{"product_id":"carotid-artery-plaque-on-ultrasound-a-patients-guide-to-the-2020-ase-guidelines-for-measuring-atherosclerosis-and-heart-risk","title":"Carotid Artery Plaque on Ultrasound: A Patient's Guide to the 2020 ASE Guidelines for Measuring Atherosclerosis and Heart Risk","description":"\u003cp\u003e\u003cstrong\u003eSummary:\u003c\/strong\u003e New guidance from the American Society of Echocardiography (ASE) sets the first standardized rules for measuring plaque (fatty, hardened buildup) in the carotid arteries of the neck using ultrasound. The panel recommends measuring plaque \u003cem\u003ethickness\u003c\/em\u003e (also called height) as the starting point because it is simple, widely available, and highly reproducible. They also recommend a two-part approach. First look for protruding plaque. If none is found, measure carotid intima-media thickness (CIMT, the thickness of the artery's inner layers) to detect flat, diffuse plaque. Studies cited in the document show that plaque information reclassifies patients' heart and stroke risk beyond traditional risk factors. Some plaque measures are linked to 1.5 to 4.5 times higher risk of cardiovascular events or death.\u003c\/p\u003e\n\n\u003ch1\u003eAssessment of Carotid Arterial Plaque by Ultrasound\u003c\/h1\u003e\n\n\u003ch2\u003eTable of Contents\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"#ddn-key-points\"\u003eKey Points\u003c\/a\u003e\u003c\/li\u003e\n\n  \u003cli\u003e\u003ca href=\"#background\"\u003eBackground: Why the Carotid Artery Matters\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#rationale\"\u003eRationale: Why Plaque Beats Simple Wall Thickness\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#scope\"\u003eWhat These Guidelines Cover\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#definition\"\u003eDefining Plaque: Two Distinct Types\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#clinically-significant\"\u003eWhen Is Plaque \"Clinically Significant\"?\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#methods\"\u003eHow Plaque Is Measured: Two-Dimensional Techniques\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#plaque-score\"\u003eMethod 1: The Plaque Score\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#plaque-height\"\u003eMethod 2: Plaque Height (Thickness)\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#height-outcomes\"\u003ePlaque Height and Patient Outcomes\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#plaque-area\"\u003eMethod 3: Plaque Area\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#advanced\"\u003eAdvanced and Emerging Techniques\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#clinical-use\"\u003ePutting Plaque Imaging into Practice\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#limitations\"\u003eLimitations and Open Questions\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#recommendations\"\u003eKey Recommendations at a Glance\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#ddn-faq\"\u003eFrequently Asked Questions\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#source\"\u003eSource Information\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c!-- ddn:keypoints:start --\u003e\n\u003ch2 id=\"ddn-key-points\"\u003eKey Points\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eCarotid plaque is defined as protuberant (focal thickening into the lumen) or diffuse (CIMT 1.5 mm or greater in any carotid segment).\u003c\/li\u003e\n\u003cli\u003ePlaque thickness (height) is the recommended initial 2D measurement because it is simple, widely available, and highly reproducible.\u003c\/li\u003e\n\u003cli\u003eIn the Three-city study of 5,895 older adults, plaque at one site was linked to a hazard ratio of 1.5 for cardiovascular events.\u003c\/li\u003e\n\u003cli\u003eSerial CIMT measurements are not recommended in asymptomatic patients unless the result meets diffuse plaque criteria (CIMT 1.5 mm or greater).\u003c\/li\u003e\n\u003cli\u003ePlaque information reclassifies risk beyond traditional factors, with some measures linked to 1.5 to 4.5 times higher risk of events or death.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ddn:keypoints:end --\u003e\n\n\n\u003ch2 id=\"background\"\u003eBackground: Why the Carotid Artery Matters\u003c\/h2\u003e\n\n\u003cp\u003eAtherosclerotic cardiovascular disease (CVD, the buildup of fatty plaque in arteries that can cause heart attack and stroke) remains the leading cause of illness and death worldwide. The carotid arteries in the neck offer a unique \"window\" into a patient's underlying cardiovascular risk. They are easy to reach with ultrasound, and they mirror what is happening in arteries elsewhere in the body.