Flow Phantoms

Hoskins, Peter

doi:10.1007/978-3-319-46407-7_12

“…The holder is open ended from the top and sealed from the bottom using an ultrasound transparent membrane made from using the latex from a latex glove and an O-ring. The acoustic properties of the latex membrane are as follows: c = 1566 m/s, ρ = 921 kg/m 3 and α = 5 dB/cm•MHz [73]. First the tissue holder is filled with deionized degassed water and then the ex vivo tissue sample is inserted in the holder in such a way as to remove any air bubbles at the waterlatex and water-tissue boundary interfaces.…”

Section: Preparation Of 3d Soft Tissue Samplesmentioning

confidence: 99%

High Intensity Focused Ultrasound (HIFU) Thermal Lesion Detection Using Local Harmonic Imaging

Gandhi

2023

Preprint

0

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<p>Local Harmonic Imaging (LHI) is an ultrasound-based method that can detect HIFU thermal lesions. This technique relies on the delivery of an acoustic radiation force to induce localized harmonic oscillations (LHO). LHO are tracked using high frame rate ultrasound imaging. In this study, it was hypothesized that the LHO amplitude for HIFU coagulated tissue is smaller than the LHO amplitude for normal tissue due to changes in the Young’s modulus. LHO amplitudes at three tissue stages were compared in porcine muscle tissue (normal: 6.53± 0.68 µm, 2 minutes HIFU: 5.01± 0.88 µm, and 4 minutes HIFU: 2.96± 0.59 µm). The Young’s moduli at these tissue stages were 11.28± 1.57 kPa, 24.21± 2.66 kPa, and 40.38± 4.38 kPa, respectively. It was concluded that the decrease in the LHO amplitude is proportional to the increase in Young’s modulus. Additionally, a theoretical model that represents the LHI technique was developed and validated.</p>

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“…The holder is open ended from the top and sealed from the bottom using an ultrasound transparent membrane made from using the latex from a latex glove and an O-ring. The acoustic properties of the latex membrane are as follows: c = 1566 m/s, ρ = 921 kg/m 3 and α = 5 dB/cm•MHz [73]. First the tissue holder is filled with deionized degassed water and then the ex vivo tissue sample is inserted in the holder in such a way as to remove any air bubbles at the waterlatex and water-tissue boundary interfaces.…”

Section: Preparation Of 3d Soft Tissue Samplesmentioning

confidence: 99%

High Intensity Focused Ultrasound (HIFU) Thermal Lesion Detection Using Local Harmonic Imaging

Gandhi

2023

Preprint

0

View full text Add to dashboard Cite

<p>Local Harmonic Imaging (LHI) is an ultrasound-based method that can detect HIFU thermal lesions. This technique relies on the delivery of an acoustic radiation force to induce localized harmonic oscillations (LHO). LHO are tracked using high frame rate ultrasound imaging. In this study, it was hypothesized that the LHO amplitude for HIFU coagulated tissue is smaller than the LHO amplitude for normal tissue due to changes in the Young’s modulus. LHO amplitudes at three tissue stages were compared in porcine muscle tissue (normal: 6.53± 0.68 µm, 2 minutes HIFU: 5.01± 0.88 µm, and 4 minutes HIFU: 2.96± 0.59 µm). The Young’s moduli at these tissue stages were 11.28± 1.57 kPa, 24.21± 2.66 kPa, and 40.38± 4.38 kPa, respectively. It was concluded that the decrease in the LHO amplitude is proportional to the increase in Young’s modulus. Additionally, a theoretical model that represents the LHI technique was developed and validated.</p>

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“…To support innovation endeavors on 3D flow imaging, it is important to devise an investigative platform that can evaluate the experimental performance of new 3D flow mapping algorithms and hardware implementations. On this topic, flow phantoms are well considered as appropriate in vitro platforms for investigating the efficacy of flow mapping techniques under controlled flow conditions (Hoskins 2008, 2017, Boote 2014, Browne 2014. They are seemingly more preferred than computational models (Balocco et al 2008, Swillens et al 2010 that cannot be used to test hardware performance.…”

Section: Introductionmentioning

confidence: 99%

Helical toroid phantom for 3D flow imaging investigations

Chee¹,

Ishii²,

Yiu³

et al. 2021

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The medical physics community has hitherto lacked an effective calibration phantom to holistically evaluate the performance of three-dimensional (3D) flow imaging techniques. Here, we present the design of a new omnidirectional, three-component (3-C) flow phantom whose lumen is consisted of a helical toroid structure (4 mm lumen diameter; helically winded for 5 revolutions over a torus with 10 mm radius; 5 mm helix radius). This phantom’s intraluminal flow trajectory embraces all combinations of x, y, and z directional components, as confirmed using computational fluid dynamics (CFD) simulations. The phantom was physically fabricated via lost-core casting with polyvinyl alcohol cryogel (PVA) as the tissue mimic. 3D ultrasound confirmed that the phantom lumen expectedly resembled a helical toroid geometry. Pulsed Doppler measurements showed that the phantom, when operating under steady flow conditions (3 ml s−1 flow rate), yielded flow velocity magnitudes that agreed well with those derived from CFD at both the inner torus (−47.6 ± 5.7 versus −52.0 ± 2.2 cm s−1; mean ± 1 S.D.) and the outer torus (49.5 ± 4.2 versus 48.0 ± 1.7 cm s−1). Additionally, 3-C velocity vectors acquired from multi-angle pulsed Doppler showed good agreement with CFD-derived velocity vectors (<7% and 10° difference in magnitude and flow angle, respectively). Ultrasound color flow imaging further revealed that the phantom’s axial flow pattern was aligned with the CFD-derived flow profile. Overall, the helical toroid phantom has strong potential as an investigative tool in 3D flow imaging innovation endeavors, such as the development of flow vector estimators and visualization algorithms.

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Flow Phantoms

Cited by 3 publications

References 50 publications

High Intensity Focused Ultrasound (HIFU) Thermal Lesion Detection Using Local Harmonic Imaging

High Intensity Focused Ultrasound (HIFU) Thermal Lesion Detection Using Local Harmonic Imaging

High Intensity Focused Ultrasound (HIFU) Thermal Lesion Detection Using Local Harmonic Imaging

Helical toroid phantom for 3D flow imaging investigations

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