Plaque echodensity and textural features are associated with histologic carotid plaque instability (original) (raw)
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Plaque Echodensity and Textural Features Are Associated With Carotid Plaque Instability
Journal of Vascular Surgery, 2015
Background: Carotid plaque echodensity and texture features predict cerebrovascular symptomatology. Our purpose was to determine the association of echodensity and textural features obtained from a digital image analysis (DIA) program with histologic features of plaque instability as well as to identify the specific morphologic characteristics of unstable plaques. Methods: Patients scheduled to undergo carotid endarterectomy were recruited and underwent carotid ultrasound imaging. DIA was performed to extract echodensity and textural features using Plaque Texture Analysis software (LifeQ Medical Ltd, Nicosia, Cyprus). Carotid plaque surgical specimens were obtained and analyzed histologically. Principal component analysis (PCA) was performed to reduce imaging variables. Logistic regression models were used to determine if PCA variables and individual imaging variables predicted histologic features of plaque instability. Results: Image analysis data from 160 patients were analyzed. Individual imaging features of plaque echolucency and homogeneity were associated with a more unstable plaque phenotype on histology. These results were independent of age, sex, and degree of carotid stenosis. PCA reduced 39 individual imaging variables to five PCA variables. PCA1 and PCA2 were significantly associated with overall plaque instability on histology (both P [ .02), whereas PCA3 did not achieve statistical significance (P [ .07). Conclusions: DIA features of carotid plaques are associated with histologic plaque instability as assessed by multiple histologic features. Importantly, unstable plaques on histology appear more echolucent and homogeneous on ultrasound imaging. These results are independent of stenosis, suggesting that image analysis may have a role in refining the selection of patients who undergo carotid endarterectomy.
Annals of Vascular Surgery, 2020
Background: The aim of this study is to investigate the correlation of clinical and ultrasound parameters with characters of vulnerable atherosclerotic carotid plaque, as evaluated at preoperative magnetic resonance angiography (MRA), in patients submitted to carotid endarterectomy (CEA), in order to develop a clinical risk score for plaque vulnerability. Methods: Preoperative data of patients submitted to CEA for significant carotid stenosis from January 1, 2012 to December 31, 2016 were retrospectively collected. The available case series was randomly divided into 2 groups, including a training (60%) and a validation series (40%). Data of plaque vulnerability were assessed at preoperative MRA scans. Univariate analysis was used on the training series to correlate the preoperative covariates available to the features of plaque vulnerability. Therefore, a backward selection procedure was performed again on the training series and on the validation series to assess if the same variables were associated to data of plaque vulnerability, in order to obtain a prediction model for the risk of plaque vulnerability. Odds ratios (ORs) with 95% confidence intervals were reported. P values <0.05 were considered statistically significant. Results: The training case series consisted of 352 patients, while the validation case series of 248 patients. After univariate analysis and logistic regression, on the training and the validation series respectively, 6 variables were significantly associated to features of vulnerable plaque at preoperative MRA. These included male sex (OR 2.05), diabetes mellitus (OR 3.06), coronary artery disease (OR 1.95), neutrophil/lymphocyte ratio (OR 17.99), platelet counts (OR 1.03), and gray-scale median value (OR 0.84). A nomogram was then obtained from the final logistic model, in order to predict the probability of the presence of vulnerable carotid plaque, using a weighted points system. This risk score was then applied to the validation series. The validation data were found to have a C-index of 0.934.
Histological verification of computerised carotid plaque characterisation
European Journal of Vascular and Endovascular Surgery, 1996
The correlation between the computerised measurement of carotid plaque echogenicity on high resolution ultrasound imaging and plaque histology was studied in 52 patients undergoing carotid endarterectomy. Thirteen plaques were from asymptomatic patients, 15 were associated with amaurosis fugax, 10 with transient ischaemic attacks and 14 with stroke. Longitudinal images of the anterior and posterior component of each plaque were obtained by ATL Ultramark-4 Duplex scanner and zoere transferred to a computer. Using an image analysis program the median of the overall grey scale content of each plaque component was evaluated and used as a measure of echogenicity. Following carotid endarterectomy each plaque specimen was divided into anterior and posterior component and then fixed, oriented, sectioned and stained in the longitudinal plane corresponding to the ultrasound image. Plaque histology sections were then examined by computer morphometric analysis and the percentage surface areas of fibrous tissue, lipid deposits and haemorrhage were calculated. This was then correlated with the grey scale median for each plaque component. Plaques with a high lipid and haemorrhage content as established histologically had a low grey scale median (Spearman correlation r =-0.351, p < 0.05) and those with a high fibrous content had a high grey scale median (r = 0.411, p < 0.001). This study has shown that computerised measurement of carotid plaque echogenicity correlates well with histology and could be used to predict plaque composition, thus identifying high risk plaques with high lipid and haemorrhage content.