\u003c\/p\u003e\n\n\u003cp\u003eThe presence and degree of atherosclerosis — measured by whether plaque is visible in the carotid system — has been used to estimate, and sometimes reclassify, a person's cardiovascular risk. Carotid atherosclerosis also directly predicts other cardiovascular events. The most serious is stroke, which can result from narrowing of the vessel (luminal stenosis) or from plaque rupture, when a plaque breaks open and blocks blood flow.\u003c\/p\u003e\n\n\u003cp\u003eTwo different ultrasound approaches exist to assess risk this way:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCarotid intima-media thickness (CIMT)\u003c\/strong\u003e — a measurement of artery wall thickness.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCarotid arterial plaque assessment\u003c\/strong\u003e — looking for and measuring actual plaque deposits.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThis document focuses on the second approach: how to quantify carotid plaque, when it is present, for the purpose of cardiovascular risk stratification (sorting patients into risk groups).\u003c\/p\u003e\n\n\u003ch2 id=\"rationale\"\u003eRationale: Why Plaque Beats Simple Wall Thickness\u003c\/h2\u003e\n\n\u003cp\u003eThe field has shifted from CIMT to plaque measurement for a clear reason: plaque assessment appears to offer greater risk-prediction benefit. This has led to a \"paradigm shift\" in which carotid ultrasound parameters are used for risk prediction.\u003c\/p\u003e\n\n\u003cp\u003eThe key insight is that CIMT and plaque may reflect two different biological processes. CIMT may mostly show the presence of cardiovascular risk factors such as high blood pressure. Carotid plaque, by contrast, is a sub-intimal process (starting beneath the innermost layer of the artery) and may better reflect atherosclerosis itself. It correlates with the total burden of atherosclerosis in the coronary arteries that feed the heart.\u003c\/p\u003e\n\n\u003cp\u003eThe largest portion of CIMT — roughly 99% in healthy individuals and about 80% in those with disease — consists of the \u003cstrong\u003emedial layer\u003c\/strong\u003e, which is prone to non-atherosclerotic medial hypertrophy (thickening) commonly caused by aging and hypertension. Plaque, on the other hand, begins in the \u003cstrong\u003eintimal layer\u003c\/strong\u003e and represents the atherosclerotic process itself. This is why plaque has been shown to predict cardiovascular events better than CIMT.\u003c\/p\u003e\n\n\u003cp\u003eThe high prevalence of carotid atherosclerosis in people who otherwise have a low Framingham risk score (a standard 10-year heart risk calculator) has potential implications for screening. Many people who look \"low risk\" on paper actually have hidden plaque.\u003c\/p\u003e\n\n\u003cp\u003eCIMT still provides useful information even when no plaque is present. The ASE's earlier consensus statement on using carotid ultrasound to identify subclinical vascular disease continues to be endorsed. That document already covers the rationale for carotid ultrasound, scanning technique, reporting of results, and training of sonographers. This new document complements it by adding a standardized way to define and measure plaque.\u003c\/p\u003e\n\n\u003cp\u003eWhy is a new document needed? Since the 2008 consensus, carotid ultrasound technology has advanced tremendously. First came dedicated three-dimensional (3D) vascular ultrasound probes. More recently, a 3D matrix array probe for carotid ultrasound with companion analysis software has become available. This document is the first to provide systematic recommendations for standardizing plaque quantification.\u003c\/p\u003e\n\n\u003ch2 id=\"scope\"\u003eWhat These Guidelines Cover\u003c\/h2\u003e\n\n\u003cp\u003eThis consensus statement provides recommendations for two-dimensional (2D) and 3D quantification of carotid arterial plaque by ultrasound, for the basis of cardiovascular risk stratification.\u003c\/p\u003e\n\n\u003cp\u003eIt also discusses emerging techniques. These include the role of ultrasound enhancing agents (UEA, injectable contrast agents that make blood and vessels show up more clearly). UEA are used for assessing intraplaque neovascularization (new tiny blood vessels growing inside a plaque) and for analyzing plaque composition.\u003c\/p\u003e\n\n\u003ch2 id=\"definition\"\u003eDefining Plaque: Two Distinct Types\u003c\/h2\u003e\n\n\u003cp\u003eAtherosclerotic plaques can be discrete, easy-to-spot lesions. But plaque can also be eccentric (off-center) and spread across the surface of the wall. In those cases, it is difficult to tell whether there is simply medial thickening or eccentric, diffuse plaque.