11 results on '"Nicolaides, Andrew"'
Search Results
2. Total plaque area and plaque echogenicity are novel measures of subclinical atherosclerosis in patients with systemic lupus erythematosus.
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Croca, Sara C, Griffin, Maura, Farinha, Filipa, Isenberg, David A, Nicolaides, Andrew, and Rahman, Anisur
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IMMUNOGLOBULIN analysis , *CAROTID artery , *BIOMARKERS , *CARDIOVASCULAR diseases risk factors , *STATISTICS , *PREDNISOLONE , *SERODIAGNOSIS , *MULTIVARIATE analysis , *AGE distribution , *HEALTH outcome assessment , *FEMORAL artery , *RISK assessment , *CARDIOVASCULAR system , *CORONARY artery disease , *APOLIPOPROTEINS , *DESCRIPTIVE statistics , *DISEASE duration , *SYSTEMIC lupus erythematosus , *HIGH density lipoproteins , *DISEASE risk factors - Abstract
Objectives Patients with SLE have an increased risk of developing cardiovascular disease (CVD). Multiple studies have shown that these patients have increased numbers of carotid plaques and greater intima-media thickness (IMT) than healthy controls. Measures such as total plaque area (TPA) and plaque echogenicity may be more sensitive and more relevant to cardiovascular risk than presence of plaque and IMT alone. Our objective was to produce the first report of TPA and echogenicity in a population of patients with SLE. Methods One hundred patients with SLE and no history of clinical CVD were recruited. Clinical, serological and treatment variables were recorded and serum was tested for antibodies to apolipoprotein A-1 and high-density lipoprotein. Both carotid and both femoral artery bifurcations of each patient were scanned to determine IMT, TPA and echogenicity of plaques. Univariable and multivariable statistical analyses were carried out to define factors associated with each of these outcomes. Results Thirty-six patients had carotid and/or femoral plaque. Increasing age was associated with presence of plaque and increased IMT. Triglyceride levels were associated with presence of plaque. Mean (s. d.) TPA was 60.8 (41.6) mm2. Patients taking prednisolone had higher TPA. Most plaques were echolucent, but increased echogenicity was associated with prednisolone therapy and persistent disease activity. Conclusion TPA and plaque echogenicity in patients with SLE are associated with different factors than those associated with presence of plaque and IMT. Longitudinal studies may show whether these outcome measures add value in the management of cardiovascular risk in SLE. [ABSTRACT FROM AUTHOR]
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- 2021
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3. Low-Cost Office-Based Cardiovascular Risk Stratification Using Machine Learning and Focused Carotid Ultrasound in an Asian-Indian Cohort.
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Jamthikar, Ankush D., Gupta, Deep, Johri, Amer M., Mantella, Laura E., Saba, Luca, Kolluri, Raghu, Sharma, Aditya M., Viswanathan, Vijay, Nicolaides, Andrew, and Suri, Jasjit S.
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This study developed an office-based cardiovascular risk calculator using a machine learning (ML) algorithm that utilized a focused carotid ultrasound. The design of this study was divided into three steps. The first step involved collecting 18 office-based biomarkers consisting of six clinical risk factors (age, sex, body mass index, systolic blood pressure, diastolic blood pressure, and smoking) and 12 carotid ultrasound image-based phenotypes. The second step consisted of the design of an ML-based cardiovascular risk calculator-called “AtheroEdge Composite Risk Score 2.0” (AECRS2.0ML) for risk stratification, considering chronic kidney disease (CKD) as the surrogate endpoint of cardiovascular disease. The last step consisted of comparing AECRS2.0ML against the currently utilized office-based CVD calculators, namely the Framingham risk score (FRS) and the World Health Organization (WHO) risk scores. A cohort of 379 Asian-Indian patients with type-2 diabetes mellitus, hypertension, and chronic kidney disease (stage 1 to 5) were recruited for this cross-sectional study. From this retrospective cohort, 758 ultrasound scan images were acquired from the far walls of the left and right common carotid arteries [mean age = 55 ± 10.8 years, 67.28% males, 91.82% diabetic, 86.54% hypertensive, and 83.11% with CKD]. The mean office-based cardiovascular risk estimates using FRS and WHO calculators were 26% and 19%, respectively. AECRS2.0ML demonstrated a better risk stratification ability having a higher area-under-the-curve against FRS and WHO by ~30% (0.871 vs. 0.669) and ~ 20% (0.871 vs. 0.727), respectively. The office-based machine-learning cardiovascular risk-stratification tool (AECRS2.0ML) shows superior performance compared to currently available conventional cardiovascular risk calculators. [ABSTRACT FROM AUTHOR]
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- 2020
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4. Does the Carotid Bulb Offer a Better 10-Year CVD/Stroke Risk Assessment Compared to the Common Carotid Artery? A 1516 Ultrasound Scan Study.
