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We postulated that the rate of blood propagating into the left atrium from the left upper pulmonic vein would be a useful measure of pulmonary capillary wedge pressure (PCWP). In 23 adult patients who were critically ill (ie, study group)... more
We postulated that the rate of blood propagating into the left atrium from the left upper pulmonic vein would be a useful measure of pulmonary capillary wedge pressure (PCWP). In 23 adult patients who were critically ill (ie, study group) and receiving mechanical ventilation, color M-mode multiplane transesophageal echocardiography was used to measure left atrial inflow propagation rate (LAIF-PR) as a potential index of PCWP measured by right heart catheterization. LAIF-PR was measured in systole and diastole as the slope of the color M-mode signal entering the left atrium from the left upper pulmonic vein. Correlation with PCWP was good for systolic (r = -0.847, P < .0001) and diastolic (r = -0.78, P < .0001) LAIF-PR. The reliability of univariate linear regression equations derived from the study group was tested in 29 subsequent patients (ie, testing group). Measured PCWP was accurately estimated within 5 mm Hg in 85% (22 of 26 patients) and 68% (17 of 25 patients) of the testing group by systolic and diastolic LAIF-PR, respectively. Color M-mode transesophageal echocardiography-derived LAIF-PR, particularly in systole, is a promising new index to estimate PCWP in patients who are critically ill.
Research Interests: Cardiology, Adolescent, Medicine, Humans, Internal Medicine, and 15 moreHemodynamics, Female, Male, Aged, Middle Aged, Observer Variation, Adult, Reproducibility of Results, Chi Square Distribution, Indexation, Linear Regression, Preload, Diastole, Cardiovascular medicine and haematology, and Heart atria
Arterial stenosis is a significant cardiovascular disease requiring accurate estimation of the pressure gradients for determining hemodynamic significance. In this paper, we propose Generalized Bernoulli Equation (GBE) utilizing... more
Arterial stenosis is a significant cardiovascular disease requiring accurate estimation of the pressure gradients for determining hemodynamic significance. In this paper, we propose Generalized Bernoulli Equation (GBE) utilizing interpolated-based method to estimate relative pressures using streamlines and pathlines from 4D Flow MRI. 4D Flow MRI data in a stenotic phantom model and computational fluid dynamics simulated velocities generated under identical flow conditions were processed by Generalized Bernoulli Equation (GBE), Reduced Bernoulli Equations (RBE), as well as the Simple Bernoulli Equation (SBE) which is clinically prevalent. Pressures derived from 4D flow MRI and noise corrupted CFD velocities were compared with pressures generated directly with CFD as well as pressures obtained using Millar catheters under identical flow conditions. It was found that SBE and RBE methods underestimated the relative pressure for lower flow rates while overestimating the relative pressure at higher flow rates. Specifically, compared to the reference pressure, SBE underestimated the maximum relative pressure by 22%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\%$$\end{document} for a pulsatile flow data with peak flow rate Qmax=80mls\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Q_{\max }=80\,\frac{\mathrm{ml}}{\mathrm{s}}$$\end{document} and overestimated by around 40%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\%$$\end{document} when Qmax=130mls\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Q_{\max }=130\,\frac{\mathrm{ml}}{\mathrm{s}}$$\end{document}. In contrast, for GBE method the relative pressure values were overestimated by 15%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\%$$\end{document} with Qmax=80mls\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Q_{\max }=80\,\frac{\mathrm{ml}}{\mathrm{s}}$$\end{document}and around 10%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\%$$\end{document} with Qmax=130mls\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Q_{\max }= 130\,\frac{\mathrm{ml}}{\mathrm{s}}$$\end{document}. GBE methods showed robust performance to additive image noise compared to other methods. Our findings indicate that GBE pressure estimation over pathlines attains the highest level of accuracy compared to GBE over streamlines, and the SBE and RBE methods.
