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Objective: Dynamic image analysis of carotid plaques has demonstrated that during systole and early diastole, all plaque components will move in the same direction (concordant motion) in some plaques. However, in others, different parts of the plaque will move in different directions (discordant motion). The aim of our study was (1) to determine the prevalence of discordant motion in symptomatic and asymptomatic plaques, (2) to develop a measurement of the severity of discordant motion, and (3) to determine the correlation between the severity of discordant motion and symptom prevalence. Methods: A total of 200 patients with 204 plaques resulting in 50% to 99% stenosis (112 asymptomatic and 92 symptomatic plaques) had video recordings available of the plaque motion during 10 cardiac cycles. Video tracking was performed using Farneback's method, which relies on frame comparisons. In our study, these were performed at 0.1-second intervals. The maximum angular spread (MAS) of the motion vectors at 10-pixel intervals in the plaque area was measured in degrees. Plaques were classified as concordant (MAS, 120°). Results: Motion was discordant in 89.1% of the symptomatic plaques but only in 17.9% of asymptomatic plaques (P < .001). The prevalence of symptoms increased with increasing MAS. For a MAS >120°, the hazard ratio for the presence of symptoms was 47.7 (95% confidence interval, 18.1-125.6) compared with the rest of the plaques after adjustment for the degree of stenosis and mean pixel motion. The area under the receiver operating characteristic curve for the prediction of the presence of symptoms using the MAS was 0.876 (95% confidence interval, 0.823-0.929). The use of the median MAS (120°) as a cutoff point classified 86% of the plaques correctly (sensitivity, 81.4%; specificity, 91.2%; positive predictive value, 90.2%; and negative predictive value, 83.0%). Conclusions: The use of the MAS value to identify asymptomatic plaques at increased risk of developing symptoms and, in particular, stroke should be tested in prospective studies. © 2020 Society for Vascular Surgery

Sponsors: et al. Frederick University IEEE Cyprus Section IEEE Region 8 Technical University of Cyprus University of Cyprus Conference code: 122340

This study proposes a unifying framework for m-Health video communication systems that provides for the joint optimization of video quality, bitrate demands, and encoding time. The framework is video modality and infrastructure independent and facilitates adaptation to the best available encoding mode that satisfies underlying technology and application imposed constraints. The scalability of the proposed algorithm is demonstrated using different HEVC encoding configurations and realistic modelling of 802.11× wireless infrastructure for emergency scenery and response videos. Extensive experimentation shows that a jointly optimal solution in the encoding time, bitrate, and video quality space is feasible.

Non-invasive ultrasound imaging of carotid plaques can provide information on the characteristics of the arterial wall including the size, morphology and texture of the atherosclerotic plaques. Several studies were carried out that demonstrated the usefulness of these feature sets for differentiating between asymptomatic and symptomatic plaques and their corresponding cerebrovascular risk stratification. The aim of this study was to develop predictive modelling for estimating the time period of a stroke event by determining the risk for short term (less or equal to three years) or long term (more than three years) events. Data from 108 patients that had a stroke event have been used. The information collected included clinical and ultrasound imaging data. The prediction was performed at base line where patients were still asymptomatic. Several image texture analysis and clinical features were used in order to create a classification model. The different features were statistically analyzed and we conclude that image texture analysis features extracted using Spatial Gray Level Dependencies method had the best statistical significance. Several predictive models were derived based on Binary Logistic Regression (BLR) and Support Vector Machines (SVM) modelling. The best results were obtained with the SVM modelling models with an average correct classifications score of 77±7% for differentiating between stroke event occurrences within 3 years versus more than 3 years. Further work is needed in investigating additional multiscale texture analysis features as well as more modelling techniques on more subjects.

