Radiomics based on three-dimensional high-resolution MR vessel wall imaging for identification of culprit plaques in symptomatic patients with middle cerebral artery atherosclerosis / 中华放射学杂志

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.

Characteristics of high-resolution magnetic resonance vessel wall imaging of cervicocerebral artery dissection and the influential factors of vascular recanalization / 中南大学学报(医学版)

OBJECTIVES@#Cervicocerebral artery dissection (CAD) is one of the important causes for ischemic stroke in young and middle-aged people. CAD is dangerous and untimely diagnosis and treatment are likely to result in severe disability. Early diagnosis and timely intervention can greatly improve the prognosis of patients. This study was to investigate the imaging features of CAD on high-resolution magnetic resonance vessel wall imaging (HRMR-VWI) and to analyze the influential factors of vascular recanalization.@*METHODS@#A total of 19 CAD patients with both baseline HRMR-VWI and follow-up data of vascular imaging in the period from April 2017 to December 2019 in Department of Radiology, Xiangya Hospital, Central South University were retrospectively analyzed. The diseased vessels were divided into a recovery group and a unrecovered group. After treatment, diseased vessels with no residual arterial dissection and no residual stenosis in the lumen were included in the recovery group. Diseased vessels with stenosis, occlusion or residual dissection were included in the unrecovered group. Diseased vessels were divided into a ischemic stroke group and a non-ischemic stroke group according to the presence or absence of ischemic stroke in the area supplied by the diseased vessels. Differences in clinical data and HRMR-VWI imaging findings were compared between the groups.@*RESULTS@#A total of 26 vessels were involved, including 14 (53.8%) internal carotid artery extracranial segment, 8 (30.8%) vertebral artery extracranial segment, 3 (11.5%) vertebral artery intracranial segment, and 1 (3.9%) basilar artery. Ischemic stroke occurred in 16 diseased vascular supply areas. Intramural hematoma was all observed in the baseline HMR-VWI of the affected vessels. There were 18 vessels (69.2%) in the recovery group and 8 vessels (30.8%) in the unrecovered group. Compared with the vessels in the recovery group, the vessels in the unrecovered group were mostly found in the intracranial segment (@*CONCLUSIONS@#Intramural hematoma is a common imaging manifestation of CAD and can be shown clearly and accurately on HRMR-VWI. Recanalization rate of CAD is high, and the recanalization of CAD in intracranial segment is slower than that of CAD in extracranial segment, which can prolong the review time.

Application of vessel wall magnetic resonance imaging in intracranial artery dissection / 中国脑血管病杂志

Intracranial artery dissection is rare in the clinic, but could account for a large proportion of young patients with intracranial vascular diseases. High-resolution magnetic resonance imaging is a direct method of vessel wall imaging and widely used in clinical practice due to advantages including high spatial resolution, high signal-to-noise ratio and strong reproducibility. The article briefly introduces the typical findings of intracranial artery dissection in high-resolution magnetic resonance imaging and the unique advantages of features such as intimal flap, double-lumen, lumen diameter change and intramural hematoma. It makes up for the deficiency of traditional lumen imaging in the diagnosis and differential diagnosis of intracranial artery dissection, providing a strong basis for the diagnosis and intervention of intracranial vascular dissection.

Disseminated Takayasu arteritis with neurovascular small and medium vessel involvement

@#Takayasu arteritis is a rare granulomatous vasculitis that is commonly classified as a large vessel disease. Small and medium vessel involvement are extremely rare, with only a few case reports describing neurovascular, ocular and cutaneous involvement. We describe a 21 year old Malaysian woman with pre-existing Takayasu arteritis confined to the large vessels, presenting one year later to our centre with status epilepticus. Extensive radiologic studies revealed diffuse encephalopathic changes and multifocal neurovascular involvement, with the vasculitis progressing to encompass the large, medium and small vessels. The patient was treated with high dose steroid therapy and discharged well with long term steroid and immunosuppressive therapy. Follow up MRI with vessel wall imaging sequence (VW-MR) and arterial spin labelling (ASL) perfusion imaging demonstrated intra and extracranial vessel wall inflammation, with generalized reduction in left sided cerebral blood flow. This case demonstrates that Takayasu arteritis is not exclusively a large vessel vasculitis, and that small and medium vessel involvement does not preclude its diagnosis.