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In this paper, we propose a framework for accelerated reconstruction of 2D phase contrast magnetic resonance images from undersampled k-space domain by using deep learning methods. Undersampling in k-space violates Nyquist Sampling and... more
In this paper, we propose a framework for accelerated reconstruction of 2D phase contrast magnetic resonance images from undersampled k-space domain by using deep learning methods. Undersampling in k-space violates Nyquist Sampling and creates artifacts in the image domain. In the proposed method, we consider the reconstruction problem as a de-aliasing problem in complex spatial domain. To test the proposed method, from fully sampled k-space data undersampling in k-space was performed in the phase-encode direction based on a probability density function which ensures maximum rate of sampling in low frequency regions. For the deep convolutional neural network (CNN) we chose the U-net architecture. The proposed CNN was trained and tested on 4D flow MRI data in 14 subjects with aortic stenosis. The reconstructed complex two channel image showed that the U-net is able to unaliase the undersampled flow images with resulting magnitude and phase difference images showing good agreement with the fully sampled magnitude and phase images. We show that the proposed method outperforms 2D compressed sensing approach of spatial total variation regularization method. Flow waveforms derived from reconstructed images closely follow flow waveforms derived from the original data. Moreover, the method is computationally fast. Each 2D magnitude and phase image is reconstructed within a second using a single GPU.
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Inaccuracy of conventional four-dimensional (4D) flow MR imaging in the presence of random unsteady and turbulent blood flow distal to a narrowing has been an important challenge. Previous investigations have revealed that shorter echo... more
Inaccuracy of conventional four-dimensional (4D) flow MR imaging in the presence of random unsteady and turbulent blood flow distal to a narrowing has been an important challenge. Previous investigations have revealed that shorter echo times (TE) decrease the errors, leading to more accurate flow assessments. In this study, as part of a 4D flow acquisition, an Ultra-Short TE (UTE) method was adopted. UTE works based on a center-out radial k-space trajectory that inherently has a short TE. By employing free induction decay sampling starting from read-out gradient ramp-up, and by combining the refocusing lobe of the slice select gradient with the bipolar flow encoding gradient, TEs of ≈1 msec may be achieved. Both steady and pulsatile flow regimes, and in each case a range of Reynolds numbers, were studied in an in-vitro model. Flow assessment at low and medium flow rates demonstrated a good agreement between 4D UTE and conventional 4D flow techniques. However, 4D UTE flow significantly outperformed conventional 4D flow, at high flow rates for both steady and pulsatile flow regimes. Feasibility of the method in one patient with Aortic Stenosis was also demonstrated. For both steady and pulsatile high flow rates, the measured flow distal to the stenotic narrowing using conventional 4D flow revealed more than 20% error compared to the ground-truth flow. This error was reduced to less than 5% using the 4D UTE flow technique. Magn Reson Med, 2014. © 2014 Wiley Periodicals, Inc.
Research Interests: Computer Science, Algorithms, Biomedical Engineering, Rheology, Medicine, and 10 moreHumans, Feasibility Studies, Three Dimensional Imaging, Image Enhancement, Reproducibility of Results, Sensitivity and Specificity, Blood Flow Velocity, Pulsatile Flow, Magnetic resonance angiography, and Aortic valve stenosis
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Limited data suggest that stress myocardial perfusion imaging and stress echocardiography have similar prognostic value for composite cardiac events. However, it is not known whether exercise echocardiography and stress thallium are... more
Limited data suggest that stress myocardial perfusion imaging and stress echocardiography have similar prognostic value for composite cardiac events. However, it is not known whether exercise echocardiography and stress thallium are similar in their prediction of specific cardiac events, eg, death, sudden death, myocardial infarction, unstable angina, and congestive heart failure. A total of 206 patients undergoing stress echocardiography and thallium-201 single-photon emission computed tomography imaging during the same exercise test were followed-up for 5 and 10 years. Multivariate Cox regression analyses incorporating clinical, exercise stress test, echocardiographic, and nuclear imaging parameters were used to predict mortality and specific cardiac events. A moderate to large amount of ischemia (> or =4 segments on the basis of a 16-segment model) by exercise stress echocardiography was the strongest predictor of overall mortality (relative risk [RR] 6.2; P <.0001), cardiac death (RR 17.6; P =.01), congestive heart failure (RR 17.4; P =.0005) or sudden death (RR 26.8; P =.003), whereas a moderate to large fixed defect (> or =2 segments on the basis of a 6-segment model) by nuclear imaging was the strongest predictor of myocardial infarction (RR 8.1; P =.0002) or unstable angina (RR 3.0; P =.005) at 5 years. The heterogeneity in the prediction of these specific cardiac events by these 2 modalities was similarly observed at 10 years. The extent of ischemia by stress echocardiography is a better predictor of overall mortality, cardiac death, congestive heart failure, or sudden death, whereas the extent of a fixed defect by nuclear imaging is a better predictor of myocardial infarction or unstable angina.