OBJECTIVE: To test the hypothesis that the size of a juxtaluminal black (hypoechoic) area (JBA) in ultrasound images of asymptomatic carotid artery plaques predicts future ipsilateral ischemic stroke. METHODS: A JBA was defined as an area of pixels with a grayscale value 10 mm(2) (P < .001). In a Cox model with ipsilateral ischemic events (amaurosis fugax, transient ischemic attack [TIA], or stroke) as the dependent variable, the JBA (8 mm(2)) was still significant after adjusting for other plaque features known to be associated with increased risk, including stenosis, grayscale median, presence of discrete white areas without acoustic shadowing indicating neovascularization, plaque area, and history of contralateral TIA or stroke. Plaque area and grayscale median were not significant. Using the significant variables (stenosis, discrete white areas without acoustic shadowing, JBA, and history of contralateral TIA or stroke), this model predicted the annual risk of stroke for each patient (range, 0.1%-10.0%). The average annual stroke risk was

Advances in communication technologies, information technology and medical technologies facilitate the development of effective systems that can be used in support of emergency healthcare (eEmergency). The objectives of the chapter are to provide an overview of the way that information and communication technologies have been used in order to develop systems for emergency healthcare support, present case studies that have been published in the literature, and describe future trends. We anticipate that eEmergency systems can significantly improve the delivery of healthcare during emergency cases. However, their use in daily practice as well as the monitoring and evaluation of these systems still remains a goal to be achieved.

AIM: The results of the Asymptomatic Carotid Atherosclerosis Study (ACAS) study have provided the first scientific evidence that in patients with asymptomatic carotid stenosis greater than 60% carotid endarterectomy reduces the risk of stroke from 2% to 1% per year. The implications are that approximately 20 operations need to be performed in order to prevent 1 stroke in 5 years. The aims of the Asymptomatic Carotid Stenosis and Risk of Stroke (ACSRS) study are to identify a subgroup or subgroups at a risk for stroke higher than 4% and a group at a risk for stroke less than 1% per year using systemic and local risk factors (plaque characterization) in addition to the degree of stenosis. The aim of this paper is to present the protocol and the results of the quality control. METHODS: The ACSRS is a multicentre natural history study of patients with asymptomatic internal carotid diameter stenosis greater than 50% in relation to the bulb. The degree of stenosis is graded using multiple established ultrasonic duplex criteria. In addition, ultrasonic plaque characterization is performed and clinical risk factors and medications are recorded. Training is provided centrally. All carotid ultrasound examinations are recorded on video-tape which together with CT-brain scans and ECG are analysed at the coordinating centre with feedback information to partner centres. RESULTS: The video recordings and analysis of data centrally with feed back information have provided quality control with a significant improvement not only in the completion of data forms but also in the grading of internal carotid stenosis and plaque recordings using ultrasound. CONCLUSION: The high level of quality of data collected will add credibility to the results of the ACSRS study and may eventually promote the development of international standards of plaque imaging and characterization

Objectives Our objective was to estimate the correlation of echodensity and textural features, using ultrasound and digital image analysis, between plaques in patients with bilateral carotid stenosis. Design Cross-sectional observational study. Methods Patients undergoing carotid endarterectomy were recruited from Vascular Surgery at the Royal Victoria and Jewish General hospitals in Montreal, Canada. Bilateral pre-operative carotid ultrasound and digital image analysis was performed to extract echodensity and textural features using a commercially available Plaque Texture Analysis software (LifeQMedical Ltd). Principal component analysis (PCA) was performed. Partial correlation coefficients for PCA and individual imaging variables between surgical and contralateral plaques were calculated with adjustment for age, sex, contralateral stenosis, and statin use. Results In the whole group (n = 104), the six identified PCA variables and 42/50 individual imaging variables were moderately correlated (r =.211-.641). Correlations between sides were increased in patients with ≥50% contralateral stenosis and symptomatic patients. Conclusion Textural and echodensity features of carotid plaques were similar between two sides in patients with bilateral stenosis, supporting the notion that plaque instability is determined by systemic factors. Patients with unstable features of one plaque should perhaps be monitored more closely or treated more aggressively for their contralateral stenosis, particularly if this is hemodynamically significant. © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Lifelong User Modelling (LUM) is a long-term vision which is a critical element in achieving lifelong personalized learning. One of the key factors for enabling LUM is making the user models scrutable, a feature used for allowing users to inspect and alter the modelling process. A Scrutable User Modelling Infrastructure (SUMI) is proposed in this paper, which attempts to include in the LUM picture two unexplored pieces of the puzzle: the social e-networking and the e-commerce domains. SUMI gathers the various user models constructed from several (life-long) user interactions with a diversity of providers from the social e-networking and e-commerce domains, passes the control to the owners of the user models by providing scrutability and privacy privileges, and enables exchanging of user information via SUMI, among services from these two domains and educational personalization systems.

