Intracranial Atherosclerosis: From Microscopy to High-Resolution Magnetic Resonance Imaging

Application of high-resolution MRI in evaluating statin efficacy on symptomatic intracranial atherosclerosis

OBJECTIVES

To investigate the efficacy of statins on symptomatic intracranial atherosclerotic plaques using high-resolution 3.0 T MR vessel wall imaging (HR-MRI).

METHODS

Patients with symptomatic intracranial atherosclerotic plaques (cerebral ischemic events within the last three months) confirmed by HR-MRI from July 2017 to August 2022 were retrospectively included in this study. The enrolled patients started statin therapy at baseline. All the patients underwent the follow-up HR-MRI examination after statin therapy for at least 3 months. A paired sample t-test and Wilcoxon rank sum test were used to evaluate the changes in plaque characteristics after statin therapy. Multivariate linear regression was further used to investigate the clinical factors associated with statin efficacy.

RESULTS

A total of 48 patients (37 males; overall mean age = 60.2 ± 11.7 years) were included in this study. The follow-up time was 7.0 (5.6-12.0) months. In patients treated with statins for > 6 months (n = 31), plaque length, wall thickness, plaque burden, luminal stenosis and plaque enhancement were significantly reduced. Similar results were found in patients with good lipid control (n = 21). Younger age, lower BMI and hypertension were associated with decreased plaque burden. Lower BMI, hypertension and longer duration of statin therapy were associated with decreased plaque enhancement. Younger age and hypertension were associated with decreased luminal stenosis (all p < 0.05).

CONCLUSION

HR-MRI can effectively evaluate plaques changes after statin therapy. Statins can reduce plaque burden and stabilize plaques. The effect of statin may have a relationship with age, BMI, hypertension, and duration of statin therapy.

CLINICAL RELEVANCE STATEMENT

High-resolution MRI can be applied to evaluate the efficacy of statins on symptomatic intracranial atherosclerotic plaques. Long-term statin use and well-controlled blood lipid levels can help reduce plaque burden and stabilize plaques.

KEY POINTS

High-resolution MRI provides great help evaluating the changes of plaque characteristics after statin therapy. Efficacy of statins is associated with duration of use, controlled lipid levels, and clinical factors. High-resolution MRI can serve as an effective method for following-up symptomatic intracranial atherosclerosis.

Hemodynamic Impairment of Blood Pressure and Stroke Mechanisms in Symptomatic Intracranial Atherosclerotic Stenosis

BACKGROUND

Hemodynamic impairment of blood pressure may play a crucial role in determining the mechanisms of stroke in symptomatic intracranial atherosclerotic stenosis). We aimed to elucidate this issue and assess the impacts of modifications to blood pressure on hemodynamic impairment.

METHODS

From the Third China National Stroke Registry III, computed fluid dynamics modeling was performed using the Newton-Krylov-Schwarz method in 339 patients with symptomatic intracranial atherosclerotic stenosis during 2015 to 2018. The major exposures were translesional systolic blood pressure (SBP) drop and poststenotic mean arterial pressure (MAP), and the major study outcomes were cortex-involved infarcts and borderzone-involved infarcts, respectively. Multivariate logistic regression models and the bootstrap resampling method were utilized, adjusting for demographics and medical histories.

RESULTS

In all, 184 (54.3%) cortex-involved infarcts and 70 (20.6%) borderzone-involved infarcts were identified. In multivariate logistic model, the upper quartile of SBP drop correlated with increased cortex-involved infarcts (odds ratio, 1.92 [95% CI, 1.03-3.57]; bootstrap analysis odds ratio, 2.07 [95% CI, 1.09-3.93]), and the lower quartile of poststenotic MAP may correlate with increased borderzone-involved infarcts (odds ratio, 2.07 [95% CI, 0.95-4.51]; bootstrap analysis odds ratio, 2.38 [95% CI, 1.04-5.45]). Restricted cubic spline analysis revealed a consistent upward trajectory of the relationship between translesional SBP drop and cortex-involved infarcts, while a downward trajectory between poststenotic MAP and borderzone-involved infarcts. SBP drop correlated with poststenotic MAP negatively (rs=-0.765; P<0.001). In generating hemodynamic impairment, simulating blood pressure modifications suggested that ensuring adequate blood pressure to maintain sufficient poststenotic MAP appears preferable to the reverse approach, due to the prolonged plateau period in the association between the translesional SBP drop and cortex-involved infarcts and the relatively short plateau period characterizing the correlation between poststenotic MAP and borderzone-involved infarcts.

CONCLUSIONS

This research elucidates the role of hemodynamic impairment of blood pressure in symptomatic intracranial atherosclerotic stenosis-related stroke mechanisms, underscoring the necessity to conduct hemodynamic assessments when managing blood pressure in symptomatic intracranial atherosclerotic stenosis.

RNF213 Polymorphisms in Intracranial Artery Dissection

The ring finger protein 213 gene (RNF213) is involved in several vascular diseases, both intracranial and systemic ones. Some variants are common in the Asian population and are reported as a risk factor for moyamoya disease, intracranial stenosis and intracranial aneurysms. Among intracranial vascular diseases, both moyamoya disease and intracranial artery dissection are more prevalent in the Asian population. We performed a systematic review of the literature, aiming to assess the rate of RNF213 variants in patients with spontaneous intracranial dissections. Four papers were identified, providing data on 53 patients with intracranial artery dissection. The rate of RNF213 variants is 10/53 (18.9%) and it increases to 10/29 (34.5%), excluding patients with vertebral artery dissection. All patients had the RNF213 p.Arg4810Lys variant. RNF213 variants seems to be involved in intracranial dissections in Asian cohorts. The small number of patients, the inclusion of only patients of Asian descent and the small but non-negligible coexistence with moyamoya disease familiarity might be limiting factors, requiring further studies to confirm these preliminary findings and the embryological interpretation.

Effect of Drug-Coated Balloon Versus Stent Angioplasty in Patients With Symptomatic Intracranial Atherosclerotic Stenosis

BACKGROUND AND OBJECTIVES

Drug-coated balloons (DCBs) have exhibited promising results in coronary and peripheral artery diseases, but conclusive evidence is lacking in intracranial vasculature. We assessed the safety and efficacy of DCBs vs stent angioplasty for symptomatic intracranial atherosclerotic stenosis (sICAS) and initially identified patients who might have benefited most from DCB treatment.

METHODS

A single-center, retrospective cohort study was conducted from June 2021 to May 2022 with 154 patients with sICAS divided into 2 treatment groups: a DCB group (with or without remedial stenting, n = 47) and a stent group (n = 107). The treatment outcomes were compared using 1:2 propensity score matching. The primary safety end point was perioperative stroke or mortality, and the primary efficacy end point was the rate of target vessel restenosis at 12 months. The degree of luminal change was analyzed as a subgroup, defined as the difference between the degree of stenosis at follow-up and immediately after intervention.

RESULTS

One hundred eighteen patients were enrolled using propensity score matching, with 43 patients in the DCB group and 75 in the stent group. The incidence of perioperative adverse events was 2.3% in the DCB group and 8.0% in the stent group (P = .420). At a median follow-up of 12 months, the incidence of restenosis (11.9% [5/43] vs 28.0% [21/75], P = .045) and the median degree of stenosis (30% [20%, 44%] vs 30% [30%, 70%], P = .009, CI [0-0.01, 0.2]) were significantly lower in the DCB group than in the stent group. DCB angioplasty effectively prevented adverse events in the target vessel area and significantly reduced the degree of luminal change in the M1 segment of the middle cerebral artery (0 [0, 15%] vs 10% [0, 50%], P = .016).

CONCLUSION

DCB angioplasty might be a safe and effective alternative to stent angioplasty to treat sICAS, particularly among patients with M1 segment of the middle cerebral artery stenosis.

Global intracranial arterial tortuosity is associated with intracranial atherosclerotic burden

The effect of arterial tortuosity on intracranial atherosclerosis (ICAS) is not well understood. This study aimed to evaluate the effect of global intracranial arterial tortuosity on intracranial atherosclerotic burden in patients with ischemic stroke. We included patients with acute ischemic stroke who underwent magnetic resonance angiography (MRA) and classified them into three groups according to the ICAS burden. Global tortuosity index (GTI) was defined as the standardized mean curvature of the entire intracranial arteries, measured by in-house vessel analysis software. Of the 516 patients included, 274 patients had no ICAS, 140 patients had a low ICAS burden, and 102 patients had a high ICAS burden. GTI increased with higher ICAS burden. After adjustment for age, sex, vascular risk factors, and standardized mean arterial area, GTI was independently associated with ICAS burden (adjusted odds ratio [adjusted OR] 1.33; 95% confidence interval [CI] 1.09-1.62). The degree of association increased when the arterial tortuosity was analyzed limited to the basal arteries (adjusted OR 1.48; 95% CI 1.22-1.81). We demonstrated that GTI is associated with ICAS burden in patients with ischemic stroke, suggesting a role for global arterial tortuosity in ICAS.

Association of plaque characteristics with long-term stroke recurrence in patients with intracranial atherosclerotic disease: a 3D high-resolution MRI-based cohort study

OBJECTIVES

To evaluate the predictive ability of plaque characteristics for long-term stroke recurrence among patients with symptomatic intracranial atherosclerotic disease (ICAD).

METHODS

This cohort study included 132 patients with acute ischemic stroke (AIS) attributed to ICAD who were recruited between July 2017 and December 2020 and followed until stroke recurrence or December 2021. Plaque surface irregularity, degree of stenosis, plaque burden, remodeling ratio, enhancement ratio, and intraplaque hemorrhage were assessed with 3-dimensional high-resolution magnetic resonance vessel wall imaging (3D HR-MRI). Data were analyzed using Cox models, receiver operating characteristic (ROC) curves, and Kaplan-Meier survival analysis.

