Carotid plaque volume in patients undergoing carotid endarterectomy

Tomographic 3D ultrasound for grading stenosis of superficial femoral artery

INTRODUCTION

Treatment decision of lower extremity peripheral arterial disease (PAD) is governed by the severity of stenosis. Tomographic 3D ultrasound (t3DUS) is a reliable imaging technique for measuring vessel stenosis. In this study we attempted to provide a precise measurement of superficial femoral artery (SFA) stenosis using t3DUS in patients with PAD.

METHODS

t3DUS was used to measure maximum stenosis percentage in SFA from 50 patients with lower extremity PAD. The maximum stenosed segment in SFA was defined using Duplex 2DUS aliasing was noted. The peak systolic velocity (PSV) was measured at the maximum stenotic site and proximal to aliasing for calculating the velocity ratio. The association between blood flow velocity ratio and the degree of stenosis measured using Duplex 2DUS and t3DUS, respectively, was assessed using Spearman rank correlation.

RESULTS

There was a strong positive correlation between velocity ratio and degree of stenosis in SFA measured using t3DUS (correlation value (r) = 0.99, p < 0.001). The correlation between Stenosis percentage and velocity ratio in SFA are as followed: <50:<2; 50-54:2-2.4; 55-59:2.5-2.9; 60-64:3-3.4; 65-69:3.5-3.9; 70-74:4-4.4; 75-79:4.5-4.9; >80:>5.

t3DUS can be used to provide precise measurement of the severity of SFA stenosis in patients with lower extremities arterial disease. The established criteria for grading SFA stenosis in this study can be applied to the current practice alongside Duplex 2DUS as it showed a strong positive correlation with velocity ratio. Further studies investigating the sensitivity and specificity of t3DUS in the assessment of stenosis in lower limbs arteries are required.

Tomographic ultrasound for three-dimensional visualization of temporal arteries

OBJECTIVE

Conventional two-dimensional ultrasound has been assessed for the non-invasive diagnosis of giant cell arteritis (GCA), but the results are operator dependent, resulting in low sensitivity. Tomographic three-dimensional (3D) ultrasound is a novel technique that enables the objective documentation of vessel geometry. Here, for the first time, its utility is assessed for visualizing temporal arteries.

METHOD

The temporal artery of 14 healthy subjects and three subjects with suspected GCA was examined using tomographic 3D ultrasound.

RESULTS

This technique enabled 3D mapping of the architecture of the temporal artery. The inner and outer vessel diameters showed considerable interindividual variability. However, calculation of the vessel wall fraction revealed the combination of vessel wall thickening and lumen narrowing, which may be indicative of GCA.

CONCLUSIONS

This proof-of-concept study indicates that tomographic 3D ultrasound can be used for objective mapping of the temporal artery. The technique must be evaluated regarding its diagnostic sensitivity in GCA before it can be introduced in clinical practice.

3-D Contrast-Enhanced Fusion Ultrasound for Accurate Volume Assessment of Vessel Lumen and Plaque in Carotid Artery Disease as Compared With Computed Tomography Angiography

OBJECTIVE

Three-dimensional contrast-enhanced fusion ultrasound (CEFUS) of atherosclerotic carotid arteries provides spatial visualization of the vessel lumen, creating a lumenography. As in 3-D computed tomography angiography (CTA), 3-D CEFUS outlines the contrast-filled lumen. Plaque and vessel contours are distinguished in 3-D CEFUS, allowing plaque volume quantification as a valid estimate of carotid plaque burden. Three-dimensional CEFUS is unproven in intermodality studies, vindicating the assessment of 3-D CEFUS applicability and comparing 3-D CEFUS and 3-D CTA lumenography as a proof-of-concept study.

METHODS

Using an ultrasound system with magnetic tracking, a linear array transducer and SonoVue contrast agent, 3-D CEFUS acquisitions were generated by spatial stitching of serial 2-D images. From 3-D CEFUS and 3-D CTA imaging, the atherosclerotic carotid arteries were reconstructed with lumenography in an offline software program for lumen and plaque volume quantification. Bland-Altman analysis was used for inter-image modality agreement.

