Literatura académica sobre el tema "Cardiac elastography"
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Artículos de revistas sobre el tema "Cardiac elastography"
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DIOMIDOVA, V. N., L. N. VASILIEVA, O. V. VALEEVA y O. V. PETROVA. "Possibilities of ultrasound elastography in assessing liver damage in chronic heart failure". Practical medicine 19, n.º 5 (2021): 27–31. http://dx.doi.org/10.32000/2072-1757-2021-5-27-31.
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The article presents the literature data on the possibilities of modern types of ultrasound elastography in hepatology and their application in various diffuse hepatic pathologies. The features and advantages of shear wave ultrasound elastography with elastometry are highlighted; the prognostic significance of this method in assessing the severity of hepatic fibrosis is presented. Among the publications, there are also noted the studies concerning the issues of elastography in cardiac liver damage in patients with chronic heart failure. The literature review showed that elastographic diagnostic methods are promising, since their sufficient informativeness was noted in the diagnosis of not only primary diffuse liver damage, but also in assessing the prognosis of the outcome of the disease. The most important advantages of elastography are speed and accessibility, non-invasiveness, possibility of primary diagnosis and assessment of the disease progression and the therapy effectiveness. At the same time, the possibilities of ultrasound elastography in general are still understudied and heir further study is relevant, especially the methods of two-dimensional elastography and shear wave elastometry for diagnosing cardiogenic liver damage in patients with chronic heart failure.
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Elgeti, Thomas, Jens Rump, Uwe Hamhaber, Sebastian Papazoglou, Bernd Hamm, Jürgen Braun y Ingolf Sack. "Cardiac Magnetic Resonance Elastography". Investigative Radiology 43, n.º 11 (noviembre de 2008): 762–72. http://dx.doi.org/10.1097/rli.0b013e3181822085.
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Elgeti, Thomas, Mark Beling, Bernd Hamm, Jürgen Braun y Ingolf Sack. "Cardiac Magnetic Resonance Elastography". Investigative Radiology 45, n.º 12 (diciembre de 2010): 782–87. http://dx.doi.org/10.1097/rli.0b013e3181ec4b63.
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Caenen, Annette, Mathieu Pernot, Kathryn R. Nightingale, Jens-Uwe Voigt, Hendrik J. Vos, Patrick Segers y Jan D’hooge. "Assessing cardiac stiffness using ultrasound shear wave elastography". Physics in Medicine & Biology 67, n.º 2 (17 de enero de 2022): 02TR01. http://dx.doi.org/10.1088/1361-6560/ac404d.
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Abstract Shear wave elastography offers a new dimension to echocardiography: it measures myocardial stiffness. Therefore, it could provide additional insights into the pathophysiology of cardiac diseases affecting myocardial stiffness and potentially improve diagnosis or guide patient treatment. The technique detects fast mechanical waves on the heart wall with high frame rate echography, and converts their propagation speed into a stiffness value. A proper interpretation of shear wave data is required as the shear wave interacts with the intrinsic, yet dynamically changing geometrical and material characteristics of the heart under pressure. This dramatically alters the wave physics of the propagating wave, demanding adapted processing methods compared to other shear wave elastography applications as breast tumor and liver stiffness staging. Furthermore, several advanced analysis methods have been proposed to extract supplementary material features such as viscosity and anisotropy, potentially offering additional diagnostic value. This review explains the general mechanical concepts underlying cardiac shear wave elastography and provides an overview of the preclinical and clinical studies within the field. We also identify the mechanical and technical challenges ahead to make shear wave elastography a valuable tool for clinical practice.
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Chang, Ian C. Y., Arvin Arani, Shivaram Poigai Arunachalam, Martha Grogan, Angela Dispenzieri y Philip A. Araoz. "Feasibility study of cardiac magnetic resonance elastography in cardiac amyloidosis". Amyloid 24, sup1 (16 de marzo de 2017): 161. http://dx.doi.org/10.1080/13506129.2017.1278689.
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Kumarasinghe, G., P. Macdonald y M. Danta. "Liver Elastography in Cardiac Disease (LECD) Trial". Heart, Lung and Circulation 20 (enero de 2011): S70—S71. http://dx.doi.org/10.1016/j.hlc.2011.05.176.
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Sandrikov, V. A., E. R. Charchyan, A. V. Lysenko, T. Yu Kulagina, A. N. Dzeranova, A. V. Novikova, S. V. Fedulova y S. O. Popov. "The first experience of intraoperative myocardial elastography in cardiac surgery patients". Medical alphabet, n.º 22 (4 de diciembre de 2024): 14–18. https://doi.org/10.33667/2078-5631-2024-22-14-18.
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The goal the work was to study the possibility of using elastography on an open heart to determine the stiffness of the left ventricular myocardium. Material and methods. Intraoperative elastography was performed in 6 patients with isolated aortic stenosis and dissecting aneurysm of the ascending aorta with aortic insufficiency. Three patients underwent surgery to replace the aortic valve with mechanical prostheses (SIM-19) and three were operated to replace the ascending aorta with an artificial prosthesis with aortic valve replacement (David’s operation). The average age of the patients was 42±9 years (42–53) years. All patients underwent surgery under conditions of artificial blood circulation. Initially, elastography was evaluated on a working heart, and then on full artificial circulation. The study was performed on a VK 5000 ultrasound device with an intraoperative «stick» type sensor at a frequency of 7.5–15 Mhz, gain of 1.6 Db, resolution of 127 hz. The deformation coefficient was evaluated. The imaging program was exposed as for neurosurgery with a frequency of 15 Mhz. Visualization was performed in B-mode, followed by obtaining shear wave elastography with calculation of the deformation coefficient. Results. Wave elastography was evaluated for various heart pathologies with different myocardial thickness. It was found that the stiffness in the studied areas of the myocardium is different. Thus, in patients with atherosclerotic aortic stenosis and a pressure gradient of more than 100 mmHg, the deformation coefficient was increased, in accordance with the thickness of the myocardium and amounted to 3.81–4.06, and in patients with aortic root dilation and aortic insufficiency, the deformation coefficient was 1.64–2.9. Conclusion. Intraoperative assessment of the left ventricular myocardial deformation coefficient is possible only on a stopped heart and gives an idea of the state of the heart muscle with the possibility of soft and hard areas. Shear wave elastography provides information about the elasticity and hardness of the tissue, which indirectly reflects the viscosity of the myocardium. This study was aimed at verifying the methodology for assessing the characteristics of the elasticity of the left ventricular myocardium for myocardial overload by pressure (aortic stenosis) and volume in case of a dissecting aortic aneurysm with aortic insufficiency.