RESULTS

Of the 132 patients, during a median follow-up of 2.8 years, stroke recurrence occurred in 35 patients. The multivariable-adjusted hazard ratio (95% confidence interval) of stroke recurrence was 3.15 (1.34-7.42) per 10% increase in plaque burden and 2.17 (1.27-3.70) for enhancement ratio. The area under the curve (AUC) to predict stroke recurrence was 0.725 (95% CI 0.629-0.822) for plaque burden, 0.692 (95% CI 0.593-0.792) for enhancement ratio, and only 0.595 (95% CI 0.492-0.699) for the Essen stroke risk score. The Kaplan-Meier survival analysis further demonstrated significant differences in survival of free recurrent stroke between patients with plaque burden or enhancement ratio below and above the optimum cut-offs (both p < 0.001).

CONCLUSION

Higher plaque burden and enhancement ratio are independent risk factors for long-term stroke recurrence among patients with symptomatic ICAD, and valuable imaging markers for predicting and stratifying risk of stroke recurrence.

CLINICAL RELEVANCE STATEMENT

In patients with symptomatic ICAD, the results of this high-resolution magnetic resonance vessel wall imaging study have potential implications for optimal management of intracranial plaques and secondary prevention of stroke recurrence based on plaque burden and enhancement ratio.

KEY POINTS

• Identification of intracranial plaque characteristics responsible for stroke recurrence is essential to preventing stroke recurrence in patients with symptomatic intracranial atherosclerotic disease. • Higher plaque burden and enhancement ratio are independent risk factors for stroke recurrence. • Plaque burden and enhancement ratio are valuable imaging markers in the prediction and stratification of the risk of stroke recurrence.

Imaging of intracranial arterial disease: a comparison between MRI and unenhanced CT

Background and purpose

Arterial calcifications on unenhanced CT scans and vessel wall lesions on MRI are often used interchangeably to portray intracranial arterial disease. However, the extent of pathology depicted with each technique is unclear. We investigated the presence and distribution of these two imaging findings in patients with a history of cerebrovascular disease.

Materials and methods

We analyzed CT and MRI data from 78 patients admitted for stroke or TIA at our institution. Vessel wall lesions were assessed on 7 T MRI sequences, while arterial calcifications were assessed on CT scans. The number of vessel wall lesions, severity of intracranial internal carotid artery (iICA) calcifications, and overall presence and distribution of the two imaging findings were visually assessed in the intracranial arteries.

Results

At least one vessel wall lesion or arterial calcification was assessed in 69 (88%) patients. Only the iICA and vertebral arteries (VA) showed a substantial number of both calcifications and vessel wall lesions. The other vessels showed almost exclusively vessel wall lesions. The number of vessel wall lesions was associated with the severity of iICA calcification (p = 0.013).

Conclusions

The number of vessel wall lesions increases with the severity of iICA calcifications. Nonetheless, the distribution of vessel wall lesions on MRI and arterial calcifications on CT shows remarkable differences. These findings support the need for a combined approach to examine intracranial arterial disease.

The value of coordinated analysis of multimodal atherosclerotic plaque imaging in the assessment of cardiovascular and cerebrovascular events

Background

Although atherosclerosis (AS) can affect multiple vascular beds, previous studies have focused on the analysis of single-site AS plaques.

Objective

The aim of this study is to explore the differences or similarities in the characteristics of atherosclerotic plaque found in the internal carotid artery, cerebral artery, and coronary artery between patients with atherosclerotic cardiovascular disease (ASCVD) and those without events.

Methods

Patients aged ≥ 18 years who underwent both high-resolution vessel wall imaging (HR-VWI) and coronary computed tomography angiography (CCTA) were retrospectively collected and categorized into the ASCVD group and the non-event group. The plaques were then categorized into culprit plaques, non-culprit plaques, and non-event plaques. Plaque morphological data such as stenosis, stenosis grades, plaque length (PL), plaque volume (PV), minimal lumen area (MLA), enhancement grade, and plaque composition data such as calcified plaque volume (CPV), fibrotic plaque volume (FPV), fibro-lipid plaque volume (FLPV), lipid plaque volume (LPV), calcified plaque volume ratio (CPR), fibrotic plaque volume ratio (FPR), fibro-lipid plaque ratio (FLPR), lipid plaque volume ratio (LPR), intraplaque hemorrhage volume (IPHV), and intraplaque hemorrhage volume ratio (IPHR)were recorded and analyzed.

Results

A total of 44 patients (mean age 66 years, SD 9 years, 28 men) were included. In cervicocephalic plaques, the ASCVD group had more severe stenosis grades (p = 0.030) and demonstrated significant differences in LPV, LPR, and CPV (p = 0.044, 0.030, 0.020) compared with the non-event group. In coronary plaques, the ASCVD group had plaques with greater stenosis (p < 0.001), more severe stenosis grades (p < 0.001), larger volumes (p = 0.001), longer length (p = 0.008), larger FLPV (p = 0.012), larger FPV (p = 0.002), and higher FPR (p = 0.043) compared with the non-event group. There were significant differences observed in stenosis (HR-VWI, CCTA: p < 0.001, p < 0.001), stenosis grades (HR-VWI, CCTA: p < 0.001, p < 0.001), plaque length (HR-VWI, CCTA: p = 0.028, p < 0.001), and plaque volume (HR-VWI, CCTA: p = 0.013, p = 0.018) between the non-event plaque, non-culprit plaque, and culprit plaque. In the image analysis of HR-VWI, there were differences observed between IPHR (p < 0.001), LPR (p = 0.001), FPV (p = 0.011), and CPV (p = 0.015) among the three groups of plaques. FLPV and FPV were significantly different among the three different plaque types from the coronary artery (p = 0.043, p = 0.022).

Conclusion

There is a consistent pattern of change in plaque characteristics between the cervicocephalic and coronary arteries in the same patient.

Emerging Concept of Intracranial Arterial Diseases: The Role of High Resolution Vessel Wall MRI

Intracranial arterial disease (ICAD) is a heterogeneous condition characterized by distinct pathologies, including atherosclerosis. Advances in magnetic resonance technology have enabled the visualization of intracranial arteries using high-resolution vessel wall imaging (HR-VWI). This review summarizes the anatomical, embryological, and histological differences between the intracranial and extracranial arteries. Next, we review the heterogeneous pathophysiology of ICAD, including atherosclerosis, moyamoya or RNF213 spectrum disease, intracranial dissection, and vasculitis. We also discuss how advances in HR-VWI can be used to differentiate ICAD etiologies. We emphasize that one should consider clinical presentation and timing of imaging in the absence of pathology-radiology correlation data. Future research should focus on understanding the temporal profile of HR-VWI findings and developing quantitative interpretative approaches to improve the decision-making and management of ICAD.

[Analysis of intracranial saccular aneurysm wall: neuroimaging and histopathological correlates]

BACKGROUND

Contrast enhancement of intracranial aneurysm wall during MRI with targeted visualization of vascular wall correlates with previous aneurysm rupture and, according to some data, may be a predictor of further rupture of unruptured aneurysms.

OBJECTIVE

To analyze possible causes of aneurysm contrast enhancement considering morphological data of aneurysm walls.

MATERIAL AND METHODS

The study included 44 patients with intracranial aneurysms who underwent preoperative MRI between November 2020 and September 2022. Each aneurysm was assessed regarding contrast enhancement pattern. Microsurgical treatment of aneurysm was accompanied by resection of its wall for subsequent histological and immunohistochemical analysis regarding thrombosis, inflammation and neovascularization. Specimens were subjected to histological and immunochemical analysis. Immunohistochemical analysis was valuable to estimate inflammatory markers CD68 and CD3, as well as neurovascularization marker SD31.

RESULTS

Aneurysms with contrast-enhanced walls were characterized by higher number of CD3+, CD68+, CD31+ cells and parietal clots. Intensity of contrast enhancement correlated with aneurysm wall abnormalities.

CONCLUSION

Contrast enhancement of aneurysm wall can characterize various morphological abnormalities.

Multimodal Neuroimaging Reveals and Guides Treatment of a Middle Cerebral Artery Web

This case report describes how neuroimaging was used to determine treatment for episodic sudden-onset weakness and numbness in the left limbs.

Risk Factors, Pathophysiologic Mechanisms, and Potential Treatment Strategies of Futile Recanalization after Endovascular Therapy in Acute Ischemic Stroke

Endovascular therapy is the first-line treatment for acute ischemic stroke. However, studies have shown that, even with the timely opening of occluded blood vessels, nearly half of all patients treated with endovascular therapy for acute ischemic stroke still have poor functional recovery, a phenomenon called "futile recanalization.". The pathophysiology of futile recanalization is complex and may include tissue no-reflow (microcirculation reperfusion failure despite recanalization of the occluded large artery), early arterial reocclusion (reocclusion of the recanalized artery 24-48 hours post endovascular therapy), poor collateral circulation, hemorrhagic transformation (cerebral bleeding following primary ischemic stroke), impaired cerebrovascular autoregulation, and large hypoperfusion volume. Therapeutic strategies targeting these mechanisms have been attempted in preclinical research; however, translation to the bedside remains to be explored. This review summarizes the risk factors, pathophysiological mechanisms, and targeted therapy strategies of futile recanalization, focusing on the mechanisms and targeted therapy strategies of no-reflow to deepen the understanding of this phenomenon and provide new translational research ideas and potential intervention targets for improving the efficacy of endovascular therapy for acute ischemic stroke.

Association between Urine Albumin-to-creatinine Ratio and Intracranial Atherosclerotic Plaque in Chinese Adults - Results from the PRECISE Study

AIMS

Intracranial plaque may cause stroke in the absence of luminal stenosis. Although urine albumin-to-creatinine ratio (ACR) has been proved an established risk factor for cardiovascular disease, stroke and carotid atherosclerosis, little is known on the relationship between urine ACR and intracranial plaque.

METHODS

Subjects with history of stroke or coronary heart disease (CHD) were excluded in the PRECISE study. The intracranial plaque was assessed by vessel wall magnetic resonance imaging (MRI). Subjects were stratified according to ACR tertiles. Logistic regression and ordinal regression were performed to analyze the association between ACR and the presence of intracranial plaque or sum of the stenosis score for each artery.

