{"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\u003eThis 2020 guideline from the American Society of Echocardiography (ASE) explains how ultrasound of the carotid (neck) arteries can detect and measure plaque — the fatty buildup inside artery walls — to estimate a person's risk of heart attack, stroke, and other cardiovascular events. The authors define two types of plaque, recommend specific measurement methods, and review research showing that plaque measurements predict risk better than older approaches such as measuring artery wall thickness alone. Because carotid plaque reflects the total burden of atherosclerosis throughout the body, including the coronary arteries, a standardized ultrasound assessment can reclassify risk in people who might otherwise appear low-risk. For patients, the key message is that finding and quantifying carotid plaque adds important information beyond traditional risk factors like cholesterol and blood pressure.\u003c\/p\u003e\n\n\u003ch1\u003eCarotid Artery Plaque on Ultrasound: A Patient's Guide to the 2020 ASE Guidelines for Measuring Atherosclerosis and Heart Risk\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=\"#why-window\"\u003eWhy the Carotid Artery Is a \"Window\" Into Heart Risk\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#why-guidelines\"\u003eWhy This Guideline Was Written\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=\"#plaque-types\"\u003eTwo Types of Plaque: Protuberant and Diffuse\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#clinically-significant\"\u003eWhen Is Carotid Plaque \"Clinically Significant\"?\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#grading\"\u003eThe New Plaque Grading System\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#plaque-score\"\u003eMeasuring Plaque with the \"Plaque Score\"\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#plaque-height\"\u003eMeasuring Maximum Plaque Height (Thickness)\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#height-outcomes\"\u003eWhat Plaque Height Means for Health Outcomes\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#plaque-area\"\u003eMeasuring Plaque Area\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#recommendations\"\u003eThe Panel's Six Key Recommendations\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#limitations\"\u003eLimitations and Caveats\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#for-patients\"\u003eWhat This Means for You\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 ultrasound can detect plaque, offering a window into atherosclerosis throughout the body.\u003c\/li\u003e\n\u003cli\u003ePlaque measurement predicts cardiovascular risk better than measuring only artery wall thickness (CIMT).\u003c\/li\u003e\n\u003cli\u003ePlaque is defined as a focal bulge into the artery lumen or diffuse wall thickness of 1.5 mm or greater.\u003c\/li\u003e\n\u003cli\u003eA plaque score and maximum plaque height are standardized methods to quantify plaque burden for risk.\u003c\/li\u003e\n\u003cli\u003eRoutine repeat CIMT testing is not recommended without symptoms unless diffuse plaque (1.5 mm) is present.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ddn:keypoints:end --\u003e\n\n\n\u003ch2 id=\"why-window\"\u003eWhy the Carotid Artery Is a \"Window\" Into Heart Risk\u003c\/h2\u003e\n\n\u003cp\u003eAtherosclerotic cardiovascular disease — a group of conditions caused by the buildup of plaque inside artery walls — remains the leading cause of illness and death worldwide. Atherosclerosis (hardening and narrowing of the arteries) can develop silently for years before it causes problems. Finding it early offers a chance to act.\u003c\/p\u003e\n\n\u003cp\u003eThe carotid arteries, located on each side of the neck, supply blood to the brain. They lie close to the skin, which makes them easy to image with ultrasound. According to the guideline authors, ultrasound of the carotid artery provides a unique \"window\" into a patient's underlying cardiovascular risk.\u003c\/p\u003e\n\n\u003cp\u003eThe presence and degree of atherosclerosis, defined by plaque detected in the carotid arterial system, has been used to estimate, classify, or reclassify an individual's cardiovascular risk. Beyond overall risk prediction, carotid atherosclerosis is also a known predictor of other cardiovascular events, such as stroke caused by narrowing of the vessel (luminal stenosis) or by plaque rupture.\u003c\/p\u003e\n\n\u003cp\u003eIn short: what happens in the neck arteries often reflects what is happening in arteries throughout the body.