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Articoli di riviste sul tema "Cardiac elastography"

Autore: Grafiati

Pubblicato: 14 dicembre 2024

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1

DIOMIDOVA, V. N., L. N. VASILIEVA, O. V. VALEEVA e O. V. PETROVA. "Possibilities of ultrasound elastography in assessing liver damage in chronic heart failure". Practical medicine 19, n. 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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2

Elgeti, Thomas, Jens Rump, Uwe Hamhaber, Sebastian Papazoglou, Bernd Hamm, Jürgen Braun e Ingolf Sack. "Cardiac Magnetic Resonance Elastography". Investigative Radiology 43, n. 11 (novembre 2008): 762–72. http://dx.doi.org/10.1097/rli.0b013e3181822085.

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Elgeti, Thomas, Mark Beling, Bernd Hamm, Jürgen Braun e Ingolf Sack. "Cardiac Magnetic Resonance Elastography". Investigative Radiology 45, n. 12 (dicembre 2010): 782–87. http://dx.doi.org/10.1097/rli.0b013e3181ec4b63.

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4

Caenen, Annette, Mathieu Pernot, Kathryn R. Nightingale, Jens-Uwe Voigt, Hendrik J. Vos, Patrick Segers e Jan D’hooge. "Assessing cardiac stiffness using ultrasound shear wave elastography". Physics in Medicine & Biology 67, n. 2 (17 gennaio 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 e Philip A. Araoz. "Feasibility study of cardiac magnetic resonance elastography in cardiac amyloidosis". Amyloid 24, sup1 (16 marzo 2017): 161. http://dx.doi.org/10.1080/13506129.2017.1278689.

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Kumarasinghe, G., P. Macdonald e M. Danta. "Liver Elastography in Cardiac Disease (LECD) Trial". Heart, Lung and Circulation 20 (gennaio 2011): S70—S71. http://dx.doi.org/10.1016/j.hlc.2011.05.176.

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7

Sandrikov, V. A., E. R. Charchyan, A. V. Lysenko, T. Yu Kulagina, A. N. Dzeranova, A. V. Novikova, S. V. Fedulova e S. O. Popov. "The first experience of intraoperative myocardial elastography in cardiac surgery patients". Medical alphabet, n. 22 (4 dicembre 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 e Svetlana V. Bayukova. "CARDIOHEPATIC SYNDROME: INNOVATIVE DIAGNOSTICS BY ULTRASOUND ELASTOGRAPHY". Acta medica Eurasica, n. 1 (31 marzo 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 e C. S. Breburda. "Ultrasonic Imaging of Myocardial Strain Using Cardiac Elastography". Ultrasonic Imaging 25, n. 1 (gennaio 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, e Tomy Varghese. "Three-dimensional canine heart model for cardiac elastography". Medical Physics 37, n. 11 (20 ottobre 2010): 5876–86. http://dx.doi.org/10.1118/1.3496326.

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Liu, Yifei, Thomas J. Royston, Dieter Klatt e E. Douglas Lewandowski. "Cardiac MR elastography of the mouse: Initial results". Magnetic Resonance in Medicine 76, n. 6 (9 gennaio 2016): 1879–86. http://dx.doi.org/10.1002/mrm.26030.

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Liu, Yi, Ge Wang e L. Z. Sun. "Anisotropic Elastography for Local Passive Properties and Active Contractility of Myocardium from Dynamic Heart Imaging Sequence". International Journal of Biomedical Imaging 2006 (2006): 1–15. http://dx.doi.org/10.1155/ijbi/2006/45957.

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Major heart diseases such as ischemia and hypertrophic myocardiopathy are accompanied with significant changes in the passive mechanical properties and active contractility of myocardium. Identification of these changes helps diagnose heart diseases, monitor therapy, and design surgery. A dynamic cardiac elastography (DCE) framework is developed to assess the anisotropic viscoelastic passive properties and active contractility of myocardial tissues, based on the chamber pressure and dynamic displacement measured with cardiac imaging techniques. A dynamic adjoint method is derived to enhance the numerical efficiency and stability of DCE. Model-based simulations are conducted using a numerical left ventricle (LV) phantom with an ischemic region. The passive material parameters of normal and ischemic tissues are identified during LV rapid/reduced filling and artery contraction, and those of active contractility are quantified during isovolumetric contraction and rapid/reduced ejection. It is found that quasistatic simplification in the previous cardiac elastography studies may yield inaccurate material parameters.

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Dore, Marta, Aime Luna, Michael Sun e Thomas Royston. "Biaxial prestress and waveguide effects on estimates of the complex shear modulus using optical elastography in a transverse isotropic cornea phantom". Journal of the Acoustical Society of America 153, n. 3_supplement (1 marzo 2023): A266. http://dx.doi.org/10.1121/10.0018799.

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Tensile prestress is inherent to the functional role of some biological tissues currently being studied using elastography, such as skeletal and cardiac muscle, arterial walls, and the cornea. Therefore, the impact of prestress coupled with waveguide effects due to small dimensions in one or more directions needs to be better understood. An experimental configuration is designed, fabricated, and experimentally tested using optical elastography. Thin layered isotropic and transversely isotropic phantoms are statically stretched biaxially in plane while simultaneously conducting optical elastography measurements of out of plane motion. Guided by analytical models and numerical finite element simulations, experimental measurements are post-processed to obtain an estimate of the complex (viscoelastic) shear modulus as a function of prestress level and frequency of vibratory motion.

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Bunting, Ethan, Clement Papadacci, Elaine Wan, Vincent Sayseng, Julien Grondin e Elisa E. Konofagou. "Cardiac Lesion Mapping In Vivo Using Intracardiac Myocardial Elastography". IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 65, n. 1 (gennaio 2018): 14–20. http://dx.doi.org/10.1109/tuffc.2017.2768301.

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Strachinaru, Mihai, Johan G. Bosch, Bas M. van Dalen, Lennart van Gils, Antonius F. W. van der Steen, Nico de Jong, Marcel L. Geleijnse e Hendrik J. Vos. "Cardiac Shear Wave Elastography Using a Clinical Ultrasound System". Ultrasound in Medicine & Biology 43, n. 8 (agosto 2017): 1596–606. http://dx.doi.org/10.1016/j.ultrasmedbio.2017.04.012.