Research Interests: Cardiology, Medicine, Heart Failure, Prospective studies, Humans, and 15 moreInternal Medicine, Cox Regression, Congestive Heart Failure, Aged, Middle Aged, Myocardial Infarction, Kentucky, Analysis of Variance, Prognosis, Myocardial Perfusion Imaging, Angina, Exercise Test, Proportional Hazards Models, Relative Risk, and Cardiovascular medicine and haematology
Research Interests: Biology, Public Health, Cardiovascular disease, Free Radical, Humans, and 15 moreClinical research, Human Body, Nitric oxide, Animals, Laboratory Animals, Antioxidant, Paradigm Shift, Vitamin E, Risk factors, Neoplasms, Cardiovascular Diseases, Risk Factors, Biological activity, Tocopherol, and Biochemistry and cell biology
beta-Blockers have been shown to reduce both morbidity and mortality rates in patients with acute coronary syndromes. However, because of potential side effects, their use is limited in patients who might benefit the most from such... more
beta-Blockers have been shown to reduce both morbidity and mortality rates in patients with acute coronary syndromes. However, because of potential side effects, their use is limited in patients who might benefit the most from such therapy. It was thought that the use of an ultra-short-acting intravenous beta-blocker might produce similar results with fewer complications in those patients with relative contraindications to beta-blocker therapy. Accordingly, we evaluated the use of esmolol in patients with acute coronary syndromes and relative contraindication to beta-blocker therapy in a prospective randomized trial. One hundred eight patients at 21 sites received an infusion of intravenous esmolol or standard therapy on admission and were followed for 6 weeks from the day of admission. The primary efficacy outcome was a composite event consisting of any of the following that occurred during the index hospitalization: death, myocardial (re)infarction, recurrent ischemia, or arrhythmia as well as silent myocardial ischemia assessed by ambulatory electrocardiographic monitoring. Safety end points including hypotension, bradyarrhythmias, new or worsening congestive heart failure, and bronchospasm were also recorded. Event rates for primary end points were similar in the 2 groups: death (2% in the standard care group vs 4% in the group receiving esmolol), myocardial (re)infarction (4% standard vs 7% esmolol), ischemia (12% vs 13%), arrhythmias (4% vs 2%), and silent ischemia (13% vs 15%). There was a higher incidence of transient hypotension in the group receiving esmolol (2% vs 16%), but all such events were noted to resolve after discontinuation of the esmolol infusion. There were no additional differences in safety end points: bradycardia (2% for those receiving standard care vs 9% receiving esmolol), new congestive heart failure (10% vs 16%), bronchospasm (0% vs 7%), and heart block (2% vs 2%). The use of an ultra-short-acting beta-blocker such as esmolol might offer an alternative to patients with contraindications to standard beta-blocker therapy. Although this trial had limited power to detect safety and efficacy differences between the 2 therapies, it was observed that safety end points, which occurred during esmolol administration, resolved readily when the infusions were decreased or discontinued. Additional testing is needed to substantiate these findings.
