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Purpose: To investigate the association between plaque enhancement and stroke recurrence in subjects with intracranial atherosclerosis. Methods: Ischemic stroke patients with symptomatic intracranial atherosclerosis were prospectively included and followed in a comprehensive stroke center. Pre- and post-contrast vessel wall images were used to evaluate plaque enhancement. Other established suggestive imaging markers were also acquired simultaneously. Univariate- and multivariate-adjusted Cox proportional hazard regression models were used to determine the association between plaque enhancement and stroke recurrence. Finally, receiver operating characteristic (ROC) curves were used to demonstrate the predictive value of different imaging markers. Results: Of the 60 subjects included, 12 (20.0%) patients presented with ipsilateral stroke recurrence during the median 12-month follow-up. Cox proportional hazard regression models indicated that plaque enhancement was an independent risk factor associated with stroke recurrence after adjusted covariates, with a hazard ratio (HR) of 14.24 and 95% confidence interval (95% CI) (1.21, 168.11), p = 0.04. In addition, border zone infarction was also statistically significant in predicting stroke recurrence in multi-variable regression (HR = 3.80; 95% CI = 1.04, 13.80; p = 0.04). Collateral status was in marginal significance (HR = 0.25; 95% CI = 0.06, 1.08; p = 0.06). ROC analysis indicated that the area under the curve and 95% CI to identify stroke recurrence are 0.67 (0.51, 0.82) for plaque enhancement and 0.71 (0.54, 0.88) for infarction pattern and collateral status and may increase to 0.82 (0.70, 0.93) by combining the three markers above. Conclusion: Plaque enhancement is independently associated with stroke recurrence in subjects with intracranial atherosclerosis and has added value to hemodynamic indicators in predicting stroke recurrence. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: To evaluate the early enhancement of coronary atherosclerotic plaque using contrast-enhanced MR angiography (CE-MRA) and investigate the association between unstable angina pectoris (UAP) and early enhancement of the plaque. Methods: Forty-one patients presenting with angina pectoris and demonstrating single-vessel disease with non-calcified plaque and significant coronary stenosis (≥50%) on CTA were consecutively recruited for coronary CE-MRA. Contrast-to-noise ratio of the culprit plaque guided by CTA was measured on a cross-sectional multi-planar reconstruction image of the plaque on both pre- and post-CE-MRA. A 50% increasing of CNR was defined as plaque enhancement. The association between early enhancement of the plaques and UAP was analyzed. Results: Thirty-seven non-calcified plaques with significant coronary stenosis were detected in the 37 patients on MRA. 4 subjects were excluded because coronary atherosclerotic plaques were inadequate for identification on MRA. Of the 37 patients, 18 patients had UAP and other 19 patients presented stable angina pectoris (SAP). Of the 37 plaques on CE-MRA, 13 and 24 plaques presented early enhancement and no enhancement, respectively. Of the 13 early-enhanced plaques, 11 (85%) and 2 (15%) were found in the patients with UAP and SAP, respectively (p <0.01). Of the 37 patients, 11 (61%) with UAP and 2 (11%) with SAP had early-enhanced plaques, respectively (p <0.01). Conclusion: CE-MRA allows detection of early enhancement of coronary atherosclerotic plaque. The early enhancement is common in unstable angina and could be a sign of vulnerability. [Copyright &y& Elsevier]

Objectives: Significant atherosclerotic stenosis or occlusion in the distal internal carotid artery (ICA) may induce diffuse wall thickening (DWT) in the upstream arterial wall. This study aimed to assess the association of atherosclerotic steno-occlusive diseases in the distal ICA with DWT in the upstream ipsilateral ICA. Methods: Individuals with atherosclerotic stenosis in the distal ICA, detected by carotid MR vessel wall imaging using 3D pre- and post-contrast T1 volume isotropic turbo spin-echo acquisition (T1-VISTA) sequence, were enrolled. The associations of vessel wall thickening, the longitudinal extent of DWT, enhancement of the upstream ipsilateral ICA, and stenosis degree in the distal ICA were examined. Results: Totally 64 arteries in 55 patients with atherosclerotic steno-occlusive distal ICAs were included. Significant correlations were found between distal ICA stenosis and DWT in the petrous ICA (r = 0.422, p = 0.001), DWT severity (r = 0.474, p < 0.001), the longitudinal extent of DWT in the ICA (r = 0.671, p < 0.001), enhancement in the petrous ICA (r = 0.409, p = 0.001), and enhancement degree (r = 0.651, p < 0.001). In addition, high degree of enhancement was correlated with both increased wall thickness and increased prevalence of DWT in the petrous ICA (both p < 0.001). Conclusions: DWT of the petrous ICA is commonly detected in patients with atherosclerotic steno-occlusive disease in the distal ICA. The degree of stenosis in the distal ICA is associated with wall thickening and its longitudinal extent in the upstream segments. Clinical relevance statement: Diffuse wall thickening is a common secondary change in atherosclerotic steno-occlusive disease in the intracranial carotid. This phenomenon constitutes a confounding factor in the distinction between atherosclerosis and inflammatory vasculopathies, and could be reversed after alleviated atherosclerotic stenosis. Key Points: • Diffuse wall thickening of the petrous internal carotid artery is commonly detected in patients with atherosclerotic steno-occlusive disease in the distal internal carotid artery. • The phenomenon of diffuse wall thickening could be reversed after stenosis alleviation. • Carotid artery atherosclerosis with diffuse wall thickening should warrant a differential diagnosis from other steno-occlusive diseases, including moyamoya diseases and Takayasu aortitis. [ABSTRACT FROM AUTHOR]

Segmentation of cerebral vasculature on MR vascular images is of great significance for clinical application and research. However, the existing cerebrovascular segmentation approaches are limited due to insufficient image contrast and complicated algorithms. This study aims to explore the potential of the emerging four-dimensional arterial spin labeling magnetic resonance angiography (4D ASL-MRA) technique for fast and accurate cerebrovascular segmentation with a simple machine-learning approach. Nine temporal features were extracted from the intensity-time signal of each voxel, and eight spatial features from the neighboring voxels. Then, the unsupervised outlier detection algorithm, i.e. Isolation Forest, is used for segmentation of the vascular voxels based on the extracted features. The total length of the centerlines of the intracranial arterial vasculature, the dice similarity coefficient (DSC), and the average Hausdorff Distance (AVGHD) on the cross-sections of small- to large-sized vessels were calculated to evaluate the performance of the segmentation approach on 4D ASL-MRA of 18 subjects. Experiments show that the temporal information on 4D ASL-MRA can largely improve the segmentation performance. In addition, the proposed segmentation approach outperforms the traditional methods that were performed on the 3D image (i.e. the temporal average intensity projection of 4D ASL-MRA) and the previously proposed frame-wise approach. In conclusion, this study demonstrates that accurate and robust segmentation of cerebral vasculature is achievable on 4D ASL-MRA by using a simple machine-learning approach with appropriate features. [ABSTRACT FROM AUTHOR]

Objectives To assess how radiomic features may be combined with plaque morphological and compositional features identified by multi-contrast MRI to improve upon conventional risk assessment models in determining culprit carotid artery lesions. Methods Fifty-five patients (mean age: 62.6; 35 males) with bilateral carotid stenosis who experienced transient ischaemic attack (TIA) or stroke were included from the CARE-II multi-centre carotid imaging trial (ClinicalTrials.gov Identifier: NCT02017756). They underwent MRI within 2 weeks of the event. Classification capability in distinguishing culprit lesions was assessed by machine learning. Repeatability and reproducibility of the results were investigated by assessing the robustness of the radiomic features. Results Radiomics combined with a relatively conventional plaque morphological and compositional metric-based model provided incremental value over a conventional model alone (area under curve [AUC], 0.819 ± 0.002 vs 0.689 ± 0.019, respectively, P  = .014). The radiomic model alone also provided value over the conventional model (AUC, 0.805 ± 0.003 vs 0.689 ± 0.019, respectively, P  = .031). T2-weighted imaging-based radiomic features had consistently higher robustness and classification capabilities compared with T1-weighted images. Higher-dimensional radiomic features outperformed first-order features. Grey Level Co-occurrence Matrix, Grey Level Dependence Matrix, and Grey Level Size Zone Matrix sub-types were particularly useful in identifying textures which could detect vulnerable lesions. Conclusions The combination of MRI-based radiomic features and lesion morphological and compositional parameters provided added value to the reference-standard risk assessment for carotid atherosclerosis. This may improve future risk stratification for individuals at risk of major adverse ischaemic cerebrovascular events. Advances in knowledge The clinical relevance of this work is that it addresses the need for a more comprehensive method of risk assessment for patients at risk of ischaemic stroke, beyond conventional stenosis measurement. This paper shows that in the case of carotid stroke, high-dimensional radiomics features can improve classification capabilities compared with stenosis measurement alone. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to determine the usefulness of magnetic resonance imaging (MRI) characteristics in discriminating H3 K27M-mutant gliomas from wildtype gliomas in the spinal cord. Materials and methods: Fifty-eight patients with spinal cord gliomas were enrolled in this study. The H3 K27 gene status was identified by Sanger sequencing or immunohistochemistry test of resection tumor specimens. The MR imaging characteristics were evaluated and compared between H3 K27M-mutant and wildtype gliomas using the χ2 test and the Mann–Whitney U test. Results: Of 58 recruited patients, 23 (39.7%) were diagnosed with H3 K27M-mutant glioma. The H3 K27M-mutant gliomas were found to more likely occur in men compared with wildtype gliomas (87.0% vs. 42.9%, p = 0.001). On T2-weighted MR images, the signal-to-noise ratio (SNR) of H3 K27M-mutant gliomas was significantly lower than that of wildtype gliomas (103.9 ± 72.0 vs. 168.9 ± 86.8, p < 0.001). Of 35 wildtype tumors, 60% showed well-defined margin but this feature was not found in all mutant tumors (p < 0.001). The SNR of tumors on contrast-enhanced T1-weighted images of the H3 K27M-mutant gliomas was significantly lower than that of wildtype gliomas (187.7 ± 160.4 vs. 295.1 ± 207.8, p = 0.006). Receiver operating-characteristic analysis revealed that area under curve (AUC) of combination of 1/SNR on T2-weighted images, 1/SNR on contrast-enhanced T1-weighted images, ill-defined margin, and sex reached 0.937 (95% CI, 0.873–1.000) in discriminating H3 K27M-mutant gliomas. Conclusions: The MR imaging characteristics are valuable in discriminating H3 K27M-mutant from wildtype gliomas in the spinal cord and the combination of these imaging features with sex had a high strength in this discrimination. [ABSTRACT FROM AUTHOR]

