Plaque Surface Irregularity Research Articles

Irregular surface of carotid atherosclerotic plaque is associated with ischemic stroke: a magnetic resonance imaging study.

ObjectiveTo determine the association between the irregularity of carotid plaque surface using multidimensional magnetic resonance imaging (MRI) of ipsilateral acute cerebral infarction (ACI) cases.MethodsPatients with recent cerebrovascular symptoms (stroke or transient ischemic attack < 2 weeks) and atherosclerotic plaque in at least one carotid artery were diagnosed by B-mode ultrasound imaging (intima-media thickness ≥ 1.5 mm) and recruited for the present study. Irregular surface was defined when plaque surface was uneven with high and low fluctuation or plaque with surface ulceration. The irregularity of carotid plaque surface was determined on axial or oblique images alone (single-dimension) and on both axial images and oblique images (multidimensions), separately. Univariate and multivariate logistic regression analyses were performed to calculate the odds ratio (OR) and the corresponding 95% CI of the irregular plaque surface in discriminating the presence of ipsilateral ACI.ResultsA total of 217 included subjects (mean age: 60.7 ± 10.2 years, 149 men) were recruited and 89 (41.0%), 88 (40.6%) and 118 (54.4%) of them exhibited irregular plaque surface on axial, oblique and multidimensional MR images, respectively. The OR of irregularity of the plaque surface was determined by multidimensional MRI to be 5.88 (95% CI: 3.16–10.96, P < 0.001) in discriminating the presence of ipsilateral ACI. Following adjustment for clinical confounding factors, this association remained statistically significant (OR = 5.65, 95% CI: 2.53–12.60, P < 0.001). The analysis included further adjustment for the presence of lipid-rich necrotic core, intraplaque hemorrhage and stenosis and the results included that this association also remained statistically significant (OR = 6.08, 95% CI: 2.52–14.68, P < 0.001).ConclusionsThe irregular plaque surface was determined by multidimensional MRI as an independent indicator for ipsilateral acute cerebral infarction.

Role of femoral artery ultrasound imaging in cardiovascular event risk prediction in a primary prevention cohort at a medium-term follow-up

BackgroundCardiovascular (CV) disease prevention guidelines have addressed how imaging may influence CV risk determined by established risk score systems in primary prevention. Nevertheless, data are lacking regarding the use of femoral artery ultrasonography for CV risk modification. Herein, we hypothesized that femoral artery plaque and its characteristics, as well as femoral intima-media thickness (fIMT) measurements, may predict major adverse cardiovascular events (MACE). MethodsSubjects free from documented CV disease who were scheduled for coronary computed tomographic angiography at our institution from September 2016-June 2017 were included. IMT measurements and plaque assessment were performed at femoral and carotid arteries. Coronary artery calcium score (CACS) was recorded. Patients were followed-up for MACE. ResultsA total of 215 subjects (mean age: 54.85 years, 47.91% male) were eligible. Median number of CV risk factors was 3. Median 10-year atherosclerotic CV disease risk based on Pooled Cohort Equation (PCE) equation was 6.3%. At a median follow-up of 24 months, 9 subjects (4.19%) had MACE. Patients who experienced MACE at follow-up were older (p=0.047), more of male gender (p=0.015), had higher serum creatinine levels despite being within reference limits (p=0.031) and PCE equation risk score (p=0.011). In patients who experienced MACE at follow-up, distal (p=0.027), bifurcation (p=0.007), and proximal carotid IMT (p=0.030) and fIMT (p=0.015) were increased. Surface irregularities and ulceration in femoral artery plaques were more common (p=0.001) and CACS was higher (p<0.001). When adjusted for other subclinical atherosclerosis imaging markers, femoral artery plaque surface irregularities and ulceration and only coronary calcification (without concomitant carotid or femoral atherosclerosis) were found to be independent predictors of MACE at follow-up (both p=0.004). ConclusionsOur data emphasize that baseline ultrasonographic assessment of the femoral arteries to define plaque characteristics may provide prognostic information for predicting MACE in a primary prevention cohort.

