Multimodal CT Study Of Ischemic Penumbra,Collateral Circulation And Prognosis In Patients With Acute Ischemic Stroke

Part? Multimodal CT study of ischemic penumbra and collateral circulation in patients with acute ischemic strokeObjectiveTo investigate the value of multimodal CT in the evaluation of the infarct core area,the ischemic penumbra and the collateral circulation in patients with acute ischemic stroke.Materials and Methods1.SubjectsA total of 32 patients were prospectively enrolled in the department of neurology from January 2017 to January 2018 in our hospital.The inclusion criterions were as follows:(1)disease within 7 days in patients with acute ischemic stroke,including cerebral infarction and TIA patients;(2)aged 18-80 years old,male or female;(3)at least one side responsible for significant stenosis or occlusion of the middle cerebral artery(diagnosis by CTA,DSA or MRA),stenosis rate?50%,clinically suspected or confirmed by atherosclerosis.All cases must meet the above three points at the same time.All examinations were approved by the patients and the ethics committee,and then the patients signed informed consent.2-MethodsMultimodal CT examination was performed in 32 patients,including Non-contrast CT(NCCT),CT perfusion(CTP)and multiphase CT angiography(mCTA).The post-processing software was used to reconstruct and analyze CTP and multiphase CTA images.Color perfusion images of cerebral blood volume(CBV),cerebral blood flow(CBF),mean transit time(MTT)and time to peak(TTP)were obtained through CTP analysis and the core area of cerebral infarction and infarction around the core area were measured for assessment of infarct core area and ischemic penumbra.Choosing rMTT>150%as the standard to assess the CBV-MTT's accuracy when diagnosing ischemic penumbra.The multiphase CTA was used to analyze the intracranial vessels and evaluate the collateral circulation,and the receiver operating characteristic(ROC)curve was used to evaluate the correlation between the multitemporal CTA collateral score and the mismatch area of CBV-MTT and CBV-TTP.Results1.32 patients underwent multimodal CT examination successfully and 31 cases of cerebral infarction and 1 case of TIA were diagnosed.All patients had moderate to severe stenosis to occlusion of the the responsible middle cerebral artery,including moderate stenosis in 6 cases(18.8%),severe stenosis in 12 cases(37.5%),occlusion in 14 cases(43.8%).12 patients with poor collateral circulation(2-3)and 20 cases with good collateral circulation(4-5)were obtained based on the multiphase CTA collateral score.2.The ipsilateral infarction core area of CBV and CBF decreased significantly,MTT and TTP were significantly prolonged(P<0.05);There was no significant difference in the CBV between the area around the infarction core and the contralateral(P = 0.116),while the CBF decreased and the TTP and MTT prolonged(P<0.05);Compared with the area around the infarction core,the CBV and CBF in the infarcted core were significantly decreased and the TTP and MTT values were longer(P<0.05).The rMTT:in the area around the infarction core was 2.4 ± 1.19,When choosing rMTT>150%as the standard for defining ischemic penumbra,the method CBV-MTT did not match had a accuracy of 71.88%.3.The area of abnormal CTP perfusion parameters in patients with good collateral circulation was smaller(P<0.05).There was no significant difference in CBV-MTT mismatch area and CBV-TTP mismatch area between in patients with good collateral circulation and poor collateral circulation(P>0.05).4.28 patients(87.5%)had CBV-MTT mismatch and CBV-TTP mismatch,the multitemporal CTA collateral score predicted that the area under the ROC curve of CBV-MTT mismatch and CBV-TTP mismatch was 0.750 and 0.754 respectively.Conclusions1.Multiphase CTA can fully show the situation of vascular stenosis or occlusion and assessment of collateral circulation;2.CTP parameters can accurately evaluate the infarct core area and the ischemic penumbra;the relative parameters rMTT results consistent with the current prevalence of rMTT>150%,which can evaluate the ischemic penumbra sector.CBV-MTT mismatch area can be regarded as ischemic penumbra;3.Patients with good collateral circulation had small CTP parameters of perfusion area;4.Based on multiphase CTA collateral scoring for CBV-MTT mismatch and CBV-TTP mismatch occurred with high diagnostic efficiency and predictive ability;5.Multimodal CT is of great value in the diagnosis of the collateral circulation,infarct core and the ischemic penumbra in the patients with acute ischemic stroke.Part? Prediction of collateral circulation and prognosis in patients with acute middle cerebral artery stroke based on multiphase CTA and CTPObjectiveTo explore the relationship between CTP