Download or read book Quantitative Ultrasound Imaging During Ablation Procedures written by Kayvan Samimi and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conventional ultrasound imaging (i.e. B-mode sonogram) is a qualitative mode of imaging based on visualizing the relative echogenicity of different tissue types within the body. This useful mode of imaging has aided clinicians for more than 50 years. However, B-mode imaging does not capture any of the frequency-dependent information that is contained within the ultrasound echo signal. Additionally, due to its qualitative nature, there is much inter-system and inter-observer variability with regard to generation and interpretation of B-mode images. Quantitative Ultrasound (QUS) methods have been developed to extract additional information by estimating acoustic properties of tissue from the frequency-domain representation of echo signals. These estimates can be converted to color-coded maps that are visualized along with conventional B-mode images to form enhanced ultrasound images. Such images can potentially provide valuable diagnostic and prognostic information to medical professionals. Some of the more important acoustic parameters of interest in QUS and tissue characterization are the ultrasonic attenuation coefficient and the backscatter coefficient. Attenuation has been studied as a potential classifier of normal and pathological liver tissue. In addition to providing pathological information for diagnosis, monitoring these QUS parameters during therapeutic procedures such as tumor ablation can lead to targeted and optimized treatment. The goals of this dissertation are to theoretically model and analyze current methods of acoustic attenuation estimation; improve attenuation estimation algorithms to enhance the quality of subsequent QUS images; and correlate changes in QUS parameter values with progression of thermally ablative procedures for ex-vivo and in-vivo liver ablations. Although QUS imaging may be used to assist clinicians in various stages of diagnosis and treatment of diseases in a multitude of bodily organs and tissue types, this dissertation focuses on thermal ablation of primary or metastatic liver tumors in order to showcase the possible benefits of the proposed estimation methods and to compare their performance with existing estimation techniques. Additionally, simulated and physical tissue-mimicking (TM) phantoms with known acoustic properties are used to statistically test and compare the accuracy and precision of these methods. Theoretical analysis and experimental results suggest that our proposed method for estimation of the ultrasonic attenuation coefficient based on measurement of frequency shifts in a normalized power-spectral representation of the ultrasonic echo signal is best suited to in-vivo QUS imaging in clinical settings and provides estimates with standard deviations that are at least three times smaller than was previously possible with other methods.
Download or read book Quantitative Ultrasound Imaging of Thermal Ablation Therapy in the Liver written by and published by . This book was released on 2014 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this dissertation is to investigate methods for delineating the extent of the thermally coagulated region following thermal ablation therapy of malignant tumors in the liver. In this dissertation, we examine quasistatic elasticity imaging for delineating the extent of the treated region. Next, we characterize scattering in normal, untreated liver and thermally coagulated liver. Finally, we examine attenuation estimation with reference phantom methods in the liver. It has been well established that the Young's modulus of thermally coagulated tissue is much larger than in untreated liver tissue, making elastographic imaging an attractive candidate for delineating the extent of thermal coagulation. In quasistatic elastographic imaging of superficial organs such as the breast, external compression may be performed with a compressor plate or the transducer itself. However, in abdominal imaging, external compression is not effective. In response, our laboratory has developed electrode displacement for strain and modulus imaging. In electrode displacement strain imaging, deformation is applied by displacing the end of the RF electrode or microwave antenna by a small amount following treatment. We present electrode displacement strain images of thermally coagulated regions in in vivo porcine animal models during open surgery. We show that cross-sectional areas of treated regions delineated on electrode displacement strain images correlate well with coagulated areas determined on optical photographs of ablated regions of the excised livers. Additionally, we present electrode displacement strain images of VX2 tumors in rabbit animal models prior to and following thermal ablation. Next, we develop mean scatterer spacing (MSS) estimation in the liver. In the liver, it has been hypothesized that periodic scattering results from a unique arrangement of microvasculature. Indeed, the liver is a unique organ because of its dual vascular supply from the hepatic artery and portal vein. We first show that utilizing a multi-taper spectral calculation results in a lower mean square error in MSS estimates using simulations of periodic tissue. Next, we show that average spectral coherence decreases in thermally coagulated liver compared with untreated liver in a small number of ex vivo RF ablations. Finally, we demonstrate that thermally coagulated regions are best modeled by aperiodic collections of scatterers, while normal liver exhibits periodicity. In the final section of the dissertation we consider attenuation estimation. This is an attractive area of research because the attenuation coefficient is approximately doubles in the liver following thermal ablation. In past works, authors have developed attenuation algorithms with the assumption that the tissue being imaged may be modeled by a collection of a large number of randomly distributed scatterers. We show that in ex vivo bovine liver the scatterer number density is small. We demonstrate that the effect this has on attenuation estimation is to significantly increase the variance in attenuation estimation relative to tissue that may be modeled with a large scatterer number density. Using computer simulation and phantom experiments we show that when the scatterer number density is sufficiently large it is possible to achieve low variance, high resolution attenuation estimates. However, as the scatterer number density decreases either spatial resolution in the attenuation estimate must be sacrificed or attenuation estimate variance will increase. We find a linear attenuation coefficient in thermally coagulated liver that is approximately double the attenuation coefficient of normal, untreated liver. However, we also find a low scatterer number density in these tissues and a correspondingly high attenuation estimation variance.