Reproducibility of 3.0T High-Resolution Magnetic Resonance Imaging for the Identification and Quantification of Middle Cerebral Arterial Atherosclerotic Plaques

Objective: To assess the reproducibility of 3.0T high-resolution magnetic resonance imaging for the identification and quantification of atherosclerotic plaques in the middle cerebral artery. Methods: Sixty-nine consecutive patients with ischemic stroke or asymptomatic stenosis (>30%) of the middle cerebral artery underwent 3.0T high-resolution magnetic resonance imaging examinations. Two independent investigators reviewed all images with 1 investigator re-evaluating all images 4 weeks later. Wall characteristics of the middle cerebral artery, including plaque surface morphology, plaque location, plaque components, and burden were identified and measured. Results: Intraobserver and interobserver agreement were all substantial in identifying plaque surface irregularity (k = 0.741, 0.555-0.897; k = 0.685, 0.490-0.843; respectively) and intraplaque hemorrhage (k = 0.654, 0.446-0.838; k = 0.605, 0.369-0.792; respectively). Intraobserver agreement was substantial (k = 0.654) and interobserver agreement was moderate (k = 0.553) for the identification of plaque fibrous caps. The total intraobserver and interobserver reproducibility was almost excellent for the identification of plaque position. With regards to vessel area measurement at the site of maximal lumen narrowing, intraobserver and interobserver reproducibility was excellent (intraclass correlation coefficient was 0.886 and 0.885, respectively) and moderate for lumen area at the site of maximal lumen narrowing (intraclass correlation coefficient was 0.695 and 0.558, respectively). In addition, intraobserver and interobserver reproducibility was excellent for vessel area and lumen area measurements at the reference sites. Conclusions: The reproducibility of 3.0T high-resolution magnetic resonance imaging for the identification and quantification of artery wall characteristics was overall acceptable. However, the reliability for lumen area measurement at the maximum narrowing site and identification of the fibrous cap needs to be improved.

Three-dimensional ultrasonographic evaluation of carotid artery plaque surface irregularity.

IntroductionThe aim of this study was to evaluate 3-dimensional (3D) ultrasonography (US) in determining the surface irregularity of carotid artery plaques.Material and methodsThis study included 50 patients (20 females and 30 males) aged between 56 and 82 years with plaques in the carotid artery which were detected during routine neck ultrasound. Simultaneously these cases were evaluated in terms of plaque echogenicities and surface characteristics with 2D and 3D US.Results3D imaging was successfully performed in 45 of the 50 cases and the technical success rate was 90%. A single plaque was detected in 64.4% of the patients, with the remaining 35.6% having more than one plaque. The lengths of the plaques ranged from 2 to 12 mm (mean: 3.98 ±1.70 mm); the widths ranged from 1.8 to 3.2 mm (mean: 2.11 ±0.37 mm). No significant difference was found between 2D and 3D plaque echo-structures (observer 1, p = 0.317; observer 2, p = 0.276), but there were significant differences between 2D and 3D plaque surface irregularities (observer 1, p = 0.002; observer 2, p = 0.004). The inter-observer agreement on 2D and 3D plaque echo-structure and surface irregularity was very good (k coefficients were 0.89 and 0.83, respectively, for echo-structure, and 0.91 and 0.95, respectively, for surface irregularity).ConclusionsThe present study shows that 3D US examination is a valuable non-invasive method for investigation of surface irregularity of carotid artery plaques.

Vessel-Wall Magnetic Resonance Imaging of Intracranial Atherosclerotic Plaque and Ischemic Stroke: A Systematic Review and Meta-Analysis.

Introduction: Vessel-wall magnetic resonance imaging (MRI) has been suggested as a valuable tool for assessing intracranial arterial stenosis with additional diagnostic features. However, there is limited conclusive evidence on whether vessel-wall MR imaging of intracranial atherosclerotic plaques provides valuable information for predicting vulnerable lesions. We conducted this systematic review and meta-analysis to evaluate which characteristics of intracranial-plaque on vessel-wall MRI are markers of culprit lesions.Methods: The MEDLINE, EMBASE, and Cochrane Library of Clinical Trials databases were searched for studies reporting the association between vessel-wall MRI characteristics of intracranial plaque and corresponding stroke events. Odds ratios (ORs) for the prevalence of stroke with intracranial-plaque MRI characteristics were pooled in a meta-analysis using a random-effects model.Results: Twenty studies were included in this review. We found a significant association between plaque enhancement (OR, 10.09; 95% CI, 5.38–18.93), positive remodeling (OR, 6.19; 95% CI, 3.22–11.92), and plaque surface irregularity (OR, 3.94; 95% CI, 1.90–8.16) with stroke events. However, no significant difference was found for the presence of eccentricity (OR, 1.22; 95% CI, 0.51–2.91).Conclusion: Based on current evidence, intracranial plaque contrast enhancement, positive remodeling, and plaque irregularity on MRI are associated with increased risk of stroke events. Our findings support the design of future studies on intracranial-plaque MRI and decision making for the management of intracranial atherosclerotic plaques.