RESULTS

The study included 39 carotid arteries. Mean lumen and plaque volume in 3-D CEFUS were 0.63 cm3 (standard deviation [SD]: 0.26) and 0.62 cm3 (SD: 0.26), respectively. Lumen volume differences between 3-D CEFUS and 3-D CTA were non-significant, with a mean difference of 0.01 cm3 (SD: 0.02, p = 0.26) and limits of agreement (LoA) range of ±0.11 cm3. Mean plaque volume difference was -0.12 cm3 (SD: 0.19, p = 0.006) with a LoA range of ±0.39 cm3.

CONCLUSION

There was strong agreement in lumenography between 3-D CEFUS and 3-D CTA. The interimage modality difference in plaque volumes was substantial because of challenging vessel wall definition in 3-D CTA. Three-dimensional CEFUS is viable in quantifying carotid plaque volume burden and can potentially monitor plaque development over time.

Accelerated Measurement of Carotid Plaque Volume Using Artificial Intelligence Enhanced 3D Ultrasound

BACKGROUND

Carotid plaque volume (CPV) can be measured by 3D ultrasound and may be a better predictor of stroke than stenosis, but analysis time limits clinical utility. This study tested the accuracy, reproducibility, and time saved of using an artificial intelligence (AI) derived semiautomatic software to measure CPV ("auto-CPV").

METHODS

Three-dimensional (3D) ultrasound images for 121 individuals were analyzed by 2 blinded operators to measure auto-CPV. Corresponding endarterectomy specimen volumes were calculated by the validated saline suspension technique. Inter-rater and intrarater agreement plus accuracy compared with the volume of the endarterectomized plaque were calculated. Measurement times were compared with previous manual CPV measurement.

RESULTS

The mean difference between auto-CPV and surgical volume was small at (±s.d.) [95% confidence interval [CI]] 0.06 (0.24) [-0.41 to 0.54] cm3. The intraclass correlation (ICC) was strong at 0.91; 95% CI 0.86-0.94. Interobserver and intraobserver error was low with mean difference (±s.d.) [95%CI] 0.01 (0.26) [-0.5 to 0.5] cm3 and 0.03 (0.19) [-0.35 to 0.40] cm3 respectively. Both showed excellent ICC with narrow confidence intervals, ICC = 0.90; 95% CI (0.85-0.94) and ICC = 0.95; 95% CI (0.92-0.96). Auto-CPV measurement took 43% the time of manual planimetry; median (IQR) 05:39 (01:58) minutes compared to 13:05 (04:15) minutes, Wilcoxon rank-sum test, P < 0.01.

CONCLUSIONS

Auto-CPV assessment is accurate, reproducible, and significantly faster than manual planimetry. Improved feasibility means that the utility of CPV can be assessed in large population studies to stratify risk in asymptomatic carotid disease or assess response to medical treatment.

Reliability of tomographic 3D ultrasound in measuring internal carotid artery plaque volume

BACKGROUND

Tomographic 3D ultrasound (t3DUS) is a promise imaging technique for quantifying carotid plaque through measuring the degree of stenosis and plaque volume. Carotid plaque volume (CPV) could add benefit in predicting the potential risk of stroke.

PURPOSE

To assess the reproducibility and accuracy of t3DUS for measuring CPV within the internal carotid artery in patients undergoing carotid endarterectomy.

MATERIAL AND METHODS

t3DUS was used to obtain CPV in vivo from 25 symptomatic patients prior to surgery. Ex vivo CPV from the carotid endarterectomy specimen was then measured using a validated saline displacement method as a reference standard. CPV for each patient was measured twice using both methods (total n = 50 per technique). Intraclass correlation coefficient (ICC) and Bland-Altman plot were used to establish bias and limit of agreement between CPV measurements.

RESULTS

There was an excellent agreement between t3DUS and reference test with respect to measuring CPV with an ICC value of 0.98 (95% confidence interval = 0.97-0.99, P < 0.001). Bias in measurements was 0.02 ± 0.11 cm3 (95% limit of agreement = -0.19 to 0.25). Intra-observer agreement of t3DUS CPV measurements was excellent with an ICC value of 0.95 (95% confidence interval = 0.92-0.97, P < 0.001). Bias in measurements was 0.004 ± 0.07 cm3 (95% limit of agreement = -0.14 to 0.15).

CONCLUSION

t3DUS is a reproducible imaging method and showed excellent agreement with the reference standard with respect to measuring CPV. These findings suggest that t3DUS has the potential to be a valuable non-invasive tool for assessing carotid plaque burden and predicting the risk of stroke.

