Viscous contributions to low-frequency scattering, power absorption, radiation force, and radiation torque for spheres in acoustic beams

2013 ◽  
Vol 133 (5) ◽  
pp. 3237-3237 ◽  
Author(s):  
Philip L. Marston
Keyword(s):  
Low Frequency ◽  
Radiation Force ◽  
Power Absorption ◽  
Acoustic Beams

scholarly journals Medical ultrasound: imaging of soft tissue strain and elasticity

2011 ◽  
Vol 8 (64) ◽  
pp. 1521-1549 ◽  
Author(s):  
Peter N. T. Wells ◽  
Hai-Dong Liang
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Ultrasonic Imaging ◽  
Low Frequency ◽  
Radiation Force ◽  
Breast Disease ◽  
Published Data ◽  
Tissue Strain ◽  
Low Frequency Vibration ◽  
Pulse Echo

After X-radiography, ultrasound is now the most common of all the medical imaging technologies. For millennia, manual palpation has been used to assist in diagnosis, but it is subjective and restricted to larger and more superficial structures. Following an introduction to the subject of elasticity, the elasticity of biological soft tissues is discussed and published data are presented. The basic physical principles of pulse-echo and Doppler ultrasonic techniques are explained. The history of ultrasonic imaging of soft tissue strain and elasticity is summarized, together with a brief critique of previously published reviews. The relevant techniques—low-frequency vibration, step, freehand and physiological displacement, and radiation force (displacement, impulse, shear wave and acoustic emission)—are described. Tissue-mimicking materials are indispensible for the assessment of these techniques and their characteristics are reported. Emerging clinical applications in breast disease, cardiology, dermatology, gastroenterology, gynaecology, minimally invasive surgery, musculoskeletal studies, radiotherapy, tissue engineering, urology and vascular disease are critically discussed. It is concluded that ultrasonic imaging of soft tissue strain and elasticity is now sufficiently well developed to have clinical utility. The potential for further research is examined and it is anticipated that the technology will become a powerful mainstream investigative tool.

Potential Applications of Vibro-acoustography in Breast Imaging

2005 ◽  
Vol 4 (2) ◽  
pp. 151-157 ◽  
Author(s):  
Azra Alizad ◽  
Dana H. Whaley ◽  
James F. Greenleaf ◽  
Mostafa Fatemi
Keyword(s):  
Soft Tissue ◽  
Medical Imaging ◽  
Breast Imaging ◽  
Low Frequency ◽  
Radiation Force ◽  
Tissue Imaging ◽  
Future Developments ◽  
Potential Applications ◽  
Potential Impact

Vibro-acoustography has gained interest in the recent years as a new modality for medical imaging. This method is based on low-frequency vibrations induced in the object by the radiation force of ultrasound. This paper focuses on potential applications of vibro-acoustography in breast imaging, including detection of microcalcifications, detection of arterial calcifications, and soft tissue imaging. In addition, we will briefly discuss our recent results of in vivo breast vibro-acoustography. Future developments and potential impact of vibro-acoustography in breast imaging are also discussed.

Measurement of the Propagation Velocity of Pulse Wave Generated by Ultrasound in Arteries

2005 ◽  
Author(s):  
Xiaoming Zhang ◽  
James F. Greenleaf
Keyword(s):  
Wave Velocity ◽  
Propagation Velocity ◽  
Pressure Wave ◽  
Pulse Wave ◽  
Low Frequency ◽  
Radiation Force ◽  
Frequency Wave ◽  
Reflected Waves ◽  
Wall Stiffness ◽  
Artery Stiffness

Arterial wall stiffness can be associated with various diseases. The stiffness of an artery can be assessed by measurement of the pulse wave velocity (PWV). Usually, PWV is estimated using the foot-to-foot method. However, the foot of the pressure wave is not very clear due to reflected waves. Also, the blood pressure wave generated by the heart is normally a low frequency wave, hence the time resolution is low. PWV is an average indicator of artery stiffness between two measuring locations, therefore, it is not easy to identify local stiffness. In this paper a short external pulse is generated in an artery by the radiation force of ultrasound. The propagation velocity of the pulse wave is measured along the artery. The temporal resolution of this method, which is in the range of microseconds, is much higher than the conventional pressure PWV method, and therefore allows the wave velocity to be measured accurately over a few millimeters.

Vibro-Acoustography: Quantification of Flow with Highly-Localized Low-Frequency Acoustic Force

2001 ◽  
Vol 23 (4) ◽  
pp. 249-256 ◽  
Author(s):  
Marek Belohlavek ◽  
Toshihiko Asanuma ◽  
Randall R. Kinnick ◽  
James F. Greenleaf
Keyword(s):  
Acoustic Emission ◽  
Rate Constant ◽  
Flow Rate ◽  
Low Frequency ◽  
Radiation Force ◽  
Flow Measurements ◽  
Rate Analysis ◽  
Dual Beam ◽  
Thin Plastic ◽  
Contrast Microbubbles

The intersection of two ultrasound beams with slightly different frequencies results in generation of a localized radiation force and stimulates emission of audio signals from targeted objects. Vibro-acoustography uses this phenomenon to probe elastic properties of objects. Vibro-acoustography of contrast microbubbles in degassed water produced quantitative flow measurements from analysis of their acoustic emission. We used a dual-beam transducer generating bursts of 40-kHz vibrations. The vibrations resulted from interference of 3.48-MHz and 3.52-MHz confocal beams intersecting at the center of a thin plastic conduit. We tested flows of 13, 48, 85, and 120 mL/min of contrast microbubbles at concentrations from 1.2 times 105 to 6 times 105 bubbles/mL. The amplitude of the acoustic emission was linear with microbubble concentrations up to a value of 3.6 times 105 bubbles/mL. A replenishment method for microbubble contrast and flow rate analysis was used with radiation force bursts deployed at 0.05, 0.1, 0.2, 0.5, 1, and 2-second pulsing intervals. The relation between the pulsing intervals and the peak amplitude was fitted by an exponential curve and a rate constant calculated for each tested flow rate. The rate constant values were linearly correlated with the tested flows. The vibro-acoustography method provides objective, quantitative, and highly-localized assessment of flow using contrast microbubbles.

scholarly journals Non-diffractive acoustic beams produce negative radiation force in certain regions

AIP Advances ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 065029
Author(s):  
Menyang Gong ◽  
Yupei Qiao ◽  
Zhonghan Fei ◽  
Yuanyuan Li ◽  
Jiehui Liu ◽  
...  
Keyword(s):  
Radiation Force ◽  
Acoustic Beams

Radiation force on spheres in acoustic beams and related aspects of scattering

2008 ◽  
Vol 123 (5) ◽  
pp. 3790-3790
Author(s):  
Philip L. Marston ◽  
David B. Thiessen
Keyword(s):  
Radiation Force ◽  
Acoustic Beams
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