\u003c\/p\u003e\n\n\u003ch2 id=\"why-guidelines\"\u003eWhy This Guideline Was Written\u003c\/h2\u003e\n\n\u003cp\u003eDoctors have used two distinct ultrasound approaches to estimate cardiovascular risk. The older approach measures the carotid intima-media thickness (CIMT), which is the thickness of the two innermost layers of the artery wall. The newer approach assesses carotid arterial plaque itself.\u003c\/p\u003e\n\n\u003cp\u003eCIMT measurement identifies areas of increased carotid artery wall thickness. It provides an easily accessible imaging biomarker for classifying cardiovascular risk in individuals and in population studies. However, questions about the precision of CIMT measurements remain. There is now recognition that assessing carotid arterial plaque offers an even greater risk stratification benefit than CIMT.\u003c\/p\u003e\n\n\u003cp\u003eThis has led to a paradigm shift — a change in the standard way of thinking — in which ultrasound parameters are used for risk prediction. The greater benefit is seen with plaque assessment compared with CIMT.\u003c\/p\u003e\n\n\u003cp\u003eWhy the difference? It is now recognized that CIMT may represent more than one distinct disease process, while plaque primarily reflects atherosclerosis itself. CIMT may predominantly reflect the presence of cardiovascular risk factors, such as high blood pressure (hypertension). Carotid plaque, in contrast, is a sub-intimal process (developing beneath the innermost artery lining) that correlates with the overall burden of atherosclerosis in the coronary vascular bed — the arteries that supply the heart muscle.\u003c\/p\u003e\n\n\u003cp\u003eOne striking finding drives this guideline: the high prevalence of carotid atherosclerosis in people who have an otherwise low Framingham risk score. The Framingham risk score is a traditional tool that estimates a person's 10-year risk of heart disease using factors such as age, cholesterol, blood pressure, and smoking. When plaque is present despite a low score, this has potential implications for screening of subclinical atherosclerosis — disease that has not yet caused symptoms.\u003c\/p\u003e\n\n\u003cp\u003eTechnology has also advanced dramatically. Since the previous ASE consensus statement was published in 2008, dedicated three-dimensional (3D) vascular ultrasound probes became widely available, and more recently a 3D matrix array probe for carotid ultrasound was released with analysis software. This document is the first to provide systematic recommendations for standardizing the quantification of carotid arterial plaque for cardiovascular risk stratification.\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 three-dimensional (3D) quantification of carotid arterial plaque by ultrasound for the purpose of cardiovascular risk stratification.\u003c\/p\u003e\n\n\u003cp\u003eThe document also discusses emerging techniques, including the role of ultrasound enhancing agents (UEA) — sometimes called \"contrast agents\" — for assessing intra-plaque neovascularization (the growth of tiny, fragile new blood vessels inside plaque) and plaque composition analysis.\u003c\/p\u003e\n\n\u003ch2 id=\"plaque-types\"\u003eTwo Types of Plaque: Protuberant and Diffuse\u003c\/h2\u003e\n\n\u003cp\u003eCarotid atherosclerosis is thought to develop beneath the intimal layer (the innermost lining of the artery) in the sub-intima. In contrast, the medial layer (the middle muscle layer) is subject to non-atherosclerotic medial hypertrophy — a thickening of the muscle layer commonly caused by aging and hypertension.\u003c\/p\u003e\n\n\u003cp\u003eThis distinction matters more than you might think. Because the largest portion of the CIMT measurement consists of the medial layer — about 99% in healthy individuals and about 80% when disease is present — CIMT has not been shown to consistently add to cardiovascular risk prediction. Carotid plaque, on the other hand, represents the atherosclerotic process itself. It starts in the intimal layer, and it has been shown to predict cardiovascular events better than CIMT.\u003c\/p\u003e\n\n\u003cp\u003eDespite this difference, it can be difficult to tell medial thickening apart from diffuse atherosclerotic plaque on an ultrasound image. Some plaques are discrete (distinct) lesions that are easy to distinguish from the surrounding wall. But plaque can also be eccentric (off-center) and spread over the surface of the wall, appearing indistinct from the media. In such cases, it is hard to know whether the image shows simple medial thickening or eccentric, diffuse plaque.