To determine the usefulness of multiparametric magnetic resonance (MR) quantitative imaging in characterizing the kidneys in systemic sclerosis (SSc) patients. Forty-six SSc patients (47.9 ± 12.8 years, 40 females) and 22 age- and sex- matched healthy volunteers (46.1 ± 13.8 years, 20 females) were recruited and underwent renal MR imaging by acquiring blood oxygen level dependent and saturated multi-delay renal arterial spin labeling (SAMURAI) sequences. The T2* value, T1 value, renal blood flow (RBF), arterial bolus arrival time (aBAT), and tissue bolus arrival time (tBAT) of renal cortex were measured and compared among diffuse cutaneous SSc (dcSSc) and limited cutaneous SSc (lcSSc) groups and healthy controls using One-way ANOVA and analyzed by logistic regression. Compared to healthy volunteers, SSc patients with normal estimated glomerular filtration rate (n = 40) had significantly lower T2* value (P = 0.026) in the left renal cortex, longer T1 value (right: P = 0.015; left: P = 0.023), lower RBF (right: P < 0.001; left: P < 0.001), and shorter tBAT (right: P < 0.001; left: P = 0.005) in both right and left renal cortex after adjusting for demographics. The dcSSc patients (n = 23) had significantly lower RBF in both right (226.7 ± 65.2 mL/100 g/min vs. 278.2 ± 73.5 mL/100 g/min, P = 0.022) and left (194.5 ± 71.5 mL/100 g/min vs. 252.7 ± 84.4 mL/100 g/min, P = 0.020) renal cortex compared to the lcSSc patients (n = 23) after adjusting for demographics, but the significance of the difference was attenuated after further adjusting for modified Rodnan skin score and digital ulcers. Multi-parametric MR quantitative imaging, particularly multi-delay ASL perfusion imaging, is a useful technique for characterizing the kidneys and classification of SSc patients. • Multiparametric MR quantitative imaging was utilized to characterize the impairment of renal microstructure and function in SSc patients. • Compared to the healthy volunteers, the SSc patients were more likely to have significantly lower T2*, longer T1, lower RBF, and shorter tBAT. • The dcSSc patients were found to have significantly lower RBF than the lcSSc patients. [ABSTRACT FROM AUTHOR]

Background: Atherosclerotic cardiovascular disease is the leading cause of death worldwide. Early detection of carotid atherosclerosis can prevent the progression of cardiovascular disease. Many (semi‐) automatic methods have been designed for the segmentation of carotid vessel wall and the diagnosis of carotid atherosclerosis (i.e., the lumen segmentation, the outer wall segmentation, and the carotid atherosclerosis diagnosis) on black blood magnetic resonance imaging (BB‐MRI). However, most of these methods ignore the intrinsic correlation among different tasks on BB‐MRI, leading to limited performance. Purpose: Thus, we model the intrinsic correlation among the lumen segmentation, the outer wall segmentation, and the carotid atherosclerosis diagnosis tasks on BB‐MRI by using the multi‐task learning technique and propose a gated multi‐task network (GMT‐Net) to perform three related tasks in a neural network (i.e., carotid artery lumen segmentation, outer wall segmentation, and carotid atherosclerosis diagnosis). Methods: In the proposed method, the GMT‐Net is composed of three modules, including the sharing module, the segmentation module, and the diagnosis module, which interact with each other to achieve better learning performance. At the same time, two new adaptive layers, namely, the gated exchange layer and the gated fusion layer, are presented to exchange and merge branch features. Results: The proposed method is applied to the CAREII dataset (i.e., 1057 scans) for the lumen segmentation, the outer wall segmentation, and the carotid atherosclerosis diagnosis. The proposed method can achieve promising segmentation performances (0.9677 Dice for the lumen and 0.9669 Dice for the outer wall) and better diagnosis accuracy of carotid atherosclerosis (0.9516 AUC and 0.9024 Accuracy) in the "CAREII test" dataset (i.e., 106 scans). The results show that the proposed method has statistically significant accuracy and efficiency. Conclusions: Even without the intervention of reviewers required for the previous works, the proposed method automatically segments the lumen and outer wall together and diagnoses carotid atherosclerosis with high performance. The proposed method can be used in clinical trials to help radiologists get rid of tedious reading tasks, such as screening review to separate normal carotid arteries from atherosclerotic arteries and to outline vessel wall contours. [ABSTRACT FROM AUTHOR]

Objective To investigate the relationship between morning blood pressure surge (MBPS) and intracranial atherosclerotic plaque burden and vulnerability. Methods A total of 267 ischaemic stroke patients were retrospectively analysed. Sleep-trough and prewaking MBPS were calculated from ambulatory blood pressure monitoring (ABPM). Plaque characteristics, including intraplaque haemorrhage (IPH), maximum wall thickness (max WT), and stenosis degree, were obtained from high-resolution MR vessel wall imaging (HR-vwMRI). Linear and logistic regression were used to detect the association. Results Subjects with the top tertile of sleep-trough MBPS (≥15.1 mmHg) had a lower prevalence (9.1% vs. 19.6%, P  = .029) of severe stenosis (≥70%) than others. Subjects within the top tertile of prewaking MBPS (≥7.6 mmHg) had a lower percentage of IPH (27.3% vs. 40.4%, P  = .035) than others. After adjusting for stroke risk factors (age, sex, diabetes, hyperlipidaemia, hyperhomocysteinaemia, smoking, and family stroke history) and 24-h mean systolic blood pressure, 10 mmHg sleep-trough MBPS increment was associated with 0.07mm max WT reduction, and the top tertile MBPS group was associated with a lower chance of severe stenosis (odd ratio = 0.407, 95% CI, 0.175-0.950). Additionally, an increased prewaking MBPS is associated with a lower incidence of IPH, with OR = 0.531 (95% CI, 0.296-0.952). Subgroup analysis demonstrated that the positive findings could only be seen in non-diabetic subjects. Conclusion Increment of MBPS is negatively associated with intracranial atherosclerotic plaque burden and vulnerability, and this relationship remains significant in the non-diabetic subgroup. Advances in knowledge This study provided evidence that MBPS was associated with the intracranial atherosclerotic plaque burden and vulnerability on HR-vwMRI. [ABSTRACT FROM AUTHOR]

Background: Atherosclerotic plaque inflammation is a well-known risk factor for the development of ischemic stroke. Purpose: To investigate the characteristics of patients with enhancing intracranial atherosclerosis and the relationship between plaque enhancement and recent cerebrovascular ischemic events by using high-resolution magnetic resonance imaging (HR-MRI). Material and Methods: A total of 141 patients (102 men; mean age = 61.1 ± 11.4 years) with intracranial atherosclerotic plaque who underwent HR-MRI were enrolled in this study. The contrast ratio (CR) and contrast enhancement of the plaques were measured. Binary logistic regression was used to estimate the association between plaque enhancement and clinical and plaque characteristics. The relationship between plaque enhancement and recent ischemic events was evaluated by multivariate logistic regression analysis. Results: Of 141 patients, plaque enhancement was detected in 80 (56.7%). Compared to patients without plaque enhancement, those with plaque enhancement had significantly lower level of high-density lipoprotein cholesterol, greater maximum plaque length, and more severe luminal stenosis. Luminal stenosis was independently associated with plaque enhancement (odds ratio [OR] = 1.026; 95% confidence interval [CI] = 1.014–1.039). Multivariate regression analysis showed that plaque enhancement was an independent indicator for recent ischemic events after adjusting for confounding factors (OR = 9.521; 95% CI = 4.301–19.900) (all P < 0.05). Conclusion: Luminal stenosis is independently associated with plaque enhancement. We observed a strong association between plaque enhancement and recent ischemic events, which suggests that plaque enhancement may serve as an indicator of its instability. [ABSTRACT FROM AUTHOR]

The purpose of this study was to demonstrate the usefulness of conventional magnetic resonance imaging (MRI) in stratification of spinal cord non-ependymal gliomas. Forty-one patients (mean age, 29.9 ± 16.8 years; 27 men) with first-diagnosed spinal cord non-ependymal gliomas underwent conventional MRI including T1-weighted, T2-weighted (T2W) and contrast-enhanced T1-weighted imaging sequences. The tumors were removed by surgery and processed by histology 1 week after MRI. Patients were divided into low-grade and high-grade groups according to histological findings. The MRI features of gliomas including signal-to-noise-ratio (SNR), margins, heterogeneity, edema, enhancement, tumor size, longitudinal location, and presence of syrinx were measured and compared between low-grade and high-grade groups using the χ2 test and the Mann-Whitney U test. The SNR of low-grade gliomas on T2W images was significantly higher than that of high-grade gliomas (165.0 ± 108.7 vs. 98.6 ± 44.4; P = 0.016 by the Mann-Whitney U test). The margins of low-grade gliomas were found to be clearer compared to that of high-grade gliomas (54.5% vs. 5.3%; P = 0.001). Receiver-operating-characteristic analysis revealed that the area under the curve of 1/SNR, margin and the combination of 1/SNR and margin was 0.722 (95% confidence interval [CI], 0.564–0.880), 0.736 (95% CI, 0.578–0.894), and 0.845 (95% CI, 0.717–0.973), respectively. No significant differences were found in the heterogeneity, edema, enhancement level, enhancement SNR, size, longitudinal location, cyst, hemorrhage, and intramedullary location between low-grade and high-grade non-ependymal gliomas (all P > 0.05). The characteristics of signal intensity and margin on T2W imaging are valuable in stratification of spinal cord non-ependymal gliomas. [ABSTRACT FROM AUTHOR]

Abstract: Background and purpose: It remains unclear whether direct vessel wall imaging can identify carotid high-risk lesions in symptomatic subjects and whether carotid plaque characteristics are more effective indicators for cerebral infarct severity than stenosis. This study sought to determine the associations of carotid plaque characteristics by MR imaging with stenosis and acute cerebral infarct (ACI) sizes on diffusion weighted imaging (DWI). Materials and methods: One hundred and fourteen symptomatic patients underwent carotid and brain MRI. ACI volume was determined from symptomatic internal carotid artery territory on DWI images. Ipsilateral carotid plaque morphological and compositional characteristics, and stenosis were also determined. The relationships between carotid plaque characteristics, stenosis and ACIs size were then evaluated. Results: In carotid arteries with 30–49% stenosis, 86.7% and 26.7% were found to have lipid-rich necrotic core (LRNC) and intraplaque hemorrhage, respectively. Furthermore, 45.8% of carotid arteries with 0–29% stenosis developed LRNCs. Carotid morphological measurements, such as % wall volume, and the LRNC size were significantly associated with ipsilateral ACIs volume before and after adjustment for significant demographic factors (age and LDL) or stenosis in patients with carotid plaque (all p <0.05). Conclusions: A substantial number of high-risk plaques characterized by vessel wall imaging exist in carotid arteries with lower grade stenosis. In addition, carotid plaque characteristics, particularly the % wall volume and LRNC size, are independently associated with cerebral infarction as measured by DWI lesions. Our findings indicate that characterizing atherosclerotic plaque by MR vessel wall imaging might be useful for stratification of plaque risk and infarction severity. [Copyright &y& Elsevier]