Research Interests: Cardiology, Medicine, Humans, Internal Medicine, Congestive Heart Failure, and 15 moreFemale, Male, Anesthesia, Aged, Middle Aged, Acute Coronary Syndrome, Myocardial Infarction, Adult, Arrhythmia, Indexation, Mortality rate, Esmolol, Calcium Channel Blockers, discontinuation, and Cardiovascular medicine and haematology
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Research Interests: Cardiology, Medicine, Echocardiography, Humans, Blood Pressure, and 15 moreFemale, Male, Mitral Valve Repair, Aged, Middle Aged, Public health systems and services research, Analysis of Variance, Doppler effect, Blood Flow Velocity, Mitral Valve Stenosis, stenosis, Mitral stenosis, Cardiovascular medicine and haematology, Doppler echocardiography, and Mitral valve
Research Interests: Cardiology, Medicine, Echocardiography, Humans, Internal Medicine, and 12 moreFemale, Middle Aged, Public health systems and services research, Thrombosis, American Heart Association, Heart Ventricles, Heart Diseases, primary myelofibrosis, Medical and Health Sciences, Cardiovascular medicine and haematology, Thrombus, and Left Ventricular Thrombus
Research Interests: Cardiology, Medicine, Humans, Internal Medicine, Blood Pressure, and 14 moreFemale, Male, Heart rate, Dimensional, Middle Aged, Adult, Atropine, Treadmill, Exercise Test, Predictive value of tests, Control Group, Stress echocardiography, Myocardial Ischemia, and Cardiovascular medicine and haematology
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An 88-year-old male presented for a routine transthoracic echocardiogram. Dilated coronary sinus was noted, raising the suspicion for persistent left superior venous cava (PLSVC). An agitated saline study from the left upper extremity... more
An 88-year-old male presented for a routine transthoracic echocardiogram. Dilated coronary sinus was noted, raising the suspicion for persistent left superior venous cava (PLSVC). An agitated saline study from the left upper extremity demonstrated a flow through the coronary sinus into the right ventricle in a parasternal long-axis view. A venogram from the right internal jugular vein showed the PLSVC drained into a much dilated coronary sinus (CS) that connected to the right atrium. The right superior vena cava was absent. PLSVC along with absent right superior vena cava is rare and the inadvertent CS cannulation may result in vessel perforation.
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Research Interests: Cardiology, Medicine, Electrocardiography, Echocardiography, Adenosine, and 15 moreHumans, Internal Medicine, Ischemia, Female, Male, Heart, Left Ventricular Dysfunction, Angioplasty, Middle Aged, Electrocardiogram, Public health systems and services research, Lactic Acid, Ischemic Preconditioning, Cardiovascular medicine and haematology, and Coronary Angioplasty
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The purpose of this study was to determine the safety of dobutamine stress transesophageal echocardiography (DS‐TEE) in the evaluation of potential coronary artery disease in obese patients. Obese patients tend to have a higher prevalence... more
The purpose of this study was to determine the safety of dobutamine stress transesophageal echocardiography (DS‐TEE) in the evaluation of potential coronary artery disease in obese patients. Obese patients tend to have a higher prevalence of hypertension, coronary artery disease, and sleep apnea conditions that could potentially predispose to complications during endoscopic procedures such as DS‐TEE. In addition, obese patients are more likely to have oxygen desaturation during upper gastrointestinal endoscopy. Thus, the safety of DS‐TEE in 90 obese patients (body mass index (BMI) ≥ 27.5 kg/m2) and 86 nonobese patients (BMI < 27.5 kg/m2) was compared. Minor complications (i.e., complications of transient duration and requiring no or only simple intervention) occurred with almost equal frequency in the nonobese and obese groups (28% vs. 29%, P = ns). Transient hypotension was observed in 9% of the obese group compared to 22% in the nonobese group (P < 0.025). However, transient hypertension was noted in 20% of the obese patients compared to 6% in the nonobese group (P < 0.01). A major complication occurred in three obese patients (3.3%), which included hypotension, marked elevation of systolic blood pressure, or ventricular fibrillation. Four patients (4.7%, P = ns) of the nonobese group had a major complication, which included sustained ventricular tachycardia in one, hypertension in one, and hypotension in two patients. No deaths occurred in either group. Although obesity should remain a consideration in the risk assessment of whether or not to perform DS‐TEE, when proper precautions are instituted DS‐TEE appears equally safe in obese as compared to nonobese patients.