\u003c\/p\u003e\n\n\u003cp\u003eBecause of this difficulty, arbitrary definitions have been proposed. A commonly reported threshold value to define diffuse plaque is a CIMT greater than 1.5 mm, or a focal intimal-medial thickening greater than 50% of the surrounding area.\u003c\/p\u003e\n\n\u003cp\u003eConfusion occurs because ultrasound resolution now allows visualization of distinct protuberant plaque lesions that can be smaller than this threshold value. In fact, the definition of plaque has varied widely from study to study:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eIn one study, plaque was defined as a 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. Depending on how it was applied, this produced plaque definitions ranging from 0.5 mm to greater than 1.5 mm.\u003c\/li\u003e\n  \u003cli\u003eAnother study defined plaque simply as a CIMT greater than 1.2 mm.\u003c\/li\u003e\n  \u003cli\u003eThe European Mannheim consensus defined plaque as a 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\u003eThe ASE writing panel chose a threshold that is slightly more conservative than the Mannheim consensus. They recommend using 1.5 mm or greater (rather than greater than 1.5 mm) as the cutoff CIMT value for the presence of diffuse plaque. A newly established Plaque Grading Consensus, described below, now allows identification and characterization of protuberant plaque lesions smaller than the CIMT threshold used for diffuse plaque. Modern ultrasound technology can visualize such small lesions in exquisite detail, allowing both quantification and even potential analysis of plaque composition.\u003c\/p\u003e\n\n\u003cblockquote\u003e\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 one of two ways: 1) any focal thickening thought to be atherosclerotic in origin that encroaches into the lumen of any segment of the carotid artery (protuberant-type plaque), or 2) in the case of diffuse vessel wall atherosclerosis, when CIMT measures 1.5 mm or greater in any segment of the carotid artery (diffuse-type plaque).\u003c\/p\u003e\n  \u003cp\u003e\u003cstrong\u003eRecommendation #2:\u003c\/strong\u003e Both protuberant and diffuse types of carotid arterial plaque should be evaluated for cardiovascular risk stratification and for the serial (repeat) assessment of atherosclerosis.\u003c\/p\u003e\n\u003c\/blockquote\u003e\n\n\u003ch2 id=\"clinically-significant\"\u003eWhen Is Carotid Plaque \"Clinically Significant\"?\u003c\/h2\u003e\n\n\u003cp\u003eSome centers consider repeat evaluation of CIMT when the value is above the 75th percentile for a person's age, race, and gender. However, there is little evidence about how often repeat testing should be done. An interval of 2 to 5 years has been used in population studies, although published evidence suggests that more frequent CIMT measurements could increase the precision of tracking CIMT progression over time.\u003c\/p\u003e\n\n\u003cp\u003eThe expert panel weighed this evidence and came to a clear conclusion: they recommend \u003cstrong\u003eagainst\u003c\/strong\u003e serial CIMT measurements for cardiovascular risk stratification, especially when the measurement does not meet the threshold for diffuse plaque (1.5 mm or greater). They note that, based on limited or anecdotal evidence, serial CIMT may still have value in the hands of some experts for research purposes, for monitoring progression or regression (shrinkage) of disease in specific cases, and as a potential tool to help change patient behavior.\u003c\/p\u003e\n\n\u003cp\u003eThe panel also acknowledges that an individual patient's CIMT can increase to 1.5 mm or greater over time, which would signal the development of diffuse atherosclerotic plaque by their definition. However, the clinical usefulness of such long-term CIMT monitoring is not yet established.\u003c\/p\u003e\n\n\u003cp\u003eOne important age-related recommendation stands out: the panel suggests that a CIMT of 1.5 mm or greater be considered a clinically significant lesion for patients younger than 65 years of age.\u003c\/p\u003e\n\n\u003ch2 id=\"grading\"\u003eThe New Plaque Grading System\u003c\/h2\u003e\n\n\u003cp\u003eThe thickness (also known as \"height\" in the long-axis ultrasound view) of a carotid plaque lesion was chosen as the initial measure to define plaque. This choice was made because thickness measurement is widely available and can be applied to both protuberant and diffuse types of plaque lesions.