B-mode ultrasound characteristics of carotid plaques in symptomatic and asymptomatic patients with low-grade stenosis

Carotid plaque features assessed using B-mode ultrasound can be useful for the prediction of cerebrovascular symptoms. Therefore, the aim of this retrospective study was to determine the ability of ultrasound B-mode imaging to differentiate between carotid plaques causing less than 50% stenosis in symptomatic and asymptomatic patients. A dataset of 1,593 patients with carotid disease who underwent carotid ultrasound between 2016 and 2021 was evaluated retrospectively between January and April of 2022. A total of 107 carotid plaques from 35 symptomatic and 52 asymptomatic patients causing low-grade stenosis on B-mode images were included in the analysis. Chi-square, independent t-test and Mann-Whitney U test were used to compare the variables. There was a significant association between hypertension and the presence of cerebrovascular symptoms (p = 0.01). Predominantly hypoechoic and hyperechoic carotid plaque were significantly associated with the presence and absence of cerebrovascular symptoms, respectively (predominantly hypoechoic: p = 0.01; predominantly hyperechoic: p = 0.02). Surface irregularity was significantly associated with the presence of cerebrovascular symptoms (p = 0.02). There is was a significant difference in the carotid plaque length and area between the symptomatic and asymptomatic patients (plaque length: symptomatic median 9 mm, interquartile range [IQR] 6 mm; asymptomatic median 6 mm, IQR 4.5 mm, p = 0.01; plaque area: symptomatic median 24 mm, IQR 30 mm; asymptomatic median 14 mm, IQR 17 mm, p = 0.01); however, this difference was not significant for plaque thickness (p = 0.55), or common carotid artery intima-media thickness (p = 0.7). Our findings indicate that hypertension patients with predominantly hypoechoic carotid plaques and plaques with an irregular surface are associated with the presence of cerebrovascular symptoms. In addition, the carotid plaques in symptomatic patients were longer and larger compared to asymptomatic patients.

Novel Imaging-Based Biomarkers for Identifying Carotid Plaque Vulnerability

Carotid artery disease has traditionally been assessed based on the degree of luminal narrowing. However, this approach, which solely relies on carotid stenosis, is currently being questioned with regard to modern risk stratification approaches. Recent guidelines have introduced the concept of the "vulnerable plaque," emphasizing specific features such as thin fibrous caps, large lipid cores, intraplaque hemorrhage, plaque rupture, macrophage infiltration, and neovascularization. In this context, imaging-based biomarkers have emerged as valuable tools for identifying higher-risk patients. Non-invasive imaging modalities and intravascular techniques, including ultrasound, computed tomography, magnetic resonance imaging, intravascular ultrasound, optical coherence tomography, and near-infrared spectroscopy, have played pivotal roles in characterizing and detecting unstable carotid plaques. The aim of this review is to provide an overview of the evolving understanding of carotid artery disease and highlight the significance of imaging techniques in assessing plaque vulnerability and informing clinical decision-making.

Feasibility and Accuracy of Measuring Carotid Plaque Volume (Burden) With Contrast-Enhanced Tomographic 3D Ultrasound and Ultrasound Image Fusion

BACKGROUND

Stenosis severity has been the indication for carotid endarterectomy (CEA) for 4 decades, but the annual stroke risk in asymptomatic carotid stenosis >70% is under 2%. Atherosclerotic volume has emerged as a risk factor for future stroke, but needs to be measured noninvasively. Tomographic ultrasound (tUS) is a novel technology that assembles 3D images in seconds. We evaluated accuracy of measuring Carotid Plaque Volume (CPV) with tUS in patients undergoing CEA.

METHOD

Consecutive patients were imaged immediately before CEA by tUS and contrast-enhanced tUS (CEtUS). CPV was measured using tUS, CEtUS, and a fused images incorporating both tUS and CEtUS by trained vascular scientists. Precise volume of the endarterectomy specimen was measured using Archimedes technique.

RESULTS

Mean ± sd (range) CPV in 129 endarterectomy specimens was 0.75 ± 0.43 cm³ (0.10-2.47 cm³). Mean ± sd CPV measured by tUS (n = 114) was 0.87 ± 0.51 cm³, CEtUS (n = 104) was 0.75 ± 0.45 cm³ and with fusion (n = 95) was 0.83 ± 0.49 cm³. Differences between specimen volume and CPV measured by tUS (0.13 ± 0.24 cm³), CEtUS (-0.01 ± 0.21 cm³) or fusion (-0.08 ± 0.20) were clinically insignificant. Intra-/interobserver differences were minimal.

