Measurement of the ultrasonic attenuation coefficient of human blood plasma during clotting in the frequency range of 8 to 22 MHz

Calor-Filho, Marcos Muniz; Machado, João Carlos

doi:10.1016/j.ultrasmedbio.2006.04.002

Cited by 17 publications

(12 citation statements)

References 19 publications

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“…The acoustic radiation force ( F RAD ) can be written in terms of the time-averaged intensity of the ultrasound field ( I ), acoustic absorption ( α ), and sound speed ( c ) (Nyborg, 1965):

F_{RAD} = \frac{2 italicαI}{c}

In the case of fluids, the acoustic radiation force generates acoustic streaming (Lighthill, 1978), whereas in tissues, it causes tissue displacement (Palmeri and Nightingale, 2011). The sound speeds of plasma and human whole blood clots are similar: 1540 m/s (Calor-Filho and Machado, 2006) and 1600 m/s (Nahirnyak et al, 2006), respectively. However, the sound absorption in human whole blood clots is two orders of magnitude larger than plasma (Calor-Filho and Machado, 2006; Nahirnyak et al, 2006).…”

Section: Discussionmentioning

confidence: 98%

“…The sound speeds of plasma and human whole blood clots are similar: 1540 m/s (Calor-Filho and Machado, 2006) and 1600 m/s (Nahirnyak et al, 2006), respectively. However, the sound absorption in human whole blood clots is two orders of magnitude larger than plasma (Calor-Filho and Machado, 2006; Nahirnyak et al, 2006). Thus, displacement of the clot by acoustic radiation force should dominate over acoustic streaming.…”

Section: Discussionmentioning

confidence: 98%

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Shaken and Stirred: Mechanisms of Ultrasound-Enhanced Thrombolysis

Bader

Gruber

Holland

2015

Ultrasound in Medicine & Biology

110

191

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The use of ultrasound and microbubbles as an effective adjuvant to thrombolytics has been demonstrated in vitro, ex vivo, and in vivo. However, the specific mechanisms of ultrasound-enhanced thrombolysis (UET) have yet to be elucidated. We present visual observations illustrating two mechanisms of UET: acoustic cavitation and radiation force. An in vitro flow model was developed to observe human whole blood clots exposed to human fresh-frozen plasma, rt-PA (0, 0.32, 1.58, or 3.15 μg/mL), and the ultrasound contrast agent Definity® (2 μL/mL). Intermittent, continuous-wave, ultrasound (120 kHz, 0.44 MPa peak-to-peak pressure) was used to insonify the perfusate. Ultraharmonic (UH) emissions indicative of stable cavitation were monitored with a passive cavitation detector. The clot was observed with an inverted microscope, and images were recorded with a charge-coupled device (CCD) camera. The images were post processed to determine the time-dependent clot diameter and root-mean-square velocity of the clot position. Clot lysis occurred preferentially surrounding large, resonant-sized bubbles undergoing stable oscillations. UH emissions from stable cavitation were found to correlate with the lytic rate. Clots were observed to translate synchronously with the initiation and cessation of the ultrasound exposure. The root-mean-square velocity of the clot correlated with the lytic rate. These data provide visual documentation of stable cavitation activity and radiation force during sub-megahertz sonothrombolysis. The observations of this study suggest that the process of clot lysis is complex, and both stable cavitation and radiation force are mechanistically responsible for this beneficial bioeffect in this in vitro model.