\u003c\/p\u003e\n\n\u003cp\u003eAdditional quantification techniques, such as area and volume, apply mostly to protuberant-type plaque. They are difficult to use in atherosclerotic lesions that are diffusely layered along the intimal wall. Such diffuse lesions may also contain focal or widespread wall calcification (calcium deposits) arranged in a concentric or eccentric pattern. Calcification can represent either atherosclerotic or non-atherosclerotic processes.\u003c\/p\u003e\n\n\u003cp\u003eThe panel's grading system standardizes the size of an individual plaque lesion for comparison across studies. It is important to note that the grading system does \u003cstrong\u003enot\u003c\/strong\u003e reflect the degree of vessel occlusion (how blocked the artery is).\u003c\/p\u003e\n\n\u003cp\u003eHere is how the grading works:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGrade I\u003c\/strong\u003e applies only to small protuberant-type plaque lesions. Ultrasound can now resolve such small protuberant lesions clearly. However, if plaque is non-protuberant (diffuse or eccentric) and less than 1.5 mm thick, it is currently not possible to tell whether the thickening is entirely due to medial thickening or is truly intimal plaque.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGrade II and Grade III\u003c\/strong\u003e apply when CIMT reaches 1.5 mm or greater. At this thickness, the framework attributes the thickening to diffuse atherosclerotic plaque (mostly intimal rather than medial), and the lesion is considered a \"plaque equivalent.\" Grades II and III measurements are applied to obviously protuberant plaque in the same manner, for simplicity.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"plaque-score\"\u003eMeasuring Plaque with the \"Plaque Score\"\u003c\/h2\u003e\n\n\u003cp\u003eInterest in plaque quantification grew significantly after the ARIC Study discovered that the simple presence or absence of plaque added information to risk stratification beyond what CIMT alone provided. Researchers reasoned that if simply knowing whether plaque exists can re-stratify patients beyond traditional risk factors, then measuring the amount of plaque might further personalize a patient's risk assessment.\u003c\/p\u003e\n\n\u003cp\u003eThe plaque score is a semi-quantitative approach — a method that gives a rough rather than exact measure. The total number of sites containing plaque along the common carotid artery (CCA), the carotid bulb (the widened area at the branching point), and the internal carotid artery (ICA) is counted and summed. This approach varies greatly among studies: some investigators count plaque lesions in any visualized segment, while others count only lesions in easily identified segments such as the distal (far) first centimeter (cm) of the CCA, the bulb, and the proximal (near) ICA.\u003c\/p\u003e\n\n\u003cp\u003eThe Rotterdam Study, a prospective, population-based study of cardiovascular disease in elderly people, used a unique process to calculate plaque score. Two key analyses from this study (with 4,217 and 6,389 participants respectively) measured the presence of carotid plaque at 6 locations in the carotid arteries: two sides each of the CCA, the bifurcation (where the artery splits), and the ICA. The total plaque score ranged from 0 to 6. It was calculated by adding the number of sites where plaque was detected, dividing by the total number of sites for which an ultrasound image was available, and multiplying by 6 (the maximum number of sites).\u003c\/p\u003e\n\n\u003cp\u003eIn the second and larger of these studies (n = 6,389), patients with plaque scores of 0, 1, 2, and 3 or more points were considered to have no, mild, moderate, or severe carotid atherosclerosis, respectively.\u003c\/p\u003e\n\n\u003cp\u003eClinical studies have shown a clear link between plaque score and future cardiovascular disease:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eIn the Three-City Study of 5,895 individuals aged 65 to 85 years who were free of cardiovascular disease at the start, plaque in one site was associated with a hazard ratio (HR) of 1.5 (95% confidence interval [CI] = 1.0 to 2.2). A hazard ratio compares the likelihood of an event in one group versus another — here, people with plaque compared with people without it.\u003c\/li\u003e\n  \u003cli\u003eThe hazard ratio for plaque at 2 or more sites was 2.2 (95% CI = 1.6 to 3.1; p \u0026lt; 0.001 for trend). In plain terms, having plaque in multiple sites roughly doubled the risk of a cardiovascular event during follow-up.