Phantom evaluation of stacked-type dual-frequency 1–3 composite transducers: A feasibility study on intracavitary acoustic angiography

Kim, Jin-Wook; Li, Sibo; Kasoji, Sandeep K.; Dayton, Paul A.; Jiang, Xiaoning

doi:10.1016/j.ultras.2015.06.009

Cited by 37 publications

(13 citation statements)

References 15 publications

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“…Despite these limitations, acoustic angiography has remarkably high resolution and contrast sensitivity relative to clinically available CEUS techniques. Further, development of a linear array dual-frequency transducer will enhance acoustic angiography with the increased depth of field and faster image acquisition required for clinical translation 57 , 58 . Nevertheless, due to the high-frequency receive bandwidth, acoustic angiography will always be limited to imaging targets within a few cm of the skin.…”

Section: Discussionmentioning

confidence: 99%

Early Assessment of Tumor Response to Radiation Therapy using High-Resolution Quantitative Microvascular Ultrasound Imaging

Kasoji¹,

Rivera²,

Gessner³

et al. 2018

Theranostics

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Measuring changes in tumor volume using anatomical imaging weeks to months post radiation therapy (RT) is currently the clinical standard for indicating treatment response to RT. For patients whose tumors do not respond successfully to treatment, this approach is suboptimal as timely modification of the treatment approach may lead to better clinical outcomes. We propose to use tumor microvasculature as a biomarker for early assessment of tumor response to RT. Acoustic angiography is a novel contrast ultrasound imaging technique that enables high-resolution microvascular imaging and has been shown to detect changes in microvascular structure due to cancer growth. Data suggest that acoustic angiography can detect longitudinal changes in the tumor microvascular environment that correlate with RT response.Methods: Three cohorts of Fisher 344 rats were implanted with rat fibrosarcoma tumors and were treated with a single fraction of RT at three dose levels (15 Gy, 20 Gy, and 25 Gy) at a dose rate of 300 MU/min. A simple treatment condition was chosen for testing the feasibility of our imaging technique. All tumors were longitudinally imaged immediately prior to and after treatment and then every 3 days after treatment for a total of 30 days. Both acoustic angiography (using in-house produced microbubble contrast agents) and standard b-mode imaging was performed at each imaging time point using a pre-clinical Vevo770 scanner and a custom modified dual-frequency transducer.Results: Results show that all treated tumors in each dose group initially responded to treatment between days 3-15 as indicated by decreased tumor growth accompanied with decreased vascular density. Untreated tumors continued to increase in both volume and vascular density until they reached the maximum allowable size of 2 cm in diameter. Tumors that displayed complete control (no tumor recurrence) continued to decrease in size and vascular density, while tumors that progressed after the initial response presented an increase in tumor volume and volumetric vascular density. The increase in tumor volumetric vascular density in recurring tumors can be detected 10.25 ± 1.5 days, 6 ± 0 days, and 4 ± 1.4 days earlier than the measurable increase in tumor volume in the 15, 20, and 25 Gy dose groups, respectively. A dose-dependent growth rate for tumor recurrence was also observed.Conclusions: In this feasibility study we have demonstrated the ability of acoustic angiography to detect longitudinal changes in vascular density, which was shown to be a potential biomarker for tumor response to RT.

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Section: Discussionmentioning

confidence: 99%

Early Assessment of Tumor Response to Radiation Therapy using High-Resolution Quantitative Microvascular Ultrasound Imaging

Kasoji¹,

Rivera²,

Gessner³

et al. 2018

Theranostics

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“…The prospect of highfrequency and therefore high-resolution image guidance may be particularly advantageous for small animal studies where anatomical features are difficult to resolve with relatively low-frequency imaging. Dual frequency transducers are currently under development for contrast-enhanced intravascular and intracavity imaging (Kim, et al 2015, Lindsey, et al 2017, Wang, et al 2017, which could be modified for image-guided therapy purposes. A dual frequency approach can also be employed to initiate PCCA phase change at high frequency and detect the unique acoustic signature of PCCA vaporization at low frequency .…”