Objectives: This study aimed to determine the association between vessel wall enhancement and progression of arterial stenosis and clinical outcomes in patients with moyamoya (MMD) using high-resolution magnetic resonance (HRMR) vessel wall imaging. Methods: Consecutive participants diagnosed with MMD were prospectively recruited and underwent HRMR at baseline and during follow-up, which had an interval period of ≥ 6 months and were clinically followed up for ≤ 24 months to record the occurrence of ischemic stroke. The relationship between vessel wall enhancement and arterial stenosis progression and stroke occurrence was evaluated. Results: HRMR vessel wall imaging was used to identify 309 stenotic lesions at the internal carotid artery (ICA) in 170 participants (mean age: 37.7 ± 11.3 years old, male: 44.1%). The baseline presence (adjusted odds ratio [aOR] = 3.57, 95% CI = 1.97–6.44, p < 0.001) and progression (aOR = 2.96, 95% CI = 1.29–6.80, p = 0.010) of vessel wall enhancement and middle cerebral artery (MCA) involvement (aOR = 4.98, 95% CI = 1.50–16.52, p = 0.009) were significantly associated with rapid progression of arterial stenosis. Furthermore, vessel wall enhancement (adjusted HR = 3.59, 95% CI = 1.33–9.70, p = 0.011) and rapid progression of arterial stenosis (adjusted HR = 4.52, 95% CI = 1.48–13.81, p = 0.008) were correlated with future stroke occurrence. Conclusion: The baseline presence of vessel wall enhancement was associated with rapid progression of arterial stenosis and increased risk for stroke in MMD patients. Our findings suggest that vessel wall enhancement may serve as a predictor of disease progression and poor outcomes in MMD. Key Points: • The baseline presence of vessel wall enhancement was significantly associated with the rapid progression of arterial stenosis. • The baseline presence of vessel wall enhancement and rapid progression of arterial stenosis were both correlated with increased risk for future occurrence of stroke. • Our findings suggest that vessel wall enhancement may serve as a predictor of rapid progression of arterial stenosis and poor outcomes in MMD patients. [ABSTRACT FROM AUTHOR]

Background and aims Prospective studies have shown a strong association between carotid intraplaque hemorrhage (IPH), detected by magnetic resonance imaging (MRI), and cerebrovascular ischemic events. However, IPH is also observed in a substantial number of asymptomatic patients. We hypothesized that there are differences in the characteristics of IPH+ plaques associated with recent symptoms, compared to IPH+ plaques not associated with recent symptoms. Methods Patients with recent (≤2 weeks) anterior circulation ischemic events were scanned using a standardized multisequence protocol. Those showing IPH bilaterally were included and analyzed for differences in T1/T2 signals, plaque morphology, and coexisting plaque characteristics between the ipsilateral symptomatic and contralateral asymptomatic sides. Results Thirty-one subjects (67 ± 9 years, 97% males) with bilateral IPH were studied. Despite comparable luminal stenosis (53 ± 42% vs. 53 ± 39%, p = 0.99), T1 signal of IPH measured as signal-intensity-ratio compared to muscle was stronger (SIR IPH-to-muscle : 5.8 ± 2.4 vs. 4.7 ± 1.8, p = 0.004) and tended to be more extensively distributed (IPH volume: 150 ± 199 vs. 88 ± 106 mm 3 , p = 0.071) on the symptomatic side. IPH+ plaques on the symptomatic side were longer (24 ± 6 vs. 21 ± 7 mm, p = 0.026) and associated with larger necrotic core volume (406 ± 354 vs. 291 ± 293 mm 3 , p = 0.039) than those on the asymptomatic side. Conclusions In recently symptomatic patients with bilateral carotid IPH, the symptomatic side showed stronger T1 signals, larger necrotic cores, and longer plaque length than the asymptomatic side. Serial studies on the temporal relationship between these imaging features and clinical events will eventually establish their diagnostic and prognostic value beyond the mere presence of IPH. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to investigate the associations between carotid vulnerable plaque features coexisting with cerebral small vessel diseases (CSVDs) and acute ischemic stroke (AIS) and, furthermore, to determine whether coexisting diseases had a stronger association with AIS than a single disease. Methods: Patients with cerebrovascular symptoms and carotid plaque were recruited from the cross-sectional, multicenter CARE-II study. The population was divided into two groups (AIS and transient ischemic stroke (TIA)). MRI features of carotid plaques (including luminal stenosis and plaque vulnerabilities) and CSVDs (such as white matter hyperintensities (WMHs) and lacunes) were evaluated. Coexisting diseases were defined as the presence of at least one carotid plaque features and one or more CSVDs feature. Multivariate logistic regression was performed to examine the associations between coexisting diseases and AIS. Results: Of the recruited 634 patients (mean age: 59.1 ± 11.3 years; 429 males), 312 (49.2%) patients had AIS. These subjects had a higher prevalence of carotid vulnerable plaques, lacunes, and moderate-to-severe WMHs (a total Fazekas score of 3–6) than those with TIA (42.6% vs. 29.5%, 59.6% vs. 26.4%, 69.9% vs. 60.6%, respectively, all p < 0.05). Multivariate analysis revealed that carotid plaque features coexisting with lacunes or moderate-to-severe WMHs had a stronger association with AIS compared to carotid lesions alone (all p < 0.05) (i.e., vulnerable plaque coexisting with lacunes vs. vulnerable plaque alone, adjusted odds ratio: 3.67 vs. 1.62). Conclusions: Carotid vulnerable plaque features coexisting with CSVDs, particularly lacunes, had a stronger association with AIS compared to carotid lesions alone in a large, symptomatic, cohort. Trial registration: Clinical trial registration URL: http://www.clinicaltrials.gov, unique identifier: NCT02017756 Key Points: • Carotid vulnerable plaque features coexisting with cerebral small vessel diseases, such as lacunes, had a stronger association with acute ischemic stroke compared to single diseases in symptomatic patients. • A comprehensive assessment of coexisting cerebrovascular diseases may help stratify the risk of acute ischemic stroke. [ABSTRACT FROM AUTHOR]

Background: Intraplaque hemorrhage (IPH) is a hallmark of carotid plaque vulnerability. We aim to investigate the association between IPH and recurrent ipsilateral ischemic stroke.Methods: Patients with a recent stroke or transient ischemic attack (TIA) were prospectively recruited and underwent an ultrasonographic examination and carotid HR VWMRI on the side consistent with symptoms. Carotid plaque was defined as carotid intima-media-thickness (IMT) by ultrasound≥1.5 mm. IPH was determined that the ratio of the plaque signal intensity relative to that of adjacent muscle was > 1.5. All enrolled patients were clinically followed until an ipsilateral ischemic stroke, TIA, carotid endarterectomy (CEA)/carotid artery stenting (CAS), or death within 12 months. Univariate analysis was used to analyze the correlation between clinical characteristics and IPH. Kaplan-Meier survival analysis and a log-rank test were used to compare recurrence-free survival time between the IPH and non-IPH groups. Cox regression models evaluated IPH as the predictor of ipsilateral stroke recurrence.Results: A total of 171 patients (mean age, 60.13 ± 10.04 years; 118 males) were included in the final analysis. Thirty-two patients (18.7%) showed carotid IPH. During the follow-up, patients with carotid IPH suffered 60.9% (14 of 23) of recurrent ipsilateral strokes and 60.0% (3 of 5) TIA. Multivariate Cox regression analysis proved IPH as a strong predictor of ipsilateral stroke; the adjusted hazard ratio (HR) was 6.64 (95% confidence interval [CI], 2.84-15.54, P < 0.001). Meanwhile, Cox regression analysis also proved that IPH could predict recurrent ischemic events; the adjusted HR was 8.08 (95% CI, 3.65-17.91, P < 0.001).Conclusions: Carotid intraplaque hemorrhage is strongly associated with recurrent ischemic events and could predict recurrent ipsilateral stroke. [ABSTRACT FROM AUTHOR]

Purpose: Many diseases can simultaneously involve renal arteries and the adjacent abdominal aorta. This study proposed a free‐breathing three‐dimensional (3D) isotropic‐resolution magnetic resonance sequence for simultaneous vessel wall imaging (VWI) of bilateral renal arteries and adjacent abdominal aorta. Methods: A respiratory‐triggered isotropic‐resolution sequence that combined the improved motion‐sensitized driven‐equilibrium (iMSDE) preparation with the spoiled gradient recalled (SPGR) readout (iMSDE‐SPGR) was proposed for simultaneous VWI of renal arteries and abdominal aorta. The proposed iMSDE‐SPGR sequence was optimized by positioning spatial saturation pulses (i.e., REST slabs) elaborately to further alleviate respiratory and gastrointestinal motion artifacts and selecting appropriate first‐order gradient moment (m1) of the iMSDE preparation. Thirteen healthy subjects and 13 patients with renal artery stenosis underwent simultaneous VWI with the optimized iMSDE‐SPGR sequence at 3.0 T. Signal‐to‐noise ratio (SNR), contrast‐to‐noise ratio (CNR), and morphology of renal arterial wall and aortic wall were measured. Reproducibility of intra‐observer, inter‐observer, and scan–rescan (n = 13 healthy subjects) in measuring SNR, CNR, and morphology was evaluated. For the reproducibility test, the agreement was determined using intraclass correlation coefficients (ICC), and the differences were compared using paired t‐test or nonparametric Wilcoxon test when appropriate. Bland–Altman plots were used to calculate the bias between observers and between scans. Results: The proposed iMSDE‐SPGR sequence was feasible for simultaneous VWI both in the healthy subjects and the patients. The sequence showed good to excellent inter‐observer (ICC: 0.615‐0.999), excellent intra‐observer (ICC: 0.801‐0.998), and scan–rescan (ICC: 0.768‐0.998) reproducibility in measuring morphology, SNR, and CNR. There were no significant differences in SNR, CNR, and morphology measurements between observers and between scans (all p > 0.05). Bland–Altman plots showed small bias in assessing SNR, CNR, and morphology. Data conclusion: The proposed free‐breathing 3D isotropic‐resolution iMSDE‐SPGR technique is feasible and reproducible for simultaneous VWI of bilateral renal arteries and adjacent abdominal aorta. [ABSTRACT FROM AUTHOR]

We compared plaque characteristics between symptomatic and asymptomatic sides in patients with bilateral carotid vulnerable plaques using magnetic resonance imaging (MRI). Participants (n = 67; mean age: 65.8 ± 7.7 years, 61 males) with bilateral carotid vulnerable plaques were included. Vulnerable plaques were characterized by intraplaque hemorrhage (IPH), large lipid-rich necrotic core (LRNC), or fibrous cap rupture (FCR) on MRI. Symptomatic vulnerable plaques showed greater plaque burden, LRNC volume (median: 221.4 vs 134.8 mm3, P =.003), IPH volume (median: 32.2 vs 22.5 mm3, P =.030), maximum percentage (Max%) LRNC (median: 51.3% vs 41.8%, P =.002), Max%IPH (median: 13.4% vs 9.5%, P =.022), cumulative slices of LRNC (median: 10 vs 8, P =.005), and more juxtaluminal IPH and/or thrombus (29.9% vs 6.0%, P =.001) and FCR (37.3% vs 16.4%, P =.007) than asymptomatic ones. After adjusting for plaque burden, differences in juxtaluminal IPH and/or thrombus (odds ratio [OR]: 5.49, 95% CI: 1.61-18.75, P =.007) and FCR (OR: 2.90, 95% CI: 1.16-7.24, P =.022) between bilateral sides remained statistically significant. For patients with bilateral carotid vulnerable plaques, symptomatic plaques had greater burden, more juxtaluminal IPH and/or thrombus, and FCR compared with asymptomatic ones. The differences in juxtaluminal IPH and/or thrombus and FCR between bilateral sides were independent of plaque burden. [ABSTRACT FROM AUTHOR]