parameters and collateral circulation,as well as assess the value of multiphase CTA collateral score and ASPECTS score of CTP parameters in the prognosis of acute cerebral artery stroke patients..Materials and Methods1.SubjectsA total of 32 prospective patients with the following criteria were enrolled in our hospital from January 2017 to January 2018,prospectively.All patients were followed up 90 ± 7 days after the onset of disease.2.MethodsAll patients underwent multimodality CT examinations including NCTT,CTP and mCTA.The baseline clinical data and neurological function scores of the patients were recorded in detail.The ASPECTS scores of NCCT,CBV,CBF,MTT and TTP were evaluated respectively.Based on multiphase CTA collateral score,patients were divided into good and poor collateral circulation group,the clinical data,neurological score and imaging parameters were were obtained and compared among patients with different grades of collateral circulation.The multivariate logistic regression analysis was used to analyze the relationship between ASPECTS score and collateral circulation in CTP parameters.The value of ROC curve was used to predict the value of collateral circulation.According to the mRS score after 90 days,the patients were divided into good and poor outcome group,poisson regression analysis of the relationship between variables of clinical and radiological features and poor outcome,multiple logistic regression models was established and the predictive value of CTP and collateral circulation for the prognosis of the patients was calculated with the area under the ROC curve.Results1.NIHSS scores at admission(11 vs.4.5,P = 0.015),mRS scores at hospital admission(4 vs.3.5,P = 0.011),NIHSS scores(5.5 vs.1,P = 0.003)at discharge,mRS scores at discharge(4 vs.1,P = 0.001)were significantly higher,outcome was worse(P<0.001)and the initial infarct volume(28.73 vs.3.25,P = 0.032)and the final infarct volume(16.95 vs.1.21,P = 0.06)was significantly larger in patients with poor collateral circulation than with good collateral circulation.CBV ASPECTS(9 vs.7.5,P = 0.044),CBF ASPECTS(8 vs.6,P = 0.013),MTT ASPECTS(6 vs.2.5,P =0.025)and TTP ASPECTS were significantly higher in patients with good collateral circulation.In the multivariate analysis,the baseline model showed that NIHSS admission(P = 0.017,OR 0.8 per point,95%CI 0.67-0.96)predicts good CC;in the multivariate model after addition of CTP parameters which showed CBF ASPECTS((P = 0.032,OR 2.46 per point,95%CI 1.08-5.62),MTT ASPECTS(P = 0.041,OR 1.6 per point,95%CI 0.65-2.26)and TTP ASPECTS(P=0.027,OR 1.83 per point,95%CI 1.07-3.12)could predict good CC.CBF ASPECTS had a larger area under the receiver operating characteristic curve for good CC(0.763)than TTP ASPECTS(0.750),MTT ASPECTS(0.738),CBV ASPECTS(0.710)or NCCT ASPECTS(0.640)at arrival.2.The good outcome was found in 19 cases(59.4%)and poor outcome in 13 patients(40.6%).We observed an increased risk of poor outcome in patients with poor collaterals on the NIHSS score>15 points(RR 3.1,95%CI 1.5-2.3)at admission,NIHSS score ?10 points at discharge(RR 3.4,95%CI 1.9-6.0),NCCT ASPECTS<7 points(RR 2.6,95%CI 1.2-5.4),CBV ASPECTS<7 points(RR 3.7,95%CI 2.0-7.0),poor collateral circulation(RR 20,95%CI 3.0-135.1),initial infarct volume(?25cm3)(RR 2.7,95%CI 1.1-6.3)and on the final infarct volume(?15cm3)(RR 3.1,95%CI 1.3-7.1).The ROC curve analysis showed that the prediction of poor clinical outcome by means of CTP adjustment was better with ASPECTS scores for all CTP parameters(area under the curve,0.879)than by the ASPECTS for each parameter.The collateral circulation independently predicted poor outcome(area under the curve,0.984).Conclusions1.Favorable CBV ASPECTS,CBF ASPECTS,MTT ASPECTS and TTP ASPECTS are associated with good collateral circulation and can be used as an independent predictor for collateral circulation in patients with acute middle cerebral artery stroke,when CC is uncertain,CBF ASPECTS can be first used to assess CC,combined with other perfusion parameters together to assess the price will have a higher diagnostic value;2.Patients with poor outcome have a lager infarct size and worse outcome.3.Unfavorable CBV ASPECTS,CBF ASPECTS,MTT ASPECTS and TTP ASPECTS are the risk factors of poor outcome,which can increase the risk of poor outcome and have additional value in predicting clinical outcome,which can be used as a powerful supplement in addition to general imaging and clinical examination when assessing and predicting the patient's outcome.4.Collateral circulation is a strong predictor of the prognosis of acute ischemic stroke.5.Multiphase CTA and CTP are of high value in predicting the collateral circulation and prognosis in patients with acute stroke of middle cerebral artery.