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“…The acoustic radiation force ( F RAD ) can be written in terms of the time-averaged intensity of the ultrasound field ( I ), acoustic absorption ( α ), and sound speed ( c ) (Nyborg, 1965):

F_{RAD} = \frac{2 italicαI}{c}

Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 98%

Shaken and Stirred: Mechanisms of Ultrasound-Enhanced Thrombolysis

Bader

Gruber

Holland

2015

Ultrasound in Medicine & Biology

110

191

View full text Add to dashboard Cite

show abstract

“…Moreover, variations in IAC obtained on plasma samples by other researchers 16,17 emphasized small and noncomparable variations in IAC during the coagulation process, for frequencies between 8 and 22 MHz. They reported a slow monotonic decrease in attenuation during the coagulation process which did not allow detection of a specific moment of coagulation.…”

Section: A Comparison Between Variations In Velocity and Iac For Clomentioning

confidence: 82%

“…However, Calor-Filho and Machado 16,17 studied the plasma coagulation process by measurement of the attenuation coefficient at frequencies between 8 and 22 MHz. They reported a slow decrease in attenuation of less than 0.2 dB/ cm during the process.…”

Section: Introductionmentioning

confidence: 99%

Interest of the attenuation coefficient in multiparametric high frequency ultrasound investigation of whole blood coagulation process

Callé

Plag

Patat

et al. 2009

The Journal of the Acoustical Society of America

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Previous studies [R. Libgot, F. Ossant, Y. Gruel, P. Lermusiaux, and F. Patat, Proc.-IEEE Utrason. Symp. 4, 2259-2262 (2005); R. Libgot-Calle, F. Ossant, Y. Gruel, P. Lermusiaux, and F. Patat, Ultrasound Med. Biol. 34, 252-264 (2008); F. Ossant, R. Libgot, P. Coupe, P. Lermusiaux, and F. Patat, Proc.-IEEE Ultrason. Symp. 2, 846-849 (2004)] showed the potential of an in vitro high frequency ultrasound (beyond 20 MHz) device to describe the blood clotting process. The parameters were simultaneously estimated in double transmission (DT) with the calculation of the velocity of longitudinal waves and in backscattering (BS) modes with the estimation of the integrated BS coefficient and the effective scatterer size. The aim of the present study was to show how the integrated attenuation coefficient (IAC) assessed in DT mode could provide additional information on this process, especially regarding the fibrin polymerization which is an important part of the coagulation process. A characteristic time t(a) of the variations in IAC that could be linked to fibrin formation was identified.

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“…Also, the ultrasound attenuation seems to be a more suitable parameter for detecting the early stage of clot formation when the hematocrit is higher than 40%. The high-frequency ultrasound-attenuation coefficient for human blood plasma during clotting was measured for frequencies ranging from 8 to 22 MHz [36]. In order to explore the effect of heparin treatment on blood coagulation, the 10-to 30-MHz high-frequency attenuation coefficient was measured for both human and rat whole blood during coagulation [31].…”

Section: Ultrasound Attenuationmentioning

confidence: 99%

Untitled

Huang¹

2011

J. Med. Biol. Eng.

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This paper provides a detailed review of the in vitro, in vivo, and clinical applications of ultrasound to understand blood coagulation. The paper focuses on the effect of blood rheology on clotting mechanisms, especially on the use of ultrasound to detect the viscoelastic properties of blood clots. After a short introduction, the paper describes how quantitative ultrasound parameters can be used to study the process of blood coagulation. Ultrasound parameters can be used for tissue characterization, and so the process of blood coagulation can be monitored continuously by measuring the ultrasound backscatter, attenuation coefficient, and velocity. Furthermore, several ultrasound elastography methods including quasi-static strain imaging, shear wave, and acoustic-radiation-force imaging are introduced for measuring the viscoelastic properties of blood clots. The advantages and drawbacks of these ultrasound-based approaches for detecting blood coagulation are discussed. Finally, new areas of research, the clinical application of ultrasound, and areas of potential future developments are presented.

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Measurement of the ultrasonic attenuation coefficient of human blood plasma during clotting in the frequency range of 8 to 22 MHz

Cited by 17 publications

References 19 publications

Shaken and Stirred: Mechanisms of Ultrasound-Enhanced Thrombolysis

Shaken and Stirred: Mechanisms of Ultrasound-Enhanced Thrombolysis

Interest of the attenuation coefficient in multiparametric high frequency ultrasound investigation of whole blood coagulation process

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