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Vasilyeva, Lidiya N., Alla G. Ksenofontova y Svetlana V. Bayukova. "CARDIOHEPATIC SYNDROME: INNOVATIVE DIAGNOSTICS BY ULTRASOUND ELASTOGRAPHY". Acta medica Eurasica, n.º 1 (31 de marzo de 2022): 9–18. http://dx.doi.org/10.47026/2413-4864-2022-1-9-18.
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The purpose of this work is to study the aspects of cardiohepatic syndrome at the present stage of medicine development, as well as the diagnostic opportunities of ultrasound elastography in its assessment. The methods of statistical analysis, generalization, comparison and systematization of data were used. The article describes in detail the current state of cardiohepatic syndrome problem. To date, the cardiohepatic syndrome, along with the well-studied cardiorenal one, is becoming more and more relevant, as it reflects the hepatotrophic effect of pathogenetic chronic heart failure factors on the liver tissue. The cardiohepatic syndrome in a broad sense is the presence of simultaneous liver and heart dysfunctions in the development of various nosologies. However, most often this symptom complex is described in the literature in a narrower sense – as a consequence of organ damage to the liver due to the development of acute and chronic heart failure. The main pathogenetic mechanism of cardiac hepatopathies is liver fibrosis. The prognosis of the disease and the life of patients depends on liver fibrosis advance. And early diagnosis of pre-existing fibrosis will make it possible to suspend the process of fibrotic scarring that has begun and its further transformation into cardiac liver cirrhosis. To date, the "gold standard" of fibrosis instrumental diagnosis is a liver biopsy, but due to restrictions and contraindications, the method is limited in its use. Ultrasound elastography is the main non-invasive method for diagnosing fibrosis. At the present stage of expanded diagnostic opportunities, several methods of ultrasonic elastography are described: strain elastography, point shear wave elastography (ARFI-elastometry), indirect transient elastography, two-dimensional shear wave elastography. The experience of using ultrasound elastography is described in the diagnosis of diffuse liver diseases – hepatitises, non-alcoholic fatty liver disease. As part of the cardiohepatic syndrome studying, the technique is innovative and requires further study.
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Varghese, Tomy, J. A. Zagzebski, P. Rahko y C. S. Breburda. "Ultrasonic Imaging of Myocardial Strain Using Cardiac Elastography". Ultrasonic Imaging 25, n.º 1 (enero de 2003): 1–16. http://dx.doi.org/10.1177/016173460302500101.
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Clinical assessment of myocardial ischemia based on visually-assessed wall motion scoring from echocardiography is semiquantitative, operator dependent, and heavily weighted by operator experience and expertise. Cardiac motion estimation methods such as tissue Doppler imaging, used to assess myocardial muscle velocity, provides quantitative parameters such as the strain-rate and strain derived from Doppler velocity. However, tissue Doppler imaging does not differentiate between active contraction and simple rotation or translation of the heart wall, nor does it differentiate tethering (passively following) tissue from active contraction. In this paper, we present a strain imaging modality called cardiac elastography that provides two-dimensional strain information. A method for obtaining and displaying both directional and magnitude cardiac elastograms and displaying strain over the entire cross-section of the heart is described. Elastograms from a patient with coronary artery disease are compared with those from a healthy volunteer. Though observational, the differences suggest that cardiac elastography may be a useful tool for assessment of myocardial function. The method is two-dimensional, real time and avoids the disadvantage of observer-dependent judgment of myocardial contraction and relaxation estimated from conventional echocardiography.
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Chen, Hao y Tomy Varghese. "Three-dimensional canine heart model for cardiac elastography". Medical Physics 37, n.º 11 (20 de octubre de 2010): 5876–86. http://dx.doi.org/10.1118/1.3496326.
Texto completoTesis sobre el tema "Cardiac elastography"
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Kwiecinski, Wojciech. "Ultrasound cardiac therapy guided by elastography and ultrafast imaging". Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066131/document.
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La fibrillation atriale affecte 2-3% des européens et nord-américains, les tachycardies ventriculaires sont liées à un risque important de mort subite. Les approches minimalement invasives comme l’Ablation par Cathéter Radiofréquence (RFCA) ont révolutionné le traitement de ces maladies, mais le taux de réussite de la RFCA est limité par le manque de techniques d’imagerie pour contrôler cette ablation thermique.Le but de cette thèse est de proposer de nouvelles approches ultrasonores pour des traitements cardiaques minimalement invasifs guidés par échographie.Pour cela nous avons d’abord validé la précision et la viabilité clinique de l’Élastographie par Ondes de Cisaillement (SWE) en tant que modalité d’imagerie quantitative et temps réel pour l’ablation thermique in vivo. Ensuite nous avons implémenté la SWE sur un transducteur intracardiaque et validé la faisabilité d’évaluer l’ablation thermique in vitro et in vivo sur cœur battant de gros animal. Puis nous avons développé un transducteur intracardiaque dual-mode pour effectuer l’ablation et l’imagerie ultrasonores avec les mêmes éléments, sur le même dispositif. Les lésions thermiques induites par Ultrasons Focalisés de Haute Intensité (HIFU) et contrôlées par la SWE ont été réalisées avec succès in vivo dans les oreillettes et les ventricules chez le gros animal. Finalement la SWE a été implémentée sur un dispositif d’imagerie et thérapie ultrasonores transœsophagien et la faisabilité de cette approche a été démontrée in vitro et in vivo. Ces approches originales pourraient conduire à de nouveaux dispositifs cliniques pour des traitements plus sûrs et contrôlés d’un large éventail d’arythmies et maladies cardiaquesAtrial fibrillation (AF) affects 2-3% of the European and North-American population, whereas ventricular tachyarrhythmia (VT) is related to an important risk of sudden death. AF and VT originate from dysfunctional electrical activity in cardiac tissues. Minimally-invasive approaches such as Radio-Frequency Catheter Ablation (RFCA) have revolutionized the treatment of these diseases; however the success rate of RFCA is currently limited by the lack of monitoring techniques to precisely control the extent of thermally ablated tissue.The aim of this thesis is to propose novel ultrasound-based approaches for minimally invasive cardiac ablation under guidance of ultrasound imaging. For this, first, we validated the accuracy and clinical viability of Shear-Wave Elastography (SWE) as a real-time quantitative imaging modality for thermal ablation monitoring in vivo. Second we implemented SWE on an intracardiac transducer and validated the feasibility of evaluating thermal ablation in vitro and in vivo on beating hearts of a large animal model. Third, a dual-mode intracardiac transducer was developed to perform both ultrasound therapy and imaging with the same elements, on the same device. SWE-controlled High-Intensity-Focused-Ultrasound thermal lesions were successfully performed in vivo in the atria and the ventricles of a large animal model. At last, SWE was implemented on a transesophageal ultrasound imaging and therapy device and the feasibility of transesophageal approach was demonstrated in vitro and in vivo. These novel approaches may lead to new clinical devices for a safer and controlled treatment of a wide variety of cardiac arrhythmias and diseases
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Caforio, Federica. "Mathematical modelling and numerical simulation of elastic wave propagation in soft tissues with application to cardiac elastography". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLX001/document.
