Dimensions and Circumferential Stress-Strain Relation in the Porcine Esophagus in Vitro Determined by Combined Impedance Planimetry and High-Frequency Ultrasound

2007 ◽  
Vol 52 (5) ◽  
pp. 1338-1344 ◽  
Author(s):  
Jingbo Zhao ◽  
Claus S. Jørgensen ◽  
Donghua Liao ◽  
Hans Gregersen
Keyword(s):  
High Frequency ◽  
Circumferential Stress ◽  
High Frequency Ultrasound ◽  
Stress Strain ◽  
Impedance Planimetry ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
Frequency Ultrasound

In vitro and in vivo high‐frequency ultrasound response of microbubbles

2006 ◽  
Vol 119 (5) ◽  
pp. 3438-3438
Author(s):  
Orlando Aristizábal ◽  
Daniel H. Turnbull ◽  
Jeffrey A. Ketterling
Keyword(s):  
High Frequency ◽  
High Frequency Ultrasound ◽  
Frequency Ultrasound

scholarly journals Optimization of subharmonic generation from ultrasound contrast agents at high frequency ultrasound

2021 ◽  
Author(s):  
Sara Iradji
Keyword(s):  
Contrast Agents ◽  
High Frequency ◽  
Ultrasound Contrast Agents ◽  
Surrounding Tissue ◽  
High Frequency Ultrasound ◽  
High Frequencies ◽  
Ultrasound Contrast ◽  
Wide Range ◽  
Frequency Ultrasound

The microcirculation can be differentiated from the surrounding tissue using high frequency ultrasound subharmonic imaging. This imaging technique relies on the detection of energy scattered from ultrasound contrast agents at half the transmit frequency due to their resonant oscillations. The current contrast agents and the subharmonic imaging parameters have not been optimized for high frequencies. Moreover, the origin of subharmonic generation from submicron bubbles is not well-understood. The size distribution of Definity™ phospholipid-shelled microbubbles was altered to find the optimal bubble size to be resonant over a wide range of high frequencies. The resonant behaviour of bubbles was investigated through in vitro attenuation measurements. The transmit frequency and pressure were varied to optimize the backscattered subharmonic signal. Alteration of Definity™ population significanatly improved the scattering for subharmonic imaging at 20 MHz. A peak negative pressure between 400 to 600 kPa is suggested for this frequency range.

scholarly journals Quantification of Endothelial αvβ3 Expression with High-Frequency Ultrasound and Targeted Microbubbles: In Vitro and In Vivo Studies

2016 ◽  
Vol 42 (9) ◽  
pp. 2283-2293 ◽  
Author(s):  
Verya Daeichin ◽  
Klazina Kooiman ◽  
Ilya Skachkov ◽  
Johan G. Bosch ◽  
Thomas L. Theelen ◽  
...  
Keyword(s):  
High Frequency ◽  
In Vivo Studies ◽  
High Frequency Ultrasound ◽  
Targeted Microbubbles ◽  
Frequency Ultrasound

2MHz ultrasound enhances t-PA-mediated thrombolysis: comparison of continuous versus pulsed ultrasound and standing versus travelling acoustic waves

2003 ◽  
Vol 89 (03) ◽  
pp. 583-589 ◽  
Author(s):  
Stefan Pfaffenberger ◽  
Branka Devcic-Kuhar ◽  
Karem El-Rabadi ◽  
Martin Gröschl ◽  
Walter Speidl ◽  
...  
Keyword(s):  
Wave Field ◽  
Acoustic Waves ◽  
High Frequency ◽  
Travelling Wave ◽  
High Frequency Ultrasound ◽  
Pulsed Ultrasound ◽  
Application Mode ◽  
Frequency Ultrasound

SummaryIn addition to fibrinolytic enzymes, ultrasound has the potential to enhance thrombolysis. High frequency ultrasound has the advantage that a combination of diagnostic and therapeutic ultrasound with only one device is possible. Therefore, we investigated the optimal high frequency (2 MHz) ultrasound field characteristics and application mode in vitro. Continuous ultrasound significantly enhanced rt-PA mediated thrombolysis: in a travelling wave field thrombolysis was augmented by 49.0 ± 14.7% and in a standing wave field by 34.8 ± 7.3%. In an intermittent application mode (1Hz, 10Hz, 100Hz, 1kHz) most efficient results were obtained for both wave fields using 1 Hz (46.4 ± 10.7% and 39.1 ± 6.6%, respectively). Referring to a possible in vivo application our in vitro data suggests that an intermittent application of a 2 MHz high frequency ultrasound using a travelling wave field would be the most potent application for lysing blood clots.

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