Importance of the imaging modality in decision making about carotid endarterectomy
Neurology, 2004
To determine the influence of all possible imaging strategies on the appropriateness ratings for carotid endarterectomy, because less accurate noninvasive techniques are replacing contrast angiography, which was used in the major efficacy trials. Methods: An expert panel, using appropriateness methodology, rated 203 scenarios where endarterectomy might be performed. Each scenario was rated where internal carotid artery stenosis was determined using five different imaging sources: 1) conventional angiography, 2) ultrasound carotid Doppler only, 3) CT (CTA) or MR (MRA) angiography only, 4) concordant results from two noninvasive carotid imaging studies, and 5) discordant results from two noninvasive studies. The scenarios deemed appropriate by conventional angiography were identified. The effect of the other imaging modalities on these results was examined. Results: Thirty-three scenarios were identified as being appropriate. Concordant imaging results had no effect on appropriateness ratings in symptomatic carotid artery disease when compared with conventional angiography. Single noninvasive imaging techniques were deemed appropriate for investigation only in the presence of severe symptomatic stenosis. In all other scenarios, single noninvasive imaging and discordant results reduced the appropriateness rating of scenarios to either uncertain benefit or inappropriateness. The single appropriate scenario for asymptomatic carotid artery stenosis was where severe stenosis was determined by concordant noninvasive imaging or by CTA or MRA alone. Conclusion: It is important to take into account both the clinical scenario and the imaging modalities utilized to determine the degree of internal carotid artery stenosis in the clinical decision making surrounding carotid endarterectomy. NEUROLOGY 2004;62:901-904 Additional material related to this article can be found on the Neurology Web site. Go to www.neurology.org and scroll down the Table of Contents for the March 23 issue to find the title link for this article.
European Journal of Vascular and Endovascular Surgery, 1995
Objective: To correlate B-mode ultrasound findings to carotid plaque histology. Design: European multicentre study (nine centres). Material and Methods: Clinical presentation and risk factors were recorded and preoperative ultrasound Duplex scanning with special emphasis on B-mode imaging studies was performed in 270 patients undergoing carotid endarterectomy. Perioperatively, macroscopic plaque features were evaluated and the removed specimens were analysed histologically for fibrous tissue, calcification and 'soft tissue" (primarily haemorrhage and lipid). Results: Males had more soft tissue than females (p = 0.0006), hypertensive patients less soft tissue than normotensive (p = 0.01) and patients with recent symptoms more soft tissue than patients with earlier symptoms (p = 0.004). There was no correlation between surface description on ultrasound images compared to the surface judged intraoperatively by the surgeon. Echogenicity on B-mode images was inversely related to soft tissue (p = 0.005) and calcification was directly related to echogenicity (p < 0.0001). Heterogeneous plaques contained more calcification than homogeneous (p = 0.003), however, there was no difference in content of soft tissue. Conclusion: Ultrasound B-mode characteristics are related to the histological composition of carotid artery plaques and to patient's history. These results may imply that patients with distant symptoms may be regarded and treated as asymptomatic patients whereas asymptomatic patients with echolucent plaques should be considered for carotid endarterectomy.
Carotid plaque volume in patients undergoing carotid endarterectomy
The British journal of surgery, 2018
The main indication for carotid endarterectomy (CEA) is severity of carotid artery stenosis, even though most strokes in carotid disease are embolic. The relationship between carotid plaque volume (CPV) and symptoms of cerebral ischaemia, and the measurement of CPV by minimally invasive tomographic ultrasound imaging, were investigated. The volume of the endarterectomy specimen was measured using a validated saline suspension technique in patients undergoing CEA. Time from last symptom and severity of stenosis measured by duplex ultrasonography were recorded. Middle cerebral artery emboli were counted using transcranial Doppler imaging (TCD) in a subset of patients. Some 339 patients were included, 270 with symptomatic and 69 with asymptomatic carotid stenosis. Mean(s.d.) CPV was higher in symptomatic than in asymptomatic patients (0·97(0·43) versus 0.74(0·41) cm ; P < 0·001). CPV did not correlate with severity of carotid stenosis (P = 0·770). Mean CPV was highest at 1·03(0·46) ...
