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A fundamental study for the development of the tissue phantom
ABSTRACTS, ULTRASONIC IMAGING AND TISSUE CHARACTERIZATION SYMPOSIUM
LOW CONTRAST RESOLUTION PHANTOM FOR USE WITH ULTRASOUND IMAGING EQUIPMENT, W. Clayman, ATS Laboratory, South Norwalk, CT 06856 A low contrast resolution phantom has been developed for use with ultrasound imaging equipment. The materials of construction are stable, non-dessicating and mimic various body tissues in velocity and attenuation. The design parameters for construction of the phantom are angular displacement of the target, (assuming a point source for the radiated energy) and contrast between the target and the bulk medium. Angular displacements encompass the range of 0.75O to lo', while contrast varies from 30 to 80 percent. Results are presented showing imaging on various types of ultrasound equipment. A FUNDAMENTAL STUDYFOR THE DEVELOPMENT OF THE TISSUE PHANTOM,Koji Saito' and Masanobu Hogaki2, IMedical Electronics Division, Toshiba Corp.: 2Tokyo Seamens
Hospital,
Tochigi,
Japan
It is well known that a tissue phantom is necessary for evaluating ultrasonic diagnostic equipment, but few studies on phantoms have been reported. We investigated the ultrasonic characteristics of soft materials for developing a phantom, and selected silicone rubber as the phantom materia 1. The following items were measured: 1) the reflection and scattering characteristics of surfaces with different rouqhness; 2) the relationship between the B mode image and surface roughness; 3) confirmation of the results by using an excised utels; 4) the relationship between the reflection angle and B mode image; 5) scattering characteristics from the microscatterers in the silicone oil. From these experiments, we obtained the following results: 1) there are considerable differences between the reflection and scattering pulse waveforms; 2) the scattering echoes play an important role in forming the ultrasound image. RODREFLECTOR RESONANCES IN ULTRASOUND TEST OBJECTS, Lance V. Hefner and Albert Goldstein, Henry Ford Hospital, Department of Radiology, Detroit, MI 48202 In pulse-echo studies the presence of a resonating reflector may alter the image produced. In an ultrasound test object inclusion of a reflector The rod reflectors capable of resonating can degrade the value of the test. incorporated into the AIUM 100 mmtest object are shown to resonate under Rod reflectors of various insonification at medical ultrasound frequencies. sizes and materials were examined to determine their resonant properties. In enclosed 100 mmtest objects the influence of the Plexiglas "window" on A theorv develoned bv Faran IJ. axial resolution measurements was studied. Acoustic Sot. Amer. 12, 405-418 (1951)] for predicting the resonant frequen-Suqqesties of rod reflectors is CornDaredto our experimental results. tions are made for avoiding rod reflectors capable of undergoing resonance at the frequencies of interest. SIMPLE MEANSOF VIEWING ULTRASOUND WAVESIN LIQUIDS, Daniel J. Harris, Corporation, Northford, CT Richard B. Bernardi, and Charles Shih, Picker 06472 Apparatus is described which permits viewing of acoustic waves in The liquids over large apertures at low cost and with little complexity. method does not use large lenses or mirrors which allows for low total cost. The method is based upon the use of crossed polarizers with beams propagating in selected liquids. Entire beams may be viewed visually or may be photographed using conventional continuous light sources. Alternatively, strobed illumination may be used to view wave fronts or pulsed wave packets. By offsetting strobe rate slightly from pulse repetition, wave packets may be seen as progressing along the path of the acoustic beam. Methods of enhancing optical signal-to-noise ratios (i.e., beam visibility) are described using careful design, selection of system components, and optimum electrical transducer drive. The system can be used for exploring the effects of ultrasound transducer design changes, of changes
187
LOW CONTRAST RESOLUTION PHANTOM FOR USE WITH ULTRASOUND IMAGING EQUIPMENT, W. Clayman, ATS Laboratory, South Norwalk, CT 06856 A low contrast resolution phantom has been developed for use with ultrasound imaging equipment. The materials of construction are stable, non-dessicating and mimic various body tissues in velocity and attenuation. The design parameters for construction of the phantom are angular displacement of the target, (assuming a point source for the radiated energy) and contrast between the target and the bulk medium. Angular displacements encompass the range of 0.75O to lo', while contrast varies from 30 to 80 percent. Results are presented showing imaging on various types of ultrasound equipment. A FUNDAMENTAL STUDYFOR THE DEVELOPMENT OF THE TISSUE PHANTOM,Koji Saito' and Masanobu Hogaki2, IMedical Electronics Division, Toshiba Corp.: 2Tokyo Seamens
Hospital,
Tochigi,
Japan
It is well known that a tissue phantom is necessary for evaluating ultrasonic diagnostic equipment, but few studies on phantoms have been reported. We investigated the ultrasonic characteristics of soft materials for developing a phantom, and selected silicone rubber as the phantom materia 1. The following items were measured: 1) the reflection and scattering characteristics of surfaces with different rouqhness; 2) the relationship between the B mode image and surface roughness; 3) confirmation of the results by using an excised utels; 4) the relationship between the reflection angle and B mode image; 5) scattering characteristics from the microscatterers in the silicone oil. From these experiments, we obtained the following results: 1) there are considerable differences between the reflection and scattering pulse waveforms; 2) the scattering echoes play an important role in forming the ultrasound image. RODREFLECTOR RESONANCES IN ULTRASOUND TEST OBJECTS, Lance V. Hefner and Albert Goldstein, Henry Ford Hospital, Department of Radiology, Detroit, MI 48202 In pulse-echo studies the presence of a resonating reflector may alter the image produced. In an ultrasound test object inclusion of a reflector The rod reflectors capable of resonating can degrade the value of the test. incorporated into the AIUM 100 mmtest object are shown to resonate under Rod reflectors of various insonification at medical ultrasound frequencies. sizes and materials were examined to determine their resonant properties. In enclosed 100 mmtest objects the influence of the Plexiglas "window" on A theorv develoned bv Faran IJ. axial resolution measurements was studied. Acoustic Sot. Amer. 12, 405-418 (1951)] for predicting the resonant frequen-Suqqesties of rod reflectors is CornDaredto our experimental results. tions are made for avoiding rod reflectors capable of undergoing resonance at the frequencies of interest. SIMPLE MEANSOF VIEWING ULTRASOUND WAVESIN LIQUIDS, Daniel J. Harris, Corporation, Northford, CT Richard B. Bernardi, and Charles Shih, Picker 06472 Apparatus is described which permits viewing of acoustic waves in The liquids over large apertures at low cost and with little complexity. method does not use large lenses or mirrors which allows for low total cost. The method is based upon the use of crossed polarizers with beams propagating in selected liquids. Entire beams may be viewed visually or may be photographed using conventional continuous light sources. Alternatively, strobed illumination may be used to view wave fronts or pulsed wave packets. By offsetting strobe rate slightly from pulse repetition, wave packets may be seen as progressing along the path of the acoustic beam. Methods of enhancing optical signal-to-noise ratios (i.e., beam visibility) are described using careful design, selection of system components, and optimum electrical transducer drive. The system can be used for exploring the effects of ultrasound transducer design changes, of changes
187