• 27.24 % had progression of ICAS during 3.15 ± 0.59 years' follow-up. • Carotid plaque is associated with ICAS progression in stroke-free population. • Carotid plaque may be an effective predictor for ICAS progression. Intracranial artery atherosclerosis (ICAS) progression is associated with stroke. However, the association of carotid plaque with ICAS progression among stroke-free participants is still unclear. This study aimed to evaluate the association between carotid plaque and ICAS progression in stroke-free participants. Stroke-free participants were recruited from a community-based cohort study. All participants underwent questionnaire interviews, blood tests, and high-resolution vessel wall magnetic resonance (MR) imaging at baseline and follow-up for around three years. The atherosclerotic plaque was defined as eccentric wall thickening on MR imaging. The presence, location, total number, and burden (maximum wall thickness, length, and stenosis) of carotid and intracranial plaque were evaluated. ICAS progression was defined as the number increased or plaque burden (maximum wall thickness, length, or stenosis increase) increased by ≥ 20 %. The association between carotid plaque and ICAS progression was evaluated using multivariable logistic regression. Of the 312 participants (mean age at baseline: 59.85 ± 13.04 years; 136 males) who completed baseline and follow-up studies with a mean time interval of 3.15 ± 0.59 years, 85 (27.24 %) had progression of ICAS during follow-up. At least one carotid plaque was detected at baseline in 167 (53.53 %) participants. In the multivariable logistic analysis, carotid plaque was a significant predictor for the progression of ICAS (odds ratio, 2.04; 95 % confidence interval, 1.06–3.92; P = 0.032). Carotid plaque is associated with intracranial artery atherosclerosis progression in stroke-free population. Our findings suggest that carotid plaque may be an effective predictor for intracranial artery atherosclerosis progression. [ABSTRACT FROM AUTHOR]

Background and Purpose: The association between risk factors and intracranial atherosclerosis disease (ICAD) determined by magnetic resonance (MR) vessel wall imaging in Chinese population has not been investigated. The aim of this study was to investigate the associations of conventional vascular risk factors with asymptomatic and symptomatic ICAD using MR vessel wall imaging in Chinese population.Methods: The study population was recruited from two cohort studies of ICASMAP and CAMERA comprised 104 symptomatic ICAD subjects (57.1 ± 11.1 years; 35.6% females), 51 asymptomatic ICAD subjects (70.1 ± 8.4 years; 50.0% females) and 418 controls (58.0 ± 13.3 years; 61.0% females) defined as asymptomatic subjects without ICAD on MR vessel wall imaging. We compared the vascular risk factors between the three groups using a multivariate logistic regression analysis.Results: Compared with controls, there was a significant positive association between age (OR: 1.07, 95% CI: 1.03-1.10, p < 0.001) and hypertension (OR: 3.03, 95% CI: 1.45-6.36, p = 0.003) and asymptomatic ICAD. There was a positive association of smoking (OR: 3.41, 95% CI: 1.57-7.42, p = 0.001), hypertension (OR: 7.43, 95% CI: 3.81-14.49, p < 0.001) and diabetes (OR: 3.54, 95% CI: 1.93-6.49, p < 0.001) and an inverse association of high-density lipoprotein (HDL) (p < 0.017) with symptomatic ICAD. Compared to asymptomatic ICAD, there was a significant inverse association of age (OR: 0.86, 95% CI: 0.81-0.92, p < 0.001) and HDL (p < 0.001) with symptomatic ICAD.Conclusion: Old age and hypertension are associated with asymptomatic ICAD and smoking, hypertension, diabetes and lower HDL are associated with an increased risk of symptomatic ICAD in Chinese population.Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT03417063. [ABSTRACT FROM AUTHOR]

Background and purpose: This study aimed to investigate the enhancement characteristics of vessel wall in patients with moyamoya disease (MMD) using 3D high-resolution magnetic resonance (MR) imaging and their relationship with initial and recurrent intracranial hemorrhage. Methods: Consecutive patients with MMD were retrospectively analyzed and classified as intracranial hemorrhagic and non-hemorrhagic groups according to the CT or MR images. The clinical features and vessel wall characteristics were compared between the two groups. Logistic regression was performed to relate the vessel wall characteristics to the initial hemorrhage in MMD patients. Patients in hemorrhagic group were followed up after surgery to evaluate the relationship between vessel wall characteristics and recurrent hemorrhage. Results: A total of 507 MMD patients including 79 hemorrhagic and 428 non-hemorrhagic MMD patients were recruited in the study. We found that hemorrhagic group had more patients with vessel wall enhancements (40.5% vs. 25.7%, p = 0.009) and more eccentric enhanced lesions (17.7% vs. 6.5%, p = 0.001) compared to those in non-hemorrhage group and vessel wall enhancements were independently associated with ipsilateral initial hemorrhage after adjusted for clinical factors (OR = 1.99, CI 1.20–3.28, p = 0.007). Furthermore, three recurrent intracranial hemorrhagic episodes in the present study were all observed in MMD patients with vessel wall enhancement during the long-term follow-up after surgery. Conclusions: Wall enhancement of intracranial vessels was significantly associated with intracranial hemorrhage in MMD patients. Our findings suggest that vessel wall enhancement may serve as a marker of intracranial hemorrhage. [ABSTRACT FROM AUTHOR]

Purpose: Vessel wall imaging techniques have been introduced to assess the burden of peripheral arterial disease (PAD) in terms of vessel wall thickness, area or volume. Recent advances in a 3D black-blood MRI sequence known as the 3D motion-sensitized driven equilibrium (MSDE) prepared rapid gradient echo sequence (3D MERGE) have allowed the acquisition of vessel wall images with up to 50 cm coverage, facilitating noninvasive and detailed assessment of PAD. This work introduces an algorithm that combines 2D slice-based segmentation and 3D user editing to allow for efficient plaque burden analysis of the femoral artery images acquired using 3D MERGE. Methods: The 2D slice-based segmentation approach is based on propagating segmentation results of contiguous 2D slices. The 3D image volume was then reformatted using the curved planar reformation (CPR) technique. User editing of the segmented contours was performed on the CPR views taken at different angles. The method was evaluated on six femoral artery images. Vessel wall thickness and area obtained before and after editing on the CPR views were assessed by comparison with manual segmentation. Difference between semiautomatically and manually segmented contours were compared with the difference of the corresponding measurements between two repeated manual segmentations. Results: The root-mean-square (RMS) errors of the mean wall thickness (tmean) and the wall area (WA) of the edited contours were 0.35 mm and 7.1 mm2, respectively, which are close to the RMS difference between two repeated manual segmentations (RMSE: 0.33 mm in tmean, 6.6 mm2 in WA). The time required for the entire semiautomated segmentation process was only 1%-2% of the time required for manual segmentation. Conclusions: The difference between the boundaries generated by the proposed algorithm and the manually segmented boundary is close to the difference between repeated manual segmentations. The proposed method provides accurate plaque burden measurements, while considerably reducing the analysis time compared to manual review. [ABSTRACT FROM AUTHOR]

Background: Previous studies reported that single vascular atherosclerosis was an effective indicator for white matter lesions (WMLs). Purpose: To investigate the added value of femoral atherosclerosis for determining severity of WMLs by carotid atherosclerosis using three-dimensional vessel wall magnetic resonance imaging (MRI). Material and Methods: Elderly individuals without cardiovascular symptoms within the previous six months were recruited. The plaque features of carotid and femoral arteries were evaluated and compared between individuals with WML score ≤ 3 and those with WML score > 3. Logistic regression and receiver operating characteristic (ROC) analyses were used to determine the value of plaque features in discriminating WMLs with score > 3. Results: In total, 112 individuals (49 men, mean age 72.0±5.6 years) were included. Participants with a WML score > 3 showed a significantly greater carotid wall area and femoral artery stenosis and higher incidence of carotid calcification and femoral artery calcification and lipid-rich necrotic cores (LRNC) compared to those with a WML score ≤ 3 (all P < 0.05). Carotid artery calcification and femoral artery calcification, LRNC, and stenosis were found to be significantly associated with severe WMLs before and after adjustment for clinical factors (odds ratio 1.51–3.79, all P < 0.05). ROC analysis showed, in discriminating severe WMLs, the area under the curve increased from 0.615 to 0.754 after combining femoral artery LRNC and stenosis with carotid calcification compared to the carotid calcification alone. Conclusion: Characteristics of femoral artery atherosclerosis determined by vessel wall MRI have added value for carotid atherosclerosis in determining the severity of WMLs. [ABSTRACT FROM AUTHOR]

To evaluate the feasibility and reproducibility of 2D and 3D black-blood sequences in measuring morphology of renal arterial wall. The 2D and 3D imaging sequences used variable-refocusing-flip-angle and constant-low-refocusing-flip-angle turbo spin echo (TSE) readout respectively, with delicately selected black-blood scheme and respiratory motion trigger for free-breathing imaging. Fourteen healthy subjects and three patients with Takayasu arteritis underwent renal artery wall imaging with 3D double inversion recovery (DIR) TSE and 2D Variable Flip Angle-TSE (VFA-TSE) black-blood sequences at 3.0 T. Four healthy subjects were randomly selected for scan-rescan reproducibility experiments. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and morphology of arterial wall were measured and compared using paired- t- test or Wilcoxon signed-rank test between 2D and 3D sequences. The inter-observer, intra-observer and scan-rescan agreements of above measurements were determined using intraclass correlation coefficient (ICC). The 2D and 3D imaging sequences showed similar morphological measurements (lumen area, wall area, mean wall thickness and maximum wall thickness) of renal arterial wall (all P > 0.05) and excellent agreement (ICC: 0.853–0.954). Compared to 2D imaging, 3D imaging exhibited significantly lower SNR lumen (P < 0.01) and SNR wall (P = 0.037), similar contrast-to-noise ratio (CNR) (P = 0.285), and higher CNR efficiency (CNR eff) (P < 0.01). Both 2D and 3D imaging showed good to excellent inter-observer (ICC: 0.723–0.997), intra-observer (ICC: 0.749–0.996) and scan-rescan (ICC: 0.710–0.992) reproducibility in measuring renal arterial wall morphology, SNR and CNR, respectively. Both high-resolution free-breathing 2D VFA-TSE and 3D DIR TSE black-blood sequences are feasible and reproducible in high-resolution renal arterial wall imaging. The 2D imaging has high SNR, whereas 3D imaging has high imaging efficiency. • Free-breathing 2D VFA-TSE and 3D DIR TSE black-blood sequences provide feasible and reproducible renal arterial imaging. • Free-breathing 2D VFA-TSE and 3D DIR TSE black-blood sequences show similar morphology, image quality and CNR in renal arterial wall imaging. • For different clinical settings, 2D VFA-TSE black-blood imaging has high SNR, whereas 3D DIR TSE black-blood imaging has high imaging efficiency. [ABSTRACT FROM AUTHOR]

To improve the signal-to-noise ratio (SNR) and image sharpness for whole brain isotropic 0.5 mm three-dimensional (3D) T 1 weighted (T 1 w) turbo spin echo (TSE) intracranial vessel wall imaging (IVWI) at 3 T. The variable flip angle (VFA) method enables useful optimization across scan efficiency, SNR and relaxation induced point spread function (PSF) for TSE imaging. A convolutional neural network (CNN) was developed to retrospectively enhance the acquired TSE image with PSF blurring. The previously developed VFA method to increase SNR at the expense of blur can be combined with the presented PSF correction to yield long echo train length (ETL) scan while the acquired image remains high SNR and sharp. The overall approach can enable an optimized solution for accelerated whole brain high-resolution 3D T 1 w TSE IVWI. Its performance was evaluated on healthy volunteers and patients. The PSF blurred image acquired by a long ETL scan can be enhanced by CNN to restore similar sharpness as a short ETL scan, which outperforms the traditional linear PSF enhancement approach. For accelerated whole brain IVWI on volunteers, the optimized isotropic 0.5 mm 3D T 1 w TSE sequence with CNN based PSF enhancement provides sufficient flow suppression and improved image quality. Preliminary results on patients further demonstrated its improved delineation for intracranial vessel wall and plaque morphology. The CNN enhanced VFA TSE imaging enables an overall image quality improvement for high-resolution 3D T 1 w IVWI, and may provide a better tradeoff across scan efficiency, SNR and PSF for 3D TSE acquisitions. • SNR and sharpness have to be compromised for long echo train length 3D TSE scans • Reduced SNR and sharpness may obscure intracranial vessel wall (IVW) depiction • Network enhanced TSE can improve IVW image quality than conventional TSE [ABSTRACT FROM AUTHOR]