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Les objectifs de cette thèse sont la modélisation mathématique et la simulation numérique de l’élastographie impulsionnelle basée sur la force de radiation acoustique (FRA) dans un tissu mou précontraint, et en particulier le myocarde. La première partie du manuscript concerne la modélisation mathématique de la FRA, la propagation d’ondes de cisaillement qui en résulte et la caractérisation de la vitesse des ondes de cisaillement pour une loi de comportement générale du tissu myocardique. Nous montrons aussi des applications pour l’estimation de l’orientation des fibres cardiaques dans le myocarde et l’évaluation de “pathologies synthétiques ”. Une des contributions principales de ce travail est le développement d’un modèle mathématique original de la FRA. En particulier, à partir d’un modèle biomécanique tridimensionnel du coeur, nous obtenons, à travers une approche asymptotique, les équations qui régissent les champs de pression et de cisaillement induits par la FRA. De plus, nous calculons une expression analytique du terme source responsable de la génération des ondes de cisaillement à partir d’une impulsion acoustique en pression. Dans la deuxième partie de la thèse, nous proposons des outils numériques efficaces pour une simulation numérique réaliste d’une expérience d’élastographie impulsionnelle dans un tissu quasi-incompressible, précontraint et fibré. La discrétisation en espace se base sur des éléments finis spectraux d’ordre élevé. Pour la discrétisation en temps, nous proposons une nouvelle méthode adaptée à l’élasticité incompressible. En particulier, seuls les termes correspondant à des vitesses infinies, associés à la contrainte d’incompressibilité, sont traités implicitement, à travers la resolution d’un problème de Poisson à chaque pas de temps de l’algorithme. En outre, nous proposons une nouvelle méthode d’ordre élevé et efficace pour la résolution d’un problème de Poisson, qui se base sur la transformée de Fourier discrèteThis PhD thesis concerns the mathematical modelling and numerical simulation of impulsive Acoustic Radiation Force (ARF)-driven Shear Wave Elastography (SWE) imaging in a prestressed soft tissue, with a specific reference to the cardiac setting. The first part of the manuscript deals with the mathematical modelling of the ARF, the resulting shear wave propagation, and the characterisation of the shear wave velocity in a general constitutive law for the myocardial tissue. We also show some applications to the extraction of fibre orientation in the myocardium and the detection of “synthetic pathologies”. One of the main contributions of this work is the derivation of an original mathematical model of the ARF. In more detail, starting from an accurate biomechanical model of the heart, and based on asymptotic analysis, we infer the governing equation of the pressure and the shear wave field remotely induced by the ARF, and we compute an analytical expression of the source term responsible for the generation of shear waves from an acoustic pressure pulse. In the second part of the PhD thesis, we propose efficient numerical tools for a realistic numerical simulation of an SWE experiment in a nearly-incompressible, pre-stressed, fibered soft tissue. The spatial discretisation is based on high-order Spectral Finite Elements (HO-SEM). Concerning the time discretisation, we propose a novel method adapted to incompressible elasticity. In particular, only the terms travelling at infinite velocity, associated with the incompressibility constraint, are treated implicitly by solving a scalar Poisson problem at each time step of the algorithm. Furthermore, we provide a novel matrix-free, high-order, fast method to solve the Poisson problem, based on the use of the Discrete Fourier Transform
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Saloux, Éric. "Validatiοn préclinique et clinique d’une nοuvelle technique nοn invasive de mesure de l’élasticité du myοcarde". Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMC415.
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L’élastographie ultrasonore est une technique qui a fait ses preuves en clinique depuis près de 10 ans pour explorer la dureté des organes statiques superficiels comme le foie le sein. Son application à l’étude des caractéristiques mécaniques du cœur est très récente et n’a fait l’objet que de quelques preuves de concept expérimentales chez l’animal et chez l’Homme. Dans ce travail, nous avons évalué in vitro, sur un modèle animal et chez l'homme atteint de sténose aortique, l'imagerie Shear Wave Elastography dans une version adaptée au cœur à partir de séquences cliniques conçues pour des organes statiques. Nous avons montré sur fantôme que les mesures réalisées à l’aide des séquences cardiaque sur sonde linéaires étaient concordantes avec les séquences de référence, alors que les mesures avec la sonde sectorielle n'étaient interprétables qu'entre 4 et 10 cm, et présentaient un champ de mesure homogène. Dans le modèle animal, nous avons montré que la rigidité systolique était affectée par les conditions de charge et corrélée à la contractilité, alors que la rigidité diastolique était indépendante des conditions de charge, de la contractilité et de la fréquence cardiaque avec une bonne concordance intra et inter animale. Chez l'homme, nous avons confirmé la nature dynamique de la dureté myocardique avec un rapport systole/diastole de 3,5, montré que la rigidité diastolique du myocarde était significativement plus élevée en cas de sténose aortique et significativement corrélée au remodelage du ventricule gauche, à la sévérité de l'obstruction aortique et à la précharge ventriculaire. Ces résultats prometteurs montrent le bénéfice clinique potentiel de cette modalité si elle était largement mise en œuvre sur des machines commercialesUltrasonic elastography is a validated technique used for almost 10 years to evaluate the stiffness of superficial static organs such as the liver and the breast. Its application to the study of the mechanical characteristics of the heart is very recent, and has been the subject of only a few experimental proof of concept studies in animals and humans. In this work, we evaluated Shear Wave Elastography imaging in a version adapted to the heart from clinical sequences designed for static organs, successively in vitro, in an animal model and in humans with aortic stenosis,. In the phantom study, we showed that measurements with cardiac sequences and linear probes were consistent with reference sequences, whereas measurements with the sectorial probe were only interpretable between 4 and 10 cm, and presented a homogeneous measurement field. In the animal model, we showed that systolic stiffness was affected by loading conditions and correlated with contractility, while diastolic stiffness was independent of loading conditions, contractility short ischemia and heart rate, with good intra- and inter-animal agreement. In humans, we confirmed the dynamic nature of myocardial stiffness with a systole/diastole ratio of 3.5, showed that diastolic myocardial stiffness was significantly higher in aortic stenosis and significantly correlated with left ventricular remodeling, severity of aortic obstruction and ventricular preload. These promising results demonstrate the potential clinical benefit of this modality if widely implemented on commercial systems
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Maksuti, Elira. "Imaging and modeling the cardiovascular system". Doctoral thesis, KTH, Medicinsk bildteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-196538.
