High frequency ultrasound with an eigen-decomposition filter to assess the effect of laser cyclophotocoagulation treatment on blood flow

Kruse, Dustin E.; Lim, Michele C.; Redline, D.E.; Eisele, P. H.; Ferrara, Katherine W.

doi:10.1109/ultsym.2002.1192578

Cited by 6 publications

(4 citation statements)

References 10 publications

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“…It is useful to note that the generation of subharmonic signals from contrast agents at conventional frequencies has been shown to be possible without the destruction of microbubbles [32]. In [17], [18] it was found that, at a 20-MHz transmit frequency, significant destruction of microbubbles did not occur until pressure levels much higher (>5 MPa) than those used in this study (1.8 MPa).…”

Section: A Performance Commentsmentioning

confidence: 77%

“…At present, work with microbubbles at high frequencies (>10 MHz) remains a relatively unexplored area in which virtually all studies have examined or assumed linear scattering [14], [15]. Initial studies have been conducted with microbubbles in high-frequency, pulsed-wave Doppler [16], [17] and color flow imaging [17], [18] experiments, which suggest the potential value of microbubbles for enhancing the signal strength from blood.…”

Section: Introductionmentioning

confidence: 99%

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High-frequency, nonlinear flow imaging of microbubble contrast agents

Goertz

Needles

Burns

et al. 2005

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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It has been shown that nonlinear scattering can be stimulated from microbubble contrast agents at high-transmit frequencies (14-32 MHz). This work was extended to demonstrate the feasibility of nonlinear contrast imaging through modifications of existing ultrasound biomicroscopy linear B-scan imaging instrumentation. In this study, we describe the development and evaluation of prototype coherent flow imaging instrumentation for nonlinear microbubble imaging using transmit frequencies from 10 to 50 MHz. Phantom validation experiments were conducted to demonstrate color and power flow imaging using nonlinear 10 MHz (subharmonic) scattering induced by a 20-MHz transmit frequency. In vivo flow imaging of a rabbit ear microvessel was successfully performed. This work indicates the feasibility of performing flow imaging at high frequencies using nonlinear scattering from microbubbles.

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Section: A Performance Commentsmentioning

confidence: 77%

Section: Introductionmentioning

confidence: 99%

High-frequency, nonlinear flow imaging of microbubble contrast agents

Goertz

Needles

Burns

et al. 2005

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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“…Several in vivo studies have indicated the possibility of using UCAs with high-frequency systems to enhance detection of the vasculature. 30,31 Recently, Goertz et al 26,32 showed the feasibility of nonlinear high-frequency imaging with UCAs, but this approach requires extensive hardware modifications to detect the nonlinear characteristics of the UCAs, and commercialization of these prototypes is still under development.…”

Section: Discussionmentioning

confidence: 99%

A Method for Assessing the Microvasculature in a Murine Tumor Model Using Contrast-Enhanced Ultrasonography

Loveless

Huamani

et al. 2008

Journal of Ultrasound in Medicine

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Objective-The purpose of this study was to develop a method for assessing tumor vascularity in a preclinical model of breast cancer using contrast-enhanced ultrasonography.Methods-Eight mice were injected with 67NR breast cancer cells on their hind limbs and imaged with ultrasonography 8 days later. Mice were injected with an ultrasound contrast agent (UCA), and a sequence of images of the resultant backscattered echoes was recorded before and after high-power "destruction" pulses for each of multiple parallel planes. From these, data maps of the maximum contrast enhancement (within each time course) were constructed for each pixel, which enabled reconstruction of high-resolution coregistered sections into a 3-dimensional (3D) volume reflecting tumor vascularity. Additional studies were performed to determine the duration and repeatability of image enhancement, and images were correlated with conventional 3D power Doppler measurements.Results-The lifetime of the UCA in vivo was found to be 4.3 ± 1.09 minutes (mean ± SD). The 3D contrast-enhanced ultrasonographic technique produced images that correlated well with power Doppler images in specific regions but also depicted additional regions of flow surrounding the power Doppler signal. The mean correlation coefficient between voxel measurements of the central slice for each animal was 0.64 ± 0.07 (P < .01). In addition, sequential studies in each animal were reproducible.Conclusions-A method producing high-resolution volumetric assessments of tumor vascularity in a preclinical model of breast cancer is shown that correlates with other ultrasonographic measures of blood flow, which may provide greater sensitivity to the microvasculature. Keywordscontrast-enhanced ultrasonography; tumor; vascularity For a tumor to grow beyond approximately 1 to 2 mm 3 , it cannot rely on the diffusion of metabolites and therefore must recruit and develop new vessels through the well-known process of angiogenesis. 1 Secretion of multiple growth factors from the tumor causes a chemotactic response from endothelial cells, which then migrate to the site to form vessels. Typically, the neovasculature arising from this process exhibits different characteristics from Ultrasound contrast agents (UCAs) are composed of small volumes of air or gas surrounded by a stabilizing shell that remain completely intravascular, making them ideal agents for vessel imaging. 6-10 Ultrasound contrast agents reflect sound strongly because they have a very different acoustic impedance from that of blood. In the presence of a sound field, the UCA begins to expand and contract. At a low input wave pressure (<50 kPa), the microbubbles behave as simple monopole oscillators, but at a higher input pressure (50-100 kPa), they may have nonlinear behavior, producing harmonics of the incident sound. At an even higher pressure (500 kPa-1MPa), the bubbles can be destroyed by extreme expansion and contraction, which can be advantageous in some applications. 11The aim of this study was to create high-resolution 3-...

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“…Transmission at such high frequencies also limits depth of penetration; and, when combined with attenuating media, very high pressures may be required to penetrate even 1 cm of tissue. Although contrast-assisted methods have demonstrated the ability to detect flow in subresolution vessels of the microcirculation [8], [13], [14], to the best of the authors' knowledge, no existing methods that take advantage of nonlinear UCA scattering have been demonstrated to resolve vessels on the scale of the microcirculation.…”

Section: Introductionmentioning

confidence: 99%

A new imaging strategy using wideband transient response of ultrasound contrast agents

Kruse

Ferrara²

2005

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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High-resolution clinical systems operating near 15 MHz are becoming more available; however, they lack sensitive harmonic imaging modes for ultrasound contrast agent (UCA) detection, primarily due to limited bandwidth. When an UCA is driven to nonlinear oscillation, a very wideband acoustic transient response is produced that extends beyond 15 MHz. We propose a novel strategy using two separate transducers at widely separated frequencies and arranged confocally to simultaneously excite and receive acoustic transients from UCAs. Experiments were performed to demonstrate that this new mode shows similar resolution, higher echo amplitudes, and greatly reduced attenuation compared to transmission at a higher frequency, and superior resolution compared to transmission and reception at a lower frequency. The proposed method is shown to resolve two 200 μm tubes with centers separated by 400 μm. Strong acoustic transients were detected for rarefaction-first 1-cycle pulses with peak-negative pressures above 300 kPa. The results of this work may lead to uses in flow and/or targeted imaging in applications requiring very high sensitivity to contrast agents.

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High frequency ultrasound with an eigen-decomposition filter to assess the effect of laser cyclophotocoagulation treatment on blood flow

Cited by 6 publications

References 10 publications

High-frequency, nonlinear flow imaging of microbubble contrast agents

High-frequency, nonlinear flow imaging of microbubble contrast agents

A Method for Assessing the Microvasculature in a Murine Tumor Model Using Contrast-Enhanced Ultrasonography

A new imaging strategy using wideband transient response of ultrasound contrast agents

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