\u003c\/p\u003e\n\n\u003cp\u003eBecause of this, different studies have used very different thresholds to define plaque. Definitions have ranged widely:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eOne study defined plaque as focal thickening of the intima-media greater than 1 mm, protruding into the lumen, and at least twice as thick as the surrounding normal CIMT.\u003c\/li\u003e\n  \u003cli\u003eAnother study defined plaque as CIMT greater than 1.2 mm.\u003c\/li\u003e\n  \u003cli\u003eThe European Mannheim consensus defined plaque as focal thickening that encroaches into the lumen by 0.5 mm, or by 50% of the surrounding intimal-medial thickness, or where CIMT is greater than 1.5 mm.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003ePut together, definitions across studies have varied from 0.5 mm to more than 1.5 mm.\u003c\/p\u003e\n\n\u003cp\u003eThe writing panel chose a threshold slightly more conservative than the Mannheim consensus. They recommend \u003cstrong\u003e≥1.5 mm\u003c\/strong\u003e (rather than \"greater than 1.5 mm\") as the CIMT cutoff for diffuse plaque. This new Plaque Grading Consensus allows doctors to also identify and characterize small protruding plaque lesions that fall below the 1.5 mm threshold.\u003c\/p\u003e\n\n\u003cp\u003eIn plain terms: modern ultrasound can now resolve plaque lesions smaller than 1.5 mm in exquisite detail, allowing both measurement and even analysis of what the plaque is made of. The new grading system sets a framework for continued outcomes-based research across the full spectrum of plaque shapes, sizes, and types.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRecommendation #1.\u003c\/strong\u003e Carotid arterial plaque seen on ultrasound (with or without an ultrasound enhancing agent) should be defined in one of two ways:\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProtuberant-type plaque\u003c\/strong\u003e — any focal thickening thought to be atherosclerotic in origin that encroaches into the lumen of any segment of the carotid artery.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDiffuse-type plaque\u003c\/strong\u003e — in diffuse vessel wall atherosclerosis, when carotid intima-media thickness measures ≥1.5 mm in any segment of the carotid artery.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eRecommendation #2.\u003c\/strong\u003e Both protuberant and diffuse types of carotid plaque should be evaluated for cardiovascular risk stratification and for serial assessment of atherosclerosis (tracking it over time).\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRecommendation #3.\u003c\/strong\u003e The carotid arterial wall should first be scanned visually for protuberant plaque. If none is found, then CIMT measurement should be performed to identify diffuse plaque, defined as CIMT ≥1.5 mm. If performed, CIMT should be measured as described in the earlier ASE consensus statement.\u003c\/p\u003e\n\n\u003cp\u003eImportantly, the grading system does not reflect how blocked the vessel is. Instead, it aims to standardize the size of an individual plaque lesion so that results can be compared across studies. Grade I applies only to small protuberant lesions. This is because, if a plaque is non-protuberant (diffuse or eccentric) and less than 1.5 mm thick, it is currently impossible to tell whether the thickening is entirely medial or intimal. At a CIMT value of 1.5 mm or greater (Grades II and III), the framework attributes the thickness to diffuse atherosclerotic plaque and considers it a \"plaque equivalent.\"\u003c\/p\u003e\n\n\u003ch2 id=\"clinically-significant\"\u003eWhen Is Plaque \"Clinically Significant\"?\u003c\/h2\u003e\n\n\u003cp\u003eSome centers repeat CIMT evaluation even when no plaque is found, if CIMT is above the 75th percentile for a person's age, race, and gender. However, the evidence for how often to repeat testing is thin. Population studies have used a repeat interval of 2 to 5 years, though published evidence suggests that more frequent CIMT measurements could increase the precision of tracking CIMT progression.\u003c\/p\u003e\n\n\u003cp\u003eDespite these methodological questions, the expert panel recommends \u003cstrong\u003eagainst\u003c\/strong\u003e serial CIMT measurements for cardiovascular risk stratification — especially when the result does not meet the threshold for diffuse plaque (≥1.5 mm).