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Understanding cardiac pumping function is crucial to guiding diagnosis, predicting outcomes of interventions, and designing medical devices that interact with the cardiovascular system. Computer simulations of hemodynamics can show how the complex cardiovascular system is influenced by changes in single or multiple parameters and can be used to test clinical hypotheses. In addition, methods for the quantification of important markers such as elevated arterial stiffness would help reduce the morbidity and mortality related to cardiovascular disease. The general aim of this thesis work was to improve understanding of cardiovascular physiology and develop new methods for assisting clinicians during diagnosis and follow-up of treatment in cardiovascular disease. Both computer simulations and medical imaging were used to reach this goal. In the first study, a cardiac model based on piston-like motions of the atrioventricular plane was developed. In the second study, the presence of the anatomical basis needed to generate hydraulic forces during diastole was assessed in heathy volunteers. In the third study, a previously validated lumped-parameter model was used to quantify the contribution of arterial and cardiac changes to blood pressure during aging. In the fourth study, in-house software that measures arterial stiffness by ultrasound shear wave elastography (SWE) was developed and validated against mechanical testing. The studies showed that longitudinal movements of the atrioventricular plane can well explain cardiac pumping and that the macroscopic geometry of the heart enables the generation of hydraulic forces that aid ventricular filling. Additionally, simulations showed that structural changes in both the heart and the arterial system contribute to the progression of blood pressure with age. Finally, the SWE technique was validated to accurately measure stiffness in arterial phantoms.QC 20161115
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Correia, Mafalda Filipa Rodrigues. "From 2D to 3D cardiovascular ultrafast ultrasound imaging : new insights in shear wave elastography and blood flow imaging". Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCC158.
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Ces travaux de thèse portent sur le développement de nouvelles modalités d’imagerie cardiovasculaire basé sur l’utilisation de l'imagerie ultrarapide 2D et 3D. Les modalités d’imagerie développées dans cette thèse appartiennent au domaine de de l’élastographie par onde de cisaillement et de l'imagerie Doppler des flux sanguins.Dans un premier temps, la technique de l’élastographie par onde de cisaillement du myocarde a été développée pour les applications cliniques. Une approche d'imagerie non-linéaire a été utilisée pour améliorer l’estimation de vitesse des ondes de cisaillement (ou la rigidité des tissus cardiaques) de manière non invasive et localisée. La validation de cette nouvelle approche de « l’imagerie par sommation cohérente harmonique ultrarapide » a été réalisée in vitro et la faisabilité in vivo a été testée chez l’humain. Dans un second temps, nous avons utilisé cette technique sur des patients lors de deux essais cliniques, chacun ciblant une population différente (adultes et enfants). Nous avons étudié la possibilité d’évaluer quantitativement la rigidité des tissus cardiaques par élastographie chez des volontaires sains, ainsi que chez des malades souffrant de cardiomyopathie hypertrophique. Les résultats ont montré que l’élastographie pourrait devenir un outil d'imagerie pertinent et robuste pour évaluer la rigidité du muscle cardiaque en pratique clinique. Par ailleurs, nous avons également développé une nouvelle approche appelée « imagerie de tenseur élastique 3-D » pour mesurer quantitativement les propriétés élastiques des tissus anisotropes comme le myocarde. Ces techniques ont été testées in vitro sur des modèles de de gels isotropes transverses. La faisabilité in vivo de l’élastographie par onde cisaillement à trois-dimensions a été également évaluée sur un muscle squelettique humain.D'autre part, nous avons développé une toute nouvelle modalité d’imagerie ultrasonore des flux coronariens basée sur l’imagerie Doppler ultrarapide. Cette technique nous a permis d'imager la circulation coronarienne avec une sensibilité élevée, grâce notamment au développement d’un nouveau filtre adaptatif permettant de supprimer le signal du myocarde en mouvement, basé sur la décomposition en valeurs singulières (SVD). Des expériences à thorax ouvert chez le porc ont permis d'évaluer et de valider notre technique et les résultats ont montré que la circulation coronaire intramurale, peut être évaluée sur des vaisseaux de diamètres allant jusqu’à 100 µm. La faisabilité sur l’homme a été démontrée chez l’enfant en imagerie clinique transthoracique.Enfin, nous avons développé une nouvelle approche d’imagerie des flux sanguins, « l’imagerie ultrarapide 3-D des flux», une nouvelle technique d'imagerie quantitative des flux. Nous avons démontré que cette technique permet d’évaluer le débit volumétrique artériel directement en un seul battement cardiaque, indépendamment de l'utilisateur. Cette technique a été mise en place à l'aide d'une sonde matricielle 2-D et d’un prototype d’échographe ultrarapide 3-D développé au sein du laboratoire. Nous avons évalué et validé notre technique in vitro sur des fantômes artériels, et la faisabilité in vivo a été démontrée sur des artères carotides humainesThis thesis was focused on the development of novel cardiovascular imaging applications based on 2-D and 3-D ultrafast ultrasound imaging. More specifically, new technical and clinical developments of myocardial shear wave elastography and ultrafast blood flow imaging are presented in this manuscript.At first, myocardial shear wave elastography was developed for transthoracic imaging and improved by a non-linear imaging approach to non-invasively and locally assess shear wave velocity measurements, and consequently tissue stiffness in the context of cardiac imaging. This novel imaging approach (Ultrafast Harmonic Coherent Compounding) was tested and validated in-vitro and the in vivo feasibility was performed in humans for biomechanical evaluation of the cardiac muscle wall, the myocardium. Then, we have translated shear wave elastography to the clinical practice within two clinical trials, each one with a different population (adults and children). In both clinical trials, we have studied the capability of shear wave elastography to assess quantitatively myocardial stiffness in healthy volunteers and in patients suffering from hypertrophic cardiomyopathy. The results in the adult population indicated that shear wave elastography may become an effective imaging tool to