\u003c\/li\u003e\n  \u003cli\u003eAdding plaque information to traditional risk factors improved the area under the curve (AUC) for cardiovascular disease prediction from 0.728 to 0.745 (p = 0.04). The AUC measures how well a test discriminates between people who will and will not have an event; 0.5 is no better than chance and 1.0 is perfect.\u003c\/li\u003e\n  \u003cli\u003eThe same addition produced a net reclassification index (NRI) of 13.7%. The NRI tells us what percentage of people were correctly moved into a higher or lower risk category based on the new information.\u003c\/li\u003e\n  \u003cli\u003eAnother study followed 367 men (mean age 78 ± 4 years) and found that the hazard ratio for death over 4 years increased from 2.89 for a plaque score of 1 to 2, up to 4.53 for a plaque score of 7 to 12.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eFor the purpose of risk prediction and standardization, the panel recommends that if a plaque score is calculated, counting should be limited to lesions in the distal 1 cm of the CCA, the bulb, and the proximal 1 cm of the ICA. Further standardization of the plaque score is still needed.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAdvantages.\u003c\/strong\u003e The plaque score is easy to perform and requires no advanced quantification software. Because individual plaque lesions are not precisely measured but simply visualized and counted, the angle or plane of imaging is less critical. Despite being a relatively rough reflection of plaque extent, the plaque score has more predictive value than simply reporting the presence or absence of plaque.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDisadvantages.\u003c\/strong\u003e The plaque score is semi-quantitative and counts only the number of lesions. It does not consider additional parameters such as the size of an individual plaque lesion, which would better reflect the overall extent of atherosclerosis. In addition, because lesions are counted at distinct sites, the score may be unclear about whether two separate plaque lesions are actually connected (contiguous), which could lead to overestimation. Conversely, there may be a large amount of contiguous protuberant plaque that forms just one large lesion — in that case, the plaque score will underestimate the true extent of atherosclerosis.\u003c\/p\u003e\n\n\u003ch2 id=\"plaque-height\"\u003eMeasuring Maximum Plaque Height (Thickness)\u003c\/h2\u003e\n\n\u003cp\u003eCarotid plaque thickness, or height, can be thought of as a variation of the maximal CIMT measurement. It differs in an important way: plaque height represents the degree to which the plaque protrudes outward (in a radial manner) from its origin along the vessel wall into the lumen (the open channel through which blood flows).\u003c\/p\u003e\n\n\u003cp\u003eHere is how the measurement is performed. Some investigators suggest using electrocardiographic (ECG) gating — timing the ultrasound images to the same phase of the cardiac cycle — so measurements are consistent between heartbeats. Typically, the sonographer makes cross-sectional (transverse) sweeps to check for the presence of plaque. Once a plaque lesion is identified, electronic calipers (measurement tools built into most ultrasound software) are placed beginning along the origin of the plaque at the vessel wall, extending into the lumen at right angles to the wall, along the most protuberant (outward-projecting) part of that particular plaque.\u003c\/p\u003e\n\n\u003cp\u003eThe maximum plaque height or thickness among all identified plaque lesions, seen in both the right and left carotid arteries, is then reported. It is important to understand that studies using this method do not add up (sum) all plaque heights. They report the single largest plaque height measured from any plaque identified 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 coefficients — a statistical measure of agreement between measurements — were 0.77 for inter-observer reliability (different readers measuring the same image) and 0.94 for intra-observer reliability (the same reader measuring the same image more than once).\u003c\/p\u003e\n\n\u003cp\u003eVariability in this method relates to identifying the exact location within the vessel wall where the plaque height measurement should begin. To reduce variability across studies, the panel recommends beginning the measurement at the adventitial-medial layer (the outer connective tissue and middle muscle layers of the artery), similar to where CIMT measurement begins.