Download or read book MRI Guided Focused Ultrasound Surgery written by Ferenc A. Jolesz and published by CRC Press. This book was released on 2007-09-26 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: MRI-Guided Focused Ultrasound Surgery will be the first publication on this new technology, and will present a variety of current and future clinical applications in tumor ablation treatment. This source helps surgeons and specialists evaluate, analyze, and utilize MRI-guided focused ultrasound surgery - bridging the gap between phase 3 clinical tr
Download or read book Ultrafast Ultrasound Imaging written by Hideyuki Hasegawa and published by MDPI. This book was released on 2018-09-21 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Ultrafast Ultrasound Imaging" that was published in Applied Sciences
Download or read book Quantitative Ultrasound in Soft Tissues written by Jonathan Mamou and published by Springer Science & Business Media. This book was released on 2013-09-26 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to parallel advances in signal processing and computer hardware in the last 15 years, quantitative ultrasound techniques have reached maturity, allowing for the construction of quantitative maps or images of soft tissues. This book will focus on 5 modern research topics related to quantitative ultrasound of soft tissues: - Spectral-based methods for tissue characterization, tissue typing, cancer detection, etc.; - Envelope statistics analysis as a means of quantifying and imaging tissue properties; - Ultrasound elastography for quantifying elastic properties of tissues (several clinical ultrasound scanners now display elastography images); - Scanning acoustic microscopy for forming images of mechanical properties of soft tissues with micron resolution (desktop size scanners are now available); and - Ultrasound computer tomography for breast cancer imaging (new ultrasound tomography systems have been developed and are currently under evaluation clinically).
Download or read book Intracardiac Echocardiography written by Frank E. Silvestry and published by CRC Press. This book was released on 2021-09-02 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intracardiac Echocardiography is the first echocardiographic textbook of its kind to specifically cover ICE. Discussing all aspects of intracardiac ultrasound, it allows readers to perfect ICE image acquisition and helps to guide interpretation of this information during interventional and electrophysiologic procedures. Unique and informative, the text explores: introductory echo physics currently available intracardiac ultrasound systems basic image acquisition the role of ICE in both the interventional and electrophysiology laboratory, as well as in the diagnostic setting. Featuring expert commentary by leaders in the field, the book also includes high quality echocardiographic images illustrating how ICE is used in a wide variety of procedures such as transseptal catheterization, PFO and ASD closure, atrial fibrillation ablation procedures, and many others.
Download or read book Functional Imaging and Modeling of the Heart written by Daniel B. Ennis and published by Springer. This book was released on 2021-06-18 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 11th International Conference on Functional Imaging and Modeling of the Heart, which took place online during June 21-24, 2021, organized by the University of Stanford. The 65 revised full papers were carefully reviewed and selected from 68 submissions. They were organized in topical sections as follows: advanced cardiac and cardiovascular image processing; cardiac microstructure: measures and models; novel approaches to measuring heart deformation; cardiac mechanics: measures and models; translational cardiac mechanics; modeling electrophysiology, ECG, and arrhythmia; cardiovascular flow: measures and models; and atrial microstructure, modeling, and thrombosis prediction.
