The Impact of Physiological Motion on Tissue Tracking During Radiation Force Imaging

Abstract Background Acoustic radiation force impulse (ARFI) imaging is a noninvasive ultrasound elastography technique for evaluating tissue stiffness. The association of liver and spleen stiffness provides additional information in the assessment of portal hypertension. The technique and normal values of spleen stiffness by point shear wave elastography (p-SWE) in pediatrics have not been well documented. Objective Our aim is to describe the feasibility and normal ARFI elastography values in the spleen for healthy children and to compare measurements in two different probe positions (the axial and sagittal planes). Materials and methods Spleen p-SWE using ARFI values were measured with a 6C1 probe in 102 healthy children (age range: 8 weeks to 17 years) divided into four age groups. An average of nine (standard deviation: two) spleen stiffness measurements were taken during free breathing in each plane (axial and sagittal). The impact of age and measurement plane in the spleen was analyzed using multivariate models. Results There was no significant difference in spleen stiffness values taken at different ages, with an average of the medians of 2.43±0.31 m/s. There was no significant difference based on probe orientation: sagittal plane (median: 2.46±0.29 m/s) and axial plane (median: 2.43±0.32 m/s) with Student’s t-test P=0.18. The mean depth of measurement varied between 2.3 cm and 3.7 cm, according to age. Conclusion Normal spleen stiffness values using ARFI imaging in children do not vary with age and correspond to a median of 2.43 m/s. No significant difference was found when using different probe positions.

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Non-Cavitation Targeted Microbubble-Mediated Single-Cell Sonoporation

Micromachines ◽

10.3390/mi13010113 ◽

2022 ◽

Vol 13 (1) ◽

pp. 113

Author(s):

Xiufang Liu ◽

Wenjun Zhang ◽

Yanshu Jing ◽

Shasha Yi ◽

Umar Farooq ◽

...

Keyword(s):

Cell Membrane ◽

Single Cell ◽

Acoustic Radiation ◽

Survival Rates ◽

Radiation Force ◽

Input Voltage ◽

High Survival ◽

Bubble Cavitation ◽

Efficient Delivery ◽

The Impact

Sonoporation employs ultrasound accompanied by microbubble (MB) cavitation to induce the reversible disruption of cell membranes and has been exploited as a promising intracellular macromolecular delivery strategy. Due to the damage to cells resulting from strong cavitation, it is difficult to balance efficient delivery and high survival rates. In this paper, a traveling surface acoustic wave (TSAW) device, consisting of a TSAW chip and a polydimethylsiloxane (PDMS) channel, was designed to explore single-cell sonoporation using targeted microbubbles (TMBs) in a non-cavitation regime. A TSAW was applied to precisely manipulate the movement of the TMBs attached to MDA-MB-231 cells, leading to sonoporation at a single-cell level. The impact of input voltage and the number of TMBs on cell sonoporation was investigated. In addition, the physical mechanisms of bubble cavitation or the acoustic radiation force (ARF) for cell sonoporation were analyzed. The TMBs excited by an ARF directly propelled cell membrane deformation, leading to reversible perforation in the cell membrane. When two TMBs adhered to the cell surface and the input voltage was 350 mVpp, the cell sonoporation efficiency went up to 83%.

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ACOUSTIC RADIATION FORCE IMPULSE (ARFI) ELASTOGRAPHY OF PANCREAS AND THE IMPACT OF GENDER, AGE AND OBESITY ON THE ARFI ELASTOGRAPHY VALUES AT PUDUCHERRY

Journal of Evidence Based Medicine and Healthcare ◽

10.18410/jebmh/2019/486 ◽

2019 ◽

Vol 6 (35) ◽

pp. 2378-2381

Author(s):

Nidhin J. K. ◽

Dilip Phansalkar ◽

George Kurian

Keyword(s):

Acoustic Radiation ◽

Radiation Force ◽

Acoustic Radiation Force ◽

Acoustic Radiation Force Impulse ◽

Arfi Elastography ◽

The Impact

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Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

Symposium - International Astronomical Union ◽

10.1017/s0074180900178404 ◽

1962 ◽

Vol 14 ◽

pp. 415-418

Author(s):

K. P. Stanyukovich ◽

V. A. Bronshten

Keyword(s):

Explosive Charge ◽

The Moon ◽

Meteorite Impacts ◽

The Earth ◽

Lunar Craters ◽

The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

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The Geosciences Applied to Lunar Exploration

Symposium - International Astronomical Union ◽

10.1017/s0074180900178222 ◽

1962 ◽

Vol 14 ◽

pp. 169-257 ◽

Cited By ~ 9

Author(s):

J. Green

Keyword(s):

Lunar Surface ◽

Probable Mechanism ◽

Point Of View ◽

Lunar Exploration ◽

Geological Model ◽

Apply Geophysics ◽

Surface Features ◽

The Impact

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.

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