CONCLUSIONS

tUS accurately measures CPV with excellent intra-/interobserver agreement. CEtUS improves accuracy if precise CPV measurement is needed for research but tUS alone would be sufficient for population screening.

State-of-the-art CT and MR imaging and assessment of atherosclerotic carotid artery disease: standardization of scanning protocols and measurements-a consensus document by the European Society of Cardiovascular Radiology (ESCR)

The European Society of Cardiovascular Radiology (ESCR) is the European specialist society of cardiac and vascular imaging. This society's highest priority is the continuous improvement, development, and standardization of education, training, and best medical practice, based on experience and evidence. The present intra-society consensus is based on the existing scientific evidence and on the individual experience of the members of the ESCR writing group on carotid diseases, the members of the ESCR guidelines committee, and the members of the executive committee of the ESCR. The recommendations published herein reflect the evidence-based society opinion of ESCR. We have produced a twin-papers consensus, indicated through the documents as respectively "Part I" and "Part II." The first document (Part I) begins with a discussion of features, role, indications, and evidence for CT and MR imaging-based diagnosis of carotid artery disease for risk stratification and prediction of stroke (Section I). It then provides an extensive overview and insight into imaging-derived biomarkers and their potential use in risk stratification (Section II). Finally, detailed recommendations about optimized imaging technique and imaging strategies are summarized (Section III). The second part of this consensus paper (Part II) is focused on structured reporting of carotid imaging studies with CT/MR. KEY POINTS: • CT and MR imaging-based evaluation of carotid artery disease provides essential information for risk stratification and prediction of stroke. • Imaging-derived biomarkers and their potential use in risk stratification are evolving; their correct interpretation and use in clinical practice must be well-understood. • A correct imaging strategy and scan protocol will produce the best possible results for disease evaluation.

Reliability and Accuracy of Tomographic 3-D Ultrasound for Grading Vessel Stenosis: A Phantom Study

The aim of this phantom study was to assess the accuracy of 3-D tomographic ultrasound (t3DUS) for grading stenosis, using the manufacturer's measurements as the gold standard. The percentage of maximum stenosis was obtained using 2-D ultrasound (2DUS) and t3DUS imaging techniques on a peripheral vascular phantom, including channels with 50%, 75% and 90% stenosis. The inter-observer reproducibility of t3DUS for grading stenosis was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman plots. Mean and mean differences were used to evaluate the accuracy of 2DUS and t3DUS in measuring maximum stenosis in all channels. Inter-operator agreement was excellent, with an ICC value of 0.99 (95% confidence interval: 0.994-0.998, p < 0.001). Bias in measurements was -0.59 ± 2.01% (95% limits of agreement: 4.54, 3.36). The mean difference (MD) between maximum stenosis measurements and reference values for all channels was lower in t3DUS than in 2DUS (t3DUS MD: +1.01%, diameter reduction 2DUS MD: -6.10%; area reduction 2DUS MD: +8.20%). Tomographic 3DUS is a reproducible and accurate imaging method for grading stenosis. The current B-mode 2DUS stenosis grading criteria used in vascular assessment may be underestimating or overestimating the percentage stenosis. Further phantom and human studies investigating the reliability of t3DUS for grading stenosis and other metrics including plaque volume are required.

Carotid Plaque Composition and the Importance of Non-Invasive in Imaging Stroke Prevention

Luminal stenosis has been the standard feature for the current management strategies in patients with atherosclerotic carotid disease. Histological and imaging studies show considerable differences between plaques with identical degrees of stenosis. They indicate that specific plaque characteristics like Intraplaque hemorrhage, Lipid Rich Necrotic Core, Plaque Inflammation, Thickness and Ulceration are responsible for the increased risk of ischemic events. Intraplaque hemorrhage is defined by the accumulation of blood components within the plaque, Lipid Rich Necrotic Core is composed of macrophages loaded with lipid, Plaque Inflammation is defined as the process of atherosclerosis itself and Plaque thickness and Ulceration are defined as morphological features. Advances in imaging methods like Magnetic Resonance Imaging, Ultrasound, Computed Tomography and Positron Emission Tomography have enabled a more detailed characterization of the plaque, and its vulnerability is linked to these characteristics, changing the management of these patients based only on the degree of plaque stenosis. Studies like Rotterdam, ARIC, PARISK, CAPIAS and BIOVASC were essential to evaluate and prove the relevance of these characteristics with cerebrovascular symptoms. A better approach for the prevention of stroke is needed. This review summarizes the more frequent carotid plaque features and the available validation from recent studies with the latest evidence.