Duplex ultrasound in cerebrovascular disease - asymptomatic carotid stenosis

Duplex ultrasound in cerebrovascular disease - asymptomatic carotid stenosis Abstract. Distal embolization originating from an ipsilateral asymptomatic carotid stenosis (ACS) is the cause of a substantial proportion of first-ever ischemic strokes. Duplex ultrasound is recommended as first-line imaging method to detect and to evaluate the extent and severity of such extracranial carotid stenoses. All patients with ACS need best cardiovascular medical therapy including smoking cessation strategies, implementation of statins, antihypertensive drugs and antiplatelet therapy. The annual stroke rate in patients with ACS has significantly declined during the last years due to improvement in medical therapy. Therefore, surgical prophylactic carotid endarterectomy or carotid stenting no longer are recommended routinely in all patients with high-grade ACS. Several studies demonstrated that not only the grade of stenosis based on hemodynamic criteria on Duplex ultrasound increases the ipsilateral stroke risk, but also morphological characteristics on B-mode ultrasound and contrast-enhanced ultrasound are associated with more vulnerable ACS with higher risk of stroke. These additional morphological features may be useful to select a subgroup of patients with ACS who may benefit from interventions. There is some evidence that a high progression rat of the grade of stenosis on duplex ultrasound, hypoechogenicity, higher plaque area, surface irregularities and ulceration on B-mode ultrasound as well as intraplaque vascularization on contrast-enhanced ultrasound of the carotid stenosis are predictors of such a vulnerable ACS. This review article gives an overview of ultrasound based and other features of ACS, which are associated with an increased ipsilateral stroke risk.

Hyperintense Plaque on Intracranial Vessel Wall Magnetic Resonance Imaging as a Predictor of Artery-to-Artery Embolic Infarction.

The aim of the present study was to investigate atherosclerotic plaque characteristics in patients with artery-to-artery (A-to-A) embolic infarction by whole-brain high-resolution magnetic resonance imaging. Seventy-four patients (mean age, 54.7±12.1 years; 59 men) with recent stroke in the territory of middle cerebral artery because of intracranial atherosclerotic disease were prospectively enrolled. Whole-brain high-resolution magnetic resonance imaging was performed in all the patients both precontrast and postcontrast administration by using a 3-dimensional T1-weighted vessel wall magnetic resonance imaging technique known as inversion-recovery prepared sampling perfection with application-optimized contrast using different flip angle evolutions. Patients were divided into A-to-A embolic infarction and non-A-to-A embolic infarction groups based on diffusion-weighted imaging findings. The characteristics of the intracranial atherosclerotic plaques were compared between groups. A total of 74 intracranial atherosclerotic plaques were analyzed (36 in A-to-A embolism group and 38 in non-A-to-A embolism group). Hyperintense plaques (HIPs) were more frequently observed in A-to-A embolism group (75.0% versus 21.1%; P<0.001). Eighteen of the 27 HIPs (66.7%) demonstrated hyperintense spots or areas located adjacent to the lumen versus 9 HIPs (33.3%) located within the plaque in A-to-A embolism group. Furthermore, a higher prevalence of plaque surface irregularity was also observed in A-to-A embolism group (41.7% versus 18.4%; P=0.029). Logistic regression analysis showed that HIP was the most powerful independent predictor of A-to-A embolic infarction (P<0.001), with the odds ratio of 11.2 (95% confidence interval, 3.5-36.2). A-to-A embolic infarction has distinct vulnerable plaque characteristics compared with non-A-to-A embolic infarction. HIP and plaque surface irregularity may predict A-to-A embolic infarction.