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16

Arani, Arvin, Shivaram P. Arunachalam, Ian C. Y. Chang, Francis Baffour, Phillip J. Rossman, Kevin J. Glaser, Joshua D. Trzasko et al. "Cardiac MR elastography for quantitative assessment of elevated myocardial stiffness in cardiac amyloidosis". Journal of Magnetic Resonance Imaging 46, n. 5 (25 febbraio 2017): 1361–67. http://dx.doi.org/10.1002/jmri.25678.

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Crutison, Joseph, Michael Sun e Thomas J. Royston. "The combined importance of finite dimensions, anisotropy, and pre-stress in acoustoelastography". Journal of the Acoustical Society of America 151, n. 4 (aprile 2022): 2403–13. http://dx.doi.org/10.1121/10.0010110.

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Dynamic elastography, whether based on magnetic resonance, ultrasound, or optical modalities, attempts to reconstruct quantitative maps of the viscoelastic properties of biological tissue, properties that are altered by disease and injury, by noninvasively measuring mechanical wave motion in the tissue. Most reconstruction strategies that have been developed neglect boundary conditions, including quasistatic tensile or compressive loading resulting in a nonzero prestress. Significant prestress is inherent to the functional role of some biological tissues currently being studied using elastography, such as skeletal and cardiac muscle, arterial walls, and the cornea. In the present article, we review how prestress alters both bulk mechanical wave motion and wave motion in one- and two-dimensional waveguides. Key findings are linked to studies on skeletal muscle and the human cornea, as one- and two-dimensional waveguide examples. This study highlights the underappreciated combined acoustoelastic and waveguide challenge to elastography. Can elastography truly determine viscoelastic properties of a material when what it is measuring is affected by both these material properties and unknown prestress and other boundary conditions?

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Glenn, Thomas, Nicole Duster, Jerry Dwek, Jose Silva-Sepulveda e Howaida G. El-Said. "Selective Use of Pulmonary Vasodilators in Patients with Fontan Physiology". Journal of Interventional Cardiology 2022 (10 novembre 2022): 1–6. http://dx.doi.org/10.1155/2022/7602793.

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Background. Fontan-associated liver disease is a well-known sequela following the Fontan procedure for patients living with single-ventricle heart disease. Pulmonary vasodilators, such as phosphodiesterase type 5 inhibitors, have emerged as a potential therapeutic option for lowering central venous pressures by reducing pulmonary vascular resistance. Method. We performed a single-center retrospective review of Fontan patients who were placed on pulmonary vasodilator therapy with prehemodynamic and posthemodynamic, MR elastography, and histologic assessments. Results. A total of 125 patients with Fontan circulation underwent surveillance with cardiac catheterization during the review period. Fifty-three (42%) patients who did not have increased end-diastolic pressures at the time of cardiac catheterization were started on phosphodiesterase type 5 inhibitor therapy. Nine patients (17%) underwent posttherapy follow-up catheterization. The mean Fontan pressure decreased from 15.4 ± 3.3 mmHg to 13.3 ± 2.5 mmHg ( p = 0.026 ), after initiation of pulmonary vasodilatory therapy. There was no change in end-diastolic pressure, transpulmonary gradient, wedge pressure, pulmonary vascular resistance, cardiac index, or saturation. Eleven patients (21%) underwent pretherapy MR elastography testing with posttherapy follow-up MR elastography. We found no improvement in liver stiffness score following the application of pulmonary vasodilators. Three patients underwent pretherapy and posttherapy liver biopsies, with variable histological changes observed within the hepatic parenchyma. Conclusions. These data demonstrate indeterminate results for the selective use of pulmonary vasodilators but highlight the need for large prospective randomized control trials of pulmonary vasodilator therapies to fully assess the benefit of such therapies in Fontan-associated liver disease.

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Zorgani, Ali, Rémi Souchon, Au-Hoang Dinh, Jean-Yves Chapelon, Jean-Michel Ménager, Samir Lounis, Olivier Rouvière e Stefan Catheline. "Brain palpation from physiological vibrations using MRI". Proceedings of the National Academy of Sciences 112, n. 42 (5 ottobre 2015): 12917–21. http://dx.doi.org/10.1073/pnas.1509895112.

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We present a magnetic resonance elastography approach for tissue characterization that is inspired by seismic noise correlation and time reversal. The idea consists of extracting the elasticity from the natural shear waves in living tissues that are caused by cardiac motion, blood pulsatility, and any muscle activity. In contrast to other magnetic resonance elastography techniques, this noise-based approach is, thus, passive and broadband and does not need any synchronization with sources. The experimental demonstration is conducted in a calibrated phantom and in vivo in the brain of two healthy volunteers. Potential applications of this “brain palpation” approach for characterizing brain anomalies and diseases are foreseen.

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Jaccard, Arnaud, Anne Cypierre, Annick Rousseau, Fatima Yagoubi, Julie Abraham, Annie Lefebvre, Elisabeth Vidal, Dominique Bordessoule e Véronique Loustaud-Ratti. "Transient Elastography (FibroScan®) for Noninvasive Assessment of Liver Amyloidosis." Blood 114, n. 22 (20 novembre 2009): 4894. http://dx.doi.org/10.1182/blood.v114.22.4894.4894.