RESULTS

2962 individuals were included with the mean age of 61.0±6.6 years. The median ACR was 11.7mg/g (interquartile range 7.0-22.0 mg/g), and the mean estimated glomerular filtration rate (eGFR) based on combination of creatinine and cystatin C was 88.5±14.8 ml/min·1.73m2. 495 (16.7%) participants had intracranial plaque. The highest ACR tertile with ACR ＞16.00mg/g was independently associated with the presence of intracranial plaque (OR 1.38, 95% CI: 1.05-1.82, p=0.02) and the odds of higher intracranial plaque burden (common OR 1.39, 95% CI: 1.05-1.83, p=0.02) after adjustment of confounding factors. No significant association was observed between eGFR and intracranial plaque presence or intracranial plaque burden.

CONCLUSIONS

Among a low-risk community-dwelling population without prior stroke or CHD in China, ACR was independently associated with intracranial plaque presence and plaque burden measured by vessel wall MRI.

Characteristics and evaluation of atherosclerotic plaques: an overview of state-of-the-art techniques

Atherosclerosis is an important cause of cerebrovascular and cardiovascular disease (CVD). Lipid infiltration, inflammation, and altered vascular stress are the critical mechanisms that cause atherosclerotic plaque formation. The hallmarks of the progression of atherosclerosis include plaque ulceration, rupture, neovascularization, and intraplaque hemorrhage, all of which are closely associated with the occurrence of CVD. Assessing the severity of atherosclerosis and plaque vulnerability is crucial for the prevention and treatment of CVD. Integrating imaging techniques for evaluating the characteristics of atherosclerotic plaques with computer simulations yields insights into plaque inflammation levels, spatial morphology, and intravascular stress distribution, resulting in a more realistic and accurate estimation of plaque state. Here, we review the characteristics and advancing techniques used to analyze intracranial and extracranial atherosclerotic plaques to provide a comprehensive understanding of atheroma.

Intracranial atherosclerotic disease: current management strategies

A stroke due to underlying intracranial large artery occlusion, which is atherosclerotic in nature, is known as intracranial atherosclerotic disease (ICAD). It is important to recognize that ischaemic stroke due to ICAD differs from extracranial disease and other stroke aetiologies and requires a nuanced approach. It is a significant cause of stroke worldwide, and severe symptomatic ICAD can present challenges from a therapeutic standpoint, including recurrent ischaemic stroke despite optimal management. Furthermore, exploring the underlying pathophysiological mechanisms responsible for the disease may be necessary while considering treatment options. This narrative review aims to provide an all-encompassing overview of this disease. Epidemiology and clinical pathophysiology will be explored in detail. The findings of large clinical trials will serve as a guide to finding the most optimized management strategies. Another critical question that arises is the treatment of acute ischaemic stroke due to large vessel occlusion with underlying intracranial atherosclerosis, is the treatment and clinical diagnosis the same as for other aetiologies of stroke (i.e. extracranial disease and nonvalvular atrial fibrillation)? Consequently, secondary prevention of patients with ischaemic stroke or transient ischaemic attack will be divided into medical therapy, risk factor control, and endovascular and surgical treatment options.

Characteristics of intracranial plaque in patients with non-cardioembolic stroke and intracranial large vessel occlusion

OBJECTIVE

To determine the characteristics of intracranial plaque proximal to large vessel occlusion (LVO) in stroke patients without major-risk cardioembolic source using 3.0 T high-resolution MRI (HR-MRI).

METHODS

We retrospectively enrolled eligible patients from January 2015 to July 2021. The multidimensional parameters of plaque such as remodelling index (RI), plaque burden (PB), percentage lipid-rich necrotic core (%LRNC), presence of discontinuity of plaque surface (DPS), fibrous cap rupture, intraplaque haemorrhage and complicated plaque were evaluated by HR-MRI.

RESULTS

Among 279 stroke patients, intracranial plaque proximal to LVO was more prevalent in the ipsilateral versus contralateral side to stroke (75.6% vs 58.8%, p<0.001). The larger PB (p<0.001), RI (p<0.001) and %LRNC (p=0.001), the higher prevalence of DPS (61.1% vs 50.6%, p=0.041) and complicated plaque (63.0% vs 50.6%, p=0.016) were observed in the plaque ipsilateral versus contralateral to stroke. Logistic analysis showed that RI and PB were positively associated with an ischaemic stroke (RI: crude OR: 1.303, 95% CI 1.072 to 1.584, p=0.008; PB: crude OR: 1.677, 95% CI 1.381 to 2.037, p<0.001). In subgroup with <50% stenotic plaque, the greater PB, RI, %LRNC and the presence of complicated plaque were more closely related to stroke, which was not evident in subgroup with ≥50% stenotic plaque.

CONCLUSION

This is the first study to report the characteristics of intracranial plaque proximal to LVO in non-cardioembolic stroke. It provides potential evidence to support different aetiological roles of <50% stenotic vs ≥50% stenotic intracranial plaque in this population.

Association of remnant cholesterol with intracranial atherosclerosis in community-based population: The ARIC study

OBJECTIVE

To evaluate the association between remnant cholesterol (remnant-C) and intracranial atherosclerotic disease (ICAD) in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS).

METHODS

We studied 1,564 participants with data on lipid profiles and high-resolution vessel wall MRI (VWMRI) from the ARIC-NCS. Remnant-C was computed as total cholesterol minus high-density lipoprotein cholesterol minus low-density lipoprotein cholesterol (LDL-C). The primary outcomes were the presence of intracranial plaques and luminal stenosis. Contributors were separated into four different groups based on remnant-C (22 mg/dL) and LDL-C (100 mg/dL) levels to investigate the function of remnant-C vs. LDL-C on ICAD. Multivariable logistic regression models were utilized to estimate the correlation among the discordant/concordant remnant-C and LDL-C, and ICAD.

RESULTS

A total of 1,564 participants were included (age 76.2 ± 5.3). After multivariable adjustment, log remnant-C was correlated with greater ICAD risk [odds ratio (OR) 1.36, 95% confidence interval (CI) 1.01 to 1.83]. The lower remnant-C/higher LDL-C group and the higher remnant-C/lower LDL-C group manifested a 1.53-fold (95% CI 1.06 to 2.20) and 1.52-fold (95% CI 1.08 to 2.14) greater risk of ICAD, relative to those having lower remnant-C/low LDL-C. Additionally, remnant-C ≥ 22 mg/dL distinguished participants at a greater risk of the presence of any stenosis compared to those at lower levels, even in participants with optimal levels of LDL-C.

CONCLUSIONS

Elevated levels of remnant-C were connected to ICAD independent of LDL-C and traditional risk factors. The mechanisms of remnant-C association with ICAD probably offer insight into preventive risk-factor of ischemic stroke.

The 2023 Taiwan Stroke Society Guidelines for the management of patients with intracranial atherosclerotic disease

Intracranial atherosclerotic disease (ICAD) is a major cause of ischemic stroke, especially in Asian populations, which has a high risk of recurrent stroke and cardiovascular comorbidities. The present guidelines aim to provide updated evidence-based recommendations for diagnosis and management of patients with ICAD. Taiwan Stroke Society guideline consensus group developed recommendations for management of patients with ICAD via consensus meetings based on updated evidences. Each proposed class of recommendation and level of evidence was approved by all members of the group. The guidelines cover six topics, including (1) epidemiology and diagnostic evaluation of ICAD, (2) nonpharmacological management of ICAD, (3) medical therapy for symptomatic ICAD, (4) endovascular thrombectomy and rescue therapy for acute ischemic stroke with underlying ICAD, (5) endovascular interventional therapy for postacute symptomatic intracranial arterial stenosis, and (6) surgical treatment of chronic symptomatic intracranial arterial stenosis. Intensive medical treatment including antiplatelet therapy, risk factor control, and life style modification are essential for patients with ICAD.

Vertebrobasilar Artery Calcification as a Risk Factor for the Development of Stroke: Case-Control Study From a Tertiary Care Center, Southern India

Background Stroke is an important cause of morbidity and mortality in developing countries. Many risk factors are well-established for the development of stroke. Atherosclerosis involving the media and intima layer of vertebrobasilar arteries has not been studied well as a risk factor for stroke. Objective To assess the degree of calcification of vertebrobasilar arteries among patients with stroke (cases), age- and gender-matched controls, and the risk of the development of stroke. Methods This was a hospital record-based case-control study with individuals with stroke as cases and age- and gender-matched individuals without stroke as controls, who underwent computed tomography imaging. The degree of calcification of vertebrobasilar arteries was assessed among cases and controls. Various other risk factors for the development of stroke such as the presence of hypertension, diabetes mellitus, and impaired lipid profile were also assessed. Results Among the 150 cases and their age- and gender-matched controls, the mean age of the subjects was 58.38 (±14.06) years. Forty percent of the individuals were males. Among the cases, right vertebral, left vertebral, and basilar artery calcifications were observed among 114 (76%), 102 (68%), and 52 (34.7%), respectively. Among controls, 71 (47.3%), 77 (51.3%), and 29 (19.3%) individuals had right vertebral, left vertebral, and basilar artery calcifications, respectively. The degree of calcification was higher among the cases in the right and left vertebral arteries than the controls (adjusted odds (aOR) of 6.61 and 2.32 and p-value <0.001 and 0.032, respectively). The risk of stroke increased with higher degrees of calcification, the presence of diabetes mellitus, and raised cholesterol levels (aOR of 9.98, 2.32, and 4 and p-value <0.001, 0.007, and 0.001, respectively). The risk of stroke increases with the presence of multiple risk factors. Conclusion The presence of higher grades of calcifications in the vertebrobasilar arteries is a major risk factor for stroke. Hence, its presence in asymptomatic individuals needs to be taken as a warning sign for the development of stroke.

Association between basilar artery stenosis features, vertebral artery stenosis and perforator stroke after stenting

BACKGROUND AND PURPOSE

We investigated the relationship between basilar artery (BA) atherosclerotic stenosis features and vertebral artery (VA) stenosis and explored whether BA stenosis features are associated with perforator stroke after stenting.