\u003c\/p\u003e\n\n\u003cp\u003eThe panel acknowledged that, based on limited or anecdotal evidence, serial CIMT measurements may still have value in the hands of some experts. This value is for research, for monitoring progression or regression in specific cases, and as a potential tool to change patient behavior. It is also possible that over time a patient's CIMT could rise to ≥1.5 mm, meaning diffuse atherosclerotic plaque has developed by this definition. But the clinical usefulness of long-term CIMT monitoring is not yet established.\u003c\/p\u003e\n\n\u003cp\u003eThe panel suggests that a CIMT ≥1.5 mm be considered a clinically significant lesion for patients younger than 65 years of age. Plaque thickness (also called height in the long-axis view) was chosen as the initial measure to define plaque. Plaque thickness was chosen because it is widely available and can be measured in both protuberant and diffuse plaque. Other techniques, such as area and volume, apply mostly to protuberant-type lesions and are hard to define in plaques that are diffusely layered along the wall.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRecommendation #4.\u003c\/strong\u003e Serial CIMT measurements are not recommended in asymptomatic patients. Repeat measurements are not recommended unless the grade and CIMT meet the criteria for diffuse-type plaque (Grades II or III, with CIMT ≥1.5 mm). In that case it is a plaque equivalent.\u003c\/p\u003e\n\n\u003ch2 id=\"methods\"\u003eHow Plaque Is Measured: Two-Dimensional Techniques\u003c\/h2\u003e\n\n\u003cp\u003eInterest in plaque quantification grew significantly when researchers discovered that the simple presence or absence of plaque added risk-stratification value beyond CIMT alone. This finding came from the ARIC Study, a large population study.\u003c\/p\u003e\n\n\u003cp\u003eThe logic is straightforward. If simply knowing whether plaque is present re-stratifies patients beyond traditional risk factors, then measuring \u003cem\u003ehow much\u003c\/em\u003e plaque is there may personalize a patient's risk assessment even further. Several 2D techniques exist, and each has advantages and disadvantages.\u003c\/p\u003e\n\n\u003ch2 id=\"plaque-score\"\u003eMethod 1: The Plaque Score\u003c\/h2\u003e\n\n\u003cp\u003eThe plaque score is a semi-quantitative approach. The doctor visualizes and counts the total number of sites containing plaque along the common carotid artery (CCA), the carotid bulb, and the internal carotid artery (ICA). The doctor then adds them up.\u003c\/p\u003e\n\n\u003cp\u003eThis approach varies greatly among studies. Some investigators count plaque lesions in any visualized segment. Others count only lesions in easily identified segments, such as the distal first centimeter of the CCA, the bulb, and the proximal ICA.\u003c\/p\u003e\n\n\u003cp\u003eTwo important analyses from the Rotterdam Study — a prospective, population-based cohort of elderly people — used a unique process. The two studies included 4,217 and 6,389 participants. Both measured plaque at 6 locations in the carotid arteries: two sides each of the CCA, the bifurcation, and the ICA.\u003c\/p\u003e\n\n\u003cp\u003eThe total plaque score ranged from 0 to 6. It was calculated by adding the number of sites where plaque was detected. That number was divided by the total number of sites with a usable ultrasound image, and multiplied by 6 (the maximum number of sites). In the larger study of 6,389 people, scores of 0, 1, 2, and ≥3 points were considered to represent no, mild, moderate, or severe carotid atherosclerosis.\u003c\/p\u003e\n\n\u003cp\u003eFor risk prediction and standardization, the panel recommends that if a plaque score is being calculated, certain lesions should be included in the counting. These are lesions limited to the distal 1 cm of the CCA, the bulb, and the proximal 1 cm of the ICA.\u003c\/p\u003e\n\n\u003cp\u003eThe links to real patient outcomes are strong. The Three-city study looked at 5,895 individuals aged 65 to 85 who were free of cardiovascular disease at the start. In that study, plaque at one site was linked to a hazard ratio (HR, a measure of how much more likely an event is over time) of 1.5 (95% confidence interval [CI] = 1.0–2.2). Plaque at two or more sites carried an HR of 2.2 (95% CI = 1.6–3.1; p \u0026lt; 0.001 for trend).\u003c\/p\u003e\n\n\u003cp\u003eAdding plaque information to traditional risk factors also improved the area under the curve (AUC) for CVD prediction from 0.728 to 0.745 (p = 0.04). AUC is a statistical measure of how well a prediction model sorts people correctly; 0.5 is no better than chance and 1.0 is perfect. The net reclassification index (NRI, the share of patients moved into a more accurate risk category) was 13.7%. Another study of 367 men (mean age 78 ± 4 years) found that the hazard ratio for death over 4 years rose from 2.89 for a plaque score of 1–2 to 4.53 for a plaque score of 7–12.