\u003c\/p\u003e\n\n\u003ch2 id=\"height-outcomes\"\u003eWhat Plaque Height Means for Health Outcomes\u003c\/h2\u003e\n\n\u003cp\u003eThe maximum plaque height measured in the manner described above has been used as a key research measure because it is simple, reproducible, and captures the most severe lesion in the artery. The original guideline document reports detailed outcome data linking maximum plaque height to future cardiovascular events.\u003c\/p\u003e\n\n\u003cp\u003eThe outcomes data from the original document were cut off in the text provided; however, the guideline's grading framework is built around the principle that plaque height is the foundational measure. The panel emphasizes that the measurement should begin at the same plane as the CIMT measurement so that results stay consistent with defining plaque beyond the 1.5 mm CIMT threshold.\u003c\/p\u003e\n\n\u003cp\u003eOne practical point for patients: a single tall plaque may carry more significance than several small flat plaques, which is why the \"maximum height\" approach is used rather than averaging or summing all lesions.\u003c\/p\u003e\n\n\u003ch2 id=\"plaque-area\"\u003eMeasuring Plaque Area\u003c\/h2\u003e\n\n\u003cp\u003eCarotid plaque area is described in the guideline as the most advanced of the 2D quantification methods. The technique begins with a manual sweep of the carotid artery, typically scanning the artery in cross-section, to identify plaque lesions in the first place. Once lesions are identified, the area of one or multiple plaques is measured, and the total value is reported.\u003c\/p\u003e\n\n\u003cp\u003eThe original guideline document continues with detailed instructions for performing plaque area measurements, followed by sections on three-dimensional plaque volume quantification, plaque vulnerability (the tendency of a plaque to rupture and cause events), contrast-enhanced ultrasound, grayscale median analysis, and multi-modality assessment of plaque. Those sections are part of the full published guideline (see Source Information below).\u003c\/p\u003e\n\n\u003cp\u003ePlaque area shares an important limitation with other advanced measurements: it is difficult to apply to atherosclerotic lesions that are diffusely layered along the intimal wall, rather than forming discrete protuberant bumps.\u003c\/p\u003e\n\n\u003ch2 id=\"recommendations\"\u003eThe Panel's Six Key Recommendations\u003c\/h2\u003e\n\n\u003cp\u003eThe guideline authors, writing on behalf of the American Society of Echocardiography, summarized their advice into six numbered recommendations. Here they are in plain language:\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDefine plaque consistently.\u003c\/strong\u003e Plaque seen on ultrasound should be defined as either: (a) any focal thickening thought to be atherosclerotic that encroaches into the lumen of any segment of the carotid artery (protuberant-type plaque), or (b) diffuse disease in which the CIMT measures 1.5 mm or greater in any segment of the carotid artery (diffuse-type plaque). This holds whether or not an ultrasound enhancing agent (contrast) is used.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCheck for both plaque types.\u003c\/strong\u003e Both protuberant and diffuse plaque should be evaluated for cardiovascular risk stratification and for tracking atherosclerosis over time.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUse a stepwise approach.\u003c\/strong\u003e First, visually scan the carotid arterial wall for protuberant plaque. If none is found, then perform CIMT measurement to look for diffuse plaque, defined as CIMT of 1.5 mm or greater. CIMT, if performed, should be measured according to the earlier ASE Consensus Statement on the Use of Carotid Ultrasound to Identify Subclinical Vascular Disease and Evaluate Cardiovascular Risk.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDo not routinely repeat CIMT.\u003c\/strong\u003e Serial CIMT measurements are not recommended in an asymptomatic patient (someone without symptoms). Repeat measurements are only recommended if the Grade and CIMT meet the criteria for diffuse-type plaque (Grades II or III, and CIMT 1.5 mm or greater) — in which case the finding is treated as a plaque equivalent.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMeasure plaque height first.\u003c\/strong\u003e Plaque thickness (height) should be measured as the initial 2D approach for quantifying carotid ultrasound plaque. Plaque height is often measured from 2D images, but it can also be obtained from a 3D image acquisition when available, to overcome the out-of-plane limitations of 2D imaging.