Study of highGresolution MR on the cerebral perforating artery related ischemic stroke / 实用放射学杂志

Objective To study the value of three-dimensional high-resolution magnetic resonance wall imaging (3D-HR-VWI)for ischemic stroke caused by perforating artery infarction.Methods Retrospectively studied 38 patients between 201 6 and 2018.3D-HR-VWI technique were used to examine the structures of the ipsilateral and contralateral lenticulostriate arteries of the lesion,to study the characteristics of the perforating artery lesion.Results There was no statistical significance in the absolute number of lenticulostriate arteries on the lesion side and the normal side (P＝0.251 2).There was statistical significance in the ratio of lenticulostriate arteries between two groups (P＝0.020).The differences of the depth of lenticulostriate arteries on lesion sides were also statistical significant between two groups (P＝0.032).The differences among risk factors including hypertension,diabetes,hyperlipidemia and smoking were not statistically significant.There was no statistical significance on the differences of vascular involvement,length of M1 lesions,etiological types, number of lenticulostriate arteries,and depth of lenticulostriate arteries among the lateral lenticulostriate artery group,the internal lenticulostriate artery group and the internal+lateral lenticulostriate artery group.Conclusion 3D-HR-VWI can show the lesions of lenticulostriate arteries and perforating arteries,which is of important in diagnosis of perforating artery infarction.

Incremental diagnostic value of neck vessel wall imaging technique with T1?weighted three?dimensional variable?flip?angle turbo spin?echo before revascularization in patients with carotid atherosclerotic disease / 中华放射学杂志

Objective To determine the feasibility of neck vessel wall imaging technology with three?dimensional variable?flip?angle turbo spin?echo (3D T1w?SPACE) for the detection of carotid atherosclerotic disease before revascularization. Methods Thirty?one patients who underwent carotid endarterectomy (CEA) and fifty?three patients who underwent carotid stenting (CAS) were enrolled prospectively. Neck vessel wall imaging examination were performed in all patients whilecarotid artery DSA were performed in all CAS patients. Quantitative measurements including stenosis, lesion length, and the presence or absence of plaque ulceration obtained with 3D T1w?SPACE and DSA were independently determined. And images of the 3D T1w?SPACE were compared with corresponding histology to identify major plaque components including intraplaque hemorrhage (IPH), lipid rich necrotic core (LRNC), and calcification (CA). The consistency rate, sensitivity, specificity, positive predictive value and negative predictive value were used to assess diagnostic value. Bland?Altman plots, intraclass correlation coefficient (ICC), and Cohen Kappa were determined. Results DSA was served as the reference standard. There was an excellent correlation between 3D T1w?SPACE and DSA images in measuring stenosis (r=0.984, P<0.01) and luminal stenosis [ICC=0.98 (95% confidence interval: 0.96-0.99)]. Bland?Altman plots showed that the two examinations were in good consistency in evaluating the extent of stenosis. Sensitivity (89.5%) and specificity (95.1%) was high in 3D T1w?SPACE images compared to DSA for the detection of ulcers. The consistency rate between 3D T1w?SPACE images and histological results for IPH, LRNC and CA detection were 85.7%, 82.1% and 92.9%, respectively. Sensitivity and specificity were 90.0% and 75.0% for IPH;83.3% and 80.0% for LRNC; 91.3% and 100.0% for CA respectively. However, lesion length measurements by using 3D T1w?SPACE were longer than those measured by using DSA (P<0.01).Conclusion Neck vessel wall imaging technology with 3D T1w?SPACE is a noninvasive and accurate technique for the diagnosis of carotid artery atherosclerotic disease before revascularization.

