Ultrasound B-mode Imaging: Beamforming and Image Formation Techniques


Book Description

Ultrasound medical imaging stands out among the other diagnostic imaging modalities for its patient-friendliness, high temporal resolution, low cost, and absence of ionizing radiation. On the other hand, it may still suffer from limited detail level, low signal-to-noise ratio, and narrow field-of-view. In the last decade, new beamforming and image reconstruction techniques have emerged which aim at improving resolution, contrast, and clutter suppression, especially in difficult-to-image patients. Nevertheless, achieving a higher image quality is of the utmost importance in diagnostic ultrasound medical imaging, and further developments are still indispensable. From this point of view, a crucial role can be played by novel beamforming techniques as well as by non-conventional image formation techniques (e.g., advanced transmission strategies, and compounding, coded, and harmonic imaging). This Special Issue includes novel contributions on both ultrasound beamforming and image formation techniques, particularly addressed at improving B-mode image quality and related diagnostic content. This indeed represents a hot topic in the ultrasound imaging community, and further active research in this field is expected, where many challenges still persist.




Beamforming in Medical Ultrasound Imaging


Book Description

This book deals with the concept of medical ultrasound imaging and discusses array signal processing in ultrasound. Signal processing using different beamforming techniques in order to achieve a desirable reconstructed image and, consequently, obtain useful information about the imaging medium is the main focus of this book. In this regard, the principles of image reconstruction techniques in ultrasound imaging are fully described, and the required processing steps are completely expanded and analyzed in detail. Simulation results to compare the performance of different beamformers are also included in this book to visualize their differences to the reader. Other advanced techniques in the field of medical ultrasound data processing, as well as their corresponding recent achievements, are also presented in this book. Simply put, in this book, processing of medical ultrasound data from different aspects and acquiring information from them in different manners are covered and organized in different chapters. Before going through the detailed explanation in each chapter, it gives the reader an overview of the considered issue and focuses his\her mind on the challenge ahead. The contents of the book are also presented in such a way that they are easy for the reader to understand. This book is recommended for researchers who study medical ultrasound data processing.




Ultrasound B-mode Imaging: Beamforming and Image Formation Techniques


Book Description

Ultrasound medical imaging stands out among the other diagnostic imaging modalities for its patient-friendliness, high temporal resolution, low cost, and absence of ionizing radiation. On the other hand, it may still suffer from limited detail level, low signal-to-noise ratio, and narrow field-of-view. In the last decade, new beamforming and image reconstruction techniques have emerged which aim at improving resolution, contrast, and clutter suppression, especially in difficult-to-image patients. Nevertheless, achieving a higher image quality is of the utmost importance in diagnostic ultrasound medical imaging, and further developments are still indispensable. From this point of view, a crucial role can be played by novel beamforming techniques as well as by non-conventional image formation techniques (e.g., advanced transmission strategies, and compounding, coded, and harmonic imaging). This Special Issue includes novel contributions on both ultrasound beamforming and image formation techniques, particularly addressed at improving B-mode image quality and related diagnostic content. This indeed represents a hot topic in the ultrasound imaging community, and further active research in this field is expected, where many challenges still persist.







Advanced beamforming techniques in ultrasound imaging and the associated inverse problems


Book Description

Ultrasound (US) allows non-invasive and ultra-high frame rate imaging procedures at reduced costs. Cardiac, abdominal, fetal, and breast imaging are some of the applications where it is extensively used as diagnostic tool. In a classical US scanning process, short acoustic pulses are transmitted through the region-of-interest of the human body. The backscattered echo signals are then beamformed for creating radiofrequency(RF) lines. Beamforming (BF) plays a key role in US image formation, influencing the resolution and the contrast of final image. The objective of this thesis is to model BF as an inverse problem, relating the raw channel data to the signals to be recovered. The proposed BF framework improves the contrast and the spatial resolution of the US images, compared with the existing BF methods. To begin with, we investigated the existing BF methods in medical US imaging. We briefly review the most common BF techniques, starting with the standard delay-and-sum BF method and emerging to the most known adaptive BF techniques, such as minimum variance BF. Afterwards, we investigated the use of sparse priors in creating original two-dimensional beamforming methods for ultrasound imaging. The proposed approaches detect the strong reflectors from the scanned medium based on the well-known Bayesian Information Criteria used in statistical modeling. Furthermore, we propose a new way of addressing the BF in US imaging, by formulating it as a linear inverse problem relating the reflected echoes to the signal to be recovered. Our approach offers flexibility in the choice of statistical assumptions on the signal to be beamformed and it is robust to a reduced number of pulse emissions. At the end of this research, we investigated the use of the non-Gaussianity properties of the RF signals in the BF process, by assuming alpha-stable statistics of US images.




Diagnostic Ultrasound Imaging: Inside Out


Book Description

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




Efficient Two-pass Beamforming Applied to Ultrasound Imaging


Book Description

In the past decade, the application of adaptive beamforming methods to medical ultrasound imaging has become a field of increased interest, due to their ability to achieve superior ultrasound image quality. Such enhancements, however, come at a high computational cost. This thesis attempts to address the following simple question: Can we maintain a superior image quality while reducing the computational cost of adaptive beamforming? Our goal is to effectively combine low-complexity nonadaptive beamforming, such as the Delay-and-Sum (DAS) technique, with high-complexity adaptive beamforming, such as the Minimum variance Distortionless Response (MVDR) technique, implemented using the Generalized Sidelobe Canceller (GSC), to obtain high-quality images at low computational cost. We propose a simple two-pass beamforming scheme for that purpose. During the first pass, our scheme processes buffered input vectors using the inexpensive DAS method and computes the corresponding envelope. Based on that envelope information, selected outputs may be recomputed during the second pass (to improve beamforming performance) using the expensive GSC beamforming method. The purpose of the first pass is to identify which nonadaptively beamformed outputs can be spared from a heavy computational load of adaptive beamforming taking place in the second pass. We have evaluated our scheme using simulated ultrasound images of a 12-point phantom and a point-scatterer-cyst phantom, achieving substantial threshold-dependent computational savings without significant degradation in image resolution and contrast, compared to pure GSC beamforming.