Objectives: This study sought to validate the performance of simultaneous non-contrast angiography and intraplaque hemorrhage (SNAP) imaging in characterizing carotid IPH by histology. Methods: Thirty-five patients with carotid atherosclerotic disease (symptomatic 50–70% stenosis or > 70% stenosis) scheduled for carotid endarterectomy underwent 3.0-T carotid MR imaging by acquiring SNAP and magnetization-prepared rapid acquisition gradient-echo (MP-RAGE) sequences. Presence and area of IPH were separately evaluated on SNAP and MP-RAGE images. Presence and area of IPH were also assessed on histology. Agreement between SNAP/MP-RAGE and histology was determined in identify and quantify IPH using Cohen kappa, Spearman correlation, and Bland-Altman analyses. Results: Of all 35 patients (mean age: 63.1 ± 8.8 years; 27 males), 128 slices with successful registration were eligible for analysis. The accuracy, sensitivity, specificity, and positive and negative predictive values were 86.7%, 85%, 89.6%, 93.2%, and 78.2% for SNAP, and 76.6%, 75%, 79.2%, 85.7%, and 65.5% for MP-RAGE in identification of IPH, respectively. In identification of IPH, the kappa value between SNAP and histology and between MP-RAGE and histology was 0.725 and 0.520, respectively. The correlation between SNAP and histology (r = 0.805, p < 0.001) was stronger than that between MP-RAGE and histology (r = 0.637, p < 0.001) in measuring IPH area. Bland-Altman analysis showed that, in measuring IPH area, the bias of SNAP (1.4 mm2, 95% CI: − 0.016 to 2.883) was smaller than that of MP-RAGE (1.7 mm2, 95% CI: − 0.039 to 3.430) compared with histology. Conclusions: This validation study by histology demonstrates that SNAP sequence better identifies and quantifies carotid intraplaque hemorrhage compared with traditional MP-RAGE sequence. Key Points: • SNAP imaging showed better agreement with histology compared with MP-RAGE imaging, especially for the IPHs with small size. • SNAP sequence is a more effective tool to identify and quantify carotid IPH than traditional sequence of MP-RAGE that can help clinicians to optimizing the treatment strategy. • The plaque components of rich lipid pools or loose matrix and chronic/old IPH (cholesterol crystals) can lead to false positive and false negative results in SNAP and MP-RAGE imaging for identifying IPH. [ABSTRACT FROM AUTHOR]

Background: Atherosclerotic plaques are often present in regions of arteries with complicated flow patterns. Vascular morphology plays important role in hemodynamics. In this study, we investigated the relationship between the geometry of the vertebrobasilar artery system and presence of basilar artery (BA) plaque.Methods: We enrolled 290 patients with posterior circulation ischemic stroke. We distinguished four configurations of the vertebrobasilar artery: Walking, Tuning Fork, Lambda, and No Confluence. Patients were divided into multi-bending (≥ 3 bends) and oligo-bending (< 3 bends) VA groups. The diameter of the vertebral artery (VA) and the number of bends in the intracranial VA segment were assessed using three-dimensional time-of-flight magnetic resonance angiography. High-resolution magnetic resonance imaging was used to evaluate BA plaques. Logistic regression models were used to determine the relationship between the geometry type and BA plaque prevalence.Results: After adjusting for sex, age, body mass index ≥ 28, hypertension, and diabetes mellitus, the Walking, Lambda, and No Confluence geometries were associated with the presence of BA plaque (all p < 0.05). Patients with multi-bending VAs in both the Walking (20/28, 71.43% vs. 6/21, 28.57%, p = 0.003) and Lambda group (19/47, 40.43% vs. 21/97, 21.65%, p = 0.018) had more plaques compared to patients with oligo-bending VAs in these groups. In the Lambda group, the difference in diameter of bilateral VAs was larger in patients with BA plaques than that in patients without BA plaques (1.4 mm [IQR: 0.9-1.6 mm] vs. 0.9 mm [IQR: 0.6-1.3 mm], p < 0.001).Conclusions: The Walking, Lambda, and No Confluence geometry, ≥ 3 bends in the VAs, and a large diameter difference between bilateral VAs are associated with the presence of BA plaque. [ABSTRACT FROM AUTHOR]

• The carotid plaque calcification is independently associated with the WMHs. • Intracranial artery atherosclerotic stenosis was not associated with the WMHs. • Carotid plaque characteristics may have closer association with the WMHs. This study aimed to investigate the associations of atherosclerotic plaque characteristics in intracranial and extracranial carotid arteries with severity of white matter hyperintensities (WMHs) in symptomatic patients using magnetic resonance (MR) imaging. Patients with cerebrovascular symptoms and carotid plaque were recruited from the cross-sectional, multicenter study of CARE-II. Luminal stenosis of intracranial and extracranial carotid arteries, carotid plaque compositional features, and WMHs were evaluated by brain structural and vascular MR imaging. The atherosclerotic plaque characteristics in intracranial and extracranial carotid arteries were compared between patients with and without moderate-to-severe WMHs (Fazekas score > 2), and their associations with severity of WMHs were analyzed using logistic regression. Of the recruited 622 patients (mean age, 58.7 ± 10.9 years; 422 males), 221 (35.5 %) had moderate-to-severe WMHs with higher prevalence of moderate-to-severe luminal stenosis (17.0 % vs. 10.4 %), intraplaque hemorrhage (15.7 % vs. 9.0 %), thin/ruptured fibrous cap (30.2 % vs. 20.4 %), calcification (44.4 % vs. 22.2 %) and lipid-rich necrotic core (63.8 % vs. 51.1 %) in carotid artery compared to those without (all P < 0.05). Multivariate logistic regression showed that carotid calcification (OR, 1.854; 95 % CI, 1.187–2.898; P = 0.007) was independently associated with moderate-to-severe WMHs after adjusting for confounding factors. No significant association was found between intracranial atherosclerotic stenosis and moderate-to-severe WMHs (P > 0.05). Carotid atherosclerotic plaque features, particularly presence of calcification, were independently associated with severity of WMHs, but such association was not found in intracranial atherosclerotic stenosis, suggesting that carotid atherosclerotic plaque characteristics may have closer association with severity of WMHs compared to intracranial atherosclerosis. [ABSTRACT FROM AUTHOR]

Background: It is valuable to explore the relationship between plaque characteristics and stroke by using three-dimensional (3D) magnetic resonance imaging (MRI) of the vessel wall. Purpose: To investigate the association between plaque enhancement score (PES) of co-existing intracranial and extracranial carotid plaques and ischemic stroke using 3D MRI. Material and Methods: Symptomatic patients were recruited and underwent cerebrovascular 3D MRI of the vessel wall. The number, enhancement degree, and stenosis of plaques in intracranial and extracranial carotid arteries were evaluated. The PES calculated by summing enhancement degree of all detected plaques was compared between patients with and without acute cerebral infarction (ACI) and its association with ACI was determined. Results: Of 157 recruited patients, 118 (75.2%) had co-existing plaques. Patients with ACI had significantly greater PES of co-existing plaques compared with those without ACI (9, interquartile range [IQR] 5–11 vs. 5, IQR 2–7, P <0.001). The odds ratio for PES of co-existing plaques in discriminating ACI was 1.410 (95% confidence interval [CI] 1.146–1.735, P = 0.001) after adjustment for stenosis, intraplaque hemorrhage, and traditional risk factors. Receiver operating characteristic curve analysis showed that, in discriminating ACI, PES had higher area under the curve (AUC 0.693–0.764) than plaque number (AUC 0.625–0.683) and enhancement degree (AUC 0.570–0.706) alone in any vascular bed. The AUC of PES of co-existing plaques combined with stenosis, NIHSS scores, intraplaque hemorrhage, hyperlipidemia, and blood pressure reached 0.847. Conclusion: Cerebrovascular plaque enhancement score combining plaque number and enhancement degree is independently associated with ACI. The enhancement score of co-existing plaques has higher strength in discriminating ACI compared with plaques in a single vascular bed. [ABSTRACT FROM AUTHOR]

Background: It has been proved that multi-contrast cardiovascular magnetic resonance (CMR) vessel wall imaging could be used to characterize carotid vulnerable plaque components according to the signal intensity on different contrast images. The signal intensity of plaque components is mainly dependent on the values of T1 and T2 relaxation. T1 mapping recently showed a potential in identifying plaque components but it is not well validated by histology. This study aimed to validate the usefulness of in vivo T1 mapping in assessing carotid vulnerable plaque components by histology. Methods: Thirty-four subjects (mean age, 64.0 ± 8.9 years; 26 males) with carotid plaques referred to carotid endarterectomy were prospectively enrolled and underwent 3 T CMR imaging from May 2017 to October 2017. The T1 values of intraplaque hemorrhage (IPH), necrotic core (NC) and loose matrix (LM) which were identified on multi-contrast vessel wall images or histology were measured on in-vivo T1 mapping. The IPHs were divided into two types based on the proportion of the area of fresh hemorrhage on histology. The T1 values of different plaque components were compared using Mann-Whitney U test and the agreement between T1 mapping and histology in identifying and quantifying IPH was analyzed with Cohen's Kappa and intraclass correlation coefficient (ICC). Results: Of 34 subjects, 19 had histological specimens matched with CMR imaging. The mean T1 values of IPH (651 ± 253 ms), NC (1161 ± 182 ms) and LM (1447 ± 310 ms) identified by histology were significantly different. The T1 values of Type 1 IPH were significantly shorter than that of Type 2 IPH (456 ± 193 ms vs. 775 ± 205 ms, p < 0.001). Moderate to excellent agreement was found in identification (kappa = 0.51, p < 0.001), classification (kappa = 0.40, p = 0.028) and segmentation (ICC = 0.816, 95% CI 0.679–0.894) of IPHs between T1 mapping and histology. Conclusions: The T1 values of carotid plaque components, particularly for intraplaque hemorrhage, are differentiable, and the stage of intraplaque hemorrhage can be classified according to T1 values, suggesting the potential capability of assessment of vulnerable plaque components by T1 mapping. [ABSTRACT FROM AUTHOR]

