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Rathbun K, Harryman C, Re A. Prolonging the shelf life of homemade gelatin ultrasound phantoms. J Med Ultrasound 2022; 30:130-134. [PMID: 35832372 PMCID: PMC9272711 DOI: 10.4103/jmu.jmu_179_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/22/2021] [Accepted: 12/07/2021] [Indexed: 11/04/2022] Open
Abstract
A significant limitation of homemade phantoms is shelf life. Our goal was to compare the impact on shelf life of easily obtained additives. Fifteen additives were mixed into a gelatin-psyllium hydrophilic mucilloid fiber phantom; three of these additives were used as a layer on top of the phantom. The mixtures were stored in the refrigerator and at room temperature. The samples were evaluated daily for microbial growth and phantom degradation. A 4% of chlorhexidine gluconate layer on top of the phantom quickly made the phantom unusable. The addition of benzoic acid and bleach to the mixture negatively affected phantom appearance with ultrasound imaging. The addition of household bleach or 4% chlorhexidine gluconate to the mixture or a 10% povidone-iodine layer on top of the phantom was the best way to preserve samples stored at room temperature. The refrigerated sample outlasted the paired room temperature sample in every case, with most room temperature samples becoming unusable by day 10 and most refrigerated samples lasting past 50 days.
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Dakok KK, Matjafri MZ, Suardi N, Oglat AA, Nabasu SE. A Review of Carotid Artery Phantoms for Doppler Ultrasound Applications. J Med Ultrasound 2021; 29:157-166. [PMID: 34729323 PMCID: PMC8515632 DOI: 10.4103/jmu.jmu_164_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/19/2021] [Accepted: 02/25/2021] [Indexed: 11/19/2022] Open
Abstract
Ultrasound imaging systems need tissue-mimicking phantoms with a good range of acoustic properties. Many studies on carotid artery phantoms have been carried out using ultrasound; hence this study presents a review of the different forms of carotid artery phantoms used to examine blood hemodynamics by Doppler ultrasound (DU) methods and explains the ingredients that constitute every phantom with their advantages and disadvantages. Different research databases were consulted to access relevant information on carotid artery phantoms used for DU measurements after which the information were presented systematically spanning from walled phantoms to wall-less phantoms. This review points out the fact that carotid artery phantoms are made up of tissue mimicking materials, vessel mimicking materials, and blood mimicking fluid whose properties matched those of real human tissues and vessels. These materials are a combination of substances such as water, gelatin, glycerol, scatterers, and other powders in their right proportions.
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Affiliation(s)
- Kyermang Kyense Dakok
- Department of Medical Physics and Radiation Science, School of Physics, Univirsti Sains Malaysia, Penang Malaysia, Nigeria
| | - Mohammed Zubir Matjafri
- Department of Medical Physics and Radiation Science, School of Physics, Univirsti Sains Malaysia, Penang Malaysia, Nigeria
| | - Nursakinah Suardi
- Department of Medical Physics and Radiation Science, School of Physics, Univirsti Sains Malaysia, Penang Malaysia, Nigeria
| | - Ammar Anwar Oglat
- Department of Medical Imaging, Faculty of Applied Medical Sciences, The Hashemite University, Zarqa, Joradan, Nigeria
| | - Seth Ezra Nabasu
- Department of Physics, Plateau State University Bokkos, Plateau State, Nigeria
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Doyle AJ, Sullivan F, Walsh J, King DM, Cody D, Browne JE. Development and Preliminary Evaluation of an Anthropomorphic Trans-rectal Ultrasound Prostate Brachytherapy Training Phantom. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:833-846. [PMID: 33358053 DOI: 10.1016/j.ultrasmedbio.2020.11.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 06/12/2023]
Abstract
The quality of the trans-rectal ultrasound (TRUS) image, and thus seed placement during the prostate brachytherapy (PBT) procedure, relies on the user's technical and clinical competency. Simulation-based medical education can provide a structured approach for the acquisition of clinical competencies, but the efficacy of the training relies on the fidelity of the training simulators. In this work, the design, development and preliminary evaluation of an anthropomorphic training phantom for TRUS PBT is described. TRUS clinical patient data informed the design of 3-D printed moulds to fabricate prostate targets. Tissue-mimicking materials were included that had the sonographic characteristics of the prostate and overlying tissues, as well as the clinically relevant physical response, to provide haptic feedback to the user. Through an iterative design process, prototypes were constructed. These prototypes were quantitatively evaluated using a specification list and evaluated by an experienced clinical brachytherapy oncologist; their feedback was implemented, and the results of this evaluation are presented.