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Viswanathan, Vijay, Jamthikar, Ankush D., Gupta, Deep, Puvvula, Anudeep, Khanna, Narendra N., Saba, Luca, Viskovic, Klaudija, Mavrogeni, Sophie, Laird, John R., Pareek, Gyan, Miner, Martin, Sfikakis, Petros P., Protogerou, Athanasios, Sharma, Aditya, Kancharana, Priyanka, Misra, Durga Prasanna, Agarwal, Vikas, Kitas, George D., Nicolaides, Andrew, and Suri, Jasjit S.
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ATHEROSCLEROSIS complications , *CARDIOVASCULAR diseases risk factors , *CAROTID artery , *CAROTID artery diseases , *CHRONIC kidney failure , *HYPERTENSION , *MEDICAL records , *TYPE 2 diabetes , *RISK assessment , *STROKE , *PHENOTYPES , *RETROSPECTIVE studies , *DESCRIPTIVE statistics , *ACQUISITION of data methodology , *DISEASE complications - Abstract
The objectives of this study are to (1) examine the "10-year cardiovascular risk" in the common carotid artery (CCA) versus carotid bulb using an integrated calculator called "AtheroEdge Composite Risk Score 2.0" (AECRS2.0) and (2) evaluate the performance of AECRS2.0 against "conventional cardiovascular risk calculators." These objectives are met by measuring (1) image-based phenotypes and AECRS2.0 score computation and (2) performance evaluation of AECRS2.0 against 12 conventional cardiovascular risk calculators. The Asian–Indian cohort (n = 379) with type 2 diabetes mellitus (T2DM), chronic kidney disease (CKD), or hypertension were retrospectively analyzed by acquiring the 1516 carotid ultrasound scans (mean age: 55 ± 10.1 years, 67% males, ∼92% with T2DM, ∼83% with CKD [stage 1-5], and 87.5% with hypertension [stage 1-2]). The carotid bulb showed a higher 10-year cardiovascular risk compared to the CCA by 18% (P <.0001). Patients with T2DM and/or CKD also followed a similar trend. The carotid bulb demonstrated a superior risk assessment compared to CCA in patients with T2DM and/or CKD by showing: (1) ∼13% better than CCA (0.93 vs 0.82, P =.0001) and (2) ∼29% better compared with 12 types of risk conventional calculators (0.93 vs 0.72, P =.06). [ABSTRACT FROM AUTHOR]
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- 2020
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5. Morphological Carotid Plaque Area Is Associated With Glomerular Filtration Rate: A Study of South Asian Indian Patients With Diabetes and Chronic Kidney Disease.
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Puvvula, Anudeep, Jamthikar, Ankush D., Gupta, Deep, Khanna, Narendra N., Porcu, Michele, Saba, Luca, Viskovic, Klaudija, Ajuluchukwu, Janet N. A., Gupta, Ajay, Mavrogeni, Sophie, Turk, Monika, Laird, John R., Pareek, Gyan, Miner, Martin, Sfikakis, Petros P., Protogerou, Athanasios, Kitas, George D., Nicolaides, Andrew, Viswanathan, Vijay, and Suri, Jasjit S.