assess cardiac muscle stiffness in clinical practice and help the characterization of hypertrophic cardiomyopathy. Likewise, we have also translated Shear Wave Elastography into four-dimensions and we have developed a new approach to map tissue elastic anisotropy in 3-D. 3-D Elastic Tensor Imaging allowed us to estimate quantitatively in a single acquisition the elastic properties of fibrous tissues. This technique was tested and validated in vitro in transverse isotropic models. The in-vivo feasibility of 3D elastic tensor imaging was also assessed in a human skeletal muscle.In parallel, we have developed a novel imaging technique for the non-invasive and non-radiative imaging of coronary circulation using ultrafast Doppler. This approach allowed us to image blood flow of the coronary circulation with high sensitivity. A new adaptive filter based on the singular value decomposition was used to remove the clutter signal of moving tissues. Open-chest swine experiments allowed to evaluate and validate this technique and results have shown that intramural coronary circulation, with diameters up to 100 µm, could be assessed. The in-vivo transthoracic feasibility was also demonstrated in humans in pediatric cardiology.Finally, we have developed a novel imaging modality to map quantitatively the blood flow in 3-D: 3-D ultrafast ultrasound flow imaging. We demonstrated that 3-D ultrafast ultrasound flow imaging can assess non-invasively, user-independently and directly volumetric flow rates in large arteries within a single heartbeat. We have evaluated and validated our technique in vitro in arterial phantoms using a 2-D matrix-array probe and a customized, programmable research 3-D ultrafast ultrasound system, and the in-vivo feasibility was demonstrated in human carotid arteries
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Robert, Jade. "Développement de modalités d'imagerie ultrasonore pour le guidage et le suivi interventionnel du traitement des arythmies cardiaques". Electronic Thesis or Diss., Lyon, 2022. http://www.theses.fr/2022LYSE1005.
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Les arythmies cardiaques sont, aujourd’hui encore, un enjeu de santé publique majeur. Certains types d’arythmies affectent plusieurs dizaines de millions de personnes dans le monde, tandis que d’autres sont la cause principale de mort subite cardiaque. Dans les cas les plus sévères, il est impératif de recourir à un traitement, afin de préserver l’intégrité du patient. Or, les méthodes interventionnelles, de guidage et de suivi de ce traitement, sont limitées, menant ainsi à un taux de récurrence parfois élevé, en fonction du type d’arythmie. Cette thèse s’intéresse alors au développement de modalités d’imagerie ultrarapide ultrasonore, pouvant pallier ces limitations. Ces modalités sont l’imagerie de l’onde électromécanique et l’élastographie passive, et pourraient offrir des informations pertinentes, jusqu’alors indisponible en clinique. Dans un premier temps, des études ex-vivo, sur cœurs isolés travaillants, ont été conduites afin d’évaluer le potentiel de l’imagerie de l’onde électromécanique. Une étude en aveugle a permis de démontrer qu’il était possible de détecter avec précision le type de stimulation et la source de contraction dans 79% des cas. Puis, deux études in-vivo, sur modèle porcin ont permis d’étudier la faisabilité de l’imagerie de l’onde électromécanique sur deux types de sondes, plus adaptées à un contexte interventionnel. Des ondes pouvant être associées à la contraction cardiaque ont été visualisées dans les deux études. Néanmoins, la visualisation dynamique de l’onde de contraction a été plus complexe dans un contexte in-vivo, puisqu’elle nécessite une interprétation, nécessairement subjective, d’un lecteur expérimenté. Pour répondre à cette limitation, une nouvelle méthode d’analyse temps-fréquence des données ultrasonores a été mise en place afin d’aboutir à une représentation plus objective de la contraction cardiaque, et ne nécessitant pas d’utilisateur expérimenté. La méthode a été validée, qualitativement et quantitativement, sur données ex-vivo, vis-à-vis de la méthode de référence utilisée en imagerie de l’onde électromécanique dans la littérature. En appliquant la méthode aux données des études in-vivo, il a pu être démontré que les schémas de contraction décrits sont similaires entre deux stimulations consécutives, et que la source de contraction est correctement positionnée lorsque la sonde de stimulation est située dans le plan. Notamment, la zone de contraction observée était cohérente avec la zone de stimulation dans le plan d’imagerie dans 81% des cas, lors des acquisitions réalisées à l’aide d’une sonde intracardiaque. Des études ex-vivo, sur échantillons cardiaques, ont été mises en place afin d’évaluer la faisabilité de détection des lésions simples et des schémas de lésions thermiques par élastographie passive. Il a été démontré sur un grand nombre d’échantillons (41 sur n = 51, 80% sur deux études) qu’une augmentation locale de la rigidité (d’un facteur 1.6 à 2.5 en moyenne), des zones lésées, était visible par élastographie. Les répartitions des lésions détectés sont cohérentes et les dimensions correctement estimées (manuellement, 1.1 à 2.8 mm d’erreur absolue, en moyenne), bien que les surfaces de lésions obtenues par élastographie passive soient encore approximatives. Finalement, une étude in-vivo sur modèle porcin a permis de démontrer la faisabilité de détecter des lésions thermiques individuelles ou en ligne par élastographie passiveCardiac arrhythmias remain a major public health issue today. Some types of arrhythmias affect tens of millions of people worldwide, while others are the main cause of sudden cardiac death. In the most severe cases, it is imperative perform a treatment in order to preserve the integrity of the patient. However, interventional methods for guiding and monitoring this treatment are limited, sometimes leading to high recurrence rates, depending on the type of arrhythmia. This thesis focuses on the development of ultrafast ultrasound imaging modalities that can overcome these limitations. These modalities are Electromechanical Wave Imaging and Passive Elastography, and could provide relevant information, until now unavailable in clinic. First, ex-vivo studies on isolated working hearts were conducted to evaluate the potential of Electromechanical Wave Imaging. A blind study demonstrated that it was possible to accurately detect the type of stimulation and the source of contraction in 79% of cases. Then, two in-vivo studies, conducted on porcine model, allowed to study the feasibility of the electromechanical wave imaging on two types of probes, more adapted to an interventional context. Waves that could be associated with cardiac contraction were