Abstract 54: Combined Vessel Wall and Perforator Imaging for Prediction of Stroke Subtype

Objective: The aim of the present study was to evaluate atherosclerotic plaque characteristics and perforating arteries together by high-resolution magnetic resonance imaging (HRMRI) and to establish their relationship with different infarction patterns. Methods: Stroke patients with artery-to-artery (A-to-A) embolism or branch atheromatous disease (BAD) in middle cerebral artery territory were prospectively enrolled and whole-brain HRMRI was performed. The characteristics of the intracranial atheroma at the maximal stenosis and the numbers of ipsilateral perforating arteries were analyzed. Results: The study involved 59 first-time stroke patients (32 A-to-A embolism and 27 BAD) with 59 culprit plaques. Hyperintensity plaques (HIP) and plaque surface irregularity were more frequently observed in A-to-A embolism group than in the BAD group ( P &lt; 0.001 and P = 0.049, respectively). Patients with A-to-A embolism infarction had more severe stenosis than patients with BAD infarction ( P &lt; 0.001). Logistic regression analysis showed that HIP was an independent predictive factor for A-to-A embolism, with odds ratio of 6.858 (95% confidence interval 1.780 – 26.421; P = 0.005). Moreover, 54 patients (31 A-to-A embolism and 23 BAD) with good-quality images were included in the analysis of perforating arteries. The average number of visualized perforating arteries was significantly lower in patients with BAD compared with A-to-A embolism ( P = 0.022). Interpretation: A-to-A embolism infarction have distinct vascular pathophysiologies in terms of plaque and perforating artery characteristics compared with BAD. Whole brain HRMRI enables the combination of vessel wall and perforating artery imaging which can predict future stroke types.

Признаки нестабильности атеросклеротической бляшки в сонных артериях у больных с острым коронарным синдромом по данным ультразвукового дуплексного сканирования

to study carotid plaques structure in patients with acute coronary syndrome by ultrasound duplex scanning. We included in this study143 patients with acute coronary syndrome (ACS) aged 32-83 years and 28 patients with documented coronary heart disease (CHD) aged 46-83 years. Duplex scanning of carotid arteries was carried out with Philips iU22 ultrasound system and L9-3 linear array transducer. Atherosclerotic plaques in CCA, CCA bifurcation, and ICA from right and left side were investigated. Off-line analysis of B-mode images and plaque gray scale median (GSM) was performed with computer semiautomated workstation MultiVox. 378 plaques of ACS and 59 plaques of CHD patients were studied. We assessed traditional (heterogenous structure, hypoechogenic component, irregular plaque surface) as well as additional (positive remodeling, "layered" structure of plaque, local calcification) criteria of plaque instability. In ACS compared with CHD group there were more plaques with hypoechogenic component (43.4 and 28.8%, p=0.0459), heterogenous structure (77.8 and 64.4%, p=0.0327), irregular surface including irregularities more than 2.0 mm (22.5 and 6.8%, p=0.0048, respectively). There was significant difference in "layered" structure (55.7 and 35.8%, p=0.0011) and insignificant difference in positive remodeling (16.3 and 7.5%, p=0.06, respectively). There were no differences of GSM value (53.1 and 57.2, p=0.24) and local calcification (23.2 and 24.5%, p=0.23, respectively). In our study ultrasound duplex scanning revealed that signs of plaque instability in carotid arteries in patients with ACS were more frequent than in patients with stable CHD. The newly introduced parameter "layered" structure of atherosclerotic plaque was found to be most significant.

Abstract 12796: Plaque Surface Irregularity and Calcification Length Within Carotid Plaque Predict Secondary Events in Patients With Coronary Artery Disease

Introduction: Although comprehensive risk factor modification is recommended, a uniform management strategy does not necessarily prevent secondary events in patients with coronary artery disease (CAD). Therefore, identification of high-risk patients who may benefit from more intensive interventions may improve prognosis. Carotid ultrasound can reliably identify systemic atherosclerosis, and carotid plaque and intima-media thickness (IMT) are known independent risk factors for CAD. However, it is unclear whether findings on carotid ultrasound can improve prediction of secondary CAD events. Methods: The study population comprised 146 consecutive patients with CAD (mean age, 66 ± 9 years; 126 with angina pectoris, 20 with myocardial infarction). IMT, plaque score, plaque area, plaque surface irregularity, and calcification length (calculated by summing the calcified lesions within each plaque accompanied by acoustic shadow) were measured at baseline. Patients were followed for 10 years to ascertain secondary CAD events. Results: Of 146 patients, secondary CAD events occurred in 63 after a median follow-up of 10 years. In univariate analysis, calcification length (P &lt; 0.05) and plaque surface irregularity (P &lt; 0.01) were associated with secondary CAD events, whereas IMT, plaque score, and plaque area were not. Multiple regression analysis demonstrated that calcification length (odds ratio, 1.06; P &lt; 0.05) and plaque surface irregularity (odds ratio, 3.85; P &lt; 0.01) remained independently associated with secondary CAD events after adjustment for age, sex, diabetes mellitus, dyslipidemia, hypertension, chronic kidney disease, and smoking. Moreover, when patients were divided into 4 groups according to calcification length and presence or absence of plaque surface irregularity, the group with longer calcification and plaque surface irregularity had greater risk of secondary CAD events (relative risk, 3.82; P &lt; 0.05). Conclusions: These findings suggest that the combination of calcification length and plaque surface irregularity has additional value beyond traditional risk classification. Intensive intervention for these high-risk patients may avoid or delay progression of atherosclerosis towards secondary CAD events.