METHODS

Patients with BA stenosis who underwent HRMRI and DSA were recruited. Patients were divided into proximal BA stenosis and middle-or-distal BA stenosis groups, and then subgroup analyses were performed based on whether they had VA stenosis. BA plaque features were evaluated by HRMRI. Artery stenosis was measured by DSA. The incidence of perforator stroke after BA stenting was recorded, and the potential association between BA stenosis features and perforator stroke was analyzed.

RESULTS

One hundred and seventy-four patients were consecutively enrolled. Patients with proximal BA stenosis had a higher proportion of severe stenosis than those with middle-or-distal BA stenosis (P = 0.027). In the subgroup analysis, this difference mainly existed in patients complicated with VA stenosis (P = 0.023). Patients with proximal BA stenosis had a higher proportion of strong plaque enhancement than those with middle-or-distal BA stenosis (P < 0.001), especially in those with vertebrobasilar junction (VBJ) stenosis (P < 0.001). Perforator stroke after BA stenting occurred in five patients, of whom four had lateral wall BA plaques, four had plaque enhancement and four had proximal BA stenosis.

CONCLUSION

Patients with proximal BA stenosis had a higher proportion of severe stenosis and strong plaque enhancement, particularly in patients complicated with VA stenosis and VBJ stenosis. Perforator stroke after BA stenting may be related to distribution, burden and characteristics of BA lesions.

Intracranial atherosclerotic plaque enhancement and long-term risk of future strokes: A prospective, longitudinal study

BACKGROUND AND PURPOSE

The prognostic significance of postcontrast enhancement of intracranial atheromatous plaque is uncertain. Prospective, long-term follow-up studies in Caucasians, using a multicenter design, are lacking. We aimed to evaluate whether this radiological sign predicts long-term new stroke in symptomatic and asymptomatic intracranial atherosclerotic disease (ICAD) patients.

METHODS

This was a prospective, observational, longitudinal, multicenter study. We included a symptomatic and an asymptomatic cohort of ICAD patients that underwent 3T MRI including high-resolution sequences focused on the atheromatous plaque. We evaluated grade of stenosis, plaque characteristics, and gadolinium enhancement ratio (postcontrast plaque signal/postcontrast corpus callosum signal). The occurrence of new events was evaluated at 3, 6, 9, and 12 months and annually thereafter. The association between plaque characteristics and new stroke was studied using Cox multiple regression survival analysis and Kaplan-Meier curves.

RESULTS

Forty-eight symptomatic and 13 asymptomatic patients were included. During 56.3 ± 16.9 months, 11 patients (18%) suffered a new event (seven ischemic, two hemorrhagic, and two transient ischemic attacks). A receiver operating characteristic curve identified an enhancement ratio of >1.77 to predict a new event. In a multivariable Cox regression, postcontrast enhancement ratio >1.77 (hazard ratio [HR]= 3.632; 95% confidence interval [CI], 1.082-12.101) and cerebral microbleeds (HR = 5.244; 95% CI, 1.476-18.629) were independent predictors of future strokes. Patients with a plaque enhancement ratio >1.77 had a lower survival free of events (p < .05).

CONCLUSIONS

High intracranial postcontrast enhancement is a long-term predictor of new stroke in ICAD patients. Further studies are needed to elucidate whether postcontrast enhancement reflects inflammatory activity of intracranial atheromatous plaque.

Correlation between characteristics of intracranial atherosclerotic plaques and ischemic stroke in high-resolution vascular wall MRI

BACKGROUND

Intracranial atherosclerotic stenosis is a major cause of ischemic stroke, accounting for 30% of ischemic strokes in Asian populations.

PURPOSE

To investigate the relationship between the degree of arterial stenosis and enhancement grade of intracranial atherosclerotic disease (ICAD), the plaque characteristics in different remodeling patterns, and its potential impact.

MATERIAL AND METHODS

A total of 210 patients diagnosed with ICAD were enrolled in this retrospective study. Patients were divided into the middle cerebral artery (MCA) group (101 cases), posterior cerebral artery (PCA) group (14 cases), basilar artery (BA) group (71 cases), and intracranial segment of vertebral artery (VA) group (90 cases) according to the difference of diseased vessels. Data on presence or absence of ischemic infarction, intracranial vascular position of lesions, plaque characteristics, ICAD enhancement grade, remodeling index, and degree of arterial stenosis were collected for analysis.

RESULTS

The incidence of ischemic infarction in enhancement grade 2 was significantly higher than that in enhancement grade 1 in MCA group (P = 0.019). Enhancement grade 2 of ICAD was an independent risk factor for the development of ischemic infarction (odds ratio = 4.60; 95% confidence interval: 1.91-11.03; P = 0.001). There was no significant statistical difference in infarct rate between different remodeling modalities (P>0.05).

CONCLUSION

Enhancement grade of ICAD is significantly associated with the degree of stenosis and the occurrence of ischemic stroke, which varies in different intracranial vessels. The pattern of vascular remodeling varies among different intracranial vessels, and the pattern of vascular remodeling has a significant impact on plaque characteristics.

Plaque modification and stabilization after drug-coated balloon angioplasty for intracranial atherosclerotic lesions

OBJECTIVES

A drug-coated balloon (DCB) has potential applications in the treatment of intracranial atherosclerotic disease (ICAD). We aimed to evaluate changes of vessel wall features of ICAD lesions after DCB treatment by using vessel wall MRI (VWMRI).

METHODS

We retrospectively included patients with symptomatic ICAD who underwent DCB angioplasty alone. The incidences of stenosis of the lumen area, vessel wall thickening, hyperintense plaques, and prominent wall enhancement were compared between the baseline and follow-up VWMRI.

RESULTS

There were 29 ICAD lesions from 29 patients, of which 22 were stenosis and 7 were occlusion. The median interval between DCB treatment and follow-up VWMRI was 4.1 [3.3, 6.7] months. After DCB treatment, follow-up VWMRI showed a significant decrease in the stenosis degree of the lumen area (83% [71%, 96%] vs 15% [3%, 41%], p < 0.001). Thirty-eight percent (11/29) of the patients observed normal appearance of the target vessel wall on follow-up VWMRI. In the stenosis group, the prevalence of hyperintense plaques decreased from 66.7% (14/21) at baseline to 23.8% (5/21) at follow-up, and prominent wall enhancement decreased from 66.7% (14/21) at baseline to 19.0%(4/21) at follow-up. The incidence of hyperintense plaques (p = 0.028) and vessel wall thickening (p = 0.018) tended to decrease with follow-up time. Although not significant (p = 0.106), a similar trend was observed between the incidence of prominent wall enhancement and follow-up time.

CONCLUSION

Vascular healing with plaque modification and stabilization occurred following DCB treatment of ICAD lesions.

KEY POINTS

• A drug-coated balloon (DCB) has potential applications in the treatment of intracranial atherosclerotic disease (ICAD). • Vascular healing with plaque modification and stabilization occurred following DCB treatment of ICAD lesions.

Single-cell atlas reveals different immune environments between stable and vulnerable atherosclerotic plaques

Introduction

Regardless of the degree of stenosis, vulnerable plaque is an important cause of ischemic stroke and thrombotic complications. The changes of the immune microenvironment within plaques seem to be an important factor affecting the characteristics of the plaque. However, the differences of immune microenvironment between stable and vulnerable plaques were remained unknown.

Methods

In this study, RNA-sequencing was performed on superficial temporal arteries from 5 traumatic patients and plaques from 3 atherosclerotic patients to preliminary identify the key immune response processes in plaques. Mass cytometry (CyTOF) technology was used to explore differences in immune composition between 9 vulnerable plaques and 12 stable plaques. Finally, immunofluorescence technique was used to validate our findings in the previous analysis.

Results

Our results showed that more CD86+CD68+ M1 pro-inflammatory macrophages were found in vulnerable plaques, while CD4+T memory cells were mainly found in stable plaques. In addition, a CD11c+ subset of CD4+T cells with higher IFN-r secretion was found within the vulnerable plaque. In two subsets of B cells, CD19+CD20-B cells in vulnerable plaques secreted more TNF-a and IL-6, while CD19-CD20+B cells expressed more PD-1 molecules.

Conclusion

In conclusion, our study suggested that M1-like macrophages are the major cell subset affecting plaque stability, while functional B cells may also contribute to plaque stability.

Effects of stent shape on focal hemodynamics in intracranial atherosclerotic stenosis: A simulation study with computational fluid dynamics modeling

Background and aims

The shape of a stent could influence focal hemodynamics and subsequently plaque growth or in-stent restenosis in intracranial atherosclerotic stenosis (ICAS). In this preliminary study, we aim to investigate the associations between stent shapes and focal hemodynamics in ICAS, using computational fluid dynamics (CFD) simulations with manually manipulated stents of different shapes.

Methods

We built an idealized artery model, and reconstructed four patient-specific models of ICAS. In each model, three variations of stent geometry (i.e., enlarged, inner-narrowed, and outer-narrowed) were developed. We performed static CFD simulation on the idealized model and three patient-specific models, and transient CFD simulation of three cardiac cycles on one patient-specific model. Pressure, wall shear stress (WSS), and low-density lipoprotein (LDL) filtration rate were quantified in the CFD models, and compared between models with an inner- or outer-narrowed stent vs. an enlarged stent. The absolute difference in each hemodynamic parameter was obtained by subtracting values from two models; a normalized difference (ND) was calculated as the ratio of the absolute difference and the value in the enlarged stent model, both area-averaged throughout the arterial wall.

Results

The differences in focal pressure in models with different stent geometry were negligible (ND<1% for all cases). However, there were significant differences in the WSS and LDL filtration rate with different stent geometry, with ND >20% in a static model. Observable differences in WSS and LDL filtration rate mainly appeared in area adjacent to and immediately distal to the stent. In the transient simulation, the LDL filtration rate had milder temporal fluctuations than WSS.

Conclusions

The stent geometry might influence the focal WSS and LDL filtration rate in ICAS, with negligible effect on pressure. Future studies are warranted to verify the relevance of the changes in these hemodynamic parameters in governing plaque growth and possibly in-stent restenosis in ICAS.