Background: Chronic alcohol consumption initially leads to asymptomatic left ventricular dysfunction, but can result in myocardial impairment and heart failure if ongoing. This study sought to characterize myocardial tissues and oxidative metabolism in asymptomatic subjects with chronic alcohol consumption by quantitative cardiovascular magnetic resonance (CMR) and 11C-acetate positron emission tomography (PET)/computed tomography (CT). Methods: Thirty-four male subjects (48.8 ± 9.1 years) with alcohol consumption > 28 g/day for > 10 years and 35 age-matched healthy male subjects (49.5 ± 9.7 years) underwent CMR and 11C-acetate PET/CT. Native and post T1 values and extracellular volume (ECV) from CMR and Kmono and K1 from PET imaging were measured. Quantitative measurements by CMR and PET imaging were compared between subjects with moderate to heavy alcohol consumption and healthy controls, and their correlations were also analyzed. Results: Compared to healthy controls, subjects with alcohol consumption showed significantly shorter native T1 (1133 ± 65 ms vs. 1186 ± 31 ms, p < 0.001) and post T1 (477 ± 42 ms vs. 501 ± 38 ms, p = 0.008) values, greater ECV (28.2 ± 2.2% vs. 26.9 ± 1.3%, p = 0.003), marginally lower Kmono (57.6 ± 12.1 min− 1 × 10− 3 vs. 63.0 ± 11.7 min− 1 × 10− 3, p = 0.055), and similar K1 (0.82 ± 0.13 min− 1 vs. 0.83 ± 0.15 min− 1, p = 0.548) after adjusting for confounding factors. There were no significant differences in CMR measurements and K1 between subjects with heavy and moderate alcohol consumption (all p > 0.05). In contrast, subjects with heavy alcohol consumption showed significantly lower Kmono values compared to those with moderate alcohol consumption (52.9 ± 12.1 min− 1 × 10− 3 vs. 63.7 ± 9.2 min− 1 × 10− 3, p = 0.012). Strong and moderate correlations were found between K1 and ECV in healthy controls (r = 0.689, p = 0.013) and subjects with moderate alcohol consumption (r = 0.518, p = 0.048), respectively. Conclusion: Asymptomatic men with heavy alcohol consumption have detectable structural and metabolic changes in myocardium on CMR and 11C-acetate PET/CT. Compared with quantitative CMR, 11C-acetate PET/CT imaging may be more sensitive for detecting differences in myocardial damage among subjects with moderate to heavy alcohol consumption. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the segment-specific progression of atherosclerotic carotid plaques using serial multi-contrast magnetic resonance (MR) imaging. Methods: Symptomatic patients with carotid 30–70% stenosis were recruited and underwent carotid MR vessel wall imaging at baseline and follow-up time point (≥ 6 months after baseline). The location of plaques was determined according to the maximum wall thickness located above or below carotid bifurcation. The baseline and changing characteristics of carotid plaques were compared between plaques above and below carotid bifurcation, and the risk factors for segment-specific plaque progression were analyzed with logistic regression. Results: Ninety-six carotid plaques from 73 patients (mean age 66.5 ± 11.4 years old) were eligible for statistical analysis. Compared with plaques located below carotid bifurcation, those above bifurcation had significantly greater stenosis at baseline (57.2 ± 13.0% vs. 50.4 ± 13.5%, p = 0.016, adjusted p = 0.005) and greater progression rate of carotid wall volume (35.2 ± 68.8 mm3/year vs. 4.2 ± 65.0 mm3/year, p = 0.026, adjusted p = 0.005) before and after adjusting for all clinical risk factors and baseline stenosis and wall volume of carotid arteries. Logistic regression showed that the related risk factors were age, hypertension, and smoke for the progression of plaques located above the bifurcation and age for plaques below the bifurcation, respectively. Conclusion: Plaques located above the bifurcation of carotid arteries had greater annual progression and correlated with more cardiovascular risk factors compared with those located below the bifurcation. [ABSTRACT FROM AUTHOR]

To theoretically compare the MR angiography (MRA) contrast mechanism of Time of Flight (TOF) and Simultaneous Non-contrast Angiography and intraPlaque hemorrhage (SNAP) for intracranial artery imaging with in-vivo validation. The contrast ratio (CR) of SNAP and TOF was simulated under different blood velocities and travel distance that the blood had flown through. The CR and the slope of CR with respect to blood velocity of SNAP and TOF were compared in theoretical simulation. Two healthy subjects (a 60 years old female and a 29 years old male) were imaged on a 3 T MR scanner with SNAP, TOF and phase contrast (PC) images as the validation set. The measured CR from the images in validation set was compared with the theoretically simulated CR by Person's correlation coefficient. The ratio of CR difference to velocity difference in the validation set was compared between TOF and SNAP with Student's t -test. Thirty patients (21 males, age: 48 ± 13.8 years) with carotid artery atherosclerotic plaque were imaged with both TOF and SNAP as the comparison test. Between TOF and SNAP, the CR and total artery length were compared with Student's t -test, and the prevalence of stenosis was compared with Cohen's kappa in comparison test. The theoretically simulated CR was significantly correlated with in-vivo measured CR from the validation set for TOF (p < 0.001) and SNAP (p < 0.001). The simulation revealed that the CR of SNAP was higher than that of TOF when the blood velocity and travel distance were within the range to have effective MRA contrast. Similarly, the in-vivo comparison test showed that SNAP had higher CR (p < 0.001 for all tested intracranial arteries) and longer total artery length (1.4 ± 0.4 m vs 1.2 ± 0.2 m, p < 0.001) than TOF. The stenosis detection performance was similar between TOF and SNAP (Cohen's kappa 0.72; 95% confidence interval: 0.51–0.93). Moreover, compared with TOF, SNAP showed higher slope of CR with respect to velocity in simulation (0.06 ± 0.02 s/cm vs 0.02 ± 0.05 s/cm, p < 0.001), and higher ratio of CR difference to velocity difference in validation test (0.47 ± 0.38 s/cm vs 0.19 ± 0.38 s/cm, p = 0.001). Compared with TOF, the SNAP shows better performance to visualize distal intracranial artery and worse performance to visualize ICA, and is more sensitive to blood velocity. [ABSTRACT FROM AUTHOR]

Background: It is still unknown that whether co-existing intracranial stenosis and extracranial carotid vulnerable plaques have higher predictive value for subsequent vascular events. This study aimed to determine the relationship between co-existing extracranial carotid vulnerable plaques and intracranial stenosis and subsequent vascular events utilizing cardiovascular magnetic resonance (CMR) vessel wall imaging. Methods: Patients who had recent cerebrovascular symptoms in anterior circulation (< 2 weeks) were consecutively enrolled and underwent multi-contrast CMR vessel wall imaging for extracranial carotid arteries and 3D time-of flight CMR angiography for intracranial arteries at baseline. After baseline examination, all patients were followed-up for at least 1 year to determined recurrence of vascular events. The co-existing cerebrovascular atherosclerosis was defined as presence of both intracranial artery stenosis and at least one the following measures of extracranial artery atherosclerosis: plaque, calcification, lipid-rich necrotic core (LRNC), or intraplaque hemorrhage. Univariate and multivariate Cox regressions were used to calculate the hazard ratio (HR) and corresponding 95% confidence interval (CI) of co-existing plaques in predicting subsequent vascular events. Results: In total, 150 patients (mean age: 61.8 ± 11.9 years; 109 males) were recruited. During the median follow-up time of 12.1 months, 41 (27.3%) patients experienced vascular events. Co-existing intracranial artery stenosis and extracranial carotid plaque (HR, 3.57; 95% CI, 1.63–7.82; P = 0.001) and co-existing intracranial artery stenosis and extracranial carotid LRNC (HR, 4.47; 95% CI, 2.15–9.27; P < 0.001) were significantly associated with subsequent vascular events, respectively. After adjusted for confounding factors and carotid stenosis, these associations remained statistically significant (HR, 5.12; 95% CI, 1.36–19.24; P = 0.016 and HR, 8.12; 95% CI, 2.41–27.31; P = 0.001, respectively). Conclusions: The co-existing cerebrovascular atherosclerotic diseases, particularly co-existing carotid lipid-rich necrotic core and intracranial stenosis, are independent predictors for subsequent vascular events. [ABSTRACT FROM AUTHOR]

This study aimed to propose a method to semi-automatically segment lumen of carotid artery on TOF-MRA images with well performance on images with weak boundary. The proposed method modified traditional level set method with double adaptive threshold (DATLS). Two thresholds were calculated from probability density function of initial region of interest. Threshold Th1 was used to generate initial contour and threshold Th2 was used to control evolution by modifying energy function of the level set. The performance of the proposed method was tested on TOF-MRA images from CARE II study via using manual delineation as reference. Sixty cases were randomly selected to compare the performance of traditional level set with DATLS, all 283 cases were used to test the robustness of DATLS and 20 cases were used to compare the intra- and inter-operator reproducibility of manual delineation with DATLS. The Dice Similarity Coefficient, Mean Contour Distance and Hausdorff Distance between the proposed method and the manual segmentation were reported. Traditional level set failed to segment carotid artery on 13 cases because of over convergence. Compared to traditional level set, DATLS showed a higher DSC (0.88 ± 0.07 vs. 0.75 ± 0.15), lower MCD (0.48 ± 0.37 mm vs. 1.89 ± 2.24 mm) and HD (1.41 ± 1.11 mm vs. 4.59 ± 4.59 mm) in the remaining 47 cases. The average DSC, MCD and HD of DATLS on 283 cases were 0.87 ± 0.09, 0.64 ± 0.87 mm and 1.76 ± 2.23 mm, respectively. Compared to manual delineation, DATLS had better reproducibility on DSC (intra-operator: 0.97 ± 0.09 and inter-operator: 0.97 ± 0.09 vs. intra-operator: 0.91 ± 0.04 and inter-operator: 0.91 ± 0.04), as well as MCD (intra-operator: 0.08 ± 0.18 mm and inter-operator: 0.13 ± 0.52 mm vs. intra-operator: 0.35 ± 0.20 mm and inter-operator: 0.37 ± 0.19 mm) and HD (intra-operator: 0.30 ± 0.66 mm and inter-operator: 0.48 ± 1.38 mm vs. intra-operator: 0.99 ± 0.79 mm and inter-operator: 0.90 ± 0.85 mm). Compared to traditional level set, DATLS out-performed on computing time, robustness and accuracy of segmentation on TOF-MRA. The proposed method using modified level set with double adaptive threshold might be a promising tool for lumen segmentation of carotid artery on TOF-MRA. [ABSTRACT FROM AUTHOR]

• Combined 3D vessel wall imaging of intra- and extra- cranial arteries help to analyze the underlying mechanisms for different types of infarction. • The CA high-risk plaque and MCA plaque presence were significantly associated with PI. • MCA plaques involved the orifice of the perforating arteries were significantly associated with PAI. Atherosclerotic plaques of carotid artery (CA) and middle cerebral artery (MCA) are important causes of acute ischemic stroke (AIS). This study was designed to jointly assess the plaque distribution and features of CA and MCA in AIS patients with pial infarction (PI) and perforating artery infarction (PAI), and to investigate the associations between plaque characteristics and ischemic infarction patterns. Imaging data of sixty-five patients from a cross-sectional study were reviewed. All the patients had acute infarction in the MCA territory on diffusion weighted imaging (DWI) and underwent CA and MCA vessel wall imaging (VWI). The CA and MCA plaque presence and high-risk features on the ipsilateral side of infarction were analyzed. The brain infarction lesions were divided into PI group vs. non-PI group, and PAI group vs. non-PAI group. Different plaque distribution types and plaque features were compared in each two groups, and their associations were investigated using binary logistic regression. Sixty-five patients (mean age, 54.6 ± 10.1 years; 61 men) were included. The CA high-risk plaque (OR: 5.683 [1.409–22.929], P = 0.015) and MCA plaque presence (OR: 3.949 [1.397–11.162], P = 0.010) were significantly associated with PI. MCA plaques that involved the orifice of the perforating arteries were significantly associated with PAI (OR: 15.167 [1.851–124.257], P = 0.011). CA and MCA plaques show distinct distribution and high-risk features in patients with PI and PAI. Combined intracranial and extracranial arteries imaging should be considered for the evaluation of the symptomatic ischemic patients. [ABSTRACT FROM AUTHOR]