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Abstract Abstract 4894 Background Liver involvement is frequent in AL amyloidosis patients, and is found in 70% of cases in autopsy series. Histologic diagnosis of amyloid deposition is mandatory, preferably by biopsies of non-hepatic tissue, liver biopsy being associated with an increased risk of bleeding. FibroScan, a non invasive method for measuring liver stiffness, is used to measure liver fibrosis in patients with viral hepatitis. We postulated that amyloid liver deposition in AL could enhance liver stiffness and that may help for the diagnosis of liver amyloidosis. Methods 41 consecutive AL patients with systemic disease seen at the French Reference Center for AL amyloidosis were analyzed: 17 had liver AL, 23 cardiac AL, and 13 no liver or cardiac involvement according to the criteria defined by the Tours Consensus Opinion on Amyloidosis (2005). All had liver stiffness measured by FibroScan simultaneously with 76 controls: 16 healthy controls, 10 multiple myeloma and 50 consecutive patients chronically infected with hepatitis C virus (HCV). According to the manufacturer's criteria, liver stiffness was interpretable in 32 (78%) of AL patients and in 68 (89%) of the control group. The Mann Whitney test with Bonferroni correction for multiple comparisons was used to compare the interpretable liver stiffness values between the groups. Results The liver stiffness was not statistically different between the healthy (median 4,6 range 2,8-6,5 KPa) and the myeloma controls (median 5,4 range 3,3-11,9 KPa) and both were considered as the negative control group. The negative control group had a liver stiffness significantly different from the HCV group (median 6,8 range 2,9-69,1 KPa, p<0.001), but not from the AL group without liver or cardiac involvement (median 6,1 range 4,2-17,5 KPa, p=0,25). The liver stiffness of AL patients with liver (with or without cardiac) involvement, was significantly higher (median 27,4 range 10,3-75 KPa) than the one of the negative control group (p<0.001), or the HCV group (p=0.001), and the AL group without liver or cardiac involvement (p=0.001). The relationship between AL liver involvement and the liver stiffness value was tested using ROC curve analysis with an optimal cut-off value of 9,8 KPa, a sensitivity of 100% (95%CI71,5 - 100,0), a specificity of 75.6% (95%CI64,6 - 84,7) and a ROC AUC of 0.92 (p=0.0001). In order to favour specificity for the diagnosis of AL liver involvement in non specific clinical situations, we chose the cut-off value of 17.5 KPa (specificity 94,87% (95%CI87,4 - 98,6), sensitivity 63,64% (95%CI30,8 - 89,1). Conclusion FibroScan is a useful non invasive tool which may suggest that a patient with undefined signs (enlarged liver, asymptomatic cholestasis, isolated monoclonal gammopathy) has liver amyloidosis and may help to define liver involvement in patients with proven amyloidosis, especially when liver stiffness reaches the cut-off value of 17,5 KPa. Disclosures No relevant conflicts of interest to declare.

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Friedrich-Rust, Mireen, Fabian Schoelzel, Sven Linzbach, Joerg Bojunga, Stefan Zeuzem e Florian Seeger. "Safety of transient elastography in patients with implanted cardiac rhythm devices". Digestive and Liver Disease 49, n. 3 (marzo 2017): 314–16. http://dx.doi.org/10.1016/j.dld.2016.11.005.

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Sui, Yi, Shivaram P. Arunachalam, Arvin Arani, Joshua D. Trzasko, Phillip M. Young, James F. Glockner, Kevin J. Glaser et al. "Cardiac MR elastography using reduced-FOV, single-shot, spin-echo EPI". Magnetic Resonance in Medicine 80, n. 1 (1 dicembre 2017): 231–38. http://dx.doi.org/10.1002/mrm.27029.

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Gennisson, Jean-Luc. "From dynamic to passive elastography, what technique used?" Journal of the Acoustical Society of America 153, n. 3_supplement (1 marzo 2023): A312. http://dx.doi.org/10.1121/10.0018966.

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Elastography is a method that allows to quantify mechanical properties of biological tissues. In medical imaging, this last technique has been developed mainly in ultrasound (US) and in magnetic resonance imaging (MRI). Both imaging techniques have advantages and drawbacks depending on the organs and pathologies investigated. In this presentation we focused on two organs, where each technique has its advantage to investigate mechanical properties: brain and muscle. In brain, the preferred technique is MRI since US propagation is very complicated through the skull bone. Taking advantage of 3D acquisition, we investigated brain tumors with a new elastography approach: passive elastography. From the natural vibration, such as cardiac beating or respiration, we locally recover the natural shear wavelength that propagates giving access a stiffness mapping of the brain. Results are compared with US acquire during neurosurgery, showing a good accordance between both techniques. In muscles, US are used to recover not only stiffness but also others mechanical parameters such as viscoelastic anisotropy or shear non-linearity. Special US sequences were developed to quantify these two parameters in different physiological conditions that change in real-time. This presentation shows that depending on the investigated organ, physicists and physicians need to adapt the imaging strategy to better characterize tissues.

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Oglat, Ammar A., e Tala Abukhalil. "Ultrasound Elastography: Methods, Clinical Applications, and Limitations: A Review Article". Applied Sciences 14, n. 10 (19 maggio 2024): 4308. http://dx.doi.org/10.3390/app14104308.

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Ultrasound is a highly adaptable medical imaging modality that offers several applications and a wide range of uses, both for diagnostic and therapeutic purposes. The principles of sound wave propagation and reflection enable ultrasound imaging to function as a highly secure modality. This technique facilitates the production of real-time visual representations, thereby assisting in the evaluation of various medical conditions such as cardiac, gynecologic, and abdominal diseases, among others. The ultrasound modality encompasses a diverse range of modes and mechanisms that serve to enhance the methodology of pathology and physiology assessment. Doppler imaging and US elastography, in particular, are two such techniques that contribute to this expansion. Elastography-based imaging methods have attracted significant interest in recent years for the non-invasive evaluation of tissue mechanical characteristics. These techniques utilize the changes in soft tissue elasticity in various diseases to generate both qualitative and quantitative data for diagnostic purposes. Specialized imaging techniques collect data by identifying tissue stiffness under mechanical forces such as compression or shear waves. However, in this review paper, we provide a comprehensive examination of the fundamental concepts, underlying physics, and limitations associated with ultrasound elastography. Additionally, we present a concise overview of its present-day clinical utilization and ongoing advancements across many clinical domains.

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Song, Pengfei, Xiaojun Bi, Daniel C. Mellema, Armando Manduca, Matthew W. Urban, James F. Greenleaf e Shigao Chen. "Quantitative Assessment of Left Ventricular Diastolic Stiffness Using Cardiac Shear Wave Elastography". Journal of Ultrasound in Medicine 35, n. 7 (20 maggio 2016): 1419–27. http://dx.doi.org/10.7863/ultra.15.08053.