Research Interests: Cardiology, Obesity, Medicine, Comorbidity, Multivariate Analysis, and 15 moreEchocardiography, Complication, Humans, Internal Medicine, Blood Pressure, Female, Male, Body Mass Index, Aged, Middle Aged, Ischemic Heart Disease, Coronary Artery Disease, Myocardial Ischemia, Equipment safety, and Cardiovascular medicine and haematology
Research Interests: Cardiology, Fatigue, Medicine, Linear models, Echocardiography, and 15 moreHumans, Internal Medicine, Female, Male, Heart rate, Exercise, Middle Aged, Adult, Ejection Fraction, Exercise Test, Oxygen Consumption, Preload, Diastole, Cardiovascular medicine and haematology, and Doppler echocardiography
Research Interests: Cardiology, Medicine, Prospective studies, Humans, Internal Medicine, and 15 moreHemodynamics, Female, Male, Aged, Middle Aged, Adult, Cardiac Output Monitoring, Prognosis, Reproducibility of Results, Heart Ventricles, Aortic Valve, Predictive value of tests, Severity of Illness Index, Aortic valve stenosis, and Cardiac output
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The quantitative analysis of cardiac motion from echocardiographic images helps clinicians in the diagnosis and therapy of patients suffering from heart disease. Quantitative analysis is usually based on TDI (Tissue Doppler Imaging) or... more
The quantitative analysis of cardiac motion from echocardiographic images helps clinicians in the diagnosis and therapy of patients suffering from heart disease. Quantitative analysis is usually based on TDI (Tissue Doppler Imaging) or speckle tracking. These methods are based on two techniques which to a large degree are independent—the Doppler phenomenon and image sequence processing, respectively. Herein, to increase the accuracy of the speckle tracking technique and to cope with the angle dependency of TDI, a combined approach dubbed TDIOF (Tissue Doppler Imaging Optical Flow) is proposed. TDIOF is formulated based on the combination of B-mode and Doppler energy terms minimized using algebraic equations and is validated on simulated images, a physical heart phantom, and in-vivo data. It was observed that the additional Doppler term is able to increase the accuracy of speckle tracking, compared to two popular motion estimation and speckle tracking techniques (Horn-Schunck and block matching methods). This observation was more pronounced when noise was present. . The magnitude and angular error for TDIOF applied to simulated images when comparing estimated motion with ground-truth motion were 15 % and 9.2 degrees/frame, respectively. The magnitude and angular error for images acquired from physical phantoms were 22 % and 15.2 degrees/frame, respectively. As an additional validation, echocardiography-derived strains were compared to tagged MRI-derived myocardial strains in the same subjects. The correlation coefficient (r) between the TDIOF-derived radial strains and tagged MRI-derived radial strains value were 0.83 (\(\mathrm{P}<0.001\) ). The correlation coefficient (r) for the TDIOF-derived circumferential strains compared to the tagged MRI-derived circumferential strains were 0.86 (\(\mathrm{P}<0.001\) ). The comparison of TDIOF-derived and block matching speckle tracking and Horn-Schunck optical flow strain values using student t-test demonstrated superiority of TDIOF (95 % confidence interval, \(\mathrm{P}<0.001\) ).
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Research Interests: Cardiology, Medicine, Echocardiography, Stroke, Humans, and 14 moreInternal Medicine, Female, Male, Follow-up studies, Risk factors, Two Stroke Engine, Recurrence, Aged, Middle Aged, Adult, Risk Factors, Transient Ischemic Attack (TIA), Patent Foramen Ovale, and Cardiovascular medicine and haematology
The quantitative analysis of cardiac motion from echocardiographic images helps clinicians in the diagnosis and therapy of patients suffering from heart disease. Quantitative analysis is usually based on tissue Doppler imaging (TDI) or... more
The quantitative analysis of cardiac motion from echocardiographic images helps clinicians in the diagnosis and therapy of patients suffering from heart disease. Quantitative analysis is usually based on tissue Doppler imaging (TDI) or speckle tracking. These methods are based on two techniques which to a large degree are independent: the Doppler phenomenon and image sequence processing. Herein, to increase the accuracy of the speckle tracking technique and to cope with the angle dependence of TDI, a combined approach dubbed tissue Doppler imaging optical flow (TDIOF) is proposed. TDIOF is formulated based on the combination of B-mode and Doppler energy terms minimized using algebraic equations and is validated on simulated images, and in vivo data. It was observed that the additional Doppler term is able to increase the accuracy of speckle tracking, compared to two popular motion estimation and speckle tracking techniques (Horn-Schunck and block matching methods). This observation was more pronounced when noise was present. The magnitude and angular error for TDIOF applied to simulated images, when comparing estimated motion with ground-truth motion, were 15% and 9.2°/frame, respectively. As an additional validation, echocardiography-derived strains were compared to tagged MRI-derived myocardial strains in the same subjects. The correlation coefficient (r) between the TDIOF-derived radial strains and tagged MRI-derived radial strains value was 0.83 (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). The correlation coefficient ( r) for the TDIOF-derived circumferential strains compared to the tagged MRI-derived circumferential strains was 0.86 (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). The comparison of TDIOF-derived and block matching speckle tracking and Horn-Schunck optical flow strain values using student t-test demonstrated superiority of TDIOF (95% confidence interval, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001).
