients with TIA stenosis of unilateral carotid artery perfusion changes were calculated in resting state in different brain regions under flow reserve CBF.timely judgment,change and progress evaluation in the areas of the brain in patients with TIA cerebral blood flow reserve capacity,and comprehensive assessm-ent of patients the short-term stroke risk.2.Get a ? CBF through 3D-pCASL technology even though the value of SPECT can not be replaced with acetazolamide stimulation test measurement of CVR value,but can be used as a simple,noninvasive,cerebrovascular reserve capacity and easy to operate under the resting technology assessment indicators,to provide image basis for clinical decision making.