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMeasure from the correct starting point.\u003c\/strong\u003e The maximal plaque height should be measured either from the side where plaque is detected (unilateral) or from both right and left carotid segments (bilateral). A caliper is placed at the adventitial plane — the same starting plane used for CIMT measurement, to stay consistent with the 1.5 mm plaque threshold — and extended into the center of the lumen at right angles to the vessel wall. The measurement can be taken from any segment (bulb, ICA, or CCA) in the long or short axis, and the view and segment should be reported.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2 id=\"limitations\"\u003eLimitations and Caveats\u003c\/h2\u003e\n\n\u003cp\u003eThe guideline authors are careful to acknowledge what this document cannot do. The grading system standardizes the size of an individual plaque lesion, but it does not reflect the degree of vessel occlusion (how blocked the artery is). A patient could have substantial plaque burden without knowing how much it narrows the vessel.\u003c\/p\u003e\n\n\u003cp\u003eQuestions about the precision of CIMT measurements remain, and the panel notes the fundamental difficulty of distinguishing medial thickening from diffuse atherosclerotic plaque. In lesions smaller than 1.5 mm that are not protuberant, current technology cannot tell whether the thickening is medial or intimal in origin.\u003c\/p\u003e\n\n\u003cp\u003eThe evidence base for repeat CIMT testing is limited. The panel's recommendation against serial CIMT measurements acknowledges that published studies on testing frequency had methodological limitations. Any value of serial CIMT in research, in monitoring individual cases, or in motivating patient behavior rests on limited or anecdotal evidence.\u003c\/p\u003e\n\n\u003cp\u003eDefinitions of plaque vary across research studies, which makes comparing results difficult. The panel's chosen threshold of 1.5 mm or greater is \"slightly more conservative\" than the Mannheim consensus, but it remains an arbitrary cutoff. The plaque score method, for all its usefulness, does not measure the size of individual lesions and can either overestimate or underestimate the true extent of atherosclerosis.\u003c\/p\u003e\n\n\u003cp\u003eFinally, the original published document was authored by experts with financial relationships to imaging and pharmaceutical companies; those relationships are disclosed in the full guideline (see below), and they are standard practice in medical guideline development.\u003c\/p\u003e\n\n\u003ch2 id=\"for-patients\"\u003eWhat This Means for You\u003c\/h2\u003e\n\n\u003cp\u003eIf your doctor orders a carotid ultrasound, the goal is often to look beyond your traditional risk factors. The presence of plaque — even in someone with a low Framingham risk score — can change how your doctor views your overall cardiovascular risk.\u003c\/p\u003e\n\n\u003cp\u003eKey points to discuss with your doctor:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePlaque is more than wall thickness.\u003c\/strong\u003e A plaque measurement may predict your risk of future cardiovascular events better than a CIMT measurement alone, because plaque directly represents atherosclerosis.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLocation matters.\u003c\/strong\u003e Plaque in the carotid arteries reflects atherosclerotic burden elsewhere, including the coronary arteries that feed your heart. It also raises the risk of stroke from narrowing or from plaque rupture.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOne number tells the story.\u003c\/strong\u003e Many experts now report the single largest plaque height rather than a sum of all plaque. A measurement of 1.5 mm or greater is considered clinically significant, especially for patients under 65.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRepeating the test has limits.\u003c\/strong\u003e Current guidelines advise against routine repeat CIMT measurements in people without symptoms, unless the first scan shows diffuse-type plaque at Grade II or III (CIMT of 1.5 mm or greater).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUltrasound is only one piece of the puzzle.\u003c\/strong\u003e Plaque detection is a risk stratification tool. It works alongside blood pressure, cholesterol, blood sugar, smoking history, and family history to guide decisions about prevention — including whether to start or intensify medications such as statins.