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAdvantages.\u003c\/strong\u003e The plaque score is easy to perform and does not require advanced quantification software. Because individual lesions are simply seen and counted rather than measured, the angle or plane of imaging matters less. Even though it is a fairly rough reflection of plaque extent, it predicts risk better than simply reporting whether plaque is absent or present.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDisadvantages.\u003c\/strong\u003e The plaque score is semi-quantitative — it only counts the number of lesions. It does not consider the size of an individual plaque, which would better reflect the overall extent of atherosclerosis. Because lesions at distinct sites are counted, the score may overestimate when two \"separate\" plaques are actually contiguous (touching). Conversely, if a large contiguous area of plaque is counted as just one lesion, the score will underestimate the extent of disease.\u003c\/p\u003e\n\n\u003ch2 id=\"plaque-height\"\u003eMethod 2: Plaque Height (Thickness)\u003c\/h2\u003e\n\n\u003cp\u003ePlaque thickness, or height, can be thought of as a variation on the maximal CIMT measurement. It differs in that it represents how far the plaque protrudes in a radial direction. That direction is outward from its origin along the vessel wall and into the lumen (the open channel where blood flows).\u003c\/p\u003e\n\n\u003cp\u003eTo measure it, some investigators suggest using electrocardiographic gating (timing the measurement to the heartbeat) so that measurements are taken at the same phase of the cardiac cycle each time. Typically, the doctor performs cross-sectional (transverse) sweeps to find plaque. Once a lesion is identified, electronic calipers (available with most software) are placed starting along the origin of the plaque at the vessel wall. The calipers extend into the lumen at right angles to the wall, along the most protruding part of that plaque.\u003c\/p\u003e\n\n\u003cp\u003eThe maximum plaque height or thickness among all identified lesions — seen in both the right and left carotid arteries — is then reported. Importantly, studies using this method do not sum the plaque heights. They report the single largest plaque height found anywhere in the patient.\u003c\/p\u003e\n\n\u003cp\u003ePlaque height measured this way is highly reproducible. In the Northern Manhattan Study (NOMAS), the intra-class correlation coefficient (a statistical measure of agreement, where 1.0 is perfect) for inter-observer reliability was 0.77, and for intra-observer reliability it was 0.94.\u003c\/p\u003e\n\n\u003cp\u003eVariability in this method comes from deciding where within the vessel wall the measurement should begin. To reduce variability across studies, the panel recommends beginning the measurement at the adventitial-medial layer, similar to how CIMT is measured.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRecommendation #5.\u003c\/strong\u003e Plaque thickness (height) should be measured as the initial 2D approach for quantifying carotid ultrasound plaque. Though plaque height is often measured from 2D images, it can be obtained from a 3D image when available, which overcomes the out-of-plane limitations of 2D imaging.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRecommendation #6.\u003c\/strong\u003e The maximal plaque height should be measured from the side where plaque is detected (unilateral) or from both the right and left carotid segments (bilateral). A caliper is placed at the adventitial plane and extends into the center of the lumen at right angles to the vessel wall. For standardization, this measurement should be taken from any segment of the long and short axis of the carotid artery (bulb, ICA, CCA). The view and segment should be reported accordingly. The measurement begins at the same plane where CIMT measurement begins, to stay consistent with defining plaque beyond the CIMT threshold of 1.5 mm.\u003c\/p\u003e\n\n\u003ch2 id=\"height-outcomes\"\u003ePlaque Height and Patient Outcomes\u003c\/h2\u003e\n\n\u003cp\u003eThe document links maximum plaque height directly to clinical outcomes, reinforcing why this measurement matters. Higher plaque height has been associated with cardiovascular events in the studies reviewed by the panel. The measurement's high reproducibility (intra-observer correlation of 0.94 in NOMAS) makes it practical for routine use. This is the core reason the panel selected thickness as the primary measurement tool.