Plaque surface irregularity and calcification length within carotid plaque predict secondary events in patients with coronary artery disease

Background and aimsAlthough comprehensive risk factor modification is recommended, a uniform management strategy does not necessarily prevent secondary events in patients with coronary artery disease (CAD). Therefore, identification of high-risk patients who may benefit from more intensive interventions may improve prognosis. Carotid ultrasound can reliably identify systemic atherosclerosis, and carotid plaque and intima-media thickness (IMT) are known independent risk factors for CAD. However, it is unclear whether findings on carotid ultrasound can improve prediction of secondary CAD events. MethodsThe study population comprised 146 consecutive patients with CAD (mean age, 66 ± 9 years; 126 with angina pectoris, 20 with acute myocardial infarction). IMT, plaque score, plaque area, plaque surface irregularity, and calcification length (calculated by summing the calcified lesions within each plaque accompanied by acoustic shadow) were measured at baseline. Patients were followed for 10 years to ascertain secondary CAD events defined as hard major adverse cardiovascular events (MACE; cardiac death and acute myocardial infarction) and as total MACE (hard MACE and angina pectoris with coronary revascularization). ResultsMultiple regression analysis demonstrated that calcification length (p < 0.05) and plaque surface irregularity (p < 0.01) remained independently associated with total MACE after adjustment for age, sex, diabetes mellitus, dyslipidemia, hypertension, chronic kidney disease, smoking, and multivessel CAD. ConclusionsThese findings suggest that the combination of calcification length and plaque surface irregularity has additional value beyond traditional risk classification. Intensive intervention for these high-risk patients may avoid or delay progression of atherosclerosis towards secondary CAD events.

Wall characteristics and mechanisms of ischaemic stroke in patients with atherosclerotic middle cerebral artery stenosis: a high-resolution MRI study

Objective:: To evaluate the characteristics of atherosclerotic middle cerebral artery (MCA) stenosis by high-resolution magnetic resonance imaging (HR-MRI) and determine the relationship between wall characteristics and infarction patterns.Methods:: Thirty-six patients with acute ischaemic stroke due to MCA stenosis underwent diffusion-weighted magnetic resonance imaging (DWI) and HR MRI. Wall characteristics of MCA, including irregular surface, superior location, T2-hyperintense of plaques and positive remodelling (PR), were analysed. Characteristics of acute infarct on DWI were categorised according to the number (single or multiple infarcts) and the pattern of cerebral infarcts (cortical, border zone or perforating artery territory infarcts). The relationship between wall characteristics and infarction patterns was evaluated.Results:: PR was observed in 20 patients, irregular surface plaque in 18 patients, superior location of plaques in 14 patients and T2-hyperintense foci in 13 patients. Seventeen patients had multiple acute cerebral infarcts and 13 showed single acute cerebral infarcts. Border zone infarcts were the most common (76.5%) among multiple acute infarcts. Penetrating artery infarcts (PAI) accounted for 76.9% of all single infarcts. Multiple infarcts were more frequently observed in patients with PR (P = 0.007) or plaque surface irregularity (P = 0.035). Single infarcts, especially PAI, were more prevalent in patients with superior plaque (P = 0.030). No statistically significant differences were observed between multiple and single infarcts in patients with T2-hyperintense lesions (P = 0.638).Conclusions:: PR or irregular surface plaques were associated with artery-to-artery embolism. Superior location of plaques was associated with PAI. HR-MRI provides insights into intracranial atherosclerosis in vivo, predictive of infarction patterns.

Advantage in Bright-blood and Black-blood Magnetic Resonance Imaging with High-resolution for Analysis of Carotid Atherosclerotic Plaques.