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Chen, Hao, Tomy Varghese, Peter S. Rahko e J. A. Zagzebski. "Ultrasound frame rate requirements for cardiac elastography: Experimental and in vivo results". Ultrasonics 49, n. 1 (gennaio 2009): 98–111. http://dx.doi.org/10.1016/j.ultras.2008.05.007.

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Pislaru, Cristina, Mahmoud M. Alashry, Filip Ionescu, Ioana Petrescu, Patricia A. Pellikka, Martha Grogan, Angela Dispenzieri e Sorin V. Pislaru. "Increased Myocardial Stiffness Detected by Intrinsic Cardiac Elastography in Patients With Amyloidosis". JACC: Cardiovascular Imaging 12, n. 2 (febbraio 2019): 375–77. http://dx.doi.org/10.1016/j.jcmg.2018.08.014.

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Salehabadi, Melika, Joseph Crutison, Lara Nammari, Dieter Klatt e Thomas Royston. "Uniaxial prestress and waveguide effects on estimates of the complex shear modulus using magnetic resonance elastography in a transverse isotropic muscle phantom and excised muscle". Journal of the Acoustical Society of America 153, n. 3_supplement (1 marzo 2023): A313. http://dx.doi.org/10.1121/10.0018973.

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Abstract (sommario):

Tensile prestress is inherent to the functional role of some biological tissues currently being studied using elastography, such as skeletal and cardiac muscle, arterial walls, and the cornea. Therefore, the impact of prestress coupled with waveguide effects due to small dimensions in one or more directions needs to be better understood. An experimental configuration is designed, fabricated and experimentally tested using magnetic resonance elastography (MRE). Cylindrically-shaped isotropic and transversely isotropic phantoms, as well as the excised cat soleus muscle are statically stretched along their main axis to specific prestrain levels while simultaneously conducting MRE measurements that enable synchronous motion-encoding in all three dimensions (polarization directions). In the case of the excised cat soleus, diffusion tensor imaging is also performed to enable a co-registered mapping of fiber structure. Guided by analytical models and numerical finite element simulations, experimental measurements are post-processed to obtain an estimate of the complex (viscoelastic) shear modulus as a function of prestress level and frequency of vibratory motion.

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Caforio, Federica, e Sébastien Imperiale. "Mathematical modelling of acoustic radiation force in transient shear wave elastography in the heart". ESAIM: Mathematical Modelling and Numerical Analysis 54, n. 6 (novembre 2020): 2319–50. http://dx.doi.org/10.1051/m2an/2020019.

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The aim of this work is to provide a mathematical model and analysis of the excitation and the resulting shear wave propagation in acoustic radiation force (ARF)-based shear wave cardiac elastography. Our approach is based on asymptotic analysis; more precisely, it consists in considering a family of problems, parametrised by a small parameter inversely proportional to the excitation frequency of the probes, the viscosity and the velocity of pressure wave propagation. We derive a simplified model for the expression of the ARF by investigating the limit behaviour of the solution when the small parameter goes to zero. By formal asymptotic analysis – an asymptotic expansion of the solution is used – and energy analysis of the nonlinear elastodynamic problem, we show that the leading-order term of the expansion is solution of the underlying, incompressible, nonlinear cardiac mechanics. Subsequently, two corrector terms are derived. The first is a fast-oscillating pressure wave generated by the probes, solution of a Helmholtz equation at every time. The second corrector term consists in an elastic field with prescribed divergence, having a function of the first corrector as a source term. This field corresponds to the shear acoustic wave induced by the ARF. We also confirm that, in cardiac mechanics, the presence of viscosity in the model is essential to derive an expression of the shear wave propagation from the ARF, and that this phenomenon is related to the nonlinearity of the partial differential equation.

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Kisliuk, Kseniya A., Aleksandr N. Bogdanov, Sergey G. Shcherbak e Svetlana V. Apalko. "Clinical, laboratory and instrumental evaluation of structural and functional changes of the liver in patients with heart failure". HERALD of North-Western State Medical University named after I.I. Mechnikov 13, n. 1 (8 giugno 2021): 27–37. http://dx.doi.org/10.17816/mechnikov50313.

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Heart failure is detected in 2% of the population. The leading causes of heart failure are coronary heart disease, arterial hypertension, and valvular heart disease. The number of patients with chronic heart failure continues to increase despite the new methods of diagnosis and treatment. A special contribution is made by damage to target organs in the development of cardiovascular pathology. Impaired liver function or congestive liver is common in heart failure and increases the risk of death and requires further study. The mechanism of liver damage in chronic heart failure is complex and multicomponent. The sensitivity and specificity of standard clinical, laboratory and instrumental methods for the diagnosis of congestive liver are insufficient. With the increase, severity and duration of venous congestion, structural changes in the architectonics occur, leading to the formation of liver fibrosis. The development of cardiac liver fibrosis leads to a complication of the course of chronic heart failure and an increase in mortality. Among the new diagnostic methods, the most important are serological markers of liver fibrosis, which have high diagnostic accuracy, as well as histological determination of fibrosis, as well as ultrasound examination of the liver in B-mode and determination of liver stiffness by elastography. Direct and indirect serological markers have a higher diagnostic value when using their combination in the composition of panels in the development of hepatopathy of different origins. An increase in the concentration of markers of fibrosis and liver stiffness during elastography correlates with the severity of heart failure and a long-term prognosis for mortality, including from extrahepatic diseases. Performing liver elastography in dynamics allows to monitor the course and treatment of heart failure. The optimal diagnostic method is a combination of direct and indirect markers of fibrosis, ultrasound diagnostics and elastography, in addition to clinical assessment of signs and direct assessment of hemodynamic parameters.

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Elgeti, Thomas, Fabian Knebel, Robert Hättasch, Bernd Hamm, Jürgen Braun e Ingolf Sack. "Shear-wave Amplitudes Measured with Cardiac MR Elastography for Diagnosis of Diastolic Dysfunction". Radiology 271, n. 3 (giugno 2014): 681–87. http://dx.doi.org/10.1148/radiol.13131605.