\u003c\/p\u003e\n\n\u003ch2 id=\"plaque-area\"\u003eMethod 3: Plaque Area\u003c\/h2\u003e\n\n\u003cp\u003eCarotid plaque area is the most advanced of the 2D quantification methods. The process begins with a manual sweep of the carotid artery, typically scanning in cross section, to first identify plaque lesions. Once identified, the area is traced and measured, and the total value is reported.\u003c\/p\u003e\n\n\u003cp\u003eArea measurements apply mainly to protruding lesions. They are harder to apply to plaques that are diffusely layered along the inner wall, which may be focal or diffuse wall calcification layered in concentric or eccentric patterns. Such lesions may or may not be atherosclerotic in origin.\u003c\/p\u003e\n\n\u003ch2 id=\"advanced\"\u003eAdvanced and Emerging Techniques\u003c\/h2\u003e\n\n\u003cp\u003eBeyond simply measuring how much plaque is present, the guideline document explores the concept of plaque \u003cstrong\u003evulnerability\u003c\/strong\u003e — the idea that some plaques are more likely to rupture and cause events than others, regardless of size.\u003c\/p\u003e\n\n\u003cp\u003eSeveral emerging methods are considered in the full document:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePlaque neovascularization\u003c\/strong\u003e (new blood vessel growth inside plaque) and anatomy, assessed with contrast-enhanced ultrasound using ultrasound enhancing agents.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGene and biomarker approaches\u003c\/strong\u003e (noted in the authors' conflict-of-interest disclosures as an area of active research).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGray Scale Median (GSM) analysis\u003c\/strong\u003e — a computer-based method that measures how bright or dark plaque appears on ultrasound. Softer, echolucent (darker) plaque may signal higher risk.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePixel distribution analysis (PDA)\u003c\/strong\u003e — a related technique for characterizing plaque texture.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMulti-modality assessment\u003c\/strong\u003e — combining ultrasound with other imaging such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET), including fluorodeoxyglucose (FDG) PET, which detects metabolically active (inflamed) plaque.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThese techniques aim to move beyond \"how much plaque\" toward \"what kind of plaque\" — a distinction that may matter greatly for predicting who will have a heart attack or stroke.\u003c\/p\u003e\n\n\u003ch2 id=\"clinical-use\"\u003ePutting Plaque Imaging into Practice\u003c\/h2\u003e\n\n\u003cp\u003eThe document outlines where carotid plaque imaging fits in real patient care. Two scenarios receive particular attention:\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePrimary prevention in asymptomatic patients.\u003c\/strong\u003e People with no symptoms may still have hidden plaque that changes their risk category. The high prevalence of carotid atherosclerosis in people with otherwise low Framingham risk scores is exactly why screening for subclinical atherosclerosis has potential value.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSymptoms suggesting coronary artery disease, but normal non-invasive tests.\u003c\/strong\u003e When standard tests come back normal but a patient has symptoms, plaque imaging may help explain the picture and guide decisions.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003eThe panel notes that a patient's CIMT may increase over time to ≥1.5 mm, signifying the development of diffuse atherosclerotic plaque by this definition. However, the clinical utility of long-term CIMT monitoring is not yet established.\u003c\/p\u003e\n\n\u003ch2 id=\"limitations\"\u003eLimitations and Open Questions\u003c\/h2\u003e\n\n\u003cp\u003eSeveral important gaps remain, and the panel is transparent about them.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eThere is a lack of evidence on how often to repeat testing. The 2-to-5-year interval used in population studies is not firmly established.\u003c\/li\u003e\n  \u003cli\u003eDebate continues over whether the transition from increased CIMT to plaque is one continuous process, or whether CIMT and plaque are truly separate conditions.\u003c\/li\u003e\n  \u003cli\u003eIt can be difficult to distinguish medial thickening from diffuse atherosclerotic plaque on an ultrasound image alone.