Plaque characteristics after endovascular treatment in patients with intracranial atherosclerotic disease

BACKGROUND

Endovascular treatment (EVT) is an alternative option for symptomatic intracranial atherosclerotic disease (ICAD). However, the effect of EVT treatment on ICAD plaques is still unclear. This study describes the ICAD plaque characteristics after EVT treatment and analyzes the effect of different EVT treatments on plaque characteristics.

METHOD

From 2017 January to 2022 January, ICAD patients who underwent endovascular treatment and had follow-up high-resolution magnetic resonance image (HRMRI) were enrolled in the study. Multiple plaque characteristics, including plaque enhancement, plaque burden, were measured based on preoperative, and follow-up HRMRI. Plaque characteristics and postoperative plaque changes were analyzed between different treatment groups.

RESULT

Finally, 50 intracranial atherosclerotic plaques in 45 patients were included. Including 28 male patients and 17 female, media age 63.0 years old. Among 50 plaques, 41 received percutaneous angioplasty (including 22 plain balloons and 19 drug-coated balloons (DCB)) and the other 9 underwent stenting. Stenosis rate, plaque burden and eccentricity index at the lesion site were significantly decreased after EVT compared with preoperative periods (p <0.001). And only the DCB group showed a significant reduction in plaque enhancement at follow-up (p < 0.001). No significant preoperative and postoperative changes in other plaque characteristics were found.

CONCLUSION

EVT treatment could compromise the characteristics of intracranial periarterial atherosclerotic plaques, and DCB treatment may result in a reduction in plaque enhancement after treatment.

The relationship between vertebrobasilar artery calcification and intracranial atherosclerosis-related occlusion in thrombectomy

Background and purpose

Distinguishing between intracranial atherosclerosis-related occlusion (ICAS-O) and non-ICAS-O can benefit strategies of identifying the need for surgical plans prior to thrombectomy. We investigated the association between vertebrobasilar artery calcification (VBAC) and ICAS-O in acute ischemic stroke patients undergoing thrombectomy.

Methods

Patients were recruited from a prospective single-center registration study who had undergone thrombectomy between October 2017 and October 2021. The enrolled patients were divided into ICAS-O and non-ICAS-O, as determined by the intraarterial therapy process. The occurrences of VBAC were recorded on intracranial non-contrast computed tomography (NCCT) scans before thrombectomy. The association between VBAC and ICAS-O was assessed using binary logistic regression.

Results

A total of 2732 patients who had undergone digital subtraction angiography were reviewed, and 314 thrombectomy patients (mean age: 65.4 years, 36.6% female) with NCCT were enrolled in this study. VBAC was detected before thrombectomy in 113 (36%) out of 314 patients. Age, hypertension, and diabetes were associated with VBAC, and a higher frequency of VBAC was identified in patients presenting posterior circulation. ICAS-O accounts for 43% (135/314) in eligible patients. From multivariable analyses, VBAC was identified as an independent predictor of ICAS-O (adjusted odds ratio, 6.16 [95% CI, 2.673–14.217], P &lt; 0.001). Meanwhile, the (VBAC[+] atrial fibrillation[-]) group displayed higher rates of ICAS-O than the (VBAC[-] atrial fibrillation [-]) group (P &lt; 0.001).

Conclusions

We demonstrated that VBAC is an independent risk factor for ICAS-O in patients who underwent thrombectomy. Patients free of atrial fibrillation with VBAC have more trend to be ICAS-O.

Posterior circulation stroke due to intracranial artery disease in the Chinese population

BACKGROUND

Little is known about the distribution of the intracranial arteries that are responsible for noncardiogenic posterior circulation stroke (PCS) in the Chinese population. Furthermore, few studies have compared the imaging manifestations and outcomes across PCS due to the disease of different intracranial arteries. Therefore, our aim was to demonstrate the distribution of the intracranial arteries that were responsible for noncardiogenic PCS and to compare the imaging manifestations and outcome across PCS due to the disease of different intracranial arteries.

METHODS

We prospectively enrolled 690 patients from 22 Chinese centers with noncardiogenic PCS due to intracranial artery disease. Intracranial artery disease was classified as intracranial vertebral artery disease (IVAD) and intracranial nonvertebral artery disease (INVAD). Clinical-radiologic patterns and outcomes were compared between IVAD and INVAD.

RESULTS

INVAD was more frequent than IVAD. Compared to the INVAD group, the IVAD group more frequently had hypertension, coronary heart disease, multiple infarcts, border zone infarcts, territorial infarcts, small cortical infarcts, multilevel infarcts, multisector infarcts, and more often had severe stenosis of the responsible artery, more often presented with decreased alertness, gaze palsy, bilateral limb weakness, ataxia, dysphagia, diplopia, vertigo, and headache. In addition, the IVAD group had a higher National Institutes of Health stroke scale score and modified Rankin Scale score at discharge and more deaths and recurrent ischemic cerebrovascular disease within 1 year of onset. Multivariable Cox regression identified IVAD as an independent predictor of recurrent ischemic cerebrovascular disease.

CONCLUSIONS

PCS due to INVAD was more common in the Chinese population. However, PCS due to IVAD had more serious clinical-radiologic patterns and worse outcomes.

Intracranial Arterial Calcifications: Potential Biomarkers of Stroke Risk and Outcome

Intracranial artery calcifications (IAC), a common and easily identifiable finding on computed tomorgraphy angiography (CTA), has gained recognition as a possible risk factor for ischemic stroke. While atherosclerosis of intracranial arteries is believed to be a mechanism that commonly contributes to ischemic stroke, and coronary artery calcification is well-established as a predictor of both myocardial infarction (MI) and ischemic stroke risk, IAC is not currently used as a prognostic tool for stroke risk or recurrence. This review examines the pathophysiology and prevalence of IAC, and current evidence suggesting that IAC may be a useful tool for prediction of stroke incidence, recurrence, and response to acute ischemic stroke therapy.

Long-Term Outcomes of Local Tirofiban Infusion for Intracranial Atherosclerosis-Related Occlusion

Local tirofiban infusion has been reported as a rescue strategy for intracranial atherosclerotic stenosis (ICAS)-related stroke. However, the long-term outcomes of local tirofiban infusion during endovascular reperfusion therapy (ERT) for ICAS-related stroke are still uncertain. This study aimed to investigate the long-term outcomes of local tirofiban infusion during ERT. We retrospectively analyzed acute patients with ICAS-related stroke who were treated with local tirofiban as a rescue strategy during ERT. The primary outcomes were ischemic stroke, transient ischemic stroke (TIA), and stroke-related death within 30 days. Secondary outcomes included ischemic stroke and TIA beyond 30 days and up to 2 years after ERT in the corresponding treated vessel, symptomatic brain hemorrhage, any stroke, and non-stroke-related death. During a median follow-up of 24.0 months, 12 patients developed an ischemic stroke and TIA (4 within 30 days and 8 afterward). The 1-year risk of stroke and TIA was 9.2% (95% confidence interval, 8.0–18.6%). This study demonstrates that 1-year outcomes of local tirofiban infusion were comparable to the results of intracranial stenting in patients with symptomatic ICAS. Local tirofiban infusion for ICAS-related stroke may be a feasible rescue strategy that can have a bridging role until the maximum effect of antiplatelet agents is achieved.

The 46.1 Antibody Mediates Neurotensin Uptake into the CNS and the Effects Depend on the Route of Intravenous Administration

Central nervous system (CNS) exposure to blood-borne biotherapeutics is limited by the restrictive nature of the brain vasculature. In particular, tightly sealed endothelial cells of the blood-brain barrier (BBB) prevent the uptake of protein and gene medicines. An approach to increase the bioavailability of such therapeutics is harnessing the BBB endothelial cells' own receptor-mediated transcytosis (RMT) mechanisms. Key to this process is a targeting ligand that can engage a BBB-resident RMT receptor. We recently identified an antibody, named 46.1, that accumulates in the mouse brain after intravenous injection. To further characterize the brain targeting and penetrating properties of clone 46.1, we conjugated neurotensin (NT) to an scFv-Fc form of the antibody (46.1-scFv-Fc-LongLinker-NT). While centrally administered NT decreases the core body temperature and locomotor activity, effects attributed to two spatially segregated brain areas, systemically administered NT has limited effects. Hence, NT can be used as a model therapeutic payload to evaluate the brain penetration of BBB-targeting antibodies and their capability to accumulate in discrete brain areas. We demonstrate that intravenously administered 46.1-scFv-Fc-LL-NT can elicit transient hypothermia and reduce drug-induced hyperlocomotion, confirming that 46.1 can deliver drug cargo to the CNS at pharmacologically relevant doses. Interestingly, when two intravenous administration routes in mice, retro-orbital and tail vein, were compared, only retro-orbital administration led to transient hypothermia. We further explored the retro-orbital route and demonstrated that the 46.1-scFv-Fc-LL-NT could enter the brain arterial blood supply directly from the retro-orbital/cavernous sinus. Taken together, the 46.1 antibody is capable of transporting drug cargo into the CNS, and at least of a portion of its CNS accumulation occurs via the cavernous sinus-arterial route.

Sex Differences in Intracranial Atherosclerotic Plaques Among Patients With Ischemic Stroke

Objective

High-risk intracranial arterial plaques are the most common cause of ischemic stroke and their characteristics vary between male and female patients. However, sex differences in intracranial plaques among symptomatic patients have rarely been discussed. This study aimed to evaluate sex differences in intracranial atherosclerotic plaques among Chinese patients with cerebral ischemia.

Methods

One hundred and ten patients who experienced ischemic events underwent 3T cardiovascular magnetic resonance vessel wall scanning for the evaluation of intracranial atherosclerotic disease. Each plaque was classified according to its likelihood of causing a stroke (as culprit, uncertain, or non-culprit). The outer wall area (OWA) and lumen area of the lesion and reference sites were measured, and the wall and plaque areas, remodeling ratio, and plaque burden (characterized by a normalized wall index) were further calculated. The composition (T1 hyperintensity, enhancement) and morphology (surface irregularity) of each plaque were analyzed. Sex differences in intracranial plaque characteristics were compared between male and female patient groups.