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KIDNEY disease diagnosis , *ATHEROSCLEROSIS , *BIOMARKERS , *CARDIOVASCULAR diseases , *CAROTID artery diseases , *GLOMERULAR filtration rate , *RISK assessment , *RETROSPECTIVE studies , *DESCRIPTIVE statistics - Abstract
We evaluated the association between automatically measured carotid total plaque area (TPA) and the estimated glomerular filtration rate (eGFR), a biomarker of chronic kidney disease (CKD). Automated average carotid intima–media thickness (cIMTave) and TPA measurements in carotid ultrasound (CUS) were performed using AtheroEdge (AtheroPoint). Pearson correlation coefficient (CC) was then computed between the TPA and eGFR for (1) males versus females, (2) diabetic versus nondiabetic patients, and (3) between the left and right carotid artery. Overall, 339 South Asian Indian patients with either type 2 diabetes mellitus (T2DM) or CKD, or hypertension (stage 1 or stage 2) were retrospectively analyzed by acquiring cIMTave and TPA measurements of their left and right common carotid arteries (CCA; total CUS: 678, mean age: 54.2 ± 9.8 years; 75.2% males; 93.5% with T2DM). The CC between TPA and eGFR for different scenarios were (1) for males and females −0.25 (P <.001) and −0.35 (P <.001), respectively; (2) for T2DM and non-T2DM −0.26 (P <.001) and −0.49 (P =.02), respectively, and (3) for left and right CCA −0.25 (P <.001) and −0.23 (P <.001), respectively. Automated TPA is an equally reliable biomarker compared with cIMTave for patients with CKD (with or without T2DM) with subclinical atherosclerosis. [ABSTRACT FROM AUTHOR]
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- 2020
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6. Deep learning fully convolution network for lumen characterization in diabetic patients using carotid ultrasound: a tool for stroke risk.
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Biswas, Mainak, Kuppili, Venkatanareshbabu, Saba, Luca, Edla, Damodar Reddy, Suri, Harman S., Sharma, Aditya, Cuadrado-Godia, Elisa, Laird, John R., Nicolaides, Andrew, and Suri, Jasjit S.
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DEEP learning , *STROKE , *ULTRASONIC imaging , *ARTIFICIAL neural networks , *FEATURE extraction , *PEOPLE with diabetes , *CAROTID artery ultrasonography , *CAROTID artery , *DIABETES , *RETROSPECTIVE studies , *RISK assessment - Abstract
Manual ultrasound (US)-based methods are adapted for lumen diameter (LD) measurement to estimate the risk of stroke but they are tedious, error prone, and subjective causing variability. We propose an automated deep learning (DL)-based system for lumen detection. The system consists of a combination of two DL systems: encoder and decoder for lumen segmentation. The encoder employs a 13-layer convolution neural network model (CNN) for rich feature extraction. The decoder employs three up-sample layers of fully convolution network (FCN) for lumen segmentation. Three sets of manual tracings were used during the training paradigm leading to the design of three DL systems. Cross-validation protocol was implemented for all three DL systems. Using the polyline distance metric, the precision of merit for three DL systems over 407 US scans was 99.61%, 97.75%, and 99.89%, respectively. The Jaccard index and Dice similarity of DL lumen segmented region against three ground truth (GT) regions were 0.94, 0.94, and 0.93 and 0.97, 0.97, and 0.97, respectively. The corresponding AUC for three DL systems was 0.95, 0.91, and 0.93. The experimental results demonstrated superior performance of proposed deep learning system over conventional methods in literature. Graphical abstract ᅟ. [ABSTRACT FROM AUTHOR]
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- 2019
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7. Nonlinear model for the carotid artery disease 10‐year risk prediction by fusing conventional cardiovascular factors to carotid ultrasound image phenotypes: A Japanese diabetes cohort study.
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Khanna, Narendra N., Jamthikar, Ankush D., Araki, Tadashi, Gupta, Deep, Piga, Matteo, Saba, Luca, Carcassi, Carlo, Nicolaides, Andrew, Laird, John R., Suri, Harman S., Gupta, Ajay, Mavrogeni, Sophie, Kitas, George D., and Suri, Jasjit S.
