Intracranial Atherosclerotic Disease With Ischemic Stroke:A Study Of High Resolution Magnetic Resonance

In our country,about 1/3 of ischemic stroke is caused by intracranial atherosclerotic disease(ICAD).The important predictors of ischemic stroke include lumen stenosis and plaque characteristics.In recent years,it has been proved that high resolution magnetic resonance vessel wall imaging(HR-VWI)can not only evaluate the degree of stenosis of atherosclerotic artery,but also show the characteristics of artery wall.The purpose of this study is to discuss whether HR-VWI can be used as a powerful tool for evaluating the degree of intracranial atherosclerosis stenosis,and to explore the imaging features of culprit plaques and the independent influencing factors.It aim to provide more valuable imaging evidence for clinical risk stratification and treatment of intracranial atherosclerosis.Part?:Magnetic Resonance Vessel Wall Imaging in the Intracranial Artery and Image Post-processing TechnologyThis study sought to evaluate the lumen stenosis of intracranial atherosclerosis and the characteristics of plaques using high-resolution magnetic resonance vessel wall imaging in patients with ischemic stroke.All the intracranial Artery were scanned coronally on a 3.0T MRI scanner with custom-designed 16 channel head-neck coil by acquiring 3-dimensional time of flight magnetic resonance angiography,conventional scanning sequence(DWI?ADC?T1WI?T2WI? FLAIR)and 3D T1 WI HR—VWI.These3 D MRI techniques can better characterized the intracranial atherosclerosis plaque with the following advantages: 1)fast scanning speed;2)high spatial resolution(0.6mm-0.8mm);3)lager longitudinal coverage(>150mm)and et al.In our study,the original images were reconstructed on the philips post-processing workstation,and to evaluate the stenosis degree of the intracranial artery and the characteristics of plaques.Part?:Evaluation of Intracranial Atherosclerosis Stenosis with HR-VWI:Comparison with TOF-MRAObjective To compare the value of HR-VWI,TOF-MRA in diagnosis of intracranial atherosclerosis stenosis,and part of patients underwent DSA examination.To explore whether HR-VWI can be used as a powerful tool for evaluating the intracranial atherosclerosis stenosis.Methods Middle-aged patients with intracranial artery ischemic events underwent HR-VWI,TOF-MRA scanners,some of them underwent DSA examination.To analyse the correlation of three methods for evaluating lumen stenosis and to evaluate the accuracy of them.Results Total 78 arteries stenosis were identified in 39 patients.Direct comparison of the degrees of stenosis detected by the three techniques.The correlation coefficient between HR-VWI and TOF-MRA of measurements was 0.785(P=0.000),The correlation coefficient between HR-VWI and TOF-MRA of measurements was 0.85(P=0.000),The correlation coefficient between TOF-MRA.17 patients underwent DSA examination.The accuracy of the HR-VWI ? TOF-MRA is88.24%?70.59% respectively.Conclusions In the assessment of intracranial artery stenosis,there is a good correlation between HR-VWI and TOF-MRA,and HR-VWI has a better accuracy compared with DSA.Therefore,HR-VWI can be used as an effective method to evaluate intracranial artery stenosis.Part?:A study with magnetic resonance vessel wall imaging on culprit Intracranial atherosclerotic plaqueObjective To evaluate the imaging features of intracranial atherosclerotic plaques by three-dimensional high-resolution magnetic resonance vessel wall imaging and to explore the independent factor of culprit plaque.Methods Middle-aged patients with intracranial artery ischemic events underwent HR-VWI scanner.To identify and analyse the plaques with luminal stenosis ? 30% in each patient and each identified intracranial plaque was classified as either culprit group or non-culprit group.To analyse the imaging features of the culprit plaque(degree of lumen stenosis,plaque burden,remodeling index,positive remodeling rate,plaque enhancement index,degree of plaque enhancement)and to explore the independent factor of culprit plaque by binary logistic regression analysis.Results Total 78 plaques were identified in 39 patients with ischemic events(39culprit plaques and 39 non-culprit plaques).The degree of enhancement was rated as strong,moderate and none in 28,4 and 7 culprit plaques,and in 5,15 and 19non-culprit plaques.intra-observer reproducibility and reliability are high for measurement of plaque enhancement index(ICC=0.80,Cronbach?=0.82).For culprit plaques group,the degree of lumen stenosis,plaque burden,plaque enhancement index,the degree of plaque enhancement(P?0.001)were significantly higher than those in the non-culprit group.A Part of indicators above were included in Binary logistic regression analysis revealing that degree of lumen stenosis(OR:4.759,95%CI:1.445 ~ 15.679,P=0.010)and strong enhancement of plaque(OR:10.154,95%CI:2.930~35.182,P =0.000)was independently associated with culprit plaques.Conclusions 3D HR-VWI evaluates intracranial atherosclerotic plaques enhancement index detects with high reproducibility and reliability.Culprit plaques have higher degree of unstability and enhancement compared to non-culprit plaque.The degree of lumen stenosis can be used as an indicator for the occurrence,development and prognosis of ischemic stroke.