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The combination of medical imaging with computational fluid dynamics (CFD) has enabled the study of 3-D blood flow on a patient-specific level. However, with models based on gated high-resolution data, the study of transient flows, and any model implementation into routine cardiac care, is challenging. This paper presents a novel pathway for patient-specific CFD modelling of the left ventricle (LV),...
Myocardial strain imaging has been shown to add significant prognostic and diagnostic value to echocardiography. While the reliability of ultrasound-based strain measurement techniques has improved considerably in terms of regional consistency and inter-reader, inter-vendor agreement; most state-of-the-art strain imaging packages constrain their analyses to individual cardiac cycles. This limitation...
Increased myocardial stiffness is characteristic of many diseases, leads to a loss of diastolic function, and is a cause of diastolic heart failure (DHF). Methods to estimate myocardial stiffness include Shear Wave Elastography (SWE). Currently, ultrasound-based cardiac SWE includes acoustic radiation force (ARF)-based methods; however, the in vivo generation and detection of shear waves in myocardium...
Echocardiography is the most used modality for the evaluation of cardiac function. To obtain a time-resolved volumetric quantification of cardiac motion, ultrafast 3-D imaging is required. Ultrafast ultrasound imaging with diverging waves has demonstrated its potential for clinical 2-D echocardiography. It has been shown that MoCo (motion compensation) strategies based on a triangle transmit arrangement...
Contrast echocardiography (CE) ultrasound with microbubble contrast agents have significantly advanced our capability in assessing cardiac function. However in conventional CE techniques with line by line scanning, the frame rate is limited to tens of frames per second, making it difficult to track the fast flow within cardiac chamber. Recent research in high frame-rate (HFR) ultrasound have shown...
Developing technological infrastructure has enabled the development of computer based biomedical systems as in many areas in the field of medicine. One of these systems are biomedical imaging systems. Many studies are being conducted for a new image processing techniques to improve the performance of this systems. Noise reduction is one of the important steps in biomedical image processing. In this...
Intracardiac echocardiography (ICE) is routinely used in many interventional procedures in cardiology. In these procedures ICE catheter is positioned with fluoroscopy guidance, which can be harmful due to ionizing X-ray radiation exposure. Positioning the ICE catheter using an interventional magnetic resonance imaging (MRI) system would enable procedures that are free of ionizing radiation, and complement...
Achieving a high frame rate in echocardiography is highly important for quantifying the short phases of the cardiac cycle that contain valuable information for medical diagnosis. Additionally, the 3D quantitative assessment of the heart would significantly improve the current measurements used in daily clinical routine. Nevertheless, obtaining ultrafast images remains a challenge due to the trade-off...
Echocardiography is one of the most widely spread modality for non-invasive 2-D imaging of the heart. However, to fully observe and quantify left ventricular function and morphology, 3-D imaging is required. The observation of the whole left ventricle remains limited by the temporal resolution of conventional 3-D echocardiography. Indeed, the only way to get wide-angle volumetric images is to merge...
Investigating myocardial dynamics through the assessment of mechanical properties of heart is a challenging problem in a murine model as the heart rate is high. The objective of this study was to compare displacements estimated using radiofrequency (RF) signals with Cardiac Elastography (CE) and Speckle Tracking Echocardiography (STE) for quantifying myocardial dynamics.
High frame-rate contrast enhanced echocardiography (HFR CE), based on pulse inversion (PI) and diverging wave transmission, was recently proposed for improving the image contrast over standard contrast enhanced ultrasound (CEUS) with focused transmission [M. Toulemonde, IUS 2016]. While it has great potential for improved quantification of myocardium perfusion, it is not clear as whether the stability...
Left intraventricular blood flow follows a range of patterns that are mostly overlooked when using conventional ultrasound Doppler techniques. Vortices, in particular, as a blood redirection mechanism, could provide important information on a patient's cardiovascular health. They are not usually visualized, however, due to the need for 2D velocity vector visualization, and their transient nature,...
Given the limited spatiotemporal resolution of 3D echocardiography, simultaneous assessment of all ventricular myocardial segments can clinically be performed using multi-plane acquisitions (MP) — i.e. biplane (BP) or triplane (TP). However, the wider field of view of MP impairs spatiotemporal resolution, thus hindering the performance of e.g. speckle tracking. Multi Line Transmit (MLT) beam forming...
Echocardiograms are acquired from standard views to ensure correct assessment of cardiac function. There is an increasing use of quantitative tools where specific views are required. Further, non-expert users of echocardiography are increasing, and thus a need for quality assurance during imaging. The aim of this project is to develop automatic and robust real-time classification of cardiac views...
Speckle tracking echocardiography (STE) is a well-established method to assess regional cardiac function. Traditionally, the left ventricular (LV) walls are divided into 18 segments (6 LV walls each with 3 segments) and the deformation parameters are measured for each of the segments. However, usually, segmental deformation curves are obtained by taking the average of an underlying strain field that...
Echocardiographic image sequences are frequently corrupted by quasi-static artifacts known as “clutter”. These artifacts are superimposed on the moving myocardium and hinder useful diagnosis. Prior work has shown the efficacy of blind source separation methods to suppress clutter while retaining underlying signal. However, the same image may be corrupted with clutter from multiple mechanisms or sources...
Contrast enhanced ultrasound (CEUS) has shown great promise in quantifying myocardial perfusion and ventricular flow. More recently high frame-rate contrast enhanced echocardiography (HFR CE), based on pulse inversion (PI) and diverging waves, has shown to significantly improve the image contrast over standard CEUS [M. Toulemonde, IUS 2016]. Both contrast pulse sequences and spatial compounding involve...
Objective myocardial deformation assessment during stress tests could help clinicians to better diagnose myocardial ischemia. However, the use of conventional focused echocardiography is compromised at increased heart rates due to its limited lateral field of view and frame rate. Ultrafast echocardiography using coherent compounding of diverging waves improves temporal resolution while maintaining...
Investigation of myocardial dynamics through the assessment of mechanical properties of the heart is a challenging problem due to tradeoff between the heart rate and ultrasound frame rate. The objective of this study was to compare displacements estimated using radiofrequency (RF) signals with Cardiac Elastography (CE) and Speckle Tracking Echocardiography (STE) for quantifying myocardial dynamics...
Contrast echocardiography (CE) ultrasound with microbubble contrast agents have significantly advanced our capability in assessing cardiac function, including myocardium perfusion imaging and quantification. However in conventional CE techniques with line by line scanning, the frame rate is limited to tens of frames per second and image quality is low. Recent research works in high frame-rate (HFR)...
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