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Arani, Arvin, Kevin L. Glaser, Shivaram P. Arunachalam, Phillip J. Rossman, David S. Lake, Joshua D. Trzasko, Armando Manduca, Kiaran P. McGee, Richard L. Ehman e Philip A. Araoz. "In vivo, high‐frequency three‐dimensional cardiac MR elastography: Feasibility in normal volunteers". Magnetic Resonance in Medicine 77, n. 1 (17 gennaio 2016): 351–60. http://dx.doi.org/10.1002/mrm.26101.

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Manduca, A., T. L. Rossman, D. S. Lake, K. J. Glaser, A. Arani, S. P. Arunachalam, P. J. Rossman et al. "Waveguide effects and implications for cardiac magnetic resonance elastography: A finite element study". NMR in Biomedicine 31, n. 10 (13 agosto 2018): e3996. http://dx.doi.org/10.1002/nbm.3996.

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34

Wallihan, Daniel B., Daniel J. Podberesky, Bradley S. Marino, Joshua S. Sticka e Suraj Serai. "Relationship of MR elastography determined liver stiffness with cardiac function after Fontan palliation". Journal of Magnetic Resonance Imaging 40, n. 6 (8 novembre 2013): 1328–35. http://dx.doi.org/10.1002/jmri.24496.

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Makūnaitė, Monika, Rytis Jurkonis, Arūnas Lukoševičius e Mindaugas Baranauskas. "Simulation of Ultrasound RF Signals Backscattered from a 3D Model of Pulsating Artery Surrounded by Tissue". Diagnostics 12, n. 2 (18 gennaio 2022): 232. http://dx.doi.org/10.3390/diagnostics12020232.

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Abstract (sommario):

Arterial stiffness is an independent predictor of cardiovascular events. The motion of arterial tissues during the cardiac cycle is important as a mechanical deformation representing vessel elasticity and is related to arterial stiffness. In addition, arterial pulsation is the main source of endogenous tissue micro-motions currently being studied for tissue elastography. Methods based on artery motion detection are not applied in clinical practice these days, because they must be carefully investigated in silico and in vitro before wide usage in vivo. The purpose of this paper is to propose a dynamic 3D artery model capable of reproducing the biomechanical behavior of human blood vessels surrounded by elastic tissue for endogenous deformation elastography developments and feasibility studies. The framework is based on a 3D model of a pulsating artery surrounded by tissue and simulation of linear scanning by Field II software to generate realistic dynamic RF signals and B-mode ultrasound image sequential data. The model is defined by a spatial distribution of motions, having patient-specific slopes of radial and longitudinal motion components of the artery wall and surrounding tissues. It allows for simulating the quantified mechanical micro-motions in the volume of the model. Acceptable simulation errors calculated between modeled motion patterns and those estimated from simulated RF signals and B-scan images show that this approach is suitable for the development and validation of elastography algorithms based on motion detection.

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Ihne-Schubert, Sandra Michaela, Oliver Goetze, Felix Gerstendörfer, Floran Sahiti, Ina Schade, Aikaterini Papagianni, Caroline Morbach et al. "Cardio-Hepatic Interaction in Cardiac Amyloidosis". Journal of Clinical Medicine 13, n. 5 (1 marzo 2024): 1440. http://dx.doi.org/10.3390/jcm13051440.

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Background: Congestion is associated with poor prognosis in cardiac amyloidosis (CA). The cardio-hepatic interaction and the prognostic impact of secondary liver affection by cardiac congestion in CA are poorly understood and require further characterisation. Methods: Participants of the amyloidosis cohort study AmyKoS at the Interdisciplinary Amyloidosis Centre of Northern Bavaria with proven transthyretin (ATTR-CA) and light chain CA (AL-CA) underwent serial work-up including laboratory tests, echocardiography, and in-depth hepatic assessment by vibration-controlled transient elastography (VCTE) and 13C-methacetin breath test. Results: In total, 74 patients with AL-CA (n = 17), ATTR-CA (n = 26) and the controls (n = 31) were analysed. ATTR-CA patients showed decreased microsomal liver function expressed by maximal percentage of dose rate (PDRpeak) related to hepatic congestion. Reduced PDRpeak in AL-CA could result from altered pharmacokinetics due to changed hepatic blood flow. Liver stiffness as a combined surrogate of chronic liver damage and congestion was identified as a predictor of all-cause mortality. Statistical modelling of the cardio-hepatic interaction revealed septum thickness, NT-proBNP and PDRpeak as predictors of liver stiffness in both CA subtypes; dilatation of liver veins and the fibrosis score FIB-4 were only significant for ATTR-CA. Conclusions: Non-invasive methods allow us to characterise CA-associated hepatic pathophysiology. Liver stiffness might be promising for risk stratification in CA.

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Caenen, Annette, Mathieu Pernot, Mathias Peirlinck, Luc Mertens, Abigail Swillens e Patrick Segers. "Anin silicoframework to analyze the anisotropic shear wave mechanics in cardiac shear wave elastography". Physics in Medicine & Biology 63, n. 7 (23 marzo 2018): 075005. http://dx.doi.org/10.1088/1361-6560/aaaffe.

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Mukaddim, Rashid Al, Nirvedh H. Meshram, Carol C. Mitchell e Tomy Varghese. "Hierarchical Motion Estimation With Bayesian Regularization in Cardiac Elastography: Simulation and $In~ Vivo$ Validation". IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 66, n. 11 (novembre 2019): 1708–22. http://dx.doi.org/10.1109/tuffc.2019.2928546.

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Borsukov, Aleksey V., Dmitry A. Doroshenko e Anastasiia I. Skutar. "DIAGNOSTIC EFFECTIVENESS OF DIFFERENT LIVER ELASTOMETRY METHODS IN PATIENTS WITH HEART FAILURE DEPENDING ON THE STAGE OF THE DISEASE". Acta medica Eurasica, n. 2 (26 giugno 2023): 1–13. http://dx.doi.org/10.47026/2413-4864-2023-2-1-13.