MRI Vessel Wall Imaging and Treatment of an Aneurysm at the Atlanto-Axial Segment of an Aberrant Vertebral Artery / 신경중재치료의학

We report a case of unique location of an aneurysm at the atlanto-axial extradural segment of a unilateral aberrant vertebral artery. The MRI vessel wall imaging findings and possible mechanism of aneurysm formation were discussed. A 5 mm extracranial vertebral artery aneurysm located at the interlaminar space between C1 and C2 was diagnosed in a woman presenting with occipital headache. The index vertebral artery ran an aberrant course at the V3 segment, where it entered the dura between C1 and C2 instead of the usual atlanto-occipital space. MR vessel wall imaging showed homogenous wall enhancement of the aneurysm sac. We surmise the anomalous course of the vertebral artery subjected the V3 segment to repeated shearing force secondary to the atlanto-axial rotational neck movement. This led to vessel wall trauma and inflammation, and subsequent aneurysm formation. The aneurysm was successfully treated with endovascular coiling with resolution of symptoms.

Assessment of Arterial Wall Enhancement for Differentiation of Parent Artery Disease from Small Artery Disease: Comparison between Histogram Analysis and Visual Analysis on 3-Dimensional Contrast-Enhanced T1-Weighted Turbo Spin Echo MR Images at 3T

OBJECTIVE: The purpose of this study was to compare the histogram analysis and visual scores in 3T MRI assessment of middle cerebral arterial wall enhancement in patients with acute stroke, for the differentiation of parent artery disease (PAD) from small artery disease (SAD). MATERIALS AND METHODS: Among the 82 consecutive patients in a tertiary hospital for one year, 25 patients with acute infarcts in middle cerebral artery (MCA) territory were included in this study including 15 patients with PAD and 10 patients with SAD. Three-dimensional contrast-enhanced T1-weighted turbo spin echo MR images with black-blood preparation at 3T were analyzed both qualitatively and quantitatively. The degree of MCA stenosis, and visual and histogram assessments on MCA wall enhancement were evaluated. A statistical analysis was performed to compare diagnostic accuracy between qualitative and quantitative metrics. RESULTS: The degree of stenosis, visual enhancement score, geometric mean (GM), and the 90th percentile (90P) value from the histogram analysis were significantly higher in PAD than in SAD (p = 0.006 for stenosis, < 0.001 for others). The receiver operating characteristic curve area of GM and 90P were 1 (95% confidence interval [CI], 0.86–1.00). CONCLUSION: A histogram analysis of a relevant arterial wall enhancement allows differentiation between PAD and SAD in patients with acute stroke within the MCA territory.

Differentiation of Deep Subcortical Infarction Using High-Resolution Vessel Wall MR Imaging of Middle Cerebral Artery

OBJECTIVE: To evaluate the utility of high-resolution vessel wall imaging (HR-VWI) of middle cerebral artery (MCA), and to compare HR-VWI findings between striatocapsular infarction (SC-I) and lenticulostriate infarction (LS-I). MATERIALS AND METHODS: This retrospective study was approved by the Institutional Review Board, and informed consent was waived. From July 2009 to February 2012, 145 consecutive patients with deep subcortical infarctions (SC-I, n = 81; LS-I, n = 64) who underwent HR-VWI were included in this study. The degree of MCA stenosis and the characteristics of MCA plaque (presence, eccentricity, location, extent, T2-high signal intensity [T2-HSI], and plaque enhancement) were analyzed, and compared between SC-I and LS-I, using Fisher's exact test. RESULTS: Stenosis was more severe in SC-I than in LS-I (p = 0.040). MCA plaque was more frequent in SC-I than in LS-I (p = 0.028), having larger plaque extent (p = 0.001), more T2-HSI (p = 0.001), and more plaque enhancement (p = 0.002). The eccentricity and location of the plaque showed no significant difference between the two groups. CONCLUSION: Both SC-I and LS-I have similar HR-VWI findings of the MCA plaque, but SC-I had more frequent, larger plaques with greater T2-HSI and enhancement. This suggests that HR-VWI may have a promising role in assisting the differentiation of underlying pathophysiological mechanism between SC-I and LS-I.

