Blood Flow Estimation Error with Intravascular Ultrasound Due to In-Plane Component of Flow

Ana, F.J. de; O’Donnell, Matthew

doi:10.1177/016173460302500306

Cited by 6 publications

(2 citation statements)

References 24 publications

(34 reference statements)

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“…Slow-time filtering retains the signal from static microbubbles and largely cancels the signal scattered by flowing microbubbles. 5,16,26,27 This allows selective imaging of static or adherent microbubbles in real time (8–10 Hz frame rate). At the end of this sequence, a high MI (MI = 1.0), high PRF destruction pulse is directed to the static or adherent microbubbles, thus facilitating local microbubble destruction and a concomitant fluorophore delivery.…”

Section: Methodsmentioning

confidence: 99%

Real-Time Technique for Improving Molecular Imaging and Guiding Drug Delivery in Large Blood Vessels: In Vitro and Ex Vivo Results

et al. 2011

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Ultrasound-based molecular imaging employs targeted microbubbles to image vascular pathology. This approach also has the potential to monitor molecularly targeted microbubble-based drug delivery. We present an image-guided drug delivery technique that uses multiple pulses to translate, image, and cavitate microbubbles in real time. This technique can be applied to both imaging of pathology in large arteries (sizes and flow comparable to those in humans) and guiding localized drug delivery in blood vessels. The microbubble translation (or pushing) efficacy of this technique was compared in a variety of flow media: saline, viscous saline (4 cp), and bovine blood. It was observed that the performance of this approach was marginally better (by 6, 4, and 2 dB) in viscous saline than in bovine blood with varying levels of hematocrit (40%, 30%, and 10%). The drug delivery efficacy of this technique was evaluated by in vitro and ex vivo experiments. High-intensity pulses mediated fluorophore (DiI) deposition on endothelial cells (in vitro) without causing cell destruction. Ex vivo fluorophore delivery experiments conducted on swine carotids of 2 and 5 mm cross-section diameter demonstrated a high degree of correspondence in spatial localization of the fluorophore delivery between the ultrasound and composite fluorescence microscopy images of the arterial cross sections.

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Section: Methodsmentioning

confidence: 99%

Real-Time Technique for Improving Molecular Imaging and Guiding Drug Delivery in Large Blood Vessels: In Vitro and Ex Vivo Results

et al. 2011

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“…As illustrated in Figure 1, the non-linear imaging mode or PI radio frequency (RF) data are “slow time” averaged to retain signals from bound microbubbles. This technique refers to temporal averaging over several transmitted pulses (de Ana et al 2003). It eliminates high frequency variations in a data set acquired over several temporally spaced observation windows.…”

Section: Methodsmentioning

confidence: 99%

Dual Frequency Method for Simultaneous Translation and Real-Time Imaging of Ultrasound Contrast Agents Within Large Blood Vessels

Patil

Rychak

Allen

et al. 2009

Ultrasound in Medicine & Biology

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A dual frequency excitation method for simultaneous translation and selective real-time imaging of microbubbles is presented. The method can distinguish signals originating from free flowing and static microbubbles. This method is implemented on a programmable scanner with a broadband linear array. The programmable interface allows for dynamic variations in the acoustic parameters and aperture attributes, enabling application of this method to large blood vessels located at varying depths. The performance of the method was evaluated in vitro (vessel diameter 2 mm) by quantifying the sensitivity of the method to various acoustic, microbubble, and fluid flow parameters. It was observed that the static microbubble response maximized at the approximate resonance frequency of the microbubble population (estimated from a coulter counter measurement), thus signifying the need for dual frequency excitation. The static microbubble signal declined from 25 to 12 dB with increasing centerline flow velocities (2.65-15.9 cm/s); indicating applicable range of flow velocities. The maximum intensity of the static microbubbles signal scaled with variations in the microbubble concentration. The rate of increment of static microbubble signal was independent of microbubble concentration. It was deduced that the rate of increment of the static microbubble signal is primarily a function of the pulse frequency, whereas the maximum static microbubble signal intensity is dependent on three parameters: a) the pulse frequency, b) the flow velocity, and c) the microbubble concentration. The proposed dual frequency sequence may enable application of radiation force for optimizing the effect of targeted imaging and modulating drug delivery in large blood vessels with high flow velocities.

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Quantitative real-time blood flow estimation with intravascular ultrasound in the presence of in-plane flow

Ana

O’Donnell

2005

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

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Blood Flow Estimation Error with Intravascular Ultrasound Due to In-Plane Component of Flow

Cited by 6 publications

References 24 publications

Real-Time Technique for Improving Molecular Imaging and Guiding Drug Delivery in Large Blood Vessels: In Vitro and Ex Vivo Results

Real-Time Technique for Improving Molecular Imaging and Guiding Drug Delivery in Large Blood Vessels: In Vitro and Ex Vivo Results

Dual Frequency Method for Simultaneous Translation and Real-Time Imaging of Ultrasound Contrast Agents Within Large Blood Vessels

Quantitative real-time blood flow estimation with intravascular ultrasound in the presence of in-plane flow

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