A Scrutable User Modelling Infrastructure (SUMI) is proposed in this paper, which focuses on three key Lifelong User Modelling (LUM) requirements: interoperability, scrutability and privacy. SUMI attempts to enrich the LUM vision by examining two unexplored "pieces of the puzzle": the social e-networking and e-commerce domains. SUMI allows users to gather their various (lifelong) models which they hold with several providers from the social e-networking and e-commerce domains, passes the control to the owners of the user models by providing scrutability and user-controlled privacy privileges, and enables exporting of these user models, or parts of them, towards educational personalization systems, after direct consent of the users-owners. Up-to-date results highlight users’ approval of six proposed scrutability and user-controlled privacy privileges which were presented during SUMI’s first evaluation, while data portability initiatives from providers of the two examined domains, combined with Semantic Web technologies, constitute the backbone of the proposed solution.

User Modeling is the core component for the majority of personalization services. It has become an important factor in the effort to personalise a diversity of web resources according to users’ characteristics and needs. While trying to move a step further and model dynamic users in a range of contexts, life-long User Modeling, the ability to model a dynamic and changing user throughout lifetime interactions with a variety of resource providers, appears to be an attractive solution. A Scrutable User Modeling Infrastructure is proposed in this paper, where a first prototype has already been designed and implemented, which blends together some key User Modeling ‘ingredients’- interoperability, scrutability, user privacy - and attempts to model the various life-long user interactions with a diversity of web-based systems from the educational, business and social networking domains.

User Modelling is the core component for the majority of personalisation systems. By keeping a model for every user, a system can successfully personalise its content and utilise available resources accordingly. While researching the literature, one can recognize the importance of achieving interoperability across various platforms and systems while attempting to personalise a large diversity of web resources. Furthermore, scrutable solutions allow users to control any modelling process that uses their information. Finally, privacy of user data while exchanging user models from one source to another must be taken in mind. With this paper, a Scrutable User Modelling Infrastructure is presented which blends together these user modelling ‘ingredients’ and, by adopting Semantic Web technologies, attempts to model a range of life-long user interactions with a variety of web-based systems from the educational, business and social networking domains.

The results of the Asymptomatic Carotid Atherosclerosis Study (ACAS) study have provided the first scientific evidence that in patients with asymptomatic carotid stenosis greater than 60% carotid endarterectomy reduces the risk of stroke from 2% to 1% per year. The implications are that approximately 20 operations need to be performed in order to prevent 1 stroke in 5 years. The aims of the Asymptomatic Carotid Stenosis and Risk of Stroke (ACSRS) study are to identify a subgroup or subgroups at a risk for stroke higher than 4% and a group at a risk for stroke less than 1% per year using systemic and local risk factors (plaque characterization) in addition to the degree of stenosis. The aim of this paper is to present the protocol and the results of the quality control.The ACSRS is a multicentre natural history study of patients with asymptomatic internal carotid diameter stenosis greater than 50% in relation to the bulb. The degree of stenosis is graded using multiple established ultrasonic duplex criteria. In addition, ultrasonic plaque characterization is performed and clinical risk factors and medications are recorded. Training is provided centrally. All carotid ultrasound examinations are recorded on video-tape which together with CT-brain scans and ECG are analysed at the coordinating centre with feedback information to partner centres.The video recordings and analysis of data centrally with feed back information have provided quality control with a significant improvement not only in the completion of data forms but also in the grading of internal carotid stenosis and plaque recordings using ultrasound.The high level of quality of data collected will add credibility to the results of the ACSRS study and may eventually promote the development of international standards of plaque imaging and characterization.

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