A preliminary study on the application of high-resolution magnetic resonance vessel wall imaging in the ;evaluation of intracranial aneurysms / 中国神经精神疾病杂志

Objective The present study was to investigate the feasibility of use of high resolution magnetic reso?nance vessel wall imaging(HR-VWI)in evaluation of intracranial aneurysms. Methods We prospectively collected data from patients who had intracranial aneurysms and received HR-VWI scan before surgical treatment or conservative treatment. Aneurysms were divided into ruptured group (n=12) and unruptured group (n=88). Aneurysm site, size, neck, aspect ratio(AR), daughter sac and aneurysmal wall enhancement scale were analyzed in both groups. Univariate and multivariate Logistic regression were performed to evaluate the risk factors of aneurysm rupture. Subgroup analysis was also performed to study symptomatic and asymptomatic unruptured aneurysms. Results Aneurysm size(t=2.187,P=0.031),AR(t=3.164,P=0.002),incidence of daughter sac(P=0.012) and aneurysmal wall enhancement scale(P<0.001)were higher in ruptured aneurysm group. Multivariate Logistic regression showed that aneurysmal wall enhance?ment scale was the only independent risk factor of ruptured aneurysms(P=0.002). Subgroup analysis showed aneurysm wall enhancement scale(P<0.001) and AR(t=3.939,P<0.001) were higher in symptomatic unruptured aneurysms. Conclusion Aneurysm wall enhancement on HR-VWI is more frequently seen in ruptured aneurysms and symptomatic unruptured aneurysms. Histological study is needed for better understanding of the mechanism of aneurysm wall enhance?ment.

Vessel Wall Imaging of the Intracranial and Cervical Carotid Arteries / 대한뇌졸중학회지

Vessel wall imaging can depict the morphologies of atherosclerotic plaques, arterial walls, and surrounding structures in the intracranial and cervical carotid arteries beyond the simple luminal changes that can be observed with traditional luminal evaluation. Differentiating vulnerable from stable plaques and characterizing atherosclerotic plaques are vital parts of the early diagnosis, prevention, and treatment of stroke and the neurological adverse effects of atherosclerosis. Various techniques for vessel wall imaging have been developed and introduced to differentiate and analyze atherosclerotic plaques in the cervical carotid artery. High-resolution magnetic resonance imaging (HR-MRI) is the most important and popular vessel wall imaging technique for directly evaluating the vascular wall and intracranial artery disease. Intracranial artery atherosclerosis, dissection, moyamoya disease, vasculitis, and reversible cerebral vasoconstriction syndrome can also be diagnosed and differentiated by using HR-MRI. Here, we review the radiologic features of intracranial artery disease and cervical carotid artery atherosclerosis on HR-MRI and various other vessel wall imaging techniques (e.g., ultrasound, computed tomography, magnetic resonance, and positron emission tomography-computed tomography).

High-Resolution MRI of Intracranial Atherosclerotic Disease / 신경중재치료의학

Intracranial atherosclerotic disease (ICAD) causes up to 10% of all ischemic strokes, and the rate of recurrent vascular ischemic events is very high. Important predictors of vulnerability in atherosclerotic plaques include the degree of stenosis and the underlying plaque morphology. Vascular wall MRI can provide information about wall structures and atherosclerotic plaque components. High-resolution (HR)-MRI in ICAD poses a greater challenge in the neurologic fields, because a high in-plane resolution and a high signal-to-noise ratio are required for vessel wall imaging of ICAD. Until now, plaque imaging of ICAD has focused on assessing the presence of a plaque and evaluating the plaque load. Going forward, evaluation of plaque vulnerability through analysis of imaging characteristics will be a critical area of research. This review introduces the acquisition protocol for HR-MRI in ICAD and the current issues associated with imaging.