• The MR imaging features of ICAD and CSVD are associated with acute ischemic stroke. • Coexistence of ICAD and CSVD maybe a stronger indicator of stroke than each alone. • surface irregularity coexisted with EPVS, lacune or WMH was a stronger indicator. Whether the coexistence of intracranial atherosclerotic disease (ICAD) and cerebral small vessel disease (CSVD) is an effective indicator for acute ischemic stroke (AIS) is unclear. This study aimed to investigate the association of coexistence of ICAD and CSVD with AIS. Patients with symptomatic ICAD were recruited from a multicenter study. All patients underwent intracranial artery vessel wall and brain magnetic resonance (MR) imaging at 3.0 T. The characteristics of T1 hyperintensity, plaque enhancement, and surface irregularity of the ICAD were assessed. The types of CSVD including enlarged perivascular space, white matter hyperintensity and lacune, and AIS were also analyzed. Logistic regressions were used to evaluate the associations of coexistence of ICAD and CSVD with AIS. Of 122 recruited patients (mean age: 56.69 ± 11.07 years; 70 males), 69 (56.56%) had AIS. Coexistence of ICAD and CSVD was more likely found in patients with AIS compared to those without AIS (all P < 0.05). After full adjustment, coexistences of surface irregularity and EPVS (odds ratio [OR], 12.770; 95% confidence interval [CI], 2.163–75.380; P = 0.005), surface irregularity and lacune (OR, 8.450; 95% CI, 2.028–35.213; P = 0.003), enhancement and lacune (OR, 13.888; 95% CI, 2.888–66.786; P = 0.001), surface irregularity and WMH (OR, 3.692; 95% CI, 1.264–10.786; P = 0.017), and enhancement and WMH (OR, 7.899; 95% CI, 2.357–26.475; P = 0.001) were significantly associated with AIS. Coexistence of intracranial atherosclerosis and cerebral small vessel disease might be a stronger indicator for acute ischemic stroke than each alone. [ABSTRACT FROM AUTHOR]

Comprehensive quantification of intracranial artery features may help us assess and understand variations of blood supply during brain development and aging. We analyzed vasculature features of 163 participants (age 56–85 years, mean of 71) from a community study to investigate if any of the features varied with age. Three-dimensional time-of-flight magnetic resonance angiography images of these participants were processed in IntraCranial artery feature extraction technique (a recently developed technique to obtain quantitative features of arteries) to divide intracranial vasculatures into anatomical segments and generate 8 morphometry and intensity features for each segment. Overall, increase in age was found negatively associated with number of branches and average order of intracranial arteries while positively associated with tortuosity, which remained after adjusting for cardiovascular risk factors. The associations with number of branches and average order were consistently found between 3 main intracranial artery regions, whereas the association with tortuosity appeared to be present only in middle cerebral artery/distal arteries. The combination of time-of-flight magnetic resonance angiography and IntraCranial artery feature extraction technique may provide an effective way to study vascular conditions and changes in the aging brain. • Increase in age was negatively associated with number of branches and average order. • Increase in age was positively associated with average tortuosity. • Vascular regions may have different age-related changes for some features. • Time-of-flight magnetic resonance angiography and IntraCranial artery feature extraction technique may provide a novel way to assess vascular condition and changes. [ABSTRACT FROM AUTHOR]

This study sought to determine the feasibility of using Simultaneous Non-contrast Angiography and intraPlaque Hemorrhage (SNAP) to detect the lipid-rich/necrotic core (LRNC), and develop a machine learning based algorithm to segment plaque components on SNAP images. Sixty-eight patients (age: 58±9 years, 24 males) with carotid artery atherosclerotic plaque were imaged on a 3 T MR scanner with both traditional multi-contrast vessel wall MR sequences (TOF, T1W, and T2W) and 3D SNAP sequence. The manual segmentations of carotid plaque components including LRNC, intraplaque hemorrhage (IPH), calcification (CA) and fibrous tissue (FT) on traditional multi-contrast images were used as reference. By utilizing the intensity and morphological information from SNAP, a machine learning based two steps algorithm was developed to firstly identify LRNC (with or without IPH), CA and FT, and then segmented IPH from LRNC. Ten-fold cross-validation was used to evaluate the performance of proposed method. The overall pixel-wise accuracy, the slice-wise sensitivity & specificity & Youden's index, and the Pearson's correlation coefficient of the component area between the proposed method and the manual segmentation were reported. In the first step, all tested classifiers (Naive Bayes (NB), Support Vector Machine (SVM), Random Forest (RF), Gradient Boosting Decision Tree (GBDT) and Artificial Neural Network (ANN)) had overall pixel-wise accuracy higher than 0.88. For RF, GBDT and ANN classifiers, the correlation coefficients of areas were all higher than 0.82 (p < 0.001) for LRNC and 0.79 for CA (p < 0.001), and the Youden's indexes were all higher than 0.79 for LRNC and 0.76 for CA, which were better than that of NB and SVM. In the second step, the overall pixel-wise accuracy was higher than 0.78 for the five classifiers, and RF achieved the highest Youden's index (0.69) with the correlation coefficients as 0.63 (p < 0.001). The RF is the overall best classifier for our proposed method, and the feasibility of using SNAP to identify plaque components, including LRNC, IPH, CA, and FT has been validated. The proposed segmentation method using a single SNAP sequence might be a promising tool for atherosclerotic plaque components assessment. [ABSTRACT FROM AUTHOR]

Abstract Reduction in cerebral blood flow (CBF), one of the major metrics for cerebral perfusion, is associated with many brain disorders. Therefore, early characterization of CBF prior to occurrence of symptoms is essential for prevention of cerebral ischemic events. We hypothesized that large artery atherosclerosis might be a potential indicator for decline in cerebral perfusion. The aim of this study was to investigate the relationship between large artery atherosclerosis and CBF in asymptomatic adults. A total of 134 asymptomatic subjects (mean age, 56.2 ± 12.8 years; 54 males) were recruited and underwent magnetic resonance (MR) imaging for brain and intracranial and extracranial carotid arteries. Presence or absence of cerebrovascular atherosclerosis was determined on MR vessel wall images. The CBF was measured with pseudo-continuous arterial spin labeling (pCASL) imaging. The CBF values in internal carotid artery (ICA) (37.2 ± 5.8 vs. 39.0 ± 4.9 ml/100 g/min, P = 0.049) and vertebrobasilar artery (VA-BA) territories (42.0 ± 6.8 vs. 44.8 ± 7.0 ml/100 g/min, P = 0.023) were significantly reduced in subjects with cerebrovascular plaque compared to those without. Presence of cerebrovascular plaque was significantly associated with CBF of VA-BA territory before (odds ratio, 2.89; 95% confidence interval, 1.37–6.08; P = 0.005) and after adjusted for confounding factors including age, gender, body-mass-index, diabetes, systolic blood pressure, hyperlipidemia and history of cardiovascular disease (odds ratio, 2.76; 95% confidence interval, 1.18–6.46; P = 0.019). In conclusion, presence of cerebrovascular atherosclerosis is independently associated with reduction in CBF measured by pCASL in asymptomatic adults, suggesting that cerebrovascular large artery atherosclerosis might be an effective indicator for impairment of cerebral microcirculation hemodynamics. Highlights • The global CBF value of subjects with cerebrovascular plaque was significantly lower than that of those without. • The CBF values in ICA and VA-BA territories were significantly reduced in subjects with cerebrovascular plaque compared to those without. • Cerebrovascular plaque was independently associated with CBF in vertebrobasilar artery territory. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the association between proximal internal carotid artery (ICA) luminal narrowing and diffuse wall thickening (DWT) in ipsilateral petrous ICA in moyamoya disease (MMD) patients.Methods: Forty-one MMD (mean age 42.8 ± 11.0 years, 19 males) and 36 atherosclerotic patients (mean age 61.5 ± 7.1 years, 31 males) and 41 healthy controls were recruited and underwent carotid MR vessel wall imaging. The luminal narrowing of proximal ICA was evaluated by the diameter ratio of ICA to common carotid artery (DRICA/CCA). The wall thickness of petrous ICA was measured on T1-VISTA images. The enhancement degree of petrous ICA was recorded and graded into four grades (none to marked) on the CE-T1-VISTA images. The correlation between wall thickness in petrous ICA and DRICA/CCA was analyzed.Results: In total, 81 arteries of MMD patients and 64 arteries of atherosclerotic patients were included for analysis. The DRICA/CCA was significantly correlated with the wall thickness in petrous ICA in MMD (r = − 0.434, P < 0.001) and atherosclerotic groups (r = − 0.604, P < 0.001). Logistic regression analysis revealed that odds ratio (OR) of DRICA/CCA was 4.433 (95% CI 1.980-9.925, P < 0.001) and 2.212 (95% CI 1.253-3.905, P = 0.006) in MMD and atherosclerotic groups in discriminating petrous ICA DWT after adjusting for confounding factors. An increasing trend was found in prevalence of DWT and wall thickness with enhancement grades in petrous ICA in MMD (P = 0.02 and P = 0.01) and atherosclerotic groups (P < 0.001 and P < 0.001), respectively.Conclusions: The proximal ICA luminal narrowing is significantly associated with wall thickness and diffuse wall thickening in ipsilateral petrous ICA in patients with carotid steno-occlusive diseases regardless of MMD or atherosclerosis. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the characteristics of atherosclerotic plaques in stroke‐related vascular beds and their relationship with stroke using three‐dimensional magnetic resonance (MR) vessel wall imaging. Methods: Fifty‐two symptomatic patients (mean age: 56.3 ± 13.4 years; 38 males) were enrolled and underwent MR vessel wall imaging for stroke‐related vascular beds including intracranial and extracranial carotid arteries and aortic arch and routine MR imaging for brain. The maximum wall thickness (Max WT) and luminal stenosis of each plaque were measured. The presence/absence of atherosclerotic plaque, intraplaque hemorrhage (IPH), and severe stenosis (stenosis >50%) at each vascular bed and acute ischemic lesion (AIL) were determined. The correlation between Max WT of each vascular bed and AIL was analyzed. Results: Of 52 patients, 24 (46.2%) had AILs, and 30 (57.7%), 34 (65.4%), and 11 (21.2%) had plaques in intracranial artery, extracranial carotid artery, and aortic arch, respectively. The prevalence of IPH and severe stenosis was 25% and 26.9% for intracranial arteries, 13.5% and 9.6% for extracranial carotid artery, and 3.8% and 0% for aortic arch, respectively. In discriminating AIL, Max WT of intracranial artery had the highest area‐under‐the‐curve (AUC = 0.84), followed by extracranial carotid artery (AUC = 0.83) and aortic arch (AUC = 0.78) after adjusted for confounding factors. The AUC of Max WT combined three stroked‐related vascular beds reached 0.87. Conclusion: Extracranial carotid arteries have the highest prevalence of plaques and intraplaque hemorrhage and severe stenosis are most frequently seen in intracranial arteries in Asian symptomatic patients. The Max WT combined three stroke‐related vascular beds show stronger predictive value for AIL than each vascular bed alone. [ABSTRACT FROM AUTHOR]

