FVH Combined With Arterial Spin Labeling Perfusion At Multiple Delay Times:The Value Of Collateral Circulation In Cerebral Ischemia

Objective To explore the value of FVH combined with multiple delay times three-dimensional pseudo-continuous arterial spin labeling(3D p CASL)in evaluating the degree of collateral circulation in patients with cerebral ischemia.Methods 1.The clinical and imaging data of 378 patients with stroke from June 2017 to December 2018 who underwent two-stage(PLD = 1.5s and 2.5s)3D p CASL and MRI plain scan were collected.According to the inclusion criteria and exclusion criteria,eligible patients were enrolled in this study.According to the CBF value results of ASL,the patients were divided into three groups: full,medium and poor compensation groups.According to the results of MRI scan,the patients were divided into cerebral infarction group and control group.The degree of collateral compensation(CBF scores),PLD=1.5s ASL arterial transit artifact(ATA scores)on original images and FLAIR vascular hyperintensities(FVH-ASPECT scores)were evaluated.The correlation between CBF scores,ATA scores and FVH-ASPECT scores was analyzed.2.Dural phase 3D p CASL data of normal population were collected,and the differences of CBF values between different genders and different sides were analyzed.Results 1.Among the 80 patients with positive FVH,the incidence of ATA was 91.43%(32/35),and there was a strong correlation between the FVH-ASPECT score and ATA score(r=0.766,P < 0.001).2.Among the 80 patients,28,38 and 14 cases were in full,medium and poor compensation group,respectively.Spearman correlation analysis showed the FVHASPECT score of the medium compensation group was medium positively correlated with CBF scores and ATA scores(r=0.586,0.408,both P-Values less than 0.05),and there was no significant correlation between the three scores of the full compensation group and the poor compensation group.3.Among 80 patients,there were 31 and 49 patients in cerebral infarction group and control group,respectively.In the infarcted group,FVH-ASPECT score was positively correlated with ATA score,FVH-ASPECT score was positively correlated with CBF improvement rate score,and CBF improvement rate score was positively correlated with ATA score(r,respectively,0.762,0.642,0.493,and P-Values all less than 0.001);In the no-infarct group,only FVH-ASPECT score was weakly correlated with ATA score(r=0.299,P=0.049),and there was no significant correlation between FVH-ASPECT score and CBF improvement rate score,CBF improvement rate score and ATA score.4.There were 8 males and 15 females in the normal group.They were divided into male and female groups.There were significant differences in CBF values between male and female on both sides and PLDs.For male group,and there were no significant differences in CBF values between both sides and PLDs.But for female group,except significant differences in CBF values between both side on 1.5s,there were significant differences in CBF values between both sides on 2.5s and same side on each PLD.Conclusion 1.For patients with cerebral infarction,FVH sign is positively correlated with the degree of collateral compensation around infarction,and the larger the range of FVH sign(FVH-ASPECT score),the better the degree of collateral compensation.2.FVH sign in patients without cerebral infarction may indicate cerebral ischemia with collateral compensation,but it is difficult to quantify the degree of collateral compensation,so perfusion imaging is needed for further evaluation.3.Arterial transit artifact(ATA)is highly correlated with FVH.ATA indicates the existence of meningeal collateral vessels in patients with cerebral ischemia and can be used as an intuitive sign of the existence of it.