Biphasic 3D-ASL Study On Collateral Circulation And Different Infarct Types And Perfusion After Severe Stenosis Or Occlusion Of Unilateral Middle Cerebral Artery

Objective: To explore the clinical value of three-dimensional arterial spin labeling(3D-ASL)technology for different infarct types and cerebral blood flow perfusion caused by severe unilateral middle cerebral artery stenosis or posterior collateral circulation compensation differentiation.Methods: A total of 56 patients with severe unilateral middle cerebral artery stenosis or occlusion in Wuzhou Hospital Affiliated to Youjiang Medical College for Nationalities from2018 to 2022 were selected for head MRI plain scan(T1WI,T2 WI,T2WI Flair),DWI,3D TOF MRA,3D-ASL(PLD1.5s and PLD 2.5S).The patients were divided into the good collateral circulation group and the poor collateral circulation group according to the arterial transit artifact.The Cerebral Blood Flow(CBF)of PLD1.5s and PLD 2.5s,the proportion of no hypoperfusion,the proportion of late retrograde Blood Flow,and the type and range of infarction were measured and compared between the affected side and the healthy side.Results:(1)In the good collateral circulation group,the CBF values of the middle cerebral artery supply area of the affected side and the healthy side in PLD1.5s were:23.84±8.46ml/(100g×min),49.50±9.59ml/(100g×min),the difference was statistically significant(P < 0.001).The CBF value of the middle cerebral artery feeding area of the affected side and the healthy side were 43.95±11.53ml/(100g×min)and 52.08±8.57ml/(100g×min),respectively,and the difference was statistically significant(P = 0.001).In the poor collateral circulation group,the CBF values of the middle cerebral artery supply area of the affected side and the healthy side in PLD1.5s were as follows: 14.32±2.94ml/(100g×min),52.12±8.26ml/(100g×min),the difference was statistically significant(P < 0.001).The CBF values of the affected side and the healthy side of PLD2.5S were 24.9±5.42ml/(100g×min)and 55.45±7.93ml/(100g×min),respectively,and the difference was statistically significant(P < 0.001).(2)The PLD1.5s CBF value of the affected middle cerebral artery in the good collateral circulation group and the poor collateral circulation group was lower than PLD2.5s,and the difference was statistically significant(P < 0.001).The PLD1.5s and PLD2.5s CBF values of the affected middle cerebral artery in the good collateral circulation group were higher than those in the poor collateral circulation group,and the differences were statistically significant(P < 0.001).(3)The proportion of the good collateral circulation group without hypoperfusion was 51.7%,and the proportion of the poor collateral circulation group without hypoperfusion was 0%.There was statistically significant difference in the proportion of hypoperfusion between the two groups(P < 0.001).(4)The proportion of late arrival retrograde blood flow in the good collateral circulation group was significantly higher than that in the poor collateral circulation group,and the difference was statistically significant(P < 0.001).(5)The overall infarct range in the good collateral circulation group was smaller than that in the poor collateral circulation group,and there were statistically significant differences in the distribution of infarct types between the two groups(P <0.001).Conclusion: Biphase 3D-ASL can evaluate the damage of cerebral blood flow perfusion after severe unilateral middle cerebral artery stenosis or occlusion,the compensation difference of collateral circulation to cerebral blood flow perfusion,and the status of cerebral blood flow perfusion,and quantify collateral circulation.Different collateral circulation has certain differences in the distribution of infarct types.The better collateral circulation,the smaller the infarct size.