Abstract Background and purpose This study sought to investigate the feasibility of three-dimensional MPRAGE in identifying the lipid-rich necrotic core (LRNC) and calcification (CA) of carotid atherosclerotic plaques. Materials and methods Twelve patients (mean age 68.4 ± 11.8 years; 7 males) with carotid atherosclerotic plaques on ultrasound were included and underwent multicontrast magnetic resonance (MR) vessel wall imaging. The contrast enhanced T1W (CE-T1W) images were considered as reference for identifying LRNC. The signal intensity of LRNC, CA, sterno-cleidomastoid muscle and fibrous tissue (FT) was measured on CE-T1W, T1W, T2W, and MPRAGE images, respectively. The relative signal intensity (rSI) of LRNC and CA against muscle or FT was compared among four sequences. Area under the curve (AUC) of rSIs of LRNC, CA and FT against muscle on MPRAGE, T1W and T2W images in discriminating the LRNC or CA from FT and the other plaque component was calculated. Results Of 352 slices, 88 (25.0%) had LRNC, 31 (8.8%) had CA, 14 (4.0%) had both LRNC and CA, and 247 (70.2%) had no components. Among four imaging sequences, MPRAGE images showed the lowest rSI of LRNC (0.34 ± 0.18) and CA (0.20 ± 0.16) against muscle, followed by T1W (0.48 ± 0.18 and 0.33 ± 0.21), CE-T1W (0.58 ± 0.23 and 0.40 ± 0.21) and T2W (0.71 ± 0.47 and 0.43 ± 0.40) images. In addition, the MPRAGE images showed the lowest rSI of LRNC (0.57 ± 0.26) and CA (0.33 ± 0.23) against FT. MPRAGE showed greater AUC than T2W and T1W in discriminating the LRNC (0.827 vs. 0.703 vs. 0.635) and CA (0.917 vs. 0.838 vs. 0.825). Conclusion MPRAGE sequence might be a potential non-contrast enhanced imaging tool for identification of carotid LRNC and CA. [ABSTRACT FROM AUTHOR]

Objective To assess association between champagne bottle neck sign (CBNS) in carotid artery and intracranial hemorrhage in patients with moyamoya disease (MMD). Methods This retrospective study included 76 consecutive patients with MMD without definite risk factors associated with intracranial hemorrhage who underwent preoperative angiography from January 2016 to December 2017. CBNS was defined as luminal diameter ratio of internal carotid artery/common carotid artery ≤0.5 on angiography. The right and left cerebral hemisphere in each patient was separately identified as hemorrhagic and nonhemorrhagic. Association between CBNS and intracranial hemorrhage was analyzed. Results Of 76 patients with MMD, intracranial hemorrhage was found in 44 of 152 (28.9%) hemispheres, and 6.8% (3/44) had multiple events. Comparing carotid arteries without intracranial hemorrhage in ipsilateral hemispheres, patients with intracranial hemorrhage in the ipsilateral hemisphere had significantly smaller luminal diameter ratio of internal carotid artery/common carotid artery (0.49 ± 0.11 vs. 0.55 ± 0.12, P < 0.01) and higher prevalence of CBNS (63.7% vs. 41.7%, P = 0.01). Comparing hemispheres with intracranial hemorrhage, patients with ipsilateral carotid artery CBNS had significantly higher prevalence of hemorrhage in posterior territories than patients without CBNS (57.1% vs. 23.1%, P = 0.05). Logistic regression revealed that CBNS was significantly associated with ipsilateral intracranial hemorrhage before (odds ratio = 2.45; 95% confidence interval, 1.19–5.05; P = 0.02) and after (odds ratio = 3.43; 95% confidence interval, 1.50–7.87; P < 0.01) adjusting for female sex, lenticulostriate anastomosis, and choroidal anastomosis. Conclusions CBNS is significantly associated with intracranial hemorrhage in the ipsilateral hemisphere in patients with MMD, particularly intracranial hemorrhage in posterior territories. Highlights • The hemorrhagic hemisphere has a smaller lumen diameter ratio of ICA/CCA in MMD. • The hemisphere with ipsilateral CBNS has a higher prevalence of posterior hemorrhage. • CBNS is significantly associated with ipsilateral intracranial hemorrhage in MMD. [ABSTRACT FROM AUTHOR]

Abstract: Objective: This study sought to investigate the relationship of atherosclerosis between intracranial and extracranial carotid arteries using three‐dimensional multicontrast magnetic resonance (MR) vessel wall imaging. Methods: Patients with recent cerebrovascular symptoms in anterior circulation were recruited and underwent MR vessel wall imaging for intracranial and extracranial carotid arteries. The plaque burden, including maximum wall thickness (Max WT) and stenosis, and presence of intraplaque hemorrhage (IPH) were assessed. The correlation of the plaque characteristics between intracranial and extracranial carotid arteries was determined. Results: In total, 107 patients (mean age: 57.0 ± 11.1 years, 69 males) were recruited. In discriminating intracranial severe stenosis (≥50% stenosis), the odds ratio (OR) of Max WT of extracranial carotid arteries was 1.41 (95% confidence interval [CI], 0.94–2.11, P = 0.095) and 1.72 (95% CI, 1.04–2.83, P = 0.034) before and after adjusting for confounding factors, respectively. The OR of stenosis of extracranial carotid arteries with increment of 10% was 1.26 (95% CI, 0.99–1.60, P = 0.054) and 1.37 (95% CI, 1.03–1.82, P = 0.033) before and after adjusting for confounding factors, in discriminating intracranial severe stenosis respectively. Receiver operating characteristic analysis revealed that the area under the curve (AUC) of Max WT, stenosis, and IPH of extracranial carotid artery plaques was 0.641, 0.605, and 0.603 in discriminating intracranial severe stenosis, respectively. After adjusting for confounding factors, the AUC of Max WT, stenosis, and presence of IPH in extracranial carotid artery plaques increased to 0.812, 0.817 and 0.781, respectively. Interpretation: Carotid artery plaque burden is significantly associated with severe intracranial artery stenosis, suggesting that extracranial carotid plaque burden might be an independent indicator for severity of intracranial artery atherosclerosis. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the usefulness of Simultaneous Non-contrast Angiography and intraPlaque haemorrhage (SNAP) imaging in characterising carotid intraplaque haemorrhage (IPH) compared with magnetisation-prepared rapid acquisition gradient-echo (MP-RAGE) sequence.Methods: Fifty-four symptomatic patients (mean age: 63.1 ± 5.7 years, 38 males) with carotid atherosclerosis were recruited and underwent carotid MR imaging. The presence and area of IPH on SNAP and MP-RAGE images were determined. The agreement in identifying IPH and its area between SNAP and MP-RAGE was analysed.Results: Of 1368 slices with acceptable image quality in 54 patients, 13% and 22.6% were found to have IPH on MP-RAGE and SNAP images, respectively. There was moderate agreement between MP-RAGE and SNAP sequences in identifying IPH (κ = 0.511, p = 0.029). The area of IPH on SNAP images was significantly larger than that on MP-RAGE images (17.9 ± 18.2 mm2 vs. 9.2 ± 10.5 mm2, p < 0.001). For IPHs detected by SNAP imaging, the area of IPHs also detected by the MP-RAGE sequence was significantly larger than that of IPHs not detected by the MP-RAGE sequence (17.9 ± 19.2 mm2 vs. 6.4 ± 6.2 mm2, p < 0.001).Conclusion: Compared with the MP-RAGE sequence, SNAP imaging detects more IPHs, particularly for smaller IPHs, suggesting that SNAP imaging might be a more sensitive tool for identification of carotid haemorrhagic plaques.Key Points: • Moderate agreement was found between SNAP and MP-RAGE in identification of IPH • SNAP imaging might be a more sensitive tool to detect carotid IPHs • Compared with the MP-RAGE sequence, SNAP imaging can detect carotid IPHs with smaller size • SNAP imaging can help clinicians to optimise the treatment strategy. [ABSTRACT FROM AUTHOR]

Purpose: This study sought to investigate the characteristics of morphology, compositions and distribution of carotid atherosclerotic plaques in asymptomatic elderly population using three dimensional (3D) multicontrast magnetic resonance vessel wall imaging.Materials and Methods: 146 asymptomatic elderly subjects (≥60years) were recruited and underwent 3D multicontrast MR vessel wall imaging for bilateral carotid arteries on a 3.0T MR scanner. The presence of carotid atherosclerotic plaque was determined and the stenosis was measured. The characteristics of plaque morphology and compositions were evaluated and compared among distal internal carotid artery (D-ICA), proximal-ICA (P-ICA), carotid bulb (CB), distal common carotid artery (D-CCA) and proximal-CCA (P-CCA).Results: Of all recruited 140 subjects (72.1±5.7years, 63 males), 87 (62.1%) had carotid plaques, 17 (12.1%) had high-risk plaques and 51 (36.4%) had multiple plaques. Of all 280 carotid arteries, only 16 (5.7%) had luminal stenosis (21.1%±11.4%). Among carotid arteries without luminal stenosis, the prevalence of plaque and high-risk plaques was 43.2% and 8.3%, respectively. Carotid plaques were mostly found in CB segment (33.9%), followed by P-ICA (13.6%), P-CCA (11.1%), D-CCA (4.6%) and D-ICA (3.6%). Age was independently associated with presence of multiple carotid plaques (odds ratio, 1.835; 95% confidence interval, 1.196-2.815; P=0.005).Conclusion: Carotid artery atherosclerotic plaques are prevalent and a substantial number of high-risk plaques can be found in the asymptomatic elderly subjects. Longitudinal studies are warranted to investigate the risk of having ischemic stroke for asymptomatic elderly individuals with carotid artery high risk plaques. [ABSTRACT FROM AUTHOR]

Background and aims Dynamic contrast-enhanced MR imaging (DCE-MRI) provides a noninvasive approach to the functional status of carotid adventitial vasa vasorum . Contrast extravasation rate, or K trans , derived from kinetic modeling of adventitial enhancement, has been correlated with plaque neovascularization and inflammation. This study sought to clarify the clinical implications of K trans by evaluating its relationship with documented cardiovascular events (CVE). Methods Seventy patients with carotid plaque at clinical ultrasound examination were recruited and imaged with a previously-described bright-blood DCE-MRI protocol (spatial resolution: 0.55 × 0.58 mm 2 ; time resolution: 18 s). Patients were classified by the presence of documented coronary and/or cerebrovascular events. Adventitial K trans was estimated via kinetic modeling of outer wall enhancement as captured by DCE-MRI. Results After excluding six patients with insufficient image quality, 64 patients (66 ± 12 years, 51 male) had DCE-MRI measurements. Patients with documented CVE showed significantly higher adventitial K trans than those without (0.056 ± 0.024 versus 0.034 ± 0.008 min −1 , p < 0.001), whereas comparable measurements were seen among the subgroups with CVE ( p > 0.05): 0.054 ± 0.027 min −1 in patients with coronary events alone, 0.056 ± 0.018 min −1 in patients with cerebrovascular events alone, and 0.069 ± 0.022 min −1 in patients with both. Carotid adventitial K trans was negatively correlated with time since clinical event (Spearman's rho = −0.40, p = 0.003). Conclusions Patients with documented CVE demonstrated increased rate of contrast extravasation from carotid adventitial vasa vasorum on DCE-MRI irrespective of the territory of events. Systemic factors implicated in the pathophysiology of acute atherothrombotic events may influence the functional status of adventitial vasa vasorum . [ABSTRACT FROM AUTHOR]