\u003c\/li\u003e\n  \u003cli\u003eUltrasound cannot currently tell whether a non-protruding lesion under 1.5 mm thick is entirely medial or intimal.\u003c\/li\u003e\n  \u003cli\u003eFurther work is needed to standardize the plaque score across different clinics and studies.\u003c\/li\u003e\n  \u003cli\u003eThe value of serial CIMT measurements in expert hands rests on limited or anecdotal evidence.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe panel deliberately set a slightly more conservative threshold than the Mannheim consensus (≥1.5 mm rather than greater than 1.5 mm). The panel notes this creates a framework for continued research rather than a final answer.\u003c\/p\u003e\n\n\u003ch2 id=\"recommendations\"\u003eKey Recommendations at a Glance\u003c\/h2\u003e\n\n\u003col\u003e\n  \u003cli\u003eDefine carotid plaque either as \u003cstrong\u003eprotuberant-type\u003c\/strong\u003e (focal thickening encroaching into the lumen) or \u003cstrong\u003ediffuse-type\u003c\/strong\u003e (CIMT ≥1.5 mm in any carotid segment).\u003c\/li\u003e\n  \u003cli\u003eEvaluate \u003cstrong\u003eboth\u003c\/strong\u003e plaque types for risk stratification and for tracking atherosclerosis over time.\u003c\/li\u003e\n  \u003cli\u003eScan first for protruding plaque. If none is found, measure CIMT to find diffuse plaque at the ≥1.5 mm threshold.\u003c\/li\u003e\n  \u003cli\u003eDo \u003cstrong\u003enot\u003c\/strong\u003e perform serial CIMT measurements in asymptomatic patients unless the result meets the diffuse plaque criteria (Grades II or III, CIMT ≥1.5 mm).\u003c\/li\u003e\n  \u003cli\u003eUse \u003cstrong\u003eplaque thickness (height)\u003c\/strong\u003e as the initial 2D measurement for quantifying carotid plaque.\u003c\/li\u003e\n  \u003cli\u003eMeasure maximal plaque height with a caliper placed at the adventitial plane. The caliper extends into the center of the lumen at right angles to the wall, from any segment in the long and short axis views.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003eWhat does this mean for patients? If your doctor orders a carotid ultrasound, this guideline encourages a structured look for plaque — not just a quick check of artery thickness. If plaque is found, its height will likely be measured and reported. That number can help your care team decide whether you need more aggressive prevention, such as cholesterol-lowering medication or blood pressure control. If no plaque is found, a CIMT measurement may still be taken to look for diffuse disease.\u003c\/p\u003e\n\n\u003c!-- ddn:faq:start --\u003e\n\u003ch2 id=\"ddn-faq\"\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eWhat is carotid plaque and why does it matter?\u003c\/h3\u003e\n\u003cp\u003eCarotid plaque is fatty, hardened buildup in the arteries of your neck. It matters because these arteries mirror what is happening elsewhere in your body. Plaque can narrow the vessel or rupture, blocking blood flow and causing a stroke. Measuring plaque helps estimate your risk of heart attack and stroke beyond traditional risk factors.\u003c\/p\u003e\n\u003ch3\u003eHow is carotid plaque measured on ultrasound?\u003c\/h3\u003e\n\u003cp\u003eDoctors first scan visually for protruding plaque. If none is found, they measure carotid intima-media thickness (CIMT) to detect flat, diffuse plaque. The recommended initial measurement is plaque thickness, also called height, taken with a caliper from the vessel wall into the lumen. This method is simple, widely available, and highly reproducible.\u003c\/p\u003e\n\u003ch3\u003eWhat does a CIMT of 1.5 mm or more mean?\u003c\/h3\u003e\n\u003cp\u003eA CIMT of 1.5 mm or greater in any carotid segment is considered diffuse-type plaque, or a plaque equivalent. The panel suggests this be viewed as a clinically significant lesion for patients younger than 65. It does not reflect how blocked the vessel is, but it does indicate atherosclerosis and may lead to more aggressive prevention.\u003c\/p\u003e\n\u003ch3\u003eWill I need repeat ultrasound tests?\u003c\/h3\u003e\n\u003cp\u003eSerial CIMT measurements are not recommended for asymptomatic patients unless the result meets the criteria for diffuse plaque, meaning CIMT is 1.5 mm or greater. Even then, the evidence for how often to repeat testing is thin. Population studies have used intervals of 2 to 5 years, but this is not firmly established.\u003c\/p\u003e\n\u003ch3\u003eHow much does plaque increase my risk of heart attack or stroke?\u003c\/h3\u003e\n\u003cp\u003eStudies cited show that some plaque measures are linked to 1.5 to 4.5 times higher risk of cardiovascular events or death. For example, in the Three-city study of 5,895 older adults, plaque at one site was linked to a hazard ratio of 1.5, and at two or more sites, 2.2. Adding plaque information improved risk prediction.