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Today, heart failure remains one of the most important public health problems. The leading pathogenetic mechanism of heart failure is stagnation in the systemic circulation, causing affection of one of the main target organs – the liver. Prolonged stagnation in the liver in combination with hypoperfusion of hepatocytes eventually results in liver fibrosis, followed by transformation into the so-called "cardiac cirrhosis". Biopsy with subsequent biopsy material examination remains the "gold standard" to diagnose liver damage, however, there are a number of limitations, risks, absolute and relative contraindications, due to which it is impossible to conduct an invasive diagnostic procedure in routine clinical practice settings. In recent years, medical community has paid much attention to an innovative non–invasive method of diagnosing liver fibrosis – ultrasound elastometry. To date, there are several types of this technique that are most commonly used in clinical practice: transient elastometry, point elastometry, two-dimensional shear wave elastography. Each of these methods has its advantages and disadvantages. The aim is to study and compare the diagnostic effectiveness (sensitivity, specificity and accuracy) of various types of ultrasound elastometry in diagnosing liver fibrosis in cardiac patients, depending on the stage of heart failure. Materials and methods. The study was conducted on the basis of diagnostic and minimally invasive technologies department at Clinical Hospital № 1 in Smolensk in the period from October 2022 to March 2023 Three groups of patients with heart failure were examined: Group 1 – patients with stage I of the disease (n = 12), group 2 – with stage II (n = 16), group 3 – with stage III (n = 11), a total of 39 patients. Comparative opportunities of transient liver elastometry, point elastometry and two-dimensional shear wave elastography in patients with various stages of heart failure were determined. The sensitivity, specificity and accuracy of the methods were evaluated. The methods of statistical analysis, generalization, comparison and systematization of data were used. The reference method was multispiral computed tomography with a quantitative assessment of the liver structure, biochemical blood analysis with De Ritis ratio determination and the FIB-4 scale. Results. In group 1, the sensitivity, specificity and accuracy indices did not differ statistically in 3 methods. In group 2 in transient elastometry: sensitivity made 58.1%, specificity – 67.4%, accuracy – 61.2%; in point elastometry: sensitivity made 64.7%, specificity – 82.6%, accuracy – 76.3%; in two–dimensional shear wave elastography: sensitivity made 87.4%, specificity – 93.1%, accuracy – 90.8%. In group 3, in transient elastometry, the study was uninformative, in point elastometry: sensitivity made 48.6%, specificity – 60.1%, accuracy – 52.3%; in two–dimensional shear wave elastography: sensitivity made 85.1%, specificity – 92.3%, accuracy – 88.4%. Conclusions. 1. In patients with stage I heart failure, the choice of a strictly defined elastometry technique is not fundamental, since the indicators of all three methods did not differ statistically. For patients with stage II and III heart failure, the use of shear wave elastometry is preferable, wherein at a late stage (stage III), the diagnostic effectiveness of two-dimensional shear wave elastography is higher than that of point elastometry. 2. Transient elastometry is less informative in patients with heart failure compared to shear wave elastometry.

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Kwiecinski, Wojciech, Francis Bessière, Elodie Constanciel Colas, W. Apoutou N’Djin, Mickaël Tanter, Cyril Lafon e Mathieu Pernot. "Cardiac shear-wave elastography using a transesophageal transducer: application to the mapping of thermal lesions in ultrasound transesophageal cardiac ablation". Physics in Medicine and Biology 60, n. 20 (25 settembre 2015): 7829–46. http://dx.doi.org/10.1088/0031-9155/60/20/7829.

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Iacob, Speranta, Andreea Jercan, Sorina Badelita, Camelia Dobrea, Ruxandra Jurcut, Monica Popescu, Mihaela Ghioca, Razvan Iacob, Liana Gheorghe e Daniel Coriu. "Systemic light chain AL with cardiac and liver involvement can be predicted by transient elastography". Journal of Hepatology 73 (agosto 2020): S782. http://dx.doi.org/10.1016/s0168-8278(20)32011-0.

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42

Wassenaar, Peter A., Chethanya N. Eleswarpu, Samuel A. Schroeder, Xiaokui Mo, Brian D. Raterman, Richard D. White e Arunark Kolipaka. "Measuring age-dependent myocardial stiffness across the cardiac cycle using MR elastography: A reproducibility study". Magnetic Resonance in Medicine 75, n. 4 (22 maggio 2015): 1586–93. http://dx.doi.org/10.1002/mrm.25760.

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43

Mirault, T., D. Lucidarme, B. Turlin, Y. Deugnier, P. Brissot, K. Kanaan, J. L. Demory et al. "Non Invasive Assessment of Hepatic Fibrosis by Measurement of Liver Stiffness in Post Transfusional Iron Overload: Preliminary Results in 15 Patients." Blood 108, n. 11 (16 novembre 2006): 3740. http://dx.doi.org/10.1182/blood.v108.11.3740.3740.