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe ultimate message is encouraging: atherosclerosis can be detected early, measured accurately, and tracked over time with a safe, painless, radiation-free ultrasound test. When plaque is found, there are proven ways to slow its progression and reduce the risk of heart attack and stroke.\u003c\/p\u003e\n\n\n\n\u003c!-- ddn:faq:start --\u003e\n\u003ch2 id=\"ddn-faq\"\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eWhat is carotid artery plaque and why does it matter for heart attack or stroke risk?\u003c\/h3\u003e\n\u003cp\u003eCarotid artery plaque is fatty buildup inside the artery wall in your neck. Ultrasound can detect it. Because plaque in the neck reflects atherosclerosis throughout your body, including heart arteries, finding it helps estimate your risk of future heart attack or stroke, beyond traditional risk factors like cholesterol and blood pressure.\u003c\/p\u003e\n\u003ch3\u003eWhat is the difference between intima-media thickness (CIMT) and carotid plaque measurement?\u003c\/h3\u003e\n\u003cp\u003eCIMT measures the thickness of the two innermost artery wall layers. Plaque measurement looks for actual atherosclerotic buildup. Plaque directly represents atherosclerosis and predicts cardiovascular events better than CIMT alone. CIMT may reflect other processes, like high blood pressure. Doctors now focus more on detecting and measuring plaque.\u003c\/p\u003e\n\u003ch3\u003eHow is carotid artery plaque defined on an ultrasound?\u003c\/h3\u003e\n\u003cp\u003ePlaque is defined in two ways: any focal thickening that bulges into the artery lumen (protuberant plaque), or diffuse disease where the artery wall inner-layer thickness is 1.5 mm or greater in any segment (diffuse plaque). Both types are evaluated for cardiovascular risk and tracking over time.\u003c\/p\u003e\n\u003ch3\u003eWhat is a carotid plaque score and what does it mean for my risk?\u003c\/h3\u003e\n\u003cp\u003eA plaque score counts how many sites in your carotid arteries have plaque. In studies, a higher score was linked to higher risk. For example, in one large study, having plaque in multiple sites roughly doubled the risk of a cardiovascular event during follow-up. The score is a semi-quantitative tool, easy to perform.\u003c\/p\u003e\n\u003ch3\u003eWhat does a carotid plaque height measurement of 1.5 mm mean?\u003c\/h3\u003e\n\u003cp\u003eA thickness of 1.5 mm or greater is considered clinically significant diffuse plaque, especially if you are younger than 65. Plaque height is measured from the vessel wall into the lumen at the thickest part. This single largest plaque measurement is used to assess cardiovascular risk.\u003c\/p\u003e\n\u003ch3\u003eShould I have repeat carotid ultrasound tests over time?\u003c\/h3\u003e\n\u003cp\u003eCurrent guidelines recommend against routine repeat CIMT measurements in people without symptoms. Repeat testing may be considered only if the first scan shows diffuse-type plaque at Grade II or III, meaning CIMT is 1.5 mm or greater. Talk with your doctor about your specific situation.\u003c\/p\u003e\n\u003ch3\u003eWhat happens after my doctor finds carotid plaque on an ultrasound?\u003c\/h3\u003e\n\u003cp\u003eFinding plaque is a risk stratification tool, not a diagnosis of imminent events. It guides prevention decisions, such as whether to start or intensify medications like statins. Plaque can be detected early, measured accurately, and tracked over time with ultrasound, and there are proven ways to slow its progression.\u003c\/p\u003e\n\u003ch3\u003eShould I get a second opinion on my carotid artery ultrasound plaque measurement?\u003c\/h3\u003e\n\u003cp\u003eYes. Carotid plaque measurements guide risk decisions such as starting statins, but plaque definitions vary and ultrasound can struggle to tell benign inner-layer thickening from true atherosclerotic plaque. A second expert review of your saved ultrasound images can confirm whether the finding meets the guideline threshold of 1.5 mm or greater, whether it is protuberant or diffuse plaque, and whether the maximum plaque height was measured correctly. Because plaque reflects atherosclerosis throughout your body, correcting a misread can meaningfully change your risk classification and prevention plan. Diagnostic Detectives Network provides independent expert second opinions.\u003c\/p\u003e\n\u003c!-- ddn:faq:end --\u003e","brand":"DiagnosticDetectives.Com","offers":[{"title":"Default Title","offer_id":47545208504476,"sku":null,"price":0.0,"currency_code":"KRW","in_stock":true}],"url":"https:\/\/diagnosticdetectives.kr\/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"}