visualized in both studies. Nevertheless, dynamic visualization of the contraction wave was more complex in an in-vivo context, as it requires subjective interpretation of a trained reader. To address this limitation, a novel method based on time-frequency analysis of ultrasound data was developed to provide a more objective representation of the cardiac contraction, without the need of a trained reader. The method was validated, qualitatively and quantitatively, on ex-vivo data, against the reference method used for Electromechanical Wave Imaging in the literature. By applying the method to the data from the in-vivo studies, it could be demonstrated that the described contraction patterns are similar between two consecutive stimulations with same conditions, and that the contraction source is correctly positioned when the stimulation probe is located in the plane. Notably, the observed contraction area was consistent with the pacing area, when located in the imaging plane, in 81% of the cases, during the study performed with an intracardiac probe. Ex-vivo studies on cardiac samples were performed to evaluate the feasibility of detecting single lesions and thermal injury patterns by Passive Elastography. It was demonstrated on a large number of samples (41 out of n = 51, 80% on two studies) that a local stiffness increase (by a factor of 1.6 to 2.5 on average), of the injured areas, was visible by elastography. The distributions of the detected lesions were consistent, and the dimensions correctly estimated (manually, 1.1 to 2.8 mm error on average), although the lesion areas detected by passive elastography were still approximate. Finally, an in-vivo study on a porcine model demonstrated the feasibility of detecting individual or in-line thermal lesions with this method
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Sayseng, Vincent Policina. "Toward clinical realization of Myocardial Elastography: Cardiac strain imaging for better diagnosis and treatment of heart disease". Thesis, 2020. https://doi.org/10.7916/d8-c6vn-cv86.
Texto completoResumen
Heart disease is the leading cause of death globally. Early diagnosis is the key to successful treatment. By providing noninvasive, non-ionizing, and real-time imaging, echocardiography plays a critical role in identifying heart disease. Compared to other imaging modalities, ultrasound has unparalleled temporal resolution. High frame-rate imaging has enabled the development of new metrics to characterize myocardial mechanics. Strain imaging measures the heart's deformation throughout the cardiac cycle, providing a quantitative assessment of cardiac health.
The intention of this dissertation is to bring Myocardial Elastography (ME) closer to clinical realization. ME is a high frame-rate strain imaging technique for transthoracic and intracardiac echocardiography. This work consists of four Aims.
There is a fundamental trade-off between spatial and temporal resolution in strain imaging. In Aim 1, the optimal transmit sequence that generates the most accurate and precise strain estimate was determined. Two common approaches to coherent compounding (full and partial aperture) were compared in simulation and in transthoracic imaging of healthy human subjects (n=5). The optimized subaperture compounding sequence (25-element subperture, 90° angular aperture, 10 virtual sources, 300 Hz frame rate) was compared to the optimized steered compounding sequence (60° angular aperture, 15° tilt, 10 virtual sources, 300 Hz frame rate) and was found to measure strain in healthy human subjects with equivalent precision. The optimal compounding configuration was then evaluated against two other high-frame rate transmit strategies, ECG-gated focused imaging, and wide-beam imaging, in simulation and in healthy subjects (n=7). Achieving the highest level of strain precision, ECG-gated focused imaging was determined to be the preferred imaging approach in patients capable of sustaining a breath hold, with compounding preferred in those unable to do so.
Rapid diagnosis is essential to successful treatment of myocardial infarction. In Aim 2, ME's ability to track infarct formation and recovery, and localize infarct using regional strain measurments, was investigated in a large animal survival model (n=11). Infarcts were generated via ligation of the left anterior descending, imaging regularly for up to 28 days. A radial strain-based metric, percentage of healthy myocardium by strain (PHM_ε), was developed as a marker for healthy myocardial tissue. PHM_ε was strongly linearly correlated with actual infarct size as determined by gross pathology (R2 = 0.80). ME was capable of diagnosing individual myocardial segments as non-infarcted or infarcted with high sensitivity (82%), specificity (92%), and precision (85%) (ROC AUC = 0.90), and tracked infarct recovery from collateral reperfusion through time.
Noninvasive strain imaging at rest can improve pre-test probability accuracy, and reduce unnecessary stress testing. In Aim 3, ME's potential to provide early diagnosis of coronary artery disease was investigated in an ongoing study. Patients undergoing myocardial perfusion imaging were recruited (n=126). Perfusion scores were used as the reference standard. Morphological transformations were integrated into the processing pipeline to reduce variability in the strain measurements. PHM_ε was reintroduced and used to differentiate between patients with and without coronary artery disease. ME was capable of distinguishing between normal patients and those with significant ischemia or infarct (subjects with perfusion defects at rest) with statistical significance (p < 0.05), although a greater sample size is needed to confirm the results.
One of the most common treatments for arrhythmia, catheter ablation, can fail if the lesion line intended to terminate the abnormal rhythm is non-contiguous. In Aim 4, the gap resolution and clinical feasibility of Intracardiac Myocardial Elastography (IME) strain imaging, an ablation monitoring technique, was investigated. Lesion size estimation and gap resolution was evaluated in an open chest canine model (n=3), wherein lesion lines consisting of three lesions and two gaps were generated in each canine left ventricle via epicardial ablation. All gaps were resolvable. Average lesion and gap areas were measured with high agreement (33 ± 14 mm2 and 30 ± 15 mm2, respectively) when compared against gross pathology (34 ± 19 mm2 and 26 ± 11 mm2, respectively). Gaps as small as 11 mm2 (3.6 mm on epicardial surface) were identifiable. Patients undergoing ablation to treat typical cavotricuspid isthmus atrial flutter (n=5) were imaged throughout the procedure. In all patients, strain decreased in the cavotricuspid isthmus after ablation (mean paired difference of -17 ± 11 %, p < 0.05).