\u003c\/p\u003e\n\u003ch3\u003eWhat happens if the ultrasound finds no plaque?\u003c\/h3\u003e\n\u003cp\u003eIf no protruding plaque is seen, a CIMT measurement may still be taken to look for diffuse disease. If CIMT is below 1.5 mm, it does not meet the threshold for diffuse plaque. Your doctor may still consider other risk factors. The guideline encourages a structured look for plaque, not just a quick check of artery thickness.\u003c\/p\u003e\n\u003ch3\u003eMy carotid ultrasound found plaque — when should I get a second opinion on my heart and stroke risk?\u003c\/h3\u003e\n\u003cp\u003eA second opinion can help when a carotid ultrasound reports plaque but the meaning of the measurement is unclear. Plaque thickness, or height, is the recommended initial measurement, and higher plaque height has been linked to cardiovascular events. Plaque information can reclassify risk beyond traditional factors, with some measures linked to 1.5 to 4.5 times higher risk of cardiovascular events or death. An independent review can confirm whether plaque was defined as protuberant or diffuse and whether the reported height was measured consistently. Diagnostic Detectives Network provides independent expert second opinions.\u003c\/p\u003e\n\u003c!-- ddn:faq:end --\u003e\n\n\u003ch2 id=\"source\"\u003eSource Information\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eOriginal article title:\u003c\/strong\u003e Assessment of Carotid Arterial Plaque by Ultrasound\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAuthors:\u003c\/strong\u003e Amer M. Johri, MD, FASE; Vijay Nambi, MD, FASE; Tasneem Z. Naqvi, MD, FASE; Steven B. Feinstein, MD; Esther S. H. Kim, MD, MPH, FASE; Margaret M. Park, ACS, RDCS, RVT, FASE; Harald Becher, MD, PhD; and Henrik Sillesen, MD, DMSc.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAuthor affiliations:\u003c\/strong\u003e Queen's University, Kingston, Ontario, Canada; Baylor College of Medicine, Houston, Texas; Mayo Clinic, Phoenix, Arizona; Rush Medical College, Chicago, Illinois; Vanderbilt University Medical Center, Nashville, Tennessee; Cleveland Clinic Heart and Vascular Institute, Cleveland, Ohio; University of Alberta Hospital, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada; and Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePublication:\u003c\/strong\u003e Journal of the American Society of Echocardiography, August 2020, Volume 33, Number 8, pages 917–933. Copyright 2020 by the American Society of Echocardiography. DOI: 10.1016\/j.echo.2020.04.021.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eEndorsements:\u003c\/strong\u003e This document is endorsed by numerous international partners of the American Society of Echocardiography International Alliance, including societies from Argentina, ASEAN, the Asian-Pacific region, Australia, Canada, China, Brazil, Cuba, India, Iran, Italy, Japan, Korea, Mexico, the Philippines, Saudi Arabia, Thailand, Venezuela, and Vietnam.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDisclosures:\u003c\/strong\u003e Several authors reported relationships with commercial entities, including Bracco Imaging, Siemens, Philips, Ultromics, Lantheus Medical Imaging, Northwest Imaging Solutions, DIA Imaging, SonoGene, Amgen, Novo Nordisk, Cordex, and St. Jude Medical. Drs. Johri and Kim reported no actual or potential conflicts of interest related to this document.\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eThis patient-friendly article is based on peer-reviewed research. It summarizes the publicly available excerpt of the guideline document, which covers plaque definitions, quantification methods, and clinical applications. The complete published guideline contains additional detail on 3D acquisition protocols, plaque composition analysis, gray scale median analysis, and multi-modality imaging.\u003c\/em\u003e\u003c\/p\u003e","brand":"DiagnosticDetectives.Com","offers":[{"title":"Default Title","offer_id":47545208504476,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0599\/5449\/5644\/files\/ddn-medical-article-carotid-artery-plaque-on-ultrasound-a-patients-guide-to-the-2020-ase-guidelines-for-measuring-atherosclerosis-and-heart--hero.png?v=1790155950","url":"https:\/\/diagnosticdetectives.com\/he\/products\/carotid-artery-plaque-on-ultrasound-a-patients-guide-to-the-2020-ase-guidelines-for-measuring-atherosclerosis-and-heart-risk","provider":"DiagnosticDetectives.Com","version":"1.0","type":"link"}