High-resolution Magnetic Resonance Vascular Wall Imaging Features Of The Middle Cerebral Artery With Local Signal Loss In 3D-TOF-MRA And Its Clinical Value

Objective:To explore the local signal of the M1 segment of the middle cerebral artery（MCA）in 3D-TOF-MRA by applying high resolution magnetic resonance vessel wall imaging（HRMR-VWI）at 3.0T.The HRMR-VWI features of the loss of signal in the M1 segment of the middle cerebral artery（MCA）and its relationship with recent ischemic stroke.Materials and methods:The imaging database of the China Japan Union Hospital of Jilin University from January 2017 to December 2021 was collected from 401 patients who showed moderate to severe stenosis（50%-99%）of the M1 segment of the MCA unilaterally or bilaterally on 3D-TOF-MRA maximum density projection（MIP）images of the head and underwent both HRMR-VWI and cranial diffusion-weighted imaging,containing 417 MCA stenoses.According to whether there was local signal loss in the M1 segment of MCA on 3D-TOF-MRA maximum density projection（MIP）images,they were divided into the M1 segment local signal loss group（224 patients with 233stenoses）and the conventional moderate-to-severe stenosis group（177 patients with184 stenoses）,and HRMR-VWI image features were extracted and analyzed in both groups,and HRMR-VWI imaging features of stenoses in both groups were compared.We also compared the HRMR-VWI imaging features of the two groups and their relationship with recent ischemic strokes.Results:1.HRMR-VWI image analysis showed 231 atherosclerotic plaques and 2occlusions in the MCA M1 segment local signal loss group,and 183 atherosclerotic plaques and 1 occlusions in the conventional moderate to severe stenosis group.2.Comparison of age,past history（history of hypertension,diabetes mellitus,hyperlipidemia,hyperhomocysteine,smoking,and alcohol consumption）between the two groups of patients with local signal loss in the M1 segment of the MCA due to atherosclerotic plaque（231 sites）and conventional moderate to severe stenosis（184 sites）revealed that between the two groups hypertension（p=0.046）,age（p=0.014）The differences were statistically significant.3.Comparing the HRMR-VWI plaque characteristics between the two groups,it was found that significantly enhanced plaques（82.3% vs.28.4%,p < 0.001）and concentric plaques（63.2% vs.34.4%,p < 0.001）were more common in the MCA M1 segment local signal loss group than in the conventional moderate-to-severe stenosis group;binary logistic regression analysis showed that significantly enhanced plaques（p < 0.001,OR=8.844,95% CI 5.372-14.562）,and concentric plaques（p=0.005,OR=2.016,95% CI 1.239-3.218）were independent correlates of local signal loss in the MCA M1 segment on 3D-TOF-MRA MIP images.4.Patients in the 3D-TOF-MRA MCA M1 segment local signal loss group were more likely to have recent ischemic stroke than the conventional moderate-to-severe stenosis group.According to binary logistic regression analysis,local signal loss in the MCA M1 segment on 3D-TOF-MRA MIP images was an independent risk factor for recent ischemic stroke（p<0.001,OR 3.546,95% CI 2.317-5.427）.Conclusion:1.Significantly enhanced plaques in the atherosclerotic vessel wall as well as concentric plaques are the important factors for local signal loss in the MCA M1 segment of moderate to severe stenosis on 3D-TOFMRA MIP images.2.The incidence of recent ischemic stroke was significantly higher in patients with local signal loss in the M1 segment of the MCA on 3D-TOF-MRA MIP images than in patients with conventional moderate to severe stenosis,which may provide an important basis for risk stratification in patients with moderate to severe stenosis in the MCA.