Resistance to Antiplatelet Therapy Is Associated With Symptoms of Cerebral Ischemia in Carotid Artery Disease

Background:

Platelet inhibitory therapy is prescribed to prevent arterial thromboembolism in patients with atherosclerotic disease. Although taken by millions of people, around 30% are resistant to the treatment they are being prescribed.

Aims:

To determine whether symptoms of cerebral ischemia, or pre-operative cerebral emboli, in patients admitted for a carotid endarterectomy were associated with resistance to aspirin or clopidogrel.

Methods:

Venous blood from 133 patients immediately before carotid endarterectomy (CEA) was analyzed for resistance to aspirin and clopidogrel by multiplate impedance aggregometry. The number of emboli/hour entering the ipsilateral middle cerebral artery was counted by transcranial Doppler (TCD) on the day before surgery in 33 of these patients.

Results:

Resistance was found in 21 (26.3%) of 100 patients taking aspirin and 14 (42%) of 33 taking clopidogrel. Mean (sd) residual platelet aggregation was significantly higher at 41.9(32) Au in patients who had suffered recent symptoms of cerebral ischemia compared with 30.8(16) Au in asymptomatic patients (p = 0.012). Residual platelet aggregation also correlated significantly with the number of emboli/hour counted by TCD in the ipsilateral middle cerebral artery (r = 0.45, p = 0.009).

Conclusion:

Antiplatelet resistance was associated with the frequency of cerebral emboli and recent symptoms of cerebral ischemia in patients with carotid disease. Definitive clinical studies are needed to explore whether testing for antiplatelet resistance should be undertaken routinely in patients starting platelet inhibitory therapy for cardiovascular disease.

Plaque imaging volume analysis: technique and application

The prevention and management of atherosclerosis poses a tough challenge to public health organizations worldwide. Together with myocardial infarction, stroke represents its main manifestation, with up to 25% of all ischemic strokes being caused by thromboembolism arising from the carotid arteries. Therefore, a vast number of publications have focused on the characterization of the culprit lesion, the atherosclerotic plaque. A paradigm shift appears to be taking place at the current state of research, as the attention is gradually moving from the classically defined degree of stenosis to the identification of features of plaque vulnerability, which appear to be more reliable predictors of recurrent cerebrovascular events. The present review will offer a perspective on the present state of research in the field of carotid atherosclerotic disease, focusing on the imaging modalities currently used in the study of the carotid plaque and the impact that such diagnostic means are having in the clinical setting.

Symptomatic vs. Asymptomatic 20-40% Internal Carotid Artery Stenosis: Does the Plaque Size Matter?

Background: Around 9–15% of ischemic strokes are related to internal carotid artery (ICA)-stenosis ≥50%. However, the extent to which ICA-stenosis <50% causes ischemic cerebrovascular events is uncertain. We examined the relation between plaque cross-sectional area and length and the risk of ischemic stroke or TIA among patients with ICA-stenosis of 20–40%.

Methods: We retrospectively identified patients admitted to the Department of Neurology, University Hospital of Würzburg, from January 2011 until September 2016 with ischemic stroke or TIA and concomitant ICA-stenosis of 20–40%, either symptomatic or asymptomatic. Plaque length and cross-sectional area were assessed on ultrasound scans.

Results: We identified 41 patients with ischemic stroke or TIA and ICA-stenosis of 20–40%; 14 symptomatic and 27 asymptomatic. The plaque cross-sectional area was significantly larger among symptomatic than asymptomatic ICA-stenosis; median values (IQR) were 0.45 (0.21–0.69) cm² and 0.27 (0.21–0.38) cm², p = 0.03, respectively. A plaque cross-sectional area ≥0.36 cm² had a sensitivity of 71% and a specificity of 76% for symptomatic compared with asymptomatic ICA-stenosis. In a sex-adjusted multivariate logistic regression, a plaque cross-sectional area ≥0.36 cm² and a plaque length ≥1.65 cm were associated with an OR (95% CI) of 5.54 (1.2–25.6), p = 0.028 and 1.78 (0.36–8.73), p = 0.48, respectively, for symptomatic ICA-stenosis.