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Abstract Background: The prognosis of liver iron overload is highly dependent on liver iron content (LIC) and the extent of liver fibrosis. Liver biopsy is the invasive reference method for fibrosis evaluation but with several limitations. Non-invasive biological methods (FibroTest, APRI) are not applicable in blood diseases. Transient elastography (TE) is a new non-invasive and rapid bedside method used to measure liver stiffness.This technique has been extensively studied with success in evaluation of liver fibrosis in HCV infection (Ziol, Hepatology 2005; Castera, Gastroenterology 2005). Until now, no data are available on evaluation of liver fibrosis by TE in highly transfused patients with iron overload. Methods: We assessed liver stiffness (kPa) by elastography measurement (Fibroscan; Echosens, Paris, France). Ishak’s and Metavir’s scales were used to stage fibrosis and hepatitis activity; LIC was measured by atomic absorption spectometry in a central laboratory (Rennes, France) and by MRI procedure according to Gandon (Lancet 2004). Cardiac MRI T2* (indirect estimation of iron heart content) was also measured by MRI according to Anderson (Eur Heart J 2001). Serum ferritin level and HCV serology were assayed in all cases. Correlation statistical analysis used Spearman’s Rho and Pearson tests and mean comparisons were done by a non-parametric Mann-Whitney test. Results: 15 liver samples (weight >1mg except 1) from monthly transfused patients (13 major beta Thalassemia, 1 sickle cell disease, 1 myelodysplastic syndrome) were analyzed. Median age was 37 years (7–75). Histological results were: 3 cirrhosis (METAVIR F=4 (F4), or Ishak’s Staging =6 (IS6)) among 5 patients with severe fibrosis (F3,F4) or (IS4-6) and 10 patients with no or mild fibrosis (F0-2) or (IS0-3). Mean ferritin was 2579 ng/ml CI 95% [1372–3786]. 2 patients were HCV positive. Correlation between LIC and ferritin was 0.82 (p<0,05); between LIC and MRI LIC: 0.88 (p<0,05); LIC and MRI Heart T2*: 0.72(p<0,05); METAVIR F score and Ishak’s grading score: 0.86 (p<0,05). A correlation was also observed between METAVIR F and elastography: 0.60(p<0,05); and mean values of elastography were significally different in patients with severe fibrosis: 9.1kPa CI95% [4.5–13.7] vs 5.9kPa CI95% [4.6–7.2] in those without sever fibrosis (p<0,05) (fig). A value of elastography above 6.25kPa (Se=80%; Sp=70%; AUROC=0.820) identified patients at risk for severe fibrosis (F3,F4 or IS 4–6) (Negative Predictive Value = 88%; Positive Predictive Value = 57%). Conclusion: A significant correlation between Metavir Fibrosis scale and elastography values was found. This new non-invasive method would be helpful to evaluate liver fibrosis and to determine patients who could avoid invasive procedures in particular in regularly transfused low risk myelodysplastic patients at risk of bleeding due to abnormal platelet function. These preliminary results will have to be confirmed in a larger population. Figure Figure

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Pereira, Mário José, Alexandra André, Mário Monteiro, Maria António Castro, Rui Mendes, Fernando Martins, Ricardo Gomes, Vasco Vaz e Gonçalo Dias. "Methodology and Experimental Protocol for Studying Learning and Motor Control in Neuromuscular Structures in Pilates". Healthcare 12, n. 2 (17 gennaio 2024): 229. http://dx.doi.org/10.3390/healthcare12020229.

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The benefits of Pilates have been extensively researched for their impact on muscular, psychological, and cardiac health, as well as body composition, among other aspects. This study aims to investigate the influence of the Pilates method on the learning process, motor control, and neuromuscular trunk stabilization, specifically in both experienced and inexperienced practitioners. This semi-randomized controlled trial compares the level of experience among 36 Pilates practitioners in terms of motor control and learning of two Pilates-based skills: standing plank and side crisscross. Data will be collected using various assessment methods, including abdominal wall muscle ultrasound (AWMUS), shear wave elastography (SWE), gaze behavior (GA) assessment, electroencephalography (EEG), and video motion. Significant intra- and inter-individual variations are expected, due to the diverse morphological and psychomotor profiles in the sample. The adoption of both linear and non-linear analyses will provide a comprehensive evaluation of how neuromuscular structures evolve over time and space, offering both quantitative and qualitative insights. Non-linear analysis is expected to reveal higher entropy in the expert group compared to non-experts, signifying greater complexity in their motor control. In terms of stability, experts are likely to exhibit higher Lyapunov exponent values, indicating enhanced stability and coordination, along with lower Hurst exponent values. In elastography, experienced practitioners are expected to display higher transversus abdominis (TrA) muscle elasticity, due to their proficiency. Concerning GA, non-experts are expected to demonstrate more saccades, focus on more Areas of Interest (AOIs), and shorter fixation times, as experts are presumed to have more efficient gaze control. In EEG, we anticipate higher theta wave values in the non-expert group compared to the expert group. These expectations draw from similar studies in elastography and correlated research in eye tracking and EEG. They are consistent with the principles of the Pilates Method and other scientific knowledge in related techniques.

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Koca, Hasan, Ayse Selcan Koc, Hilmi Erdem Sumbul e Mevlut Koc. "Liver stiffness increases in patients with severe pericardial effusion, especially in the presence of cardiac tamponade". Medical Ultrasonography 22, n. 2 (11 maggio 2020): 133. http://dx.doi.org/10.11152/mu-2295.

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Aims: Liver stiffness (LS) is associated with central venous pressure and pericardial effusion (PE) may be associated with these increased pressures. The aim of this study was to investigate the change in LS obtained by liver elastography (LE) in patients with severe PE and its usefulness for the diagnosis of cardiac tamponade.Materials and methods: Forty-patients with severe-PE were included in this study. All patients underwent LE examination in addition to echocardiography. Patients were divided into 2 groups: with and without cardiac tamponade.Results: In patients with cardiac tamponade, LS values, inspiratory-expiratory vena cava inferior (VCI) diameters and presence of <50% inspiratory-VCI collapse was significantly higher. LS value and inspiratory-VCI diameter before pericardiocentesis independently determined the risk of cardiac tamponade. Each 1kPa increase in LS value and 1mm increase in inspiratory-VCI diameter increased the risk of cardiac tamponade by 4.9-times and 40.8%, respectively. When the cut-off value of 10kPa for LS was analyzed, it determined the presence of cardiac tamponade with ≥90% sensitivity and specificity. The higher LS before pericardiocentesis and the decrease in LS after pericardiocentesis (Δ-Liver stiffness of 5.91±1.79 kPa in first group and 2.31±1.25 kPa in the second group) was interpreted to be directly related to the pathophysiology of systemic congestion due to PE.Conclusion: In all patients with severe PE, and especially in patients with cardiac tamponade, the LS is significantly increased and this modification can be explained by the systemic congestion. However, this being the first study to evaluate LS in patients with severe PE and cardiac tamponade, the data should be confirmed by multicenter prospective studies.

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Chen, Becky, Richard A. Schreiber, Derek G. Human, James E. Potts e Orlee R. Guttman. "Assessment of Liver Stiffness in Pediatric Fontan Patients Using Transient Elastography". Canadian Journal of Gastroenterology and Hepatology 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/7125193.

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Background. Hepatic fibrosis is a potential complication following Fontan surgery and heralds long-term risk for cirrhosis. Transient elastography (TE) is a rapid, noninvasive method to assess liver fibrosis by measuring liver stiffness.Objectives. To compare liver stiffness and liver biochemistries in pediatric Fontan patients with age- and sex-matched controls and to determine patients’ acceptance of TE.Methods. Patients were recruited from British Columbia Children’s Hospital. Twenty-two Fontan patients (15 males) were identified. Demographic information and cardiac data were collected. TE was measured using size-appropriate probes.Results. The median age of the Fontan cohort was 13.7 (5.9–16.8) years. Time from Fontan surgery to TE was 9.6 (1.0–12.9) years. The median Fontan circuit pressure was 13 (11–14) mmHg. TE values were higher in Fontan patients versus controls (18.6 versus 4.7 kPa,p<0.001). There was no association between TE values and patient age (r=0.41,p=0.058), time since Fontan surgery (r=0.40,p=0.062), or median Fontan circuit pressure (CVP) (r=0.35,p=0.111). Patients found TE to be nonpainful, convenient, and safe.Conclusions. TE is feasible to assess liver stiffness in children following Fontan surgery. Pediatric Fontan patients have markedly elevated liver stiffness values. TE may have important utility in liver care follow-up of pediatric Fontan patients.

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Sawicki, Rafał, Samuel Mazur, Piotr Kotarski, Katarzyna Sklinda e Jerzy Walecki. "A non-cardiac applications of T1-mapping". Wiedza Medyczna 3, n. 2 (22 novembre 2021): 10–14. http://dx.doi.org/10.36553/wm.87.

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T1-mapping has proven to be a valuable tool in cardiac imaging. While mainly used in cardiac MRI, it is investigated for usage and application of T1-mapping to imaging of other organs and systems, including abdominal imaging, musculoskeletal imaging or neuroradiology, resulting in potential new prospects for medical imaging. T1-mapping provides numerical data on an inherent, physical property of imaged tissue – enabling quantitative and comparative assessment of tissue characterization f.ex. fibrosis, amyloid contents, fatty transformation, myelinization or contrast enhancement as well as lesion characterization. Reports of application of T1-mapping in assessment of liver, kidney or pancreas fibrosis create perspectives of reducing the number of invasive diagnostic procedures, such as biopsies, as well as monitoring treatment response or disease progression. Furthermore T1-mapping can potentially replace MR elastography in assessment of liver fibrosis or used in thyroid fibrosis to define degree of destruction in AIT or other thyroid diseases. In neuroradiology T1-mapping is promising in the spine imaging, enabling better characterization of spinal cord lesions also has a potential to evaluate effectiveness of conservative or operative treatment. There are also successful reports of employing T1-mapping in orbital imaging, such as in predicting steroid resistant diplopia in Graves’ disease or in evaluation of diabetic cataracts. In musculoskeletal imaging, T1-relaxation could be a possible biomarker of bone quality that could play a role in osteoporotic fracture risk assessment. In conclusion, T1-mapping shows promise as a quantitative method complementary to standard MR imaging beyond cardiac MRI, and needs further research and validation efforts to establish its place in standard diagnostic protocols.

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Sabbadini, A., L. B. H. Keijzer, H. J. Vos, N. de Jong e M. D. Verweij. "Fundamental modeling of wave propagation in temporally relaxing media with applications to cardiac shear wave elastography". Journal of the Acoustical Society of America 147, n. 5 (maggio 2020): 3091–99. http://dx.doi.org/10.1121/10.0001161.

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Hong, Wei, Rui-qiang Guo, Jin-ling Chen, E.-Hui Han e Tian Wu. "The implementation of the elastography score in combination with ultrasound prevents unnecessary biopsy of cardiac lesions". Biomedicine & Pharmacotherapy 97 (gennaio 2018): 395–401. http://dx.doi.org/10.1016/j.biopha.2017.10.081.

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de Korte, Chris L., Hendrik H. G. Hansen e Anton F. W. van der Steen. "Vascular ultrasound for atherosclerosis imaging". Interface Focus 1, n. 4 (giugno 2011): 565–75. http://dx.doi.org/10.1098/rsfs.2011.0024.

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Cardiovascular disease is a leading cause of death in the Western world. Therefore, detection and quantification of atherosclerotic disease is of paramount importance to monitor treatment and possible prevention of acute events. Vascular ultrasound is an excellent technique to assess the geometry of vessel walls and plaques. The high temporal as well as spatial resolution allows quantification of luminal area and plaque size and volume. While carotid arteries can be imaged non-invasively, scanning of coronary arteries requires invasive intravascular catheters. Both techniques have already demonstrated their clinical applicability. Using linear array technology, detection of disease as well as monitoring of pharmaceutical treatment in carotid arteries are feasible. Data acquired with intravascular ultrasound catheters have proved to be especially beneficial in understanding the development of atherosclerotic disease in coronary arteries. With the introduction of vascular elastography not only the geometry of plaques but also the risk for rupture of plaques might be identified. These so-called vulnerable plaques are frequently not flow-limiting and rupture of these plaques is responsible for the majority of cerebral and cardiac ischaemic events. Intravascular ultrasound elastography studies have demonstrated a high correlation between high strain and vulnerable plaque features, both ex vivo and in vivo . Additionally, pharmaceutical intervention could be monitored using this technique. Non-invasive vascular elastography has recently been developed for carotid applications by using compound scanning. Validation and initial clinical evaluation is currently being performed. Since abundance of vasa vasorum (VV) is correlated with vulnerable plaque development, quantification of VV might be a unique tool to even prevent this from happening. Using ultrasound contrast agents, it has been demonstrated that VV can be identified and quantified. Although far from routine clinical application, non-invasive and intravascular ultrasound VV imaging might pave the road to prevent atherosclerotic disease in an early phase. This paper reviews the conventional vascular ultrasound techniques as well as vascular ultrasound strain and vascular ultrasound VV imaging.

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