Background:About 50% of the cerebral ischemia events are induced by intracranial and extracranial atherosclerosis. This study aimed to evaluate the feasibility and accuracy for displaying atherosclerotic plaques in carotid arteries and analyzing their ingredients by using high-resolution new magnetic resonance imaging (MRI) techniques.Methods:Totally, 49 patients suspected of extracranial carotid artery stenosis were subjected to cranial MRI scan and magnetic resonance angiography (MRA) examination on carotid arteries, and high-resolution bright-blood and black-blood MRI analysis was carried out within 1 week. Digital subtraction angiography (DSA) examination was carried out for 16 patients within 1 month.Results:Totally, 103 plaques were detected in the 49 patients, which were characterized by localized or diffusive thickening of the vessel wall, with the intrusion of crescent-shaped abnormal signal into lumens. Fibrous cap was displayed as isointensity in T1-weighted image (T1WI) and hyperintensities in proton density weighted image (PDWI) and T2-weighted image (T2WI), lipid core was displayed as isointensity or slight hyperintensities in T1WI, isointensity, hyperintensities or hypointensity in PDWI, and hypointensity in T2WI. Calcification in plaques was detected in 11 patients. Eight patients were detected with irregular plaque surface or ulcerative plaques, which were characterized by irregular intravascular space surface in the black-blood sequences, black hypointensity band was not detected in three-dimensional time-of-flight, or the hypointensity band was not continuous, and intrusion of hyperintensities into plaques can be detected. Bright-blood and black-blood techniques were highly correlated with the diagnosis of contrast-enhanced MRA in angiostenosis degree, Rs = 0.97, P < 0.001. In comparison to DSA, the sensitivity, specificity, and accuracy of MRI diagnosis of stenosis for ≥50% were 88.9%, 100%, and 97.9%, respectively.Conclusions:High-resolution bright-blood and black-blood sequential MRI analysis can accurately analyze ingredients in atherosclerotic plaques. Determined by DSA, MRI diagnosis of stenosis can correctly evaluate the serious degree of arteriostenosis.

Ultrasound Tissue Characterization of Vulnerable Atherosclerotic Plaque

A thrombotic occlusion of the vessel fed by ruptured coronary atherosclerotic plaque may result in unstable angina, myocardial infarction or death, whereas embolization from a plaque in carotid arteries may result in transient ischemic attack or stroke. The atherosclerotic plaque prone to such clinical events is termed high-risk or vulnerable plaque, and its identification in humans before it becomes symptomatic has been elusive to date. Ultrasonic tissue characterization of the atherosclerotic plaque is possible with different techniques—such as vascular, transesophageal, and intravascular ultrasound—on a variety of arterial segments, including carotid, aorta, and coronary districts. The image analysis can be based on visual, video-densitometric or radiofrequency methods and identifies three distinct textural patterns: hypo-echoic (corresponding to lipid- and hemorrhage-rich plaque), iso- or moderately hyper-echoic (fibrotic or fibro-fatty plaque), and markedly hyperechoic with shadowing (calcific plaque). Hypoechoic or dishomogeneous plaques, with spotty microcalcification and large plaque burden, with plaque neovascularization and surface irregularities by contrast-enhanced ultrasound, are more prone to clinical complications than hyperechoic, extensively calcified, homogeneous plaques with limited plaque burden, smooth luminal plaque surface and absence of neovascularization. Plaque ultrasound morphology is important, along with plaque geometry, in determining the atherosclerotic prognostic burden in the individual patient. New quantitative methods beyond backscatter (to include speed of sound, attenuation, strain, temperature, and high order statistics) are under development to evaluate vascular tissues. Although not yet ready for widespread clinical use, tissue characterization is listed by the American Society of Echocardiography roadmap to 2020 as one of the most promising fields of application in cardiovascular ultrasound imaging, offering unique opportunities for the early detection and treatment of atherosclerotic disease.

High-resolution MRI of the vessel wall in patients with symptomatic atherosclerotic stenosis of the middle cerebral artery