Prediction of High-Risk Asymptomatic Carotid Plaques Based on Ultrasonic Image Features
IEEE Transactions on Information Technology in Biomedicine, 2012
Carotid plaques have been associated with ipsilateral neurological symptoms. High-resolution ultrasound can provide information not only on the degree of carotid artery stenosis but also on the characteristics of the arterial wall including the size and consistency of atherosclerotic plaques. The aim of this study is to determine whether the addition of ultrasonic plaque texture features to clinical features in patients with asymptomatic internal carotid artery stenosis (ACS) improves the ability to identify plaques that will produce stroke. 1121 patients with ACS have been scanned with ultrasound and followed for a mean of 4 years. It is shown that the combination of texture features based on secondorder statistics spatial gray level dependence matrices (SGLDM) and clinical factors improves stroke prediction (by correctly predicting 89 out of the 108 cases that were symptomatic). Here, the best classification results of 77 ± 1.8% were obtained from the use of the SGLDM texture features with support vector machine classifiers. The combination of morphological features with clinical features gave slightly worse classification results of 76 ± 2.6%. These findings need to be further validated in additional prospective studies. Index Terms-Assessment of stroke risk, plaque imaging, ultrasound image analysis. I. INTRODUCTION A therosclerosis of the internal carotid artery (ICA) is an important risk factor for stroke. Using the North American symptomatic carotid endarterectomy trial method [1] for the determination of stenosis the risk of stroke has been shown to range between 0.1-1.6% per year for asymptomatic individuals with ICA stenosis <75-80%. The risk rises to 2-3%
Asymptomatic carotid stenosis and risk stratification
2019
Carotid endarterectomy in patients with asymptomatic carotid stenosis (ACS) is controversial. Researchers focus on identification of the vulnerable carotid plaque to improve patients' selection for surgery. However, there is no consensus on a specific algorithm. Also, most studies analyse static plaque measurements, despite carotid plaques being dynamic structures. The aims of this thesis were to determine the association of clinical parameters and ultrasonic plaque characteristics with stroke and mortality risk; also, stroke risk in terms of time. The final endpoint was to provide new methods of stroke and mortality stratification and assess new features of plaque instability, in patients with ACS. In a natural history study of 1121 patients with ACS, a high-risk subgroup with annual stroke risk of 7.2%, based on clinical parameters, was identified. Independent stroke predictors were creatinine, severity of stenosis, history of contralateral neurological events and progression of stenosis. A model based on six computer-extracted plaque texture features, predicting cerebrovascular events in the first two years, was developed. Finally, a subgroup of patients with 100% 5-year cardiovascular mortality was identified. Independent predictors of cardiovascular mortality were male gender, age, diabetes, stenosis >80%, not taking aspirin, cardiac failure and left ventricular hypertrophy. In the final part of the thesis, quantification of discordant plaque motion and its relationship to symptoms was evaluated. In a cross-sectional study, involving 116 patients (58 symptomatic and 58 asymptomatic), discordant motion was associated with a high prevalence of symptomatic carotid plaques. A method of objective computerised measurements for identification and quantification of discordant plaque motion was developed. The optimal predictor and a cutoff point for discordant motion were found. Plaque motion analysis is a potential tool in stroke risk stratification. It should be tested, in combination with other plaque features, in prospective studies of patients with ACS. mortality. Predicting CV mortality 5.5 Discussion CHAPTER 6: Plaque motion analysis study. Association of visual classification of plaque motion with symptoms-An objective measurement of discordant motion and its relationship to symptoms Glossary
Journal of Vascular Surgery Cases, 2015
Current Level I evidence demonstrates no benefit for carotid endarterectomy in symptomatic patients with <50% carotid stenoses. However, unstable plaque morphology is increasingly recognized in the genesis of ischemic cerebral events. New advanced imaging technology, such as contrast-enhanced magnetic resonance angiography and ultrasound imaging, are emerging as important adjuncts in the evaluation of this patient population. We present a case where both modalities were beneficial in identifying plaque instability manifested by intraplaque hemorrhage and neovascularization in a patient with recurrent cerebral ischemic events and hemodynamically insignificant carotid disease. (J Vasc Surg Cases 2015;1:90-3.) Level I evidence derived from the North American Symptomatic Carotid Endarterectomy Trial 1 and the European Carotid Surgery Trial 2 established the role of carotid endarterectomy (CEA) for patients with symptomatic >50% internal carotid artery (ICA) stenoses. Conversely, these investigations demonstrated no benefit for CEA for symptomatic patients with <50% stenoses compared with medical management. We recently encountered a patient with a unilateral hemodynamically insignificant ICA stenosis who experienced recurrent cerebral ischemic events despite maximum medical therapy and without other potential causes. On the basis of magnetic resonance angiography (MRA) and contrast-enhanced duplex findings, we proceeded with CEA. This case illustrates that rarely one may encounter a patient with an unstable plaque in the absence of hemodynamic significance and who should be managed with CEA. The patient consented to publication of this report.