Results

Overall, 311 plaques were detected in 110 patients with ischemic stroke (81 and 29 male and female patients, respectively). The OWA (P &lt; 0.001) and wall area (P &lt; 0.001) of intracranial arterial lesions were significantly larger in male patients. Regarding culprit plaques, the plaque burden in male patients was similar to that in female patients (P = 0.178, odds ratio [OR]: 0.168, 95% confidence interval [CI]: −0.020 to 0.107). However, the prevalence of plaque T1 hyperintensity was significantly higher than that in female patients (P = 0.005, OR: 15.362, 95% CI: 2.280–103.49). In the overall ischemic stroke sample, intracranial T1 hyperintensity was associated with male sex (OR: 13.480, 95% CI: 2.444–74.354, P = 0.003), systolic blood pressure (OR: 1.019, 95% CI: 1.002–1.036, P = 0.031), and current smoker (OR: 3.245, 95% CI: 1.097–9.598, P = 0.033).

Conclusion

For patients with ischemic stroke, the intracranial plaque burden in male patients was similar to that in female patients; however, the plaque characteristics in male patients are associated with higher risk, especially in culprit plaques.

Changes of Atherosclerotic Plaque in Cerebral Artery Stenosis According to High-Resolution MR Imaging

Atherosclerosis can affect multiple arteries, and result in stroke and heart disease. Clinical and conventional imaging is insufficient to predict the progression of atherosclerosis. This study investigates risk factors that rely on high-resolution magnetic resonance imaging (HR-MRI). Patients with cerebral artery stenosis who had undergone HR-MRI at least twice were included. The demographics, risk factors, and proportion of patients with cerebral artery stenosis were investigated. The association between atherosclerotic plaque characteristics and the progression or regression of artery stenosis was also analyzed. A total of 42 patients were analyzed, with a median follow-up of 16.88 ± 12.53 months. The mean age of all subjects was 63.1 ± 9.15 years, and 83.3% of them were male. The incidences of stenosis of the basilar, proximal internal carotid, and middle cerebral arteries were 21.4%, 61.9%, and 16.7%, respectively. Intraplaque hemorrhage (IPH) was detected in 20 (47.6%) patients. Multivariate analysis showed that age (odds ratio (OR), 0.87; p = 0.014), smoking (OR, 0.11; p = 0.033), and IPH regression (OR, 10.13; p = 0.027) were associated with stenosis regression. The progression of IPH (OR, 115.80; p = 0.007) was associated with stenosis progression. Results suggest that IPH on HR-MRI is associated with changes in cerebral atherosclerotic stenosis.

Application and interpretation of vessel wall magnetic resonance imaging for intracranial atherosclerosis: a narrative review

Background and Objective

Atherosclerosis is a systemic disease that occurs in the arteries, and it is the most important causative factor of ischemic stroke. Vessel wall magnetic resonance imaging (VWMRI) is one of the best non-invasive methods for displaying the vascular features of intracranial atherosclerosis. The main clinical applications of this technique include the exploration of the pathogenesis of intracranial atherosclerotic lesions, follow-up monitoring, and treatment prognosis judgment. As the demand for intracranial VWMRI increases in clinical practice, radiologists should be aware of the selection of imaging parameters and how they affect image quality, clinical indications, evaluation methods, and limitations in interpreting these images. Therefore, this review focused on describing how to perform and interpret VWMRI of intracranial atherosclerotic lesions.

Methods

We searched the studies on the application of VWMRI in the PubMed database from January 1, 2000 to March 31, 2022, and focused on the analysis of related studies on VWMRI in atherosclerotic lesions, including technical application, expert consensus, imaging characteristics, and the clinical significance of intracranial atherosclerotic lesions.

Key Content and Findings

We reviewed and summarized recent advances in the clinical application of VWMRI in atherosclerotic diseases. Currently accepted principles and expert consensus recommendations for intracranial VWMRI include high spatial resolution, multiplanar two and three-dimensional imaging, multiple tissue-weighted sequences, and blood and cerebrospinal fluid suppression. Understanding the characteristics of VWMRI of normal intracranial arteries is the basis for interpreting VWMRI of atherosclerotic lesions. Evaluating VWMRI imaging features of intracranial atherosclerotic lesions includes plaque morphological and enhancement characteristics. The evaluation of atherosclerotic plaque stability is the highlight of VWMRI.

Conclusions

VWMRI has a wide range of clinical applications and can address important clinical questions and provide critical information for treatment decisions. VWMRI plays a key role in the comprehensive evaluation and prevention of intracranial atherosclerosis. However, intracranial VWMRI is still unable to obtain in vivo plaque pathological specimens for imaging—pathological comparison is the most significant limitation of this technique. Further technical improvements are expected to reduce acquisition time and may ultimately contribute to a better understanding of the underlying pathology of lesions on VWMRI.

Silent brain infarction is associated with carotid siphon calcification in ischemic stroke patients

BACKGROUND

Silent brain infarction (SBI) had a higher prevalence in ischemic stroke patients than healthy population. Intracranial artery calcification, as the important component of atherosclerosis, is a known risk factor of ischemic stroke. Whether it is also the risk factor of SBI is uncertain. We aimed to assess the association between SBI and carotid siphon calcification (CSC) in ischemic stroke patients.

METHODS

We retrospectively collected consecutive data of acute ischemic stroke patients with and without SBI by Magnetic Resonance Imaging (MRI) and calcification using non-contrast Computerized Tomography (NCCT). We used a histopathologically validated method to score the circularity, thickness, and morphology of calcification. Clinical characteristics, prevalence and pattern (intimal and medial) of CSC were compared between patients with and without SBI. The association of CSC and SBI was investigated by logistic regression analysis.

RESULTS

Totally, 303 acute ischemic stroke patients were enrolled, of whom 260 (85.8%) had CSC. Patients with SBI were older (64.5 ± 10.4 years vs. 61.3 ± 12.1 years, P = 0.032), had a higher proportion of hypertension (77.5% vs. 65.7%, P = 0.035). Of the 260 CSC patients, there's no significant difference except for hyperlipidemia between patients with SBI and without SBI. The prevalence of intimal pattern of CSC was higher in those with SBI (adjusted odds ratio 2.42, 95% CI 1.219-4.794).

CONCLUSIONS

Patients with SBI at acute phase of ischemic stroke have more risk factors than mentioned previously. SBI associated with the intimal pattern of CSC which relate to the atherosclerosis process in symptomatic ischemic stroke patients.

Association between vascular calcification in intracranial vertebrobasilar circulation and luminal stenosis

INTRODUCTION

The study aims to assess the correlation and association between calcium burden and luminal stenosis in the vertebrobasilar circulation.

METHODS

We evaluated 166 patients [mean age, 79.8 ± 8.8 (SD) with 93 males] with stroke symptoms. The calcification patterns were assessed on non-contrast CT (NCCT); quantitative calcium burden [Agatston-Janowitz (AJ) calcium score, volume, and mass] on the initial non-contrast phase of CT perfusion (CTP); and the qualitative and quantitative luminal stenosis on CT angiography (CTA) studies. We calculated the correlation coefficient and association between measures of calcium burden and luminal stenosis.

RESULTS

Two hundred twenty-eight of 498 arteries (45.8%) had detectable calcification on NCCT and measurable stenosis in 169 of 498 arteries (33.9%) on CTA. We found a moderate correlation between qualitative calcium burden and qualitative (0.51 for R1 and 0.62 for R2, p < 0.01) as well as quantitative luminal stenosis (0.67 for R1 and 0.69 for R2, p < 0.01). There was a moderate correlation of AJ score (0.66), volume (0.68), and mass of calcification (0.60, p < 0.01) with luminal stenosis measurements. The quantitative calcium burden and luminal stenosis showed statistically significant differences between different qualitative categories of calcium burden (p < 0.001 in both readers). However, severe stenosis was not seen even with the advanced circumferential wall calcification (mean stenosis of 35.3-40.7%).

CONCLUSION

Our study showed a moderate correlation between higher burden of vascular calcification and the degree of luminal stenosis. However, higher calcium burden and circumferential wall calcification were not associated with severe luminal stenosis.

Relationship Between Hypertension and Basilar Atherosclerosis in Chinese Han Population: A High-Resolution Magnetic Resonance Imaging Study

Objective

To investigate the relationship between hypertension and basilar atherosclerosis evaluated by high-resolution magnetic resonance imaging (HR-MRI) in the Chinese Han population.

Methods

High resolution-MRI vessel wall imaging was performed in selected 193 patients for various indications. Multivariable logistic regression models based on odds ratio (OR) with their associated 95% confidence interval (CI) were used to assess the relationship between hypertension and basilar artery (BA) plaque, moderate or severe stenosis of BA plaque, and vulnerable plaque. A linear regression model was used to assess the relationship between hypertension and BA plaque numbers.

Results

Patients with hypertension had a higher proportion of BA plaque and vulnerable plaque as well as more number of enhancements of BA plaque and serious plaque compared with normotensive patients (all values of p < 0.05). Multivariable logistic regression analysis indicated that patients with hypertension had an increased risk for and more number of enhancements of BA plaque (adjusted-OR: 4.32, 95% CI 1.89–9.88, p < 0.001; adjusted-β: 0.55, 95% CI 0.14–0.96, p = 0.009, respectively) and had a higher proportion of moderate or severe stenosis of BA plaque and vulnerable plaque (adjusted-OR: 3.08, 95% CI 0.77–12.32, p = 0.111; adjusted-OR: 4.52, 95% CI 1.50–13.64, p = 0.007, respectively) compared with the normotensive group. Moreover, there was a saturation effect of age on the prevalence of BA plaque and vulnerable plaque.

Conclusion

Hypertension was the independent risk factor of BA plaque and vulnerable plaque assessed by HR-MRI in the Chinese Han population.

Integrated head and neck imaging of symptomatic patients with stroke using simultaneous non-contrast cardiovascular magnetic resonance angiography and intraplaque hemorrhage imaging as compared with digital subtraction angiography

BACKGROUND

Both stenosis rate and intraplaque hemorrhage (IPH) are important predictors of stroke risk. Simultaneous non-contrast angiography and intraplaque hemorrhage (SNAP) cardiovascular magnetic resonance (CMR) imaging can detect both stenosis rate and IPH. We aimed to evaluate consistency between SNAP and digital subtraction angiography (DSA) to assess symptomatic patients with stroke and explore the performance of SNAP to identify IPH and the clinical factors associated with IPH.

METHODS

Eighty-one symptomatic patients with stroke, admitted to Wuhan Union Hospital who underwent CMR high-resolution vessel wall imaging (HR-VWI) and SNAP, were retrospectively identified. For patients who received interventional therapy, the imaging functions of SNAP and HR-VWI were compared with DSA. The diameters of the intracranial and carotid vessels were measured, and stenotic vessels were identified. The consistency of SNAP and HR-VWI in identifying IPH was also examined, and the correlations between IPH and clinical factors were analyzed.

RESULTS

SNAP was more consistent with DSA than HR-VWI in measuring vascular stenosis (intraclass correlation coefficient [ICC]SNAP-DSA = 0.917, ICC HR-VWI-DSA = 0.878). Regarding the diameter measurements of each intracranial and carotid vessel segment, SNAP was superior or similar to HR-VWI, and both were consistent with DSA in the measurement of major intracranial vascular segments. HR-VWI and SNAP exhibited acceptable agreement in identifying IPH (Kappa = 0.839, 95% confidence interval [CI]: 0.704-0.974). Patients who underwent interventional therapy had a higher plaque burden (P < 0.001). Patients with IPH had lower levels of high-density lipoprotein cholesterol (HDL) (P = 0.038) and higher levels of blood glucose (P = 0.007) and cystatin C (P = 0.040).

CONCLUSIONS

CMR SNAP is consistent with DSA in measuring vessel diameters and identifying atherosclerosis stenosis in each intracranial and carotid vessel segment. SNAP is also a potential alternative to HR-VWI in identifying stenosis and IPH.

Characterization of Restenosis following Carotid Endarterectomy Using Contrast-Enhanced Vessel Wall MR Imaging

BACKGROUND AND PURPOSE

Restenosis is an important determinant of the long-term efficacy of carotid endarterectomy. Our aim was to assess the role of high-resolution vessel wall MR imaging for characterizing restenosis after carotid endarterectomy.

MATERIALS AND METHODS

Patients who underwent vessel wall MR imaging after carotid endarterectomy were included in this study. Restenotic lesions were classified as myointimal hyperplasia or recurrent atherosclerotic plaques based on MR imaging features of lesion compositions. Imaging characteristics of myointimal hyperplasia were compared with those of normal post-carotid endarterectomy and recurrent plaque groups. Recurrent plaques were matched with primary plaques by categories of stenosis, and differences in plaque features were compared between the 2 groups.

RESULTS

Twenty-two recurrent lesions from 18 patients (14 unilateral and 4 bilateral) were classified as myointimal hyperplasia or recurrent plaque. Myointimal hyperplasia showed no difference in enhancement compared with normal post-carotid endarterectomy vessels (5 unilateral) but showed stronger enhancement than recurrent plaques (80.10% [SD, 42.42%] versus 56.74% [SD, 46.54%], P = .042). A multivariate logistic regression model of plaque-feature detection in recurrent plaques compared with primary plaques adjusted for maximum wall thickness revealed that recurrent plaques were longer (OR, 4.27; 95% CI, 1.32-13.85; P = .015) and more likely to involve a flow divider and side walls (OR, 6.96; 95% CI, 1.37-35.28; P = .019). Recurrent plaques had a higher prevalence of intraplaque hemorrhage (61.5% versus 30.8%, P = .048) by a χ² test, but compositional differences were not significant in the multivariate model.

CONCLUSIONS

Vessel wall MR imaging can distinguish recurrent plaques from myointimal hyperplasia and reveal features that may differ between primary and recurrent plaques, highlighting its value for evaluating patients with carotid restenosis.

Intracranial Arterial Calcification and Intracranial Atherosclerosis: Close but Different

Background and Purpose

Intracranial arterial calcification (IAC) may be present in the intimal or medial arterial layer. This study aimed to elucidate the link between the calcification and atherosclerotic disease in the intracranial vasculature.

Methods

Consecutive patients with acute ischemic stroke were included. Bilateral intracranial segment of the internal carotid artery, M1 segment of the middle cerebral artery, intracranial segment of the vertebral artery, and the basilar artery were visualized by the multi-detector computed tomography (CT) and vessel-wall magnetic resonance imaging (vwMRI) within 14 days after stroke onset. IAC was into the intimal or medial pattern. Subsequently, on the vwMRI, we assessed the luminal stenosis, eccentricity, plaque burden, and intraplaque hemorrhage (IPH) as markers of atherosclerosis at each IAC site.

Results

Among 69 patients with stroke, IAC was identified in 35% of (161/483) artery segments, of which 61.5% were predominantly intimal calcification and 38.5% were predominantly medial calcification. About 79.8% of intimal calcifications and 64.5% of medial calcifications co-existed with atherosclerotic plaques. Intimal calcification was associated with luminal stenosis (p = 0.003) caused by atherosclerotic lesions. Compared with the medial IAC, intimal IAC was more often accompanied by eccentric plaques (p = 0.02), larger plaque burden (p = 0.001), and IPH (p = 0.001).

Conclusion

Our multimodal imaging-based comparison study on intracranial arteriosclerosis demonstrated that intimal IAC, compared with medial IAC, was more often accompanied by the luminal stenosis, larger plaque burden, eccentricity, and IPH, providing strong evidence for clinical evaluation on the mechanism, risk, and prognosis of ischemic stroke.

Histology-Verified Intracranial Artery Calcification and Its Clinical Relevance With Cerebrovascular Disease

Intracranial artery calcification (IAC) was regarded as a proxy for intracranial atherosclerosis (ICAS). IAC could be easily detected on routine computer tomography (CT), which was neglected by clinicians in the previous years. The evolution of advanced imaging technologies, especially vessel wall scanning using high resolution-magnetic resonance imaging (HR-MRI), has aroused the interest of researchers to further explore the characteristics and clinical impacts of IAC. Recent histological evidence acquired from the human cerebral artery specimens demonstrated that IAC could mainly involve two layers: the intima and the media. Accumulating evidence from histological and clinical imaging studies verified that intimal calcification is more associated with ICAS, while medial calcification, especially the internal elastic lamina, contributes to arterial stiffness rather than ICAS. Considering the highly improved abilities of novel imaging technologies in differentiating intimal and medial calcification within the large intracranial arteries, this review aimed to describe the histological and imaging features of two types of IAC, as well as the risk factors, the hemodynamic influences, and other clinical impacts of IAC occurring in intimal or media layers.

Predictive power of high-resolution vessel wall magnetic resonance imaging in ischemic stroke

BACKGROUND AND OBJECTIVE

Intracranial atherosclerotic disease (ICAD) is a key contributor to ischemic stroke and has a high recurrence rate. This study aimed to investigate the function of high-resolution vessel wall MRI (HR-VW-MRI) and evaluate plaque characteristics in patients with ICAD.

METHODS

A consecutive series of patients with ICAD who underwent HR-VW-MRI were enrolled, and imaging measurements were acquired. Baseline clinical characteristics were identified. Telephone follow-up was conducted every three months. The endpoint events were the first onset or recurrence of ischemic stroke and new clinical vascular events. Patients were divided into groups with or without events according to whether the endpoint event occurred.

RESULTS

A total of 70 patients (mean age = 57.6 years old) were enrolled. The median follow-up duration was 182 days. During the follow-up, 10 patients developed ischemic stroke, experienced endpoint events, and were found with 44 plaques in the artery area. A total of 169 plaques were further found in 70 patients. There were significant differences in EI, HST1, surface features, and WA reference between the two groups (P < 0.05). Logistic analysis showed that grade 2 enhancements, stenosis degree ≥ 50%, HST1, and surface features were independent prognostic factors of the onset of stroke, caused by ICAD.

CONCLUSION

This prospective study demonstrates that HR-VW-MRI can identify atherosclerotic plaques in the cerebral artery and high-risk plaques, which may contribute to the prevention of ICAD and guide clinical treatment.

Rescue Endovascular Treatment for Emergent Large Vessel Occlusion With Underlying Intracranial Atherosclerosis: Current State and Future Directions

Intracranial atherosclerosis (ICAS) is one of the most common causes of stroke worldwide and is associated with high risk of stroke recurrence. While the most common clinical presentation is acute–subacute transient ischemic attack or ischemic stroke, occasionally, patients with underlying ICAS present with acute occlusion of the affected vessel. Diagnosis and endovascular management of ICAS-related emergent large vessel occlusion (ELVO) can be challenging. Herein, we review the current evidence supporting endovascular management of ICAS-related ELVO and discuss future directions.

Outcome of Wingspan Stent Using Aggressive Post-stent Balloon Dilation for Intracranial Atherosclerosis Stenosis

Background: Wingspan stent has gained interest for better long-term outcomes for intracranial atherosclerosis disease (ICAD). However, in-stent restenosis still presents as a problem and may cause postoperative neurological events. We aimed to find a way to prevent in-stent restenosis.

Method: Patients with stenosis >70% ICAD were treated with wingspan stent and were retrospectively reviewed. The patients were separated into two groups: one with post-dilation and the other without post-dilation. The outcomes of wingspan stenting were compared immediately after the surgery and at a 1-year follow-up.

Results: Overall, 28 patients were included for analysis, with 15 patients undergoing post-dilation and 13 patients not undergoing the procedure. The extent of stenosis was significantly lower in the post-dilation group than in the no post-dilation group, both immediately after the surgery (14.8 ± 10.2 vs. 28.5 ± 14.5%, p < 0.01) and at 1-year follow-up (25.8 ± 18.0 vs. 50.1 ± 23.2%, p < 0.01). The post-dilation method immediately expanded the stent diameter (2.89 ± 0.48 vs. 3.05 ± 0.44 mm, p < 0.001), and the diameter still increased at 1-year follow-up (3.05 ± 0.44 vs. 3.12 ± 0.43 mm, p < 0.01) due to the self-expandable property of the wingspan. Similarly, in the no post-dilation group, the stent size was also increased (2.70 ± 0.67 vs. 2.80 ± 0.64 mm, p < 0.01). However, at 1-year follow up, the luminal diameter was stationary in the post-dilation group (2.36 ± 0.73 vs. 2.46 ± 0.82 mm, p = 0.88) and decreased in the no post-dilation group (2.24 ± 0.56 vs. 1.60 ± 0.79 mm, p < 0.01). The periprocedural complication rate was similar between the groups.

Conclusion: The post-dilation method can be feasibly performed and can offer better stent expansion and apposition in the wingspan system. By applying this technique, we might prevent in-stent restenosis and improve neurological outcomes.

Combined Assessment of Elevated Plasma Lipoprotein-Associated Phospholipase A2 and Plaque Enhancement Improved Accuracy in the Risk of Acute Ischemic Stroke in Patients with Intracranial Artery Stenosis

PURPOSE

We evaluated the relationship between plasma lipoprotein-associated phospholipase A₂ (Lp-PLA₂) concentration and plaque characteristics in patients with intracranial artery stenosis and their clinical relevance in acute ischemic stroke.

METHODS

Eighty-seven patients with intracranial atherosclerotic stenosis (66 males, 21 females) were retrospectively enrolled. Plasma Lp-PLA₂ concentration was measured, and vessel wall magnetic resonance imaging (VW-MRI) was used to determine intracranial vascular stenosis and plaque characteristics, including plaque enhancement, surface morphology, and T₁ hyperintensity. Binary logistic regression was used to evaluate the relationship between Lp-PLA₂ concentration and plaque characteristics of intracranial artery after adjusting for demographic and confounding factors and to assess their diagnostic efficacy for the risk of acute ischemic stroke.

RESULTS

After adjustment for demographic, medication and related lipid factors, Lp-PLA₂ elevation was associated with plaque enhancement (odds ratio [OR]=12.7, 95% confidence interval [CI] 2.51-64.82, P=0.002) and surface irregularity (OR=2.9, 95% CI 1.06-7.98, P=0.038). Both Lp-PLA₂ elevation (OR=8.8, 95% CI 1.64-47.72, P=0.011) and plaque enhancement (OR=34.3, 95% CI 5.88-200.4, P=0.001) were associated with acute ischemic stroke. Receiver operating characteristic curve analysis showed that the area under the curve for Lp-PLA₂ concentration and plaque enhancement combined in the diagnosis of acute ischemic stroke was 0.884, significantly higher than that for Lp-PLA₂ concentration (0.724) and plaque enhancement (0.794) alone.

CONCLUSION

Elevated Lp-PLA₂ is associated with plaque enhancement and plaque surface irregularity. Combined assessment of Lp-PLA₂ concentration and plaque enhancement is of greater diagnostic value for the risk of acute ischemic stroke in patients with intracranial artery stenosis.

Cardiovascular Risk Factors Affect Specific Segments of the Intracranial Vasculature in High-Resolution (HR) Vessel Wall Imaging (VWI)

OBJECTIVES

Luminal-based imaging have identified different risk factors for extracranial and intracranial atherosclerosis (ICAS), but these techniques are known to underestimate the true extent of the disease. High-resolution (HR) vessel wall imaging (VWI) has recently gained recognition as a valuable tool in the assessment of ICAS. The aim of this study is to determine the association between cardiovascular risk factors and specific intracranial vessel segment involvement using HR-VWI.

MATERIALS AND METHODS

From January 2017 to January 2020, consecutive patients ≥ 18 years-old undergoing HR-VWI of the brain were identified. Patients with history of primary or secondary vasculitis, reversible cerebral vasoconstriction syndrome, or moya-moya were excluded. The presence of vessel wall thickening and enhancement were assessed in the perpendicular plane for each vessel segment by two neuroradiologists. Univariate and multivariate analyses were performed to assess associations between imaging findings and cardiovascular risk factors. Interrater reliability was calculated.

RESULTS

Seventy-one patients (39 men; mean age: 55.9 years) were included. Vessel wall enhancement was seen in 39/71 (55%). A total number of 105 vessel segments demonstrated abnormal enhancement and 79/105 (75%) had an eccentric pattern. Eccentric vessel wall enhancement was independently associated with age >65 years-old in the ICA (OR 9.0, CI 2.1 - 38.2, p < 0.01) and proximal MCA (OR 4.0, CI 1.2 - 13.2, p = 0.02), and with hyperlipidemia in the posterior circulation (OR 44.0, CI2.9-661.0, p<0.01).

CONCLUSION

There is a significant association between eccentric vessel wall enhancement of the ICA and proximal MCA in patients with age > 65; and of the proximal posterior circulation (basilar - PCA1) with hyperlipidemia.

Macrocalcification of intracranial vertebral artery may be related to in-stent restenosis: lessons learned from optical coherence tomography

BACKGROUND

Calcification has been proven to be a marker of atherosclerosis and is related to an increased risk of ischemic stroke. Additionally, calcification was reported to be prevalent in patients with stenotic lesions of the intracranial vertebral artery. Thus, reliable imaging facilities for evaluating plaque calcification have remarkable significance in guiding stenting and predicting patient outcomes. Optical coherence tomography (OCT) has a unique advantage in its ability to detect calcium and to achieve three-dimensional volumetric calcium characterization.

METHODS

From March 2017 to September 2018, seven cases of calcified lesions with intracranial vertebral artery stenosis were investigated using OCT, before and after the placement of an Apollo balloon-mounted stent. Transcranial color-coded duplex sonography was performed to identify restenosis with a mean follow-up time of 13.3 months in this case series.

RESULTS

All calcified lesions were evaluated quantitatively and qualitatively using OCT. Among all cases, five had macrocalcifications and two had spotty calcifications. Severe in-stent restenosis was observed in two cases, both with macrocalcifications.

CONCLUSIONS

This study suggests a potential relationship between macrocalcifications and the risk of in-stent restenosis of the intracranial vertebral artery. These preliminary findings obtained from a limited sample should be verified by prospective large-scale studies.

Characteristics of symptomatic plaque on high-resolution magnetic resonance imaging and its relationship with the occurrence and recurrence of ischemic stroke

BACKGROUND

Atherosclerosis is the most common cause of ischemia stroke. Computed tomographic angiography (CTA) and digital subtraction angiography (DSA) are used to evaluate the degree of lumen stenosis. However, these examinations are invasive and can only reveal mild to moderate stenosis. High-resolution magnetic resonance imaging (HRMRI) seems a more intuitive way to show the pathological changes of vascular wall. Hence, we conducted a systematic retrospective study to determine the characteristics of symptomatic plaques in patients with intracranial atherosclerosis on HRMRI and their association with the occurrence and recurrence of ischemic stroke events.

METHODS

The PubMed database was searched for relevant studies reported from January 31, 2010, to October 31, 2020.

RESULTS

We selected 14 clinical outcome studies. We found that plaque enhancement and positive remodeling on HRMRI indicate symptomatic plaques. Besides, intraplaque hemorrhage and positive remodeling index are closely related to the occurrence of stroke. However, it is still controversial whether the initial enhancement of plaque and the occurrence and recurrence of stroke are related. There is also no significant correlation between vascular stenosis and symptomatic plaque or the occurrence and recurrence of ischemic stroke.

CONCLUSION

High-resolution magnetic resonance imaging can be used as an assessment tool to predict the risk of stroke onset and recurrence in patients with atherosclerosis, but further research is also needed.

Supracardiac atherosclerosis in embolic stroke of undetermined source: the underestimated source

The term 'embolic stroke of undetermined source' (ESUS) is used to describe patients with a non-lacunar ischaemic stroke without any identified embolic source from the heart or the arteries supplying the ischaemic territory, or any other apparent cause. When the ESUS concept was introduced, covert atrial fibrillation was conceived to be the main underlying cause in the majority of ESUS patients. Another important embolic source in ESUS is the atherosclerotic plaque in the carotid, vertebrobasilar, and intracranial arteries, or the aortic arch-collectively described as supracardiac atherosclerosis. There is emerging evidence showing that the role of supracardiac atherosclerosis is larger than it was initially perceived. Advanced imaging methods are available to identify plaques which high embolic risk. The role of novel antithrombotic strategies in these patients needs to be assessed in randomized controlled trials. This review presents the evidence which points towards a major aetiological association between atherosclerotic plaques and ESUS, summarizes the imaging features which may aid to identify plaques more likely to be associated with ESUS, discusses strategies to reduce the associated stroke risk, and highlights the rationale for future research in this field.

Intracranial Atherosclerotic Burden and Cerebral Parenchymal Changes at 7T MRI in Patients With Transient Ischemic Attack or Ischemic Stroke

The relevance of intracranial vessel wall lesions detected with MRI is not fully established. In this study (trial identification number: NTR2119; www.trialregister.nl), 7T MRI was used to investigate if a higher vessel wall lesion burden is associated with more cerebral parenchymal changes in patients with ischemic stroke or transient ischemic attack (TIA). MR images of 82 patients were assessed for the number of vessel wall lesions of the large intracranial arteries and for cerebral parenchymal changes, including the presence and number of cortical, small subcortical, and deep gray matter infarcts; lacunes of presumed vascular origin; cortical microinfarcts; and periventricular and deep white matter hyperintensities (WMHs). Regression analyses showed that a higher vessel wall lesion burden was associated with the presence of small subcortical infarcts, lacunes of presumed vascular origin, and deep gray matter infarcts (relative risk 1.18; 95% CI, 1.03–1.35) and presence of moderate-to-severe periventricular WMHs (1.21; 95% CI, 1.03–1.42), which are all manifestations of small vessel disease (SVD). The burden of enhancing vessel wall lesions was associated with the number of cortical microinfarcts only (1.48; 95% CI, 1.04–2.11). These results suggest an interrelationship between large vessel wall lesion burden and cerebral parenchymal manifestations often linked to SVD or, alternatively, that vascular changes occur in both large and small intracranial arteries simultaneously.