Download or read book Tumor Ablation written by Eric van Sonnenberg and published by Springer Science & Business Media. This book was released on 2008-09-08 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is an enormous sense of excitement in the communities of cancer research and cancer care as we move into the middle third of the ?rst decade of the 21st century. For the ?rst time,there is a true sense of c- ?dence that the tools provided by the human genome project will enable cancer researchers to crack the code of genomic abnormalities that allow tumor cells to live within the body and provide highly speci?c, virtually non-toxic therapies for the eradication,or at least ?rm control of human cancers. There is also good reason to hope that these same lines of inquiry will yield better tests for screening, early detection, and prev- tion of progression beyond curability. While these developments provide a legitimate basis for much op- mism, many patients will continue to develop cancers and suffer from their debilitating effects, even as research moves ahead. For these in- viduals, it is imperative that the cancer ?eld make the best possible use of the tools available to provide present day cancer patients with the best chances for cure, effective palliation, or, at the very least, relief from symptoms caused by acute intercurrent complications of cancer. A modality that has emerged as a very useful approach to at least some of these goals is tumor ablation by the use of physical or physiochemical approaches.
Download or read book Diagnostic Ultrasound Imaging Inside Out written by Thomas L. Szabo and published by Academic Press. This book was released on 2013-12-05 with total page 829 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diagnostic Ultrasound Imaging provides a unified description of the physical principles of ultrasound imaging, signal processing, systems and measurements. This comprehensive reference is a core resource for both graduate students and engineers in medical ultrasound research and design. With continuing rapid technological development of ultrasound in medical diagnosis, it is a critical subject for biomedical engineers, clinical and healthcare engineers and practitioners, medical physicists, and related professionals in the fields of signal and image processing. The book contains 17 new and updated chapters covering the fundamentals and latest advances in the area, and includes four appendices, 450 figures (60 available in color on the companion website), and almost 1,500 references. In addition to the continual influx of readers entering the field of ultrasound worldwide who need the broad grounding in the core technologies of ultrasound, this book provides those already working in these areas with clear and comprehensive expositions of these key new topics as well as introductions to state-of-the-art innovations in this field. - Enables practicing engineers, students and clinical professionals to understand the essential physics and signal processing techniques behind modern imaging systems as well as introducing the latest developments that will shape medical ultrasound in the future - Suitable for both newcomers and experienced readers, the practical, progressively organized applied approach is supported by hands-on MATLAB® code and worked examples that enable readers to understand the principles underlying diagnostic and therapeutic ultrasound - Covers the new important developments in the use of medical ultrasound: elastography and high-intensity therapeutic ultrasound. Many new developments are comprehensively reviewed and explained, including aberration correction, acoustic measurements, acoustic radiation force imaging, alternate imaging architectures, bioeffects: diagnostic to therapeutic, Fourier transform imaging, multimode imaging, plane wave compounding, research platforms, synthetic aperture, vector Doppler, transient shear wave elastography, ultrafast imaging and Doppler, functional ultrasound and viscoelastic models
Download or read book Ultrasound Elastography for Biomedical Applications and Medicine written by Ivan Z. Nenadic and published by John Wiley & Sons. This book was released on 2018-10-25 with total page 919 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrasound Elastography for Biomedical Applications and Medicine Ivan Z. Nenadic, Matthew W. Urban, James F. Greenleaf, Mayo Clinic Ultrasound Research Laboratory, Mayo Clinic College of Medicine, USA Jean-Luc Gennisson, Miguel Bernal, Mickael Tanter, Institut Langevin – Ondes et Images, ESPCI ParisTech CNRS, France Covers all major developments and techniques of Ultrasound Elastography and biomedical applications The field of ultrasound elastography has developed various techniques with the potential to diagnose and track the progression of diseases such as breast and thyroid cancer, liver and kidney fibrosis, congestive heart failure, and atherosclerosis. Having emerged in the last decade, ultrasound elastography is a medical imaging modality that can noninvasively measure and map the elastic and viscous properties of soft tissues. Ultrasound Elastography for Biomedical Applications and Medicine covers the basic physics of ultrasound wave propagation and the interaction of ultrasound with various media. The book introduces tissue elastography, covers the history of the field, details the various methods that have been developed by research groups across the world, and describes its novel applications, particularly in shear wave elastography. Key features: Covers all major developments and techniques of ultrasound elastography and biomedical applications. Contributions from the pioneers of the field secure the most complete coverage of ultrasound elastography available. The book is essential reading for researchers and engineers working in ultrasound and elastography, as well as biomedical engineering students and those working in the field of biomechanics.
Download or read book Irreversible Electroporation written by Boris Rubinsky and published by Springer Science & Business Media. This book was released on 2009-11-25 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-thermal irreversible electroporation is a new minimally invasive surgical p- cedure with unique molecular selectivity attributes – in fact it may be considered the first clinical molecular surgery procedure. Non-thermal irreversible electro- ration is a molecular selective mode of cell ablation that employs brief electrical fields to produce nanoscale defects in the cell membrane, which can lead to cell death, without an effect on any of the other tissue molecules. The electrical fields can be produced through contact by insertion of electrode needles around the undesirable tissue and non-invasively by electromagnetic induction. This new - dition to the medical armamentarium requires the active involvement and is of interest to clinical physicians, medical researchers, mechanical engineers, che- cal engineers, electrical engineers, instrumentation designers, medical companies and many other fields and disciplines that were never exposed in their training to irreversible electroporation or to a similar concept. This edited book is designed to be a comprehensive introduction to the field of irreversible electroporation to those that were not exposed or trained in the field before and can also serve as a reference manual. Irreversible electroporation is broad and interdisciplinary. Therefore, we have made an attempt to cover every one of the various aspects of the field from an introductory basic level to state of the art.
Download or read book Ultrasound Imaging and Therapy written by Aaron Fenster and published by Taylor & Francis. This book was released on 2015-05-08 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: Up-to-Date Details on Using Ultrasound Imaging to Help Diagnose Various DiseasesDue to improvements in image quality and the reduced cost of advanced features, ultrasound imaging is playing a greater role in the diagnosis and image-guided intervention of a wide range of diseases. Ultrasound Imaging and Therapy highlights the latest advances in usin
Download or read book Foundations of Biomedical Ultrasound written by Richard S. C. Cobbold and published by Oxford University Press. This book was released on 2006-09-07 with total page 844 pages. Available in PDF, EPUB and Kindle. Book excerpt: Foundations of Biomedical Ultrasound provides a thorough and detailed treatment of the underlying physics and engineering of medical ultrasound practices. It covers the fundamental engineering behind ultrasound equipment, properties of acoustic wave motion, the behavior of waves in various media, non-linear waves and the creation of images. The most comprehensive book on the subject, Foundations of Biomedical Ultrasound is an indispensable reference for any medical professional working with ultrasound imaging, and a comprehensive introduction to the subject for students. The author has been researching and teaching biomedical ultrasonics at the University of Toronto for the past 25 years.
Download or read book Photons Plus Ultrasound written by Alexander A. Oraevsky and published by . This book was released on 2012 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes Proceedings Vol. 7821
Download or read book Catheter Ablation of Persistent Atrial Fibrillation written by Mark D. O'Neill and published by Remedica Publishing. This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigates electrogram interpretation in atrial fibrillation. Describes a pragmatic approach to the targeting of such electrograms, and provides what is believed to be the mechanism underlying specific activation patterns. Illustrated with tracings and anatomical maps, it provides a detailed guide which electrophysiologists and cardiologists will find indispensable.
Download or read book Emerging Therapeutic Ultrasound written by Jun-ru Wu and published by World Scientific. This book was released on 2006-08-10 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: With contributions by internationally re-knowned authorities and experts in the field of ultrasonic imaging, this book provides comprehensive reviews on basic physical principles and applications of emerging and rapidly developing therapeutic techniques.In specific, reviews of mechanisms for bioeffects of ultrasound relevant to therapeutic applications, high intensity focused ultrasound and its application in surgery, ultrasound assisted target drug and gene delivery, as well as transdermal drug delivery are discussed.The book will be a useful reference source for graduate students, academics and researchers.
Download or read book Electrocardiographic Imaging written by Maria S. Guillem and published by Frontiers Media SA. This book was released on 2020-04-17 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrical activity in the myocardium coordinates the contraction of the heart, and its knowledge could lead to a better understanding, diagnosis, and treatment of cardiac diseases. This electrical activity generates an electromagnetic field that propagates outside the heart and reaches the human torso surface, where it can be easily measured. Classical electrocardiography aims to interpret the 12-lead electrocardiogram (ECG) to determine cardiac activity and support the diagnosis of cardiac pathologies such as arrhythmias, altered activations, and ischemia. More recently, a higher number of leads is used to reconstruct a more detailed quantitative description of the electrical activity in the heart by solving the so-called inverse problem of electrocardiography. This technique is known as ECG imaging. Today, clinical applications of ECG imaging are showing promising results in guiding a variety of electrophysiological interventions such as catheter ablation of atrial fibrillation and ventricular tachycardia. However, in order to promote the adoption of ECG imaging in the routine clinical practice, further research is required regarding more accurate mathematical methods, further scientific validation under different preclinical scenarios and a more extensive clinical validation