Together, these Aims intend to translate a promising imaging method from research to clinical reality.
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Bunting, Ethan Armel. "Performance Analysis and Optimization of 2-D Cardiac Strain Imaging for Clinical Applications". Thesis, 2017. https://doi.org/10.7916/D8BP07J3.
Texto completoResumen
Heart disease has remained the deadliest disease in the United States for the past 100 years. Imaging methods are frequently employed in cardiology in order to help clinicians diagnose the specific type of heart disease and to guide treatment decisions. Ultrasound is the most frequently used imaging modality in cardiology because it is inexpensive, portable, easy to use, and extremely safe for patients. Using a variety of imaging processing techniques, deformations exhibited by the cardiac tissue during contraction can be imaged with ultrasound and used as an indicator of myocardial health.
This dissertation will demonstrate the clinical implementation of two ultrasound-based strain estimation techniques developed in the Ultrasound and Elasticity Imaging Laboratory at Columbia University. Each of the two imaging methods will be tailored for clinical applications using techniques for optimal strain estimation derived from ultrasound and imaging processing theory. The motion estimation rate (MER) used for strain estimation is examined in the context of the theoretical Strain Filter and used to increase the precision of axial strain estimation. Diverging beam sequences are used to achieve full-view high MER imaging within a single heartbeat. At approximately 500 Hz, the expected elastographic signal-to-noise ratio (E(SNRe|ε)) of the axial strain becomes single-peaked, indicating an absence of “peak-hopping” errors which can severely corrupt strain estimation. In order to mediate the tradeoff in spatial resolution resulting from the use of diverging beams, coherent spatial compounding is used to increase the accuracy of the lateral strain estimation, resulting in a more physiologic strain profile. A sequence with 5 coherently compounded diverging waves is used at 500 Hz to improve the radial SNRe of the strain estimation compared to a single-source diverging sequence at 500 Hz.
The first technique, Myocardial Elastography (ME), is used in conjunction with an intracardiac echocardiography (ICE) system to image the formation of thermal ablation lesions in vivo using a canine model (n=6). By comparing the systolic strain before and after the formation of a lesion, lesion maps are generated which allow for the visualization of the lesion in real-time during the procedure. A good correlation is found between the lesion maps and the actual lesion volume as measured using gross pathology (r2=0.86). The transmurality of the lesions are also shown to be in good agreement with gross pathology. Finally, the feasibility of imaging gaps between neighboring lesions is established. Lesion size and the presence of gaps have been associated with the success rate of cardiac ablation procedures, demonstrating the value of ME as a potentially useful technique for clinicians to help improve patient outcomes following ablation procedures.
The second technique, Electromechanical Wave Imaging (EWI), is implemented using a transthoracic echocardiography system in a study of heart failure patients (n=16) and healthy subjects (n=4). EWI uses the transient inter-frame strains to generate maps of electromechanical activation, which are then used to distinguish heart failure patients from healthy controls (p<.05). EWI was also shown to be capable of distinguishing responders from non-responders to cardiac resynchronization therapy (CRT) on the basis of the activation time of the lateral wall. These results indicate that EWI could be used as an adjunct tool to monitor patient response to CRT, in addition to helping guide lead placement prior to device implantation.
Libros sobre el tema "Cardiac elastography"
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Sayseng, Vincent Policina. Toward clinical realization of Myocardial Elastography: Cardiac strain imaging for better diagnosis and treatment of heart disease. [New York, N.Y.?]: [publisher not identified], 2020.
Buscar texto completoCapítulos de libros sobre el tema "Cardiac elastography"
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Konofagou, Elisa. "Myocardial Elastography". En Cardiac Mapping, 1073–82. Chichester, UK: John Wiley & Sons, Ltd, 2019. http://dx.doi.org/10.1002/9781119152637.ch84.
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Kolipaka, Arunark. "Cardiac Magnetic Resonance Elastography". En Protocols and Methodologies in Basic Science and Clinical Cardiac MRI, 237–59. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-53001-7_7.
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Ibrahim, El-Sayed, Simon Lambert y Ralph Sinkus. "Cardiac Magnetic Resonance Elastography (MRE)". En Heart Mechanics Magnetic Resonance Imaging, 449–500. Taylor & Francis Group, 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742: CRC Press, 2017. http://dx.doi.org/10.1201/9781315119090-9.
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Heyde, Brecht, Oana Mirea y Jan D'hooge. "Cardiac Strain and Strain Rate Imaging". En Ultrasound Elastography for Biomedical Applications and Medicine, 143–60. Chichester, UK: John Wiley & Sons, Ltd, 2018. http://dx.doi.org/10.1002/9781119021520.ch11.
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Eyerly-Webb, Stephanie A., Maryam Vejdani-Jahromi, Vaibhav Kakkad, Peter Hollender, David Bradway y Gregg Trahey. "Acoustic Radiation Force-based Ultrasound Elastography for Cardiac Imaging Applications". En Ultrasound Elastography for Biomedical Applications and Medicine, 504–19. Chichester, UK: John Wiley & Sons, Ltd, 2018. http://dx.doi.org/10.1002/9781119021520.ch32.
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Lesniak-Plewinska, Beata, M. Kowalski, S. Cygan, E. Kowalik y K. Kaluzynski. "Experimental setup with dual chamber cardiac phantom for ultrasonic elastography". En IFMBE Proceedings, 559–62. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-89208-3_133.
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Varghese, Tomy, Q. Chen, P. Rahko y James Zagzebski. "Cardiac Elastography, Full-Field Development". En Encyclopedia of Biomaterials and Biomedical Engineering, Second Edition - Four Volume Set, 506–13. CRC Press, 2008. http://dx.doi.org/10.1201/b18990-49.
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"Cardiac Elastography, Full-Field Development". En Encyclopedia of Biomaterials and Biomedical Engineering, Second Edition, 506–13. CRC Press, 2008. http://dx.doi.org/10.1081/e-ebbe2-120023467.
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Li, Yan, Karen L. Fang, Zhi Huang, Yun Lu, Bin Zhang y Yali Yao. "Advancements in Cardiovascular Diagnostics". En Coronary and Cardiothoracic Critical Care, 1–19. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-8185-7.ch001.