Section: Future Directions -Potential For Ultrasound-mediated Gi Drugmentioning

confidence: 99%

Ultrasound-Stimulated Phase-Change Contrast Agents for Transepithelial Delivery of Macromolecules, Toward Gastrointestinal Drug Delivery

Fix

Koppolu

Novell

et al. 2019

Ultrasound in Medicine & Biology

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The gastrointestinal (GI) tract presents a notoriously difficult barrier for macromolecular drug delivery, especially for biologics. Herein, we demonstrate that ultrasound-stimulated phase change contrast agents (PCCAs) can transiently disrupt Caco-2 monolayers and improve the transepithelial transport of a macromolecular model drug. With ultrasound treatment in the presence of PCCAs, we achieved a maximum of 44±15% transepithelial delivery of 70 kDa FITCdextran, compared to negligible delivery through sham control monolayers. Among all tested rarefactional pressures (300-600 kPa), dextran delivery efficiency was consistently greatest at 300 kPa. To explore this unexpected finding, we quantified stable and inertial cavitation energy generated by various ultrasound exposure conditions. In general, lower pressures resulted in more persistent cavitation activity over 30 second exposure times, which may explain the enhanced dextran delivery efficiency. Thus, a unique advantage of using low boiling point PCCAs for this application is that the same low-pressure pulses can be used to induce vaporization and provide maximal delivery.

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“…Further extension of the penetration depth would require designing transducers with deeper focal depths and/or lower combinations of frequencies. 28, 34, 40 …”

Section: Discussionmentioning

confidence: 99%

“…Further development of dual-frequency transducers in new form factors is required to deliver acoustic angiography to new applications in human imaging. 28, 34, 36 …”

Section: Discussionmentioning

confidence: 99%

High Resolution Ultrasound Superharmonic Perfusion Imaging: In Vivo Feasibility and Quantification of Dynamic Contrast-Enhanced Acoustic Angiography

et al. 2016

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Mapping blood perfusion quantitatively allows localization of abnormal physiology and can improve understanding of disease progression. Dynamic contrast-enhanced ultrasound is a low-cost, real-time technique for imaging perfusion dynamics with microbubble contrast agents. Previously, we have demonstrated another contrast agent-specific ultrasound imaging technique, acoustic angiography, which forms static anatomical images of the superharmonic signal produced by microbubbles. In this work, we seek to determine whether acoustic angiography can be utilized for high resolution perfusion imaging in vivo by examining the effect of acquisition rate on superharmonic imaging at low flow rates and demonstrating the feasibility of dynamic contrast-enhanced superharmonic perfusion imaging for the first time. Results in the chorioallantoic membrane model indicate that frame rate and frame averaging do not affect the measured diameter of individual vessels observed, but that frame rate does influence the detection of vessels near and below the resolution limit. The highest number of resolvable vessels was observed at an intermediate frame rate of 3 Hz using a mechanically-steered prototype transducer. We also demonstrate the feasibility of quantitatively mapping perfusion rate in 2D in a mouse model with spatial resolution of ~100 µm. This type of imaging could provide non-invasive, high resolution quantification of microvascular function at penetration depths of several centimeters.

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Phantom evaluation of stacked-type dual-frequency 1–3 composite transducers: A feasibility study on intracavitary acoustic angiography

Cited by 37 publications

References 15 publications

Early Assessment of Tumor Response to Radiation Therapy using High-Resolution Quantitative Microvascular Ultrasound Imaging

Early Assessment of Tumor Response to Radiation Therapy using High-Resolution Quantitative Microvascular Ultrasound Imaging

Ultrasound-Stimulated Phase-Change Contrast Agents for Transepithelial Delivery of Macromolecules, Toward Gastrointestinal Drug Delivery

High Resolution Ultrasound Superharmonic Perfusion Imaging: In Vivo Feasibility and Quantification of Dynamic Contrast-Enhanced Acoustic Angiography

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