Intracranial atherosclerosis is associated with recurrent ischemic stroke. High-resolution MRI (HR MRI) can provide information about atheroma in vivo. We aimed to analyze and compare vascular wall imaging characteristics between patients with symptomatic and asymptomatic atherosclerotic stenosis of the middle cerebral artery (MCA) using 3.0 Tesla HR MRI. The HR MRI protocol included four different scans: black blood T1-weighted, T2-weighted and proton density-weighted MRI, as well as three-dimensional turbo spin echo imaging techniques with multiplanar reconstruction. Plaque characteristics, including location, morphology, and signal intensity, were analyzed in 51 patients (29 symptomatic, 22 asymptomatic) with atherosclerotic stenosis of the middle cerebral artery. The vessel wall area, lumen area, and plaque area (PA) were also calculated and compared between the symptomatic and asymptomatic groups. We found that PA, remodeling index (RI), and positive remodeling (PR) prevalence were significantly greater in the symptomatic group than in the asymptomatic group (PA: p=0.033; RI: p=0.020; PR: p=0.032). Plaque location in the superior aspect of the vessel wall and irregular plaque surface were more frequently observed in the symptomatic group than in the asymptomatic group (superior location: p=0.031; irregular surface: p=0.036). Moreover, multivariate logistic regression identified plaque location on the superior wall as an independent predictor of symptomatic MCA stenosis (odds ratio: 4.471; p=0.039). Therefore, we can conclude that patients with symptomatic atherosclerotic stenosis of the MCA are more likely to have larger plaques, PR, superiorly located plaques, and irregular plaque surface. These characteristics are promising factors for stratifying stroke risk.

Abstract T P180: Ultrasound Characteristics of Symptomatic Carotid Plaques: A Systematic Review and Meta-analysis

Background and Purpose: Ultrasound is the most commonly used imaging modality for assessment of carotid artery stenosis. A number of studies have demonstrated that surface irregularities, heterogeneous echotexture and hypoechoic plaques are risk factors for acute ischemic stroke. We performed a systematic review and meta-analysis of the literature to better define the risk of stroke based off of the sonographic characteristics of carotid plaques. Materials and Methods: We performed a comprehensive literature search evaluating the association of carotid plaque characteristics on ultrasound with ischemic outcomes. We included both case-control and cohort studies examining the relationship between complex plaque and acute ischemic stroke. Complex plaque was defined as plaque that had any of the following characteristics: heterogeneous plaque echogenicity, hypoechoic plaque, plaque neovascularization, plaque surface irregularity, plaque ulceration, and intraplaque motion. Meta-analyses using the random-effects model were performed for complex plaque and each of the individual complex plaque characteristics. Results: A total of 1013 articles were screened and 30 studies with 11528 patients (3054 symptomatic and 8474 asymptomatic) were included. The odds ratios for the association between complex plaque and ischemic symptoms was 5.18 (95%CI=4.63-5.79). Heterogeneous echotexture (OR=11.72, 95%CI=9.82-13.98), intraplaque motion (OR=1.57, 95%CI=1.02-2.41), plaque echolucency (OR=3.23, 95%CI=2.72-3.84), plaque neovascularity (OR=5.66, 95%CI=3.15-10.16) and plaque ulceration (OR=2.65, 95%CI=1.89-3.73) were all associated with ischemic symptoms. Surface irregularity without frank ulceration was not associated with ischemic symptoms (OR=1.35, 95%CI=0.98-1.86). Conclusions: Complex plaque, heterogeneous plaque echogenicity, hypoechoic plaque, plaque neovascularization, plaque ulceration and intraplaque motion are associated with ischemic symptoms. Assessment of carotid plaque on ultrasound provides stroke risk information beyond measurement of luminal stenosis.

Sex-associated differences in the modulation of vascular risk in patients with asymptomatic carotid stenosis.

In this study, we aimed to identify determinants of the different sex-related stroke risk in subjects with asymptomatic internal carotid artery (ICA) stenosis. In all, 492 women (44.4%) and 617 men (55.6%), with unilateral ⩾ 60% asymptomatic ICA stenosis, were prospectively evaluated with a median follow-up of 37 months (interquartile range, 26 to 43). Vascular risk profile, plaque characteristics, stenosis progression, and common carotid artery intima-media thickness were investigated. Outcome measure was the occurrence of ischemic stroke ipsilateral to ICA stenosis. Myocardial infarction, contralateral stroke and transient ischemic attack were considered as competing events. The incidence rate of ipsilateral stroke over the entire follow-up period was 0.16%: 0.09% (95% confidence interval (CI) 0.05 to 0.15) in women and 0.22% (95% CI 0.17 to 0.29) in men (log-rank test, P<0.001). Stenosis progression significantly influenced the risk of ipsilateral stroke in both men (subhazard ratio, SHR, 8.99) and women (SHR 4.89). Stenosis degree (71% to 90%, SHR 2.35; 91% to 99%, SHR 3.38) and irregular plaque surface (SHR 2.32) were relevant risk factors for ipsilateral stroke only in men. Our findings suggest that characteristics of the stenosis and plaque exert a different effect in modulating vascular risk in the two sexes. Understanding sex differences in cardiovascular disease could help to target sex-specific future therapies.

