Triplet pulse sequence for superior microbubble/tissue contrast

Umemura, Shin‐ichiro; Azuma, Takashi; Kuribara, Hiroshi; Kanda, H.

doi:10.1109/ultsym.2003.1293438

Cited by 6 publications

(3 citation statements)

References 1 publication

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“…25) The objective of this study is to develop a high-speed imaging method specific to the acoustic cavitation microbubbles generated by therapeutic exposures such as trigger HIFU exposure. A triplet pulse (3P) sequence, 26) in which the second-harmonic and fundamental components of the received echo are cancelled, was employed for this purpose. This method has been reported to have detected echoes from contrast microbubbles at a specificity higher than that in the PI method.…”

Section: Introductionmentioning

confidence: 99%

Selective detection of cavitation bubbles by triplet pulse sequence in high-intensity focused ultrasound treatment

Iwasaki

Nagaoka

Yoshizawa

et al. 2018

Jpn. J. Appl. Phys.

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Acoustic cavitation bubbles are known to enhance the heating effect in high-intensity focused ultrasound (HIFU) treatment. The detection of cavitation bubbles with high sensitivity and selectivity is required to predict the therapeutic and side effects of cavitation, and ensure the efficacy and safety of the treatment. A pulse inversion (PI) technique has been widely used for imaging microbubbles through enhancing the second-harmonic component of echo signals. However, it has difficulty in separating the nonlinear response of microbubbles from that due to nonlinear propagation. In this study, a triplet pulse (3P) method was investigated to specifically image cavitation bubbles by extracting the 1.5th fractional harmonic component. The proposed 3P method depicted cavitation bubbles with a contrast ratio significantly higher than those in conventional imaging methods with and without PI. The results suggest that the 3P method is effective for specifically detecting microbubbles in cavitation-enhanced HIFU treatment.

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Section: Introductionmentioning

confidence: 99%

Selective detection of cavitation bubbles by triplet pulse sequence in high-intensity focused ultrasound treatment

Iwasaki

Nagaoka

Yoshizawa

et al. 2018

Jpn. J. Appl. Phys.

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“…e.g. a 3-pulse sequence with 0°-120°-240°-phase coding [2]. A concept that is now commonly used is to go to low acoustic pressure levels (low mechanical index), where tissue harmonics are negligible but the nonlinear response of microbubbles is already noticeable.…”

Section: B Low MI Imagingmentioning

confidence: 99%

“…The two pulse are transmitted one after the other separated by a certain time span to allow the echoes ( ) ( ) 1 2 and e t e t (2) to have returned to the transducer before the next pulse is transmitted. In the following, we will reset the time scale with every transmission so that 0 t = corresponds to the same given depth for all echoes.…”

Section: A Processing Basicsmentioning

confidence: 99%

Optimized contrast agent imaging considering different sources of nonlinearity

Wilkening¹,

Hansen²,

Fischer³

et al.

IEEE Ultrasonics Symposium, 2005.

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So called "Low MI" imaging techniques for contrast agents limit the acoustic pressure level at the expense of signal-tonoise ratio (SNR) in order to reduce both, microbubble destruction and effects of nonlinear signal propagation in tissue ("tissue harmonics"). More than two transmissions per beam line may be required to re-gain sufficient SNR. Thus, the frame rate is reduced. If the microbubbles are not too fragile or destruction less of an issue, the generation of tissue harmonics becomes the limiting factor. We propose a nonlinear processing of echoes resulting from a two-pulse phase (pulse) inversion transmit sequence, where the original two echoes and nonlinear combinations thereof are separately filtered and then superimposed to optimally discriminate between microbubbles and tissue, even if nonlinear wave propagation in tissue is not negligible.

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