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Objective:To investigate the value of radiomics based on three-dimensional high resolution MR vessel wall imaging (3D HRMR-VWI) for identifying culprit plaques in symptomatic patients with middle cerebral atherosclerosis.Methods:The clinical and imaging features of 117 patients (139 middle cerebral artery plaques) with cerebrovascular diseases in Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from October 2018 to October 2020 were respectively reviewed. Stratified random sampling was used to divide 139 plaques into training set (97 plaques) and validation set (42 plaque) at the ratio of 7∶3. The plaques were divided into 69 culprit plaques and 70 non-culprit plaques based on plaque MR features and clinical symptoms. The clinical and imaging characteristics of culprit plaques and non-culprit plaques were compared by independent sample t-test, Mann-Whitney U test and χ 2 test, and factors with significant difference between two groups in univariate analysis were further analyzed by multivariate logistic regression to find out the independent predictors of culprit plaques. Radiomics features were extracted, screened and radiomics model was constructed using pre-and post-contrast 3D HRMR-VWI based on the training set. The combined model was constructed by combining the independent predictors and radiomics model. Receiver operating characteristic curve and area under curve (AUC) were used to evaluate the efficacy of each model, and DeLong test was used to compare the efficacy of different models. Results:Significant difference was found in intraplaque hemorrhage, lumen area of stenosis, stenosis diameter, stenosis rate, plaque burden and enhancement rate between culprit and non-culprit plaques (all P<0.05). Multivariate logistic regression analysis confirmed that only intraplaque hemorrhage was the independent predictor for culprit plaques (OR=7.045,95%CI 1.402-35.397, P=0.018). In the validation set, the AUC of the pre-contrast 3D HRMR-VWI model was lower than that of the post-contrast 3D HRMR-VWI model ( Z=-2.01, P=0.044). The AUC of pre+post-contrast 3D HRMR-VWI model was not significantly different from that of post-contrast 3D HRMR-VWI model ( Z=0.79, P=0.427). The AUC showed no significant difference between combined model and pre+post-contrast 3D HRMR-VWI model ( Z=-0.59, P>0.05). The combined model showed the best performance in predicting culprit plaques of middle cerebral artery (AUC=0.939), with the sensitivity, specificity and accuracy of 95.24%, 76.19% and 85.71%. Conclusion:Radiomics based on 3D HRMR-VWI has potential values in identifying culprit plaques in symptomatic patients with middle cerebral atherosclerosis.
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Objective To observe the value of three-dimensional arterial spin labeling (3D-ASL) PWI in evaluating postoperative cerebral perfusion changes in patients with Moyamoya disease.Methods Totally 19 patients of Moyamoya disease confirmed with DSA were enrolled.All the patients received revascularization.Before and after operation,3D-ASL PWI and dynamic susceptibility contrast perfusion weighted imaging (DSC-PWI) were performed.ROI was located in the region with obvious perfusion changes supplied by middle cerebral artery on the operating side.Then the cerebral blood flow (CBF) was measured on 3D-ASL images,and time to peak (TTP) was measured on DSC-PWI images before and after operation.The differences of CBF and TTP before and after operation were compared,as well as the improvement rate of CBF,TTP and clinical symptoms.Results Before and after operation,CBF was (41.40±11.36) ml/(100 g · min) and (54.10±16.69) ml/(100 g · min),respectively,and the difference was statistically significant (t=-4.273,P＜0.01).TTP was (28.66 ± 3.21) s and (26.44 ± 3.93) s,respectively,and the difference was also statistically significant (t =-2.936,P＜0.01).The improvement rate of clinical symptoms was 84.21％ (16/19),of CBF was 78.95％ (15/19) and of TTP was 68.42％ (13/19),the differences of improvement rate had no statistically significant (P=0.625).Conclusion 3D-ASL PWI is noninvasive,no contrast agent need to be used,and can be used to evaluate perfusion changes after operation of revascularization in patients with Moyamoya disease.