A Novel Ultrasound-Based Carotid Plaque Risk Index Associated with the Presence of Cerebrovascular Symptoms.

The purpose of this study was to determine the efficacy of a novel ultrasound-based carotid plaque risk index (CPRI) in predicting the presence of cerebrovascular symptoms in patients with carotid artery stenosis. This was a cross-sectional, observational study involving 56 patients (mean age 76.6 years, 62.5 % male). Plaque grayscale median (GSM) and surface irregularity indices (SII) were measured in 82 stenosed carotid arteries (range 10 - 95 %) and combined with the degree of stenosis (DOS) in the form of (DOS*SII)/(1 + GSM). A reduced index DOS/(1 + GSM) not incorporating plaque surface irregularities was also investigated. Receiver operating characteristic curves (ROC) were used to study the diagnostic efficacy of CPRI, comparing against DOS and an equivalent risk index constructed using a conventional logistic regression based method with model parameters optimized to the dataset (CPRIlogistic). There were 42 stenosed carotid arteries with cerebrovascular symptoms, and 40 without symptoms. The presence of symptoms significantly correlated with DOS, GSM and SII (p < 0.01). The median CPRI of the symptomatic (asymptomatic) groups were 23.2 (9.2) compared with 0.71 (0.30) for CPRIlogistic (p < 0.01). The diagnostic performance of CPRI exceeded that of CPRIlogistic and DOS, and demonstrated a better separation of the symptomatic and asymptomatic groups. Our novel risk index combines quantitative measures of carotid plaque echogenicity and surface irregularities with the degree of stenosis. It is a better predictor of cerebrovascular symptoms than the degree of stenosis and could be valuable in studies and clinical trials aimed at identifying vulnerable carotid artery stenoses.

Arterial remodeling in middle cerebral artery atherosclerotic stenosis:a high-resolution MRI study

To investigate remodeling mode of moderate or severe atherosclerotic stenosis of the middle cerebral artery (MCA) using high resolution MRI. Thirty-seven consecutive symptomatic patients with atherosclerotic MCA stenosis were imaged with a 3.0-T magnetic resonance scanner. The HR-MRI protocol included four different scans: T1-weighted black blood imaging, T2-weighted MR, proton density (PD)-weighted MR, and 3D-SPACE. The wall area (VA), lumen area (LA) and plaque area (PA) were calculated. The characterization of the plaque on HR-MRI was analysed. And the difference between positive remodeling (PR) and non-postive remodeling (non-PR) was explored. Thirty-four patients imaging was appropriate for analyse. Positive remodeling was found in 19 lesions. Compared with the non-PR group, the PR group had greater WA [(10.9 ± 2.5) mm² and (9.2 ± 1.9) mm², P = 0.039)] and greater PA [(6.4 ± 1.9) mm² and (3.9 ± 1.1) mm², P = 0]. High intensity on DWI and irregularity of plaque surface were more frequently observed in PR than non-PR. In patients with MCA atherosclerosis, PR lesions contain larger plaques than non-PR lesions and are probably with high risk for plaque rupture and subsequent stroke.

Comparison and Accuracy of Carotid Plaque Analysis Between Two- and Three-Dimensional Ultrasound Imaging

Plaque characterization using traditional two-dimensional (2D) imaging and/or three-dimensional (3D) ultrasonographic (US) techniques is a new method for evaluating artery wall morphology and plaque risk stratification. The purpose of this study was to assess and compare 2D and 3D US, measuring the interobservation differences for specific plaque-imaging analyses. Phantoms that simulated various types of atherosclerotic plaque pathology were imaged and findings reported by three experienced sonographers. Interobservation agreement and subanalyses were created. For each type of plaque pathology, agreement was moderate; however, conformity increased with the application of 3D US versus 2D US alone. Agreement was best for the identification of fissures, ulcerations, and irregular plaque surface. Advanced sonographic techniques for carotid plaque imaging provide a reproducible method in the analysis and morphologic assessment of simulated carotid atheromatous lesions, with superior interobserver variability. Three-dimensional US improves visualization of some pathologies and may provide additional information in the evaluation and risk stratification of vulnerable carotid plaque.