Acoustical Imaging

The formation of images by ultrasound is a fascinating study, with well-established, yet rapidly growing, applic­ ations in medicine and with increasing relevance to a surprisingly disparate set of problems in the non-destructive examination of materials and components. The present volume is a record of the research presented at the Twelfth International Symposium on Acoustic Imaging, held in London during July 1982. Whilst, therefore, it offers primarily a snap-shot in time of a rapidly developing field, it is so organized that it will also serve as a high-speed entry into the literature for someone embarking, for the first time, on· researches in this branch of applied science. As in previous volumes, some of the work reported is concerned with topics which, whilst of critical importance to the performance of any imaging system, - e.g. transducers, signal processing may not address themselves to image formation per se. A new departure is the inclusion of photo-acoustic imaging a subject of rapidly growing importance for many of the same application areas relevant to acoustical imaging. Front Matter....Pages i-xiii Considerations of Contrast in the Helium Acoustic Microscope....Pages 1-11 Acoustic Microscopy at Temperatures less than 0.2°K....Pages 13-25 Planar Acoustic Microscope Lens....Pages 27-36 Coverslip Induced Artifacts in High Resolution Scanning Laser Acoustic Microscope Images....Pages 37-45 Ultrasonic Focussing in Absorptive Fluids....Pages 47-60 Scanning Photoacoustic Microscopy and Detection of Subsurface Structure....Pages 61-65 Applications of Acoustic Microscopy in the Semiconductor Industry....Pages 67-78 Application of Scanning Acoustic Microscope to the Study of Fracture and Wear....Pages 79-87 Acoustic Microscopy for Materials Studies....Pages 89-99 Material Characterization by Acoustic Microscope with Line-Focus Beam....Pages 101-111 NDE of Solids with a Mechanically B—Scanned Acoustic Microscope....Pages 113-123 Scanning Acoustic Microscopy inside Ceramic Samples....Pages 125-135 Ultrasonic-Wave Generation by Surface and Bulk Heating in Multimaterial Structures....Pages 137-145 Scanned Photothermal Imaging of Subsurface Structure....Pages 147-155 Acoustical Imaging of near Surface Properties at the Rayleigh Critical Angle....Pages 157-174 An Experimental Investigation of the ‘hosepipe’ Technique of Real-Time C-Scanning....Pages 175-184 A Stochastical Imaging Procedure....Pages 185-191 Lateral Inverse Filtering of Ultrasonic B-Scan Images....Pages 193-202 Texture Classification of B-Scan Ultrasound Images : An Assessment Using Tissue Models....Pages 203-211 Reduction of Speckle in Ultrasound B-Scans by Digital Processing....Pages 213-224 Optical Processing of Linear Array Ultrasonic Images....Pages 225-233 Inverse Filtering to Minimize the Effect of Mechanical Aberration in Focusing Piezoelectric Transducers....Pages 235-248 The Application of Maximum Entropy to the Processing of Ultrasonic Images of Nuclear Reactor Components Immersed in Liquid Sodium....Pages 249-257 A Self-Focusing Ultrasonic Image Reconstruction Technique....Pages 259-268 New Possibilities in Data Measurement, Signal Processing and Information Extraction: Philosophy and Results....Pages 269-279 A Method for Improving Acoustic Switching Ratio in Opto-Acoustic Transducers....Pages 281-291 The Design of Electric Excitations for the Formation of Desired Temporal Responses of Highly Efficient Transducers....Pages 293-305 A Linear Monolithic Receiving Array of PVDF Transducers for Transmission Cameras....Pages 307-316 Physical Limitations of Optically-Scanned Acoustic Imaging Transducers at Ultrasonic Frequencies above 10MHz....Pages 317-326 Particle Velocity and Displacement Patterns of Disc Transducers with Amplitude Shading....Pages 327-338 Recent Developments in Axicon Imaging....Pages 339-350 Enhanced Trapped Energy Mode Array Transducer Using Thickness Overtones....Pages 351-360 A Theoretical Study of the Transient Behaviour of Ultrasonic Transducers in Linear Arrays....Pages 361-370 An Experimental Method for Characterizing Ultrasonic Transducers....Pages 371-380 A Two-Dimensional Phased Array with an Extended Depth of Focus: Some Preliminary Results....Pages 381-390 Estimation of ECHO Scattered from Strongly Scattering Medium....Pages 391-400 Directivity Patterns in Inhomogeneous Acoustic Media....Pages 401-412 Tissue Ultrasonic Attenuation Well Modelized by a Mellin-Convolution....Pages 413-422 Three-Dimensional Imaging of Soft Tissue with Dispersive Attenuation....Pages 423-433 Elastic Wave Imaging with the Aid of an Inversion Transformation....Pages 435-441 Numerical Techniques for the Inverse Acoustical Scattering Problem in Layered Media....Pages 443-457 Pulse and Impulse Response in Human Tissues....Pages 459-467 Two-Dimensional Diffraction Scanning of Both Fresh and Fixed Normal and Cancerous Human Hepatic Tissue....Pages 469-478 An Approach to Tissue Characterization Based on Wave Theory Using a New Velocity Analysis Technique....Pages 479-491 Short Time Fourier Analysis and Diffraction Effect in Biological Tissue Characterization....Pages 493-503 Tissue Characterisation Using Acoustic Microscopy....Pages 505-516 Ultrasonic Doppler Vessel Imaging in the Diagnosis of Arterial Disease....Pages 517-528 Real-Time Two-Dimensional Blood Flow Imaging Using a Doppler Ultrasound Array....Pages 529-538 Measurement of Blood Flow Using Ultrasound....Pages 539-546 Large Area Doppler Array for the Rapid Investigation of the Breast....Pages 547-552 Ultrasound Computerized Tomography Using Transmission and Reflection Mode: Application to Medical Diagnosis....Pages 553-563 Synthetic Aperture Tomographic Imaging for Ultrasonic Diagnostics....Pages 565-578 A Clinical Prototype Ultrasonic Transmission Tomographic Scanner....Pages 579-587 Ultrasonic Tomography for Differential Thermography....Pages 589-597 Further Results on Diffraction Tomography Using Rytov’s Approximation....Pages 599-608 A Backward Projection Algorithm Which Corrects for Object Motion in a Scanning Acoustical Imaging System....Pages 609-619 3-D Active Incoherent Ultrasonic Imaging....Pages 621-634 Acoustical Imaging Using the Phase of Echo Waveforms....Pages 635-641 Nde Imaging with Multielement Arrays....Pages 643-663 Acoustical Holographic Scanners....Pages 665-674 Second Time around Echo Immunity from Pseudo Stereoscopic Holographic Imaging....Pages 675-686 UHB Imaging....Pages 687-696 Expansion of Acoustic Hologram Apertures Using Arma Modelling Techniques....Pages 697-707 Array Systems for Underwater Viewing by Acoustical Holography....Pages 709-720 Acoustic Determination of Sub-Bottom Density Profiles Using a Parametric Sound Source....Pages 721-732 Abnormal Backscattering off Low Roughness Surface of Metallic Object Immersed in Water....Pages 733-742 Back Matter....Pages 743-776