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Affiliation(s)
- Andrea J Doyle
- School of Physics, Medical Ultrasound Physics and Technology Group, Centre for Industrial and Engineering Optics, Focas, Technological University Dublin, Dublin, Ireland; Health Professions Education Centre, Royal College of Surgeons in Ireland, Dublin, Ireland.
| | - Frank Sullivan
- Prostate Cancer Institute, National University of Ireland Galway, Galway, Ireland; Department of Radiotherapy, Galway Clinic, Galway, Ireland
| | - John Walsh
- School of Creative Arts, City Campus, Technological University Dublin, Dublin, Ireland
| | | | - Dervil Cody
- School of Physics, Medical Ultrasound Physics and Technology Group, Centre for Industrial and Engineering Optics, Focas, Technological University Dublin, Dublin, Ireland
| | - Jacinta E Browne
- School of Physics, Medical Ultrasound Physics and Technology Group, Centre for Industrial and Engineering Optics, Focas, Technological University Dublin, Dublin, Ireland; Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
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Chee AJY, Ishii T, Yiu BYS, Yu ACH. Helical toroid phantom for 3D flow imaging investigations. Phys Med Biol 2021; 66:045029. [PMID: 33586671 DOI: 10.1088/1361-6560/abda99] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
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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Affiliation(s)
- Adrian J Y Chee
- Schlegel Research Institute for Aging and Department of Electrical and Computer Engineering, University of Waterloo, Waterloo ON, Canada
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Malone AJ, Cournane S, Naydenova IG, Fagan AJ, Browne JE. Polyvinyl alcohol cryogel based vessel mimicking material for modelling the progression of atherosclerosis. Phys Med 2020; 69:1-8. [DOI: 10.1016/j.ejmp.2019.11.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 10/31/2019] [Accepted: 11/15/2019] [Indexed: 01/03/2023] Open
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Malone A, Chari D, Cournane S, Naydenova I, Fagan A, Browne J. Investigation of the assessment of low degree (<50%) renal artery stenosis based on velocity flow profile analysis using Doppler ultrasound: An in-vitro study. Phys Med 2019; 65:209-218. [PMID: 31518907 DOI: 10.1016/j.ejmp.2019.08.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/21/2019] [Accepted: 08/23/2019] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Renal arterial stenosis can lead to disrupted renal function due to reduced blood flow to the kidneys and is largely thought to be caused by atherosclerosis. Current diagnostic strategies for renal arterial stenosis rely on detecting large degree stenoses (>50%). This study aimed to test the viability of using Doppler ultrasound to assess velocity profiles to detect the presence of low degree (<50%) stenoses. METHODS A series of anatomically realistic renal artery flow phantoms were constructed exhibiting a range of low degree stenoses (symmetric and asymmetric). The behaviour of fluid flow in the phantoms was examined using Doppler ultrasound and analysed to calculate the clinical biomarker, wall shear stress. RESULTS A number of fluid behaviours were observed in relation to stenosis degree: asymmetric stenoses tended to result in a skewing of peak velocities away from the centre of the vessel towards the outer wall, the magnitude of increase in velocity was observed to correlate with stenosis degree, and the wall shear stