Output Measurements For Medical Ultrasound

Medical applications of ultrasound range from therapy, foetal monitoring, diagnostic imaging and blood flow measurement, to surgery and lithotripsy. Ever since the earliest developments of medical ultrasound there has been an interest in the measurement and characterisation of the ultrasonic fields generated in these applications, either for assessment of performance of equipment or for safety. Until recently, procedures for acoustic output measurements were ill-defined, but standards are now being developed internationally by the International Electrotechnical Commission (1EC) and reliable commercial measuring equipment is becoming more widely available. The aim of this book is to introduce acoustic output measurement techniques and to provide an insight into the measurement methods. The material presented is based on a course originally run during November 1989 at the National Physical Laboratory. In addition to the lectures, the course consisted of a series of practicals to allow participants to gain experience of making measurements. Teddington, UK Roy C. Preston February 1991 Contents List of Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii List of Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 Safety of Diagnostic Ultrasonic Equipment: The Relevance of Acoustic Output Information to the Clinical User R. C. Preston 1. 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 2 The Relevance of Acoustic Output Information. . . . . . . . . . . . . 6 1. 2. 1 What Is Acoustic Output Information? . . . . . . . . . . . . . . . . . . . 6 1. 2. 2 What Is Acoustic Output Information Used For? . . . . . . . 6 1. 2. 3 Why Should You Know the Acoustic Output Levels of Your Equipment? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1. 2. 4 Are Acoustic Output Levels Really that Important? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

All healthcare professionals practising ultrasound in a clinical setting should receive accredited training in the principles and practice of ultrasound scanning. This second edition of Diagnostic Ultrasound: Physics and Equipment provides a comprehensive introduction to the physics, technology and safety of ultrasound equipment, with high quality ultrasound images and diagrams throughout. It covers all aspects of the field at a level intended to meet the requirements of UK sonography courses. New to this edition: • Updated descriptions of ultrasound technology, quality assurance and safety. • Additional chapters dedicated to 3D ultrasound, contrast agents and elastography. • New glossary containing definitions of over 500 terms. The editors and contributing authors are all authorities in their areas, with contributions to the scientific and professional development of ultrasound at national and international level.

One of the first applications of ultrasound was in submarine sonar equip ment. Since then ultrasound has found increasing applications, particularly in industry, but increasingly in biomedicine. For many years ultrasound has been used in physical therapy, although only in the past decade or two has it evolved from laboratory curiosity to a well-established diagnostic imaging modality. Ultrasound is now a widely accepted, indeed pervasive, diagnos tic and therapeutic tool in the medical field, and its applications are increasing rapidly. Our intent in developing this book is to provide a coherent tutorial intro duction to the field of medical ultrasound at a level suitable for those en tering the area from either medical or scientific backgrounds. The topics discussed should be of interest to nearly all medical and health care per sonnel needing to understand or operate ultrasonic devices, including clini cians, medical technicians, physiotherapists, medical physicists, and other biomedical scientists interested in the field. The book opens with a description of the basic principles of propagating acoustic waves, explains how they interact with a wide range of biological systems, and outlines the effects they produce. To provide practical infor mation to operators of ultrasound equipment, we have included thorough coverage of the details of ultrasonic instrumentation and measurement techniques, and set forth the framework for an effective quality assurance program.

Ultrasonic Exposimetry presents the fundamentals of ultrasonics and discusses the theoretical background of acoustic wave generation and reception. Measurements, instrumentation, and interpretation of measured data (including error analysis) are examined in detail.