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Background: Carotid artery atherosclerosis is highly prevalent in the general population and is a well-established risk factor for acute ischemic stroke. Although the morphological characteristics of vulnerable plaques are well recognized, there is a lack of consensus in reporting and interpreting carotid plaque features., Objectives: The aim of this paper is to establish a consistent and comprehensive approach for imaging and reporting carotid plaque by introducing the Plaque-RADS (Reporting and Data System) score., Methods: A panel of experts recognized the necessity to develop a classification system for carotid plaque and its defining characteristics. Using a multimodality analysis approach, the Plaque-RADS categories were established through consensus, drawing on existing published reports., Results: The authors present a universal classification that is applicable to both researchers and clinicians. The Plaque-RADS score offers a morphological assessment in addition to the prevailing quantitative parameter of "stenosis." The Plaque-RADS score spans from grade 1 (indicating complete absence of plaque) to grade 4 (representing complicated plaque). Accompanying visual examples are included to facilitate a clear understanding of the Plaque-RADS categories., Conclusions: Plaque-RADS is a standardized and reliable system of reporting carotid plaque composition and morphology via different imaging modalities, such as ultrasound, computed tomography, and magnetic resonance imaging. This scoring system has the potential to help in the precise identification of patients who may benefit from exclusive medical intervention and those who require alternative treatments, thereby enhancing patient care. A standardized lexicon and structured reporting promise to enhance communication between radiologists, referring clinicians, and scientists., Competing Interests: Funding Support and Author Disclosures The views expressed in this paper are those of the authors and do not reflect the official policy of the Department of Army/Navy/Air Force, Department of Defense, or U.S. Government. The identification of specific products or scientific instrumentation does not constitute endorsement or implied endorsement on the part of the author, Department of Defense, or any component agency. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose: Magnetic resonance (MR) imaging detection of methemoglobin, a molecular marker of intraplaque hemorrhage (IPH), in atherosclerotic plaque is a promising method of assessing stroke risk. However, the multicenter imaging studies required to further validate this technique necessitate the development of IPH phantoms to standardize images acquired across different scanners. This study developed a set of phantoms that modeled methemoglobin-laden IPH for use in MR image standardization., Procedures: A time-stable material mimicking the MR properties of methemoglobin in IPH was created by doping agarose hydrogel with gadolinium and sodium alginate. This material was used to create a phantom that consisted of 9 cylindrical IPH sites (with sizes from 1 to 8 mm). Anatomical replicas of IPH-positive atherosclerosis were also created using 3D printed molds. These plaque replicas also modeled other common plaque components including a lipid core and atheroma cap. T1 mapping and a magnetization-prepared rapid acquisition gradient echo (MPRAGE) carotid imaging protocol were used to assess phantom realism and long-term stability., Results: Cylindrical phantom IPH sites possessed a T1 time of 335 ± 51 ms and exhibited little change in size or MPRAGE signal intensity over 31 days; the mean (SD) magnitude of changes in size and signal were 6.4 % (2.7 %) and 7.3 % (6.7 %), respectively. IPH sites incorporated into complex anatomical plaque phantoms exhibited contrast comparable to clinical images., Conclusions: The cylindrical IPH phantom accurately modeled the short T1 time characteristic of methemoglobin-laden IPH, with the IPH sites exhibiting little variation in imaging properties over 31 days. Furthermore, MPRAGE images of the anatomical atherosclerosis replicas closely matched those of clinical plaques. In combination, these phantoms will allow for IPH imaging protocol standardization and thus facilitate future multicenter IPH imaging., (© 2022. The Author(s).)

Current guidelines for primary and secondary prevention of stroke in patients with carotid atherosclerosis are based on the quantification of the degree of stenosis and symptom status. Recent publications have demonstrated that plaque morphology and composition, independent of the degree of stenosis, are important in the risk stratification of carotid atherosclerotic disease. This finding raises the question as to whether current guidelines are adequate or if they should be updated with new evidence, including imaging for plaque phenotyping, risk stratification, and clinical decision-making in addition to the degree of stenosis. To further this discussion, this roadmap consensus article defines the limits of luminal imaging and highlights the current evidence supporting the role of plaque imaging. Furthermore, we identify gaps in current knowledge and suggest steps to generate high-quality evidence, to add relevant information to guidelines currently based on the quantification of stenosis., (© 2021 by American Journal of Neuroradiology.)

Background: In the last 20-30 years, there have been many advances in imaging and therapeutic strategies for symptomatic and asymptomatic individuals with carotid artery stenosis. Our aim was to examine contemporary multinational practice standards., Methods: Departmental Review Board approval for this study was obtained, and 3 authors prepared the 44 multiple choice survey questions. Endorsement was obtained by the European Society of Neuroradiology, American Society of Functional Neuroradiology, and African Academy of Neurology. A link to the online questionnaire was sent to their respective members and members of the Faculty Advocating Collaborative and Thoughtful Carotid Artery Treatments (FACTCATS). The questionnaire was open from May 16 to July 16, 2019., Results: The responses from 223 respondents from 46 countries were included in the analyses including 65.9% from academic university hospitals. Neuroradiologists/radiologists comprised 68.2% of respondents, followed by neurologists (15%) and vascular surgeons (12.9%). In symptomatic patients, half (50.4%) the respondents answered that the first exam they used to evaluate carotid bifurcation was ultrasound, followed by computed tomography angiography (CTA, 41.6%) and then magnetic resonance imaging (MRI 8%). In asymptomatic patients, the first exam used to evaluate carotid bifurcation was ultrasound in 88.8% of respondents, CTA in 7%, and MRA in 4.2%. The percent stenosis upon which carotid endarterectomy or stenting was recommended was reduced in the presence of imaging evidence of "vulnerable plaque features" by 66.7% respondents for symptomatic patients and 34.2% for asymptomatic patients with a smaller subset of respondents even offering procedural intervention to patients with <50% symptomatic or asymptomatic stenosis., Conclusions: We found heterogeneity in current practices of carotid stenosis imaging and management in this worldwide survey with many respondents including vulnerable plaque imaging into their decision analysis despite the lack of proven benefit from clinical trials. This study highlights the need for new clinical trials using vulnerable plaque imaging to select high-risk patients despite maximal medical therapy who may benefit from procedural intervention., (© 2021 S. Karger AG, Basel.)

Objectives: The goal of this study was to compare the risk of stroke between patients with carotid artery disease with and without the presence of intraplaque hemorrhage (IPH) on magnetic resonance imaging., Background: IPH in carotid stenosis increases the risk of cerebrovascular events. Uncertainty remains whether risk of stroke alone is increased and whether stroke is predicted independently of known risk factors., Methods: Data were pooled from 7 cohort studies including 560 patients with symptomatic carotid stenosis and 136 patients with asymptomatic carotid stenosis. Hazards of ipsilateral ischemic stroke (primary outcome) were compared between patients with and without IPH, adjusted for clinical risk factors., Results: IPH was present in 51.6% of patients with symptomatic carotid stenosis and 29.4% of patients with asymptomatic carotid stenosis. During 1,121 observed person-years, 66 ipsilateral strokes occurred. Presence of IPH at baseline increased the risk of ipsilateral stroke both in symptomatic (hazard ratio [HR]: 10.2; 95% confidence interval [CI]: 4.6 to 22.5) and asymptomatic (HR: 7.9; 95% CI: 1.3 to 47.6) patients. Among patients with symptomatic carotid stenosis, annualized event rates of ipsilateral stroke in those with IPH versus those without IPH were 9.0% versus 0.7% (<50% stenosis), 18.1% versus 2.1% (50% to 69% stenosis), and 29.3% versus 1.5% (70% to 99% stenosis). Annualized event rates among patients with asymptomatic carotid stenosis were 5.4% in those with IPH versus 0.8% in those without IPH. Multivariate analysis identified IPH (HR: 11.0; 95% CI: 4.8 to 25.1) and severe degree of stenosis (HR: 3.3; 95% CI: 1.4 to 7.8) as independent predictors of ipsilateral stroke., Conclusions: IPH is common in patients with symptomatic and asymptomatic carotid stenosis and is a stronger predictor of stroke than any known clinical risk factors. Magnetic resonance imaging might help identify patients with carotid disease who would benefit from revascularization., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Identification of carotid artery atherosclerosis is conventionally based on measurements of luminal stenosis and surface irregularities using in vivo imaging techniques including sonography, CT and MR angiography, and digital subtraction angiography. However, histopathologic studies demonstrate considerable differences between plaques with identical degrees of stenosis and indicate that certain plaque features are associated with increased risk for ischemic events. The ability to look beyond the lumen using highly developed vessel wall imaging methods to identify plaque vulnerable to disruption has prompted an active debate as to whether a paradigm shift is needed to move away from relying on measurements of luminal stenosis for gauging the risk of ischemic injury. Further evaluation in randomized clinical trials will help to better define the exact role of plaque imaging in clinical decision-making. However, current carotid vessel wall imaging techniques can be informative. The goal of this article is to present the perspective of the ASNR Vessel Wall Imaging Study Group as it relates to the current status of arterial wall imaging in carotid artery disease., (© 2018 by American Journal of Neuroradiology.)

Objective: Magnetic resonance of the carotid arteries provides important insight into plaque composition and vulnerability in addition to the traditional measure of stenosis. The purpose of this study was to evaluate the cost-effectiveness of MR imaging as a first-line modality to assess carotid disease and guide management for high-risk patients with <50% stenosis., Methods: Using TreeAge Pro, a cost-effectiveness simulation was conducted comparing two strategies: (a) standard of care first-line carotid duplex ultrasound (DUS) with regular follow-up, vs (b) first-line MR assessment of stenosis and intraplaque haemorrhage (MRIPH) in which patients with IPH received annual DUS surveillance and immediate carotid endarterectomy in case of plaque progression., Results: For patients aged 70 years old, using a first-line MRIPH strategy resulted in a 16.8% relative risk reduction in strokes compared to DUS (0.080 vs 0.097 strokes per patient per lifetime), and an increased quality-adjusted-life years (12.23 vs 12.20) at an increased cost of $897.33 over a patient's lifetime ($5784.53 vs $4887.20 average total cost per patient per lifetime). The incremental cost-effectiveness ratio was $29,744 per quality-adjusted-life years. MRIPH remained cost-effective below a willingness-to-pay threshold of $50,000 for 91.8% of sensitivity analyses., Conclusion: MRIPH was found to be a cost-effective first-line tool to identify asymptomatic patients at high risk for stroke requiring annual surveillance and prompt management. Advances in Knowledge: Using MR imaging as a fist-line method to detect the presence of IPH provides clinically useful and cost-effective information that allows for enhanced risk evaluation and primary stroke prevention.

Background and Purpose: Stroke rates are higher in men compared with women in the fourth through seventh decades of life, and higher rates may result from differences in carotid intraplaque hemorrhage (IPH), an unstable atherosclerotic plaque component. We report age-specific sex differences in the presence of magnetic resonance imaging-depicted carotid IPH., Methods: Patients (n=1115) underwent magnetic resonance imaging for carotid IPH between 2005 and 2014. Low-grade carotid stenosis patients (n=906) without prior endarterectomy were eligible for this cross-sectional study., Results: Of the 906 patients included (mean age±SD in years, 66.98±15.15), 63 (6.95%) had carotid IPH. In men and women, carotid IPH was present in 11.43% (48 of 420) and 3.09% (15 of 486), respectively ( P <0.0001). Multivariable logistic regression analysis confirmed greater odds of carotid IPH in men for all ages: 45 to 54 (odds ratio=45.45; 95% confidence interval, 3.43-500), 55 to 64 years (odds ratio=21.74; 95% confidence interval, 3.21-142.86), 65 to 74 years (odds ratio=10.42; 95% confidence interval, 2.91-37.04), and ≥75 years (odds ratio=5.00; 95% confidence interval, 2.31-10.75). Male sex modified the effect of age on the presence of carotid IPH (β=0.074; SE=0.036; P =0.0411)., Conclusions: Men have greater age-specific odds of magnetic resonance imaging-depicted carotid IPH compared with women. With increasing age post-menopause, the odds of carotid IPH in women becomes closer to that of men. Delayed onset of carotid IPH in women, an unstable plaque component, may partly explain differential stroke rates between sexes, and further studies are warranted., (© 2017 American Heart Association, Inc.)

The incorporation of a short, easy-to-acquire and simple to read sequence to visualize the vessel wall and detect intraplaque hemorrhage (IPH) is achievable now. Demonstration of IPH may be helpful in primary or secondary prevention of neuroischemic events, assessment prior to carotid intervention and the general definition of an individual's vascular phenotype. The addition of an IPH-detecting vessel wall sequence only adds 5 to 6 minutes to a standard carotid MRI examination making clinical translation feasible and achievable., (Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine if complicated plaque can be found by using magnetic resonance (MR) imaging-depicted intraplaque hemorrhage (IPH), even among symptomatic patients with low-grade (≤50%) carotid stenosis., Materials and Methods: The institutional ethics review board approved this retrospective study and waived requirements for written informed consent. Symptomatic patients with bilateral 0%-50% carotid stenosis referred for carotid MR imaging were considered. Risk factors (age, sex, hypertension, diabetes, hyperlipidemia, myocardial infarction, atrial fibrillation, smoking, coronary artery disease, and cerebrovascular disease), medications (antihypertensive drugs, diabetes drugs, statins, and aspirin), and the brain side causing symptoms were recorded. MR-depicted IPH prevalence in the carotid arteries ipsilateral and contralateral to the symptomatic side was compared by using the Fisher exact test. Multivariable regression was used to compare the MR-depicted IPH prevalence, while adjusting for risk factors and medications., Results: A total of 217 patients (434 carotid arteries) were included. MR-depicted IPH was found in 13% (31 of 233) of carotid arteries ipsilateral and 7% (14 of 201) of arteries contralateral to symptoms (P < .05). Male sex (P < .05) and increasing age (P < .05) were associated with MR-depicted IPH after controlling for risk factors and medications., Conclusion: Complicated carotid atheroma can be found among symptomatic patients with low-grade (≤50%) stenosis, and this is associated with male sex and increasing age. MR-depicted IPH may be useful to stratify risk for patients with low-grade carotid stenosis.

Background and Purpose: The main objective of this study was to evaluate CT angiographic (CTA) features that are able to predict the presence of intraplaque hemorrhage (IPH) as defined by MR-IPH., Methods: One hundred sixty-seven consecutive patients (mean age 69 years, SD 12.8; 58 females) underwent both MR-IPH and CTA within 3 weeks. MR-IPH, the gold standard, was performed at 1.5 T using a neurovascular phased-array coil as a coronal T1-weighted 3-dimensional fat-suppressed acquisition. CTA was performed using a 4-slice or a 64-slice CT machine and evaluated, blinded to MR-IPH findings, for carotid stenosis, plaque density, and plaque ulceration. Plaque density was defined as the mean attenuation of plaque at the site of maximum stenosis and 2 sections above and below. Plaque ulceration was defined as outpouching of contrast into the plaque at least 2 mm deep on any single plane., Results: Prevalence of IPH increased at higher degrees of carotid stenosis. Mean CT plaque density was higher for plaques with MRI-defined IPH (47 Hounsfield units) compared with without IPH (43 Hounsfield units; P=0.02). However, significant overlap between distributions of plaque densities limited the value of mean plaque density for prediction of IPH. CTA plaque ulceration had high sensitivity (80.0% to 91.4%), specificity (93.0% to 92.3%), positive predictive value (72.0% to 71.8%), and negative predictive value (95.0% to 97.9%) for prediction of IPH. Interobserver agreement for presence/absence of CTA plaque ulceration was excellent (kappa=0.80)., Conclusions: CTA plaque ulceration, but not mean CTA plaque density, was useful for prediction of IPH as defined by the MR-IPH technique.

Purpose: To investigate the association between magnetic resonance (MR) imaging-depicted intraplaque hemorrhage (IPH) in the carotid artery wall and the risk of future ipsilateral cerebrovascular events in men with asymptomatic moderate carotid stenosis by using a rapid three-dimensional T1-weighted fat-suppressed spoiled gradient-echo sequence., Materials and Methods: The institutional ethics review board approved this retrospective chart review and waived the requirement for written informed consent. All patients gave informed verbal consent at follow-up telephone interviews. Ninety-one men (mean age, 74.8 years; range, 47-88 years) who attended a vascular clinic between 2003 and 2006, who had asymptomatic carotid stenosis (50%-70% at Doppler ultrasonography), and who had undergone MR imaging for IPH detection were retrospectively identified. Seventy-five men with 98 eligible carotid arteries were included in the study. Patients were followed for a minimum of 1 year (mean follow-up, 24.92 months; range, 12-43 months). Kaplan-Meier survival and univariate Cox regression analyses were conducted to compare future ipsilateral cerebrovascular event rates between carotid arteries with and those without MR-depicted IPH., Results: Of the 98 carotid arteries included, 36 (36.7%) had MR-depicted IPH. Six cerebrovascular events (two strokes and four transient ischemic attacks) occurred in the carotid arteries with IPH, as compared with no clinical events in the carotid arteries without IPH. Univariate Cox regression analysis confirmed that MR-depicted IPH was associated with an increased risk of cerebrovascular events (hazard ratio, 3.59; 95% confidence interval: 2.48, 4.71; P < .001). MR-depicted IPH negatively predicted outcomes (negative predictive value = 100%)., Conclusion: In this cohort with asymptomatic moderate carotid stenosis, MR-depicted IPH was associated with future ipsilateral cerebrovascular events. Conversely, patients without MR-depicted IPH remained asymptomatic during follow-up. The absence of IPH at MR imaging, therefore, may be a reassuring marker of plaque stability and of a lower risk of thromboembolism.

Background: Carotid endarterectomy is beneficial in severe (>70%) symptomatic carotid stenosis. The risk of stroke in moderate carotid stenosis (50%-69%) is modest, and so the role of carotid endarterectomy in this group is unclear. Intraplaque hemorrhage is associated with advanced atherosclerosis and can be detected in the carotid arteries by magnetic resonance imaging. This study evaluates whether magnetic resonance imaging detected intraplaque hemorrhage (MR IPH) can identify patients with symptomatic mild to moderate carotid stenosis who are at higher risk of ipsilateral transient ischemic attack (TIA) and stroke., Methods: Prospective longitudinal cohort study of symptomatic patients with mild to moderate (30%-69%) carotid stenosis followed up for 2 years after imaging for IPH using magnetic resonance imaging., Results: Sixty four participants were followed up for a median of 28 months (interquartile range 26-30) after MRI of the carotid arteries. Thirty-nine (61%) ipsilateral arteries showed intraplaque hemorrhage. During follow-up, five ipsilateral strokes and a total of 14 ipsilateral ischemic events were observed. Thirteen of these ischemic events, of which five were strokes, occurred in those with ipsilateral carotid intraplaque hemorrhage (hazard ratio = 9.8, 95% confidence interval 1.3-75.1, P = .03)., Conclusions: MR IPH is a good predictor of ipsilateral stroke and TIA in patients with symptomatic mild to moderate (30%-69%) carotid stenosis. This technique could help in the selection of patients for carotid endarterectomy.

Background: Microembolization detected during the dissection phase of carotid endarterectomy (CEA) is associated with plaque instability and might be associated with perioperative morbidity. Intraplaque hemorrhage is found in unstable plaques and is detectable using magnetic resonance imaging (MRI). We aimed to ascertain whether intraplaque hemorrhage as seen on carotid MRI predicts particulate embolization in the dissection phase of CEA., Methods: Patients with high-grade symptomatic carotid stenosis undergoing CEA were prospectively enrolled. All underwent preoperative MRI assessment of the carotid arteries for intraplaque hemorrhage and transcranial Doppler scanning during the dissection phase of the CEA to assess the presence of microembolic signals. Associations between intraplaque hemorrhage and intraoperative microembolic signals were studied., Results: Analysis was undertaken on 60 participants; of these, 36 (60%) showed ipsilateral carotid MRI intraplaque hemorrhage, and 24 (40%) did not. Microembolic signals were detected during the dissection phase in 23 (38.3%) participants, and 19 had MRI-detected intraplaque hemorrhage. The association between carotid intraplaque hemorrhage and the presence of dissection phase microembolic signals was significant (odds ratio [OR], 5.6; 95% confidence interval [CI], 1.6 to 19.7, P = .007), even after controlling for age, sex, individual surgeon, degree of stenosis, and delay from symptom to CEA (adjusted OR, 5.8; 95% CI, 1.1 to 30.4, P = .037)., Conclusion: Intraplaque hemorrhage as detected by carotid MRI predicts particulate embolization during the dissection phase of CEA. This imaging technique can be used to identify patients with increased intraoperative thromboembolic risk, and this could influence preventive strategies.

Background: It is recognized that complicated plaque largely accounts for the morbidity and mortality from atherosclerosis. Ideally, investigation of symptomatic and asymptomatic patients would identify atheromatous plaques independently of stenosis. We have previously shown that a magnetic resonance direct thrombus imaging (MRDTI) technique demonstrates complicated atheroma as high signal within the carotid arterial wall. We used this technique to examine the prevalence of complicated carotid plaque in vivo in the ipsilateral arteries of recently symptomatic patients with suspected carotid artery stenosis and to compare this with their contralateral arteries and with those of healthy age- and sex-matched controls., Methods and Results: The carotid arteries of 120 patients with suspected severe carotid artery stenosis and previous acute cerebral ischemia were imaged using MRDTI, as were 28 control arteries. High signal was not seen in any control artery. However, there was a 60% prevalence of high signal, suggestive of complicated plaque in the patients' ipsilateral arteries. The prevalence of high signal was significantly greater in the patients' ipsilateral vessels compared with the contralateral, asymptomatic side (60% versus 36%, chi2 P<0.001), particularly for vessels of only moderate stenosis., Conclusions: MRDTI high signal suggestive of complicated plaque is prevalent in the ipsilateral carotid arteries of patients with carotid stenosis and recent cerebral ischemic events. MRDTI has a potential role in identifying "at risk" plaque, studying atherogenesis and the effects of plaque-modifying strategies.

Background: Thromboembolic disease secondary to complicated carotid atherosclerotic plaque is a major cause of cerebral ischemia. Clinical management relies on the detection of significant (>70%) carotid stenosis. A large proportion of patients suffer irreversible cerebral ischemia as a result of lesser degrees of stenosis. Diagnostic techniques that can identify nonstenotic high-risk plaque would therefore be beneficial. High-risk plaque is defined histologically if it contains hemorrhage/thrombus. Magnetic resonance direct thrombus imaging (MRDTI) is capable of detecting methemoglobin within intraplaque hemorrhage. We assessed this as a marker of complicated plaque and compared its accuracy with histological examination of surgical endarterectomy specimens., Methods and Results: Sixty-three patients underwent successful MRDTI and endarterectomy with histological examination. Of these, 44 were histologically defined as complicated (type VI plaque). MRDTI demonstrated 3 false-positive and 7 false-negative results, giving a sensitivity and specificity of 84%, negative predictive value of 70%, and positive predictive value of 93%. The interobserver (kappa=0.75) and intraobserver (kappa=0.9) agreement for reading MRDTI scans was good., Conclusions: MRDTI of the carotid vessels in patients with cerebral ischemia is an accurate means of identifying histologically confirmed complicated plaque. The high contrast generated by short T1 species within the plaque allows for ease of interpretation, making this technique highly applicable in the research and clinical setting for the investigation of carotid atherosclerotic disease.

Current guidelines for primary and secondary prevention of stroke in patients with carotid atherosclerosis are based on the quantification of the degree of stenosis and symptom status. Recent publications have demonstrated that plaque morphology and composition, independent of the degree of stenosis, are important in the risk stratification of carotid atherosclerotic disease. This finding raises the question as to whether current guidelines are adequate or if they should be updated with new evidence, including imaging for plaque phenotyping, risk stratification, and clinical decision-making in addition to the degree of stenosis. To further this discussion, this roadmap consensus article defines the limits of luminal imaging and highlights the current evidence supporting the role of plaque imaging. Furthermore, we identify gaps in current knowledge and suggest steps to generate high-quality evidence, to add relevant information to guidelines currently based on the quantification of stenosis.

Identification of carotid artery atherosclerosis is conventionally based on measurements of luminal stenosis and surface irregularities using in vivo imaging techniques including sonography, CT and MR angiography, and digital subtraction angiography. However, histopathologic studies demonstrate considerable differences between plaques with identical degrees of stenosis and indicate that certain plaque features are associated with increased risk for ischemic events. The ability to look beyond the lumen using highly developed vessel wall imaging methods to identify plaque vulnerable to disruption has prompted an active debate as to whether a paradigm shift is needed to move away from relying on measurements of luminal stenosis for gauging the risk of ischemic injury. Further evaluation in randomized clinical trials will help to better define the exact role of plaque imaging in clinical decision-making. However, current carotid vessel wall imaging techniques can be informative. The goal of this article is to present the perspective of the ASNR Vessel Wall Imaging Study Group as it relates to the current status of arterial wall imaging in carotid artery disease.