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The cardiology diagnostic are the methods of identifying current or past heart conditions, which can advise caregivers on patient diagnosis and provide a proper therapy plan, nowadays couple new diagnostic methods have been developed and some of them like radionuclide myocardial perfusion imaging, coronary computed tomography angiogram, cardiac magnetic resonance imaging, intravascular ultrasonography, optical coherence tomography, intravascular thermography, intravascular elastography, and near-infrared spectroscopy have been approved for clinical use. Not only the advanced technologies, the new biomarkers, and genetic markers may provide new potential targets for the diagnosis, therapy, and prevention of heart diseases.
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Li, Yan, Karen L. Fang, Zhi Huang, Yun Lu, Bin Zhang y Yali Yao. "Advancements in Cardiovascular Diagnostics". En Emerging Applications, Perspectives, and Discoveries in Cardiovascular Research, 194–211. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-2092-4.ch011.
Texto completoResumen
The cardiology diagnostic are the methods of identifying current or past heart conditions, which can advise caregivers on patient diagnosis and provide a proper therapy plan, nowadays couple new diagnostic methods have been developed and some of them like radionuclide myocardial perfusion imaging, coronary computed tomography angiogram, cardiac magnetic resonance imaging, intravascular ultrasonography, optical coherence tomography, intravascular thermography, intravascular elastography, and near-infrared spectroscopy have been approved for clinical use. Not only the advanced technologies, the new biomarkers, and genetic markers may provide new potential targets for the diagnosis, therapy, and prevention of heart diseases.
Actas de conferencias sobre el tema "Cardiac elastography"
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Konofagou, Elisa E., Timothy Harrigan y Scott Solomon. "Cardiac elastography: detecting pathological changes in myocardium tissues". En Medical Imaging 2003, editado por William F. Walker y Michael F. Insana. SPIE, 2003. http://dx.doi.org/10.1117/12.479932.
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Liu, Chih-Hao, Manmohan Singh, Shang Wang, John P. Leach, Irina V. Larina, James F. Martin, Kirill V. Larin y Justin Rippy. "Assessment of the biomechanical changes in cardiac tissue after myocardial infarction with optical coherence elastography". En Optical Elastography and Tissue Biomechanics VI, editado por Kirill V. Larin y Giuliano Scarcelli. SPIE, 2019. http://dx.doi.org/10.1117/12.2510762.
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Bunting, Ethan, Clement Papadacci, Elaine Wan, Julien Grondin y Elisa Konofagou. "Intracardiac myocardial elastography for lesion quantification in cardiac radiofrequency ablation". En 2016 IEEE International Ultrasonics Symposium (IUS). IEEE, 2016. http://dx.doi.org/10.1109/ultsym.2016.7728575.
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Azeloglu, E. U. y K. D. Costa. "Dynamic AFM elastography reveals phase dependent mechanical heterogeneity of beating cardiac myocytes". En 2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 2009. http://dx.doi.org/10.1109/iembs.2009.5335316.
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Al Mukaddim, Rashid, Kayvan Samimi, Allison Rodgers, Timothy A. Hacker y Tomy Varghese. "Comparison of cardiac displacements in a murine model of myocardial ischemia using Cardiac Elastography and speckle tracking echocardiography". En 2017 IEEE International Ultrasonics Symposium (IUS). IEEE, 2017. http://dx.doi.org/10.1109/ultsym.2017.8092143.
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Mukaddim, Rashid Al, Kayvan Samimi, Allison Rodgers, Timothy A. Hacker y Tomy Varghese. "Comparison of cardiac displacements in a murine model of myocardial ischemia using cardiac elastography and Speckle Tracking Echocardiography". En 2017 IEEE International Ultrasonics Symposium (IUS). IEEE, 2017. http://dx.doi.org/10.1109/ultsym.2017.8092281.
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Caenen, Annette, Abdullah Thabit, Darya Shcherbakova, Abigail Swillens, Patrick Segers, Mathieu Pernot y Luc Mertens. "The effect of stretching on transmural shear wave anisotropy in cardiac shear wave elastography". En 2017 IEEE International Ultrasonics Symposium (IUS). IEEE, 2017. http://dx.doi.org/10.1109/ultsym.2017.8092507.
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Caenen, Annette, Mathieu Pemot, Mathias Peirlinck, Luc Mertens y Patrick Segers. "Analyzing the Shear Wave Mechanics in Cardiac Shear Wave Elastography Using Finite Element Simulations". En 2018 IEEE International Ultrasonics Symposium (IUS). IEEE, 2018. http://dx.doi.org/10.1109/ultsym.2018.8579698.
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Liang, Yun, Hui Zhu, Thomas Gehrig y Morton H. Friedman. "Coronary Artery Wall Strain Estimation From Clinical IVUS Images". En ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176256.
Texto completoResumen
Atherosclerotic plaque rupture is responsible for the majority of acute coronary syndromes and myocardial infarctions. Intravascular ultrasound (IVUS) imaging is a widely available clinical technique providing real time cross-sectional images of the vessel wall and plaque morphometry. However, IVUS echo images have limited ability to predict the vulnerability of the plaque. The mechanical behavior of the plaque is consistent with its underlying components, suggesting that measurements of plaque mechanical response can be used to assess the likelihood of plaque rupture [1]. Arterial wall strain in response to luminal pressure change is such a measurable quantity. IVUS elastography has been developed to measure the radial strain through correlation analysis of the IVUS radiofrequency (RF) signal [2]. Due to the movements of IVUS catheter caused by cardiac motion and the nonlinearity of tissue deformation, reliable strain is obtained by elastography only when the tissue motion is aligned with the RF direction and the RF traces correspond to the same axial location. This is difficult to achieve in vivo. We have developed a strain estimation method based on IVUS image registration. This 2D processing method has the ability to overcome in-plane catheter movement and heterogeneous tissue deformation, thereby increasing its accuracy. Using retrospectively retrieved cardiac phase information, we propose a practical method to estimate cross-sectional coronary arterial wall strain distribution from clinically acquired images during a conventional IVUS procedure.
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Engel, Aaron J., Hao H. Hsu, Pengfei Song y Gregory R. Bashford. "Cardiac atrial kick shear wave elastography with ultrafast diverging wave imaging: An in vivo pilot study". En 2017 IEEE International Ultrasonics Symposium (IUS). IEEE, 2017. http://dx.doi.org/10.1109/ultsym.2017.8092742.
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