Conclusion: Large plaques might increase the risk of ischemic stroke or TIA among patients with low-grade ICA-stenosis of 20–40%. Sufficiently powered prospective longitudinal cohort studies are needed to definitively test the stroke risk stratification value of carotid plaque length and cross-sectional area in the setting of current optimal medical treatment.

Carotid Intraplaque-Hemorrhage Volume and Its Association with Cerebrovascular Events

BACKGROUND AND PURPOSE

Our aim was to assess the relationship between volume and percentage of intraplaque hemorrhage measured using CT and the occurrence of cerebrovascular events at the time of CT.

MATERIALS AND METHODS

One-hundred-twenty-three consecutive subjects (246 carotid arteries) with a mean age of 69 years who underwent CTA were included in this retrospective study. Plaque volume of components and subcomponents (including intraplaque hemorrhage volume) was quantified with dedicated software.

RESULTS

Forty-six arteries were excluded because no plaque was identified. In the remaining 200 carotid arteries, a statistically significant difference was found between presentation with cerebrovascular events and lipid volume (P = .002), intraplaque hemorrhage volume (P = .002), percentage of lipid (P = .002), percentage of calcium (P = .001), percentage of intraplaque hemorrhage (P = .001), percentage of lipid-intraplaque hemorrhage (P = .001), and intraplaque hemorrhage/lipid ratio (P = .001). The highest receiver operating characteristic area under the curve was obtained with the intraplaque hemorrhage volume with a value of 0.793 (P = .001), percentage of intraplaque hemorrhage with an area under the curve of 0.812 (P = .001), and the intraplaque hemorrhage/lipid ratio with an area under the curve value of 0.811 (P = .001).

CONCLUSIONS

Results of our study suggest that Hounsfield unit values <25 have a statistically significant association with the presence of cerebrovascular events and that the ratio intraplaque hemorrhage/lipid volume represents a strong parameter for the association of cerebrovascular events.

An Ex Vivo Evaluation of Tomographic 3-D Ultrasound, B-Mode Ultrasound, CT And MR Imaging to Measure Artery Diameter, Length and Wall Volume

Precise measurement of luminal diameter in arteries is important when planning interventional vascular procedures in patients. Measuring wall volume may be important in detecting early artery disease and in the assessment of treatments to prevent atherosclerosis. An ex vivo phantom using porcine arteries was used to evaluate the accuracy with which (i) B-mode ultrasound, (ii) 3-D tomographic ultrasound (tUS), (iii) computed tomography (CT) and (iv) magnetic resonance imaging (MRI) measured length, diameters and volume. The mean error in inner-to-inner diameter measurements by B mode, tUS, CT and MRI were 0.08 ± 0.26, -0.73 ± 0.96 mm, 0.09 ± 0.55 and 0.60 ± 1.01 mm, respectively. The mean error in outer-to-outer diameter measurements by B mode, tUS, CT and MRI were -1.33 ± 0.61, -1.03 ± 0.35, 0.02 ± 1.00 and -0.47 ± 1.32 mm, respectively. The mean error in volume measurements by B mode, tUS, CT and MRI were -0.54 ± 0.62, -0.06 ± 0.09, 0.01 ± 0.18 and -0.20 ± 0.32 cm³, respectively. Errors in length and diameters remain within clinically acceptable thresholds where MRI was the least accurate. tUS was the most accurate method of volume measurement.

Non-invasive ultrasound-based imaging of atherosclerosis

Early detection of vascular damage in atherosclerosis and accurate assessment of cardiovascular risk factors are the basis for appropriate treatment strategies in cardiovascular medicine. The current review focuses on non-invasive ultrasound-based methods for imaging of atherosclerosis. Endothelial dysfunction is an accepted early manifestation of atherosclerosis. The most widely used technique to study endothelial function is non-invasive, flow-mediated dilation of the brachial artery under high-resolution ultrasound imaging. Although an increased intima-media thickness value is associated with future cardiovascular events in several large population studies, systematic use is not recommended in clinical practice for risk assessment of individual persons. Carotid plaque analysis with grey-scale median, 3-D ultrasound or contrast-enhanced ultrasound are promising techniques for further scientific work in prevention and therapy of generalized atherosclerosis.