Research Interests: Computer Science, Algorithms, Artificial Intelligence, Physics, Computer Vision, and 14 moreBiomedical Engineering, Medicine, Optical Flow, Humans, Computer Simulation, Movement, Female, Male, Middle Aged, Doppler effect, Reproducibility of Results, Speckle noise, Electrical And Electronic Engineering, and Heart Diseases
Research Interests: Cardiology, Medicine, Echocardiography, Humans, Internal Medicine, and 15 moreFemale, Male, Aged, Middle Aged, Adult, Saline, Sensitivity and Specificity, Sodium Chloride, Contrast Media, Cohort Studies, Patent Foramen Ovale, Severity of Illness Index, cardiac cycle, cutoff, and Cardiovascular medicine and haematology
Research Interests: Cardiology, Bipolar Disorder, Medicine, Humans, Internal Medicine, and 15 moreAffective Disorders, Cerebrovascular Disease, Female, Male, Middle Aged, Electrocardiogram, Affective, Adult, Cardiovascular Risk Factor, Cardiovascular Diseases, Asymptomatic, Exercise Test, Exercise Tolerance, General Population, and Medical and Health Sciences
Research Interests: Cardiology, Electrocardiography, Echocardiography, Humans, Ischemia, and 15 moreBlood Pressure, Anesthesia, Heart rate, Experimental Study, Clinical Sciences, Angioplasty, Coronary heart disease, Circulation, Coronary Circulation, Indexation, Blood Flow Velocity, Chest Pain, Ischemic Preconditioning, Cardiovascular medicine and haematology, and collateral circulation
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Research Interests: Cardiology, Medicine, Echocardiography, Congenital Heart Defects, Humans, and 15 moreInternal Medicine, Bicuspid Aortic Valve, Female, Male, Differential Diagnosis, Artifacts, Aged, Calcinosis, Adult, Diagnostic Accuracy, Cardiomyopathies, Aortic Valve, Calcification, Bicuspid Valve, and Cardiovascular medicine and haematology
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In this article, the name of the GLORIA-AF investigator Anastasios Kollias was given incorrectly as Athanasios Kollias in the Acknowledgements. The original article has been corrected.
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Segmentation of the aorta from CT and MR data is important in order to quantitatively assess diseases of the aorta including aortic dissection and distention of aortic aneurysm, among others. In this paper, we propose a segmentation... more
Segmentation of the aorta from CT and MR data is important in order to quantitatively assess diseases of the aorta including aortic dissection and distention of aortic aneurysm, among others. In this paper, we propose a segmentation method to extract exact the 3D boundary of the aorta via graph-cuts segmentation. The graph-cuts technique is able to avoid local minima with global optimization and can be applied to 3D and higher dimension with fast computation. We performed 3D segmentation using this method for five CT data sets. The user selects seed points for aorta region as 'object' and surrounding tissues as 'background' on an axial slice of the 3D CT data and the algorithm calculates the cost of n-link (neighborhood-link) and t-link (terminal-link), and computes the minimum cut separating the aorta from the background by applying the max-flow/min-cut algorithm. Results were validated against manually traced aorta boundaries. The mean Dice Similarity Coefficient for the five 3D segmentations was 0.9381. The 3D segmentation took less than five minutes for data sets of size 512×512×244 to 512×512×284.
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The heart contains c-kit+, lineage- cardiac stem cells (CSCs). Although CSCs improve postinfarction LV dysfunction in animals, their efficacy in humans is unknown. In February 2009, we began SCIPIO...