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CAROTID artery ultrasonography , *CARDIOVASCULAR diseases risk factors , *STATISTICS , *GLYCOSYLATED hemoglobin , *HYPERTENSION , *CAROTID artery diseases , *CAROTID intima-media thickness , *HEMOGLOBINS , *AGE distribution , *DIABETES , *LOW density lipoproteins , *RISK assessment , *SEX distribution , *INTER-observer reliability , *AUTOMATION , *DATA analysis , *BODY mass index , *SMOKING , *STATISTICAL correlation , *PHENOTYPES , *LONGITUDINAL method , *DISEASE risk factors - Abstract
Motivation: This study presents a novel nonlinear model which can predict 10‐year carotid ultrasound image‐based phenotypes by fusing nine traditional cardiovascular risk factors (ethnicity, gender, age, artery type, body mass index, hemoglobin A1c, hypertension, low‐density lipoprotein, and smoking) with five types of carotid automated image phenotypes (three types of carotid intima‐media thickness (IMT), wall variability, and total plaque area). Methodology: Two‐step process was adapted: First, five baseline carotid image‐based phenotypes were automatically measured using AtheroEdge™ (AtheroPoint™, CA, USA) system by two operators (novice and experienced) and an expert. Second, based on the annual progression rates of cIMT due to nine traditional cardiovascular risk factors, a novel nonlinear model was adapted for 10‐year predictions of carotid phenotypes. Results: Institute review board (IRB) approved 204 Japanese patients' left/right common carotid artery (407 ultrasound scans) was collected with a mean age of 69 ± 11 years. Age and hemoglobin were reported to have a high influence on the 10‐year carotid phenotypes. Mean correlation coefficient (CC) between 10‐year carotid image‐based phenotype and age was improved by 39.35% in males and 25.38% in females. The area under the curves for the 10‐year measurements of five phenotypes IMTave10yr, IMTmax10yr, IMTmin10yr, IMTV10yr, and TPA10yr were 0.96, 0.94, 0.90, 1.0, and 1.0. Inter‐operator variability between two operators showed significant CC (P < 0.0001). Conclusions: A nonlinear model was developed and validated by fusing nine conventional CV risk factors with current carotid image‐based phenotypes for predicting the 10‐year carotid ultrasound image‐based phenotypes which may be used risk assessment. [ABSTRACT FROM AUTHOR]
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- 2019
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8. Plaque Tissue Morphology-Based Stroke Risk Stratification Using Carotid Ultrasound: A Polling-Based PCA Learning Paradigm.
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Saba, Luca, Jain, Pankaj, Suri, Harman, Ikeda, Nobutaka, Araki, Tadashi, Singh, Bikesh, Nicolaides, Andrew, Shafique, Shoaib, Gupta, Ajay, Laird, John, and Suri, Jasjit
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ATHEROSCLEROSIS , *ARTIFICIAL intelligence , *BIOMARKERS , *CAROTID artery , *FACTOR analysis , *RESEARCH methodology , *RISK assessment , *DIAGNOSIS ,STROKE risk factors - Abstract
Severe atherosclerosis disease in carotid arteries causes stenosis which in turn leads to stroke. Machine learning systems have been previously developed for plaque wall risk assessment using morphology-based characterization. The fundamental assumption in such systems is the extraction of the grayscale features of the plaque region. Even though these systems have the ability to perform risk stratification, they lack the ability to achieve higher performance due their inability to select and retain dominant features. This paper introduces a polling-based principal component analysis (PCA) strategy embedded in the machine learning framework to select and retain dominant features, resulting in superior performance. This leads to more stability and reliability. The automated system uses offline image data along with the ground truth labels to generate the parameters, which are then used to transform the online grayscale features to predict the risk of stroke. A set of sixteen grayscale plaque features is computed. Utilizing the cross-validation protocol (K = 10), and the PCA cutoff of 0.995, the machine learning system is able to achieve an accuracy of 98.55 and 98.83%corresponding to the carotidfar wall and near wall plaques, respectively. The corresponding reliability of the system was 94.56 and 95.63%, respectively. The automated system was validated against the manual risk assessment system and the precision of merit for same cross-validation settings and PCA cutoffs are 98.28 and 93.92%for the far and the near wall, respectively.PCA-embedded morphology-based plaque characterization shows a powerful strategy for risk assessment and can be adapted in clinical settings. [ABSTRACT FROM AUTHOR]
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- 2017
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9. PCA-based polling strategy in machine learning framework for coronary artery disease risk assessment in intravascular ultrasound: A link between carotid and coronary grayscale plaque morphology.
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Araki, Tadashi, Ikeda, Nobutaka, Shukla, Devarshi, Jain, Pankaj K., Londhe, Narendra D., Shrivastava, Vimal K., Banchhor, Sumit K., Saba, Luca, Nicolaides, Andrew, Shafique, Shoaib, Laird, John R., and Suri, Jasjit S.
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CORONARY arteries , *DISEASE risk factors , *CORONARY disease , *PERCUTANEOUS coronary intervention , *INTRAVASCULAR ultrasonography , *ENDARTERECTOMY , *MACHINE learning - Abstract
Background and objective Percutaneous coronary interventional procedures need advance planning prior to stenting or an endarterectomy. Cardiologists use intravascular ultrasound (IVUS) for screening, risk assessment and stratification of coronary artery disease (CAD). We hypothesize that plaque components are vulnerable to rupture due to plaque progression. Currently, there are no standard grayscale IVUS tools for risk assessment of plaque rupture. This paper presents a novel strategy for risk stratification based on plaque morphology embedded with principal component analysis (PCA) for plaque feature dimensionality reduction and dominant feature selection technique. The risk assessment utilizes 56 grayscale coronary features in a machine learning framework while linking information from carotid and coronary plaque burdens due to their common genetic makeup. Method This system consists of a machine learning paradigm which uses a support vector machine (SVM) combined with PCA for optimal and dominant coronary artery morphological feature extraction. Carotid artery proven intima-media thickness (cIMT) biomarker is adapted as a gold standard during the training phase of the machine learning system. For the performance evaluation, K -fold cross validation protocol is adapted with 20 trials per fold. For choosing the dominant features out of the 56 grayscale features, a polling strategy of PCA is adapted where the original value of the features is unaltered. Different protocols are designed for establishing the stability and reliability criteria of the coronary risk assessment system (cRAS). Results Using the PCA-based machine learning paradigm and cross-validation protocol, a classification accuracy of 98.43% (AUC 0.98) with K = 10 folds using an SVM radial basis function (RBF) kernel was achieved. A reliability index of 97.32% and machine learning stability criteria of 5% were met for the cRAS. Conclusions This is the first Computer aided design (CADx) system of its kind that is able to demonstrate the ability of coronary risk assessment and stratification while demonstrating a successful design of the machine learning system based on our assumptions. [ABSTRACT FROM AUTHOR]
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- 2016
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10. A new method for IVUS-based coronary artery disease risk stratification: A link between coronary & carotid ultrasound plaque burdens.
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Araki, Tadashi, Ikeda, Nobutaka, Shukla, Devarshi, Londhe, Narendra D., Shrivastava, Vimal K., Banchhor, Sumit K., Saba, Luca, Nicolaides, Andrew, Shafique, Shoaib, Laird, John R., and Suri, Jasjit S.
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INTRAVASCULAR ultrasonography , *CORONARY heart disease risk factors , *CARDIOLOGISTS , *ATHEROSCLEROSIS , *SUPPORT vector machines , *CAROTID intima-media thickness - Abstract
Interventional cardiologists have a deep interest in risk stratification prior to stenting and percutaneous coronary intervention (PCI) procedures. Intravascular ultrasound (IVUS) is most commonly adapted for screening, but current tools lack the ability for risk stratification based on grayscale plaque morphology. Our hypothesis is based on the genetic makeup of the atherosclerosis disease, that there is evidence of a link between coronary atherosclerosis disease and carotid plaque built up. This novel idea is explored in this study for coronary risk assessment and its classification of patients between high risk and low risk. This paper presents a strategy for coronary risk assessment by combining the IVUS grayscale plaque morphology and carotid B-mode ultrasound carotid intima-media thickness (cIMT) – a marker of subclinical atherosclerosis. Support vector machine (SVM) learning paradigm is adapted for risk stratification, where both the learning and testing phases use tissue characteristics derived from six feature combinational spaces, which are then used by the SVM classifier with five different kernels sets. These six feature combinational spaces are designed using 56 novel feature sets. K -fold cross validation protocol with 10 trials per fold is used for optimization of best SVM-kernel and best feature combination set. IRB approved coronary IVUS and carotid B-mode ultrasound were jointly collected on 15 patients (2 days apart) via : (a) 40 MHz catheter utilizing iMap (Boston Scientific, Marlborough, MA, USA) with 2865 frames per patient (42,975 frames) and (b) linear probe B-mode carotid ultrasound (Toshiba scanner, Japan). Using the above protocol, the system shows the classification accuracy of 94.95% and AUC of 0.95 using optimized feature combination. This is the first system of its kind for risk stratification as a screening tool to prevent excessive cost burden and better patients’ cardiovascular disease management, while validating our two hypotheses. [ABSTRACT FROM AUTHOR]
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- 2016
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11. 2083060 A New Technique For Compartmental-IMT Estimation in Presence of Bulb in Carotid Ultrasound Scans: a Stroke Risk Assessment System.
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Suri, Jasjit, Ikeda, Nobutaka, Gupta, Ajay, Bose, Soumyo, Acharjee, Suvojit, Saba, Luca, Cuadrado-Godia, Elisa, Dey, Nilanjan, Laird, John, and Nicolaides, Andrew
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ULTRASONIC imaging , *RISK assessment , *IMAGE quality analysis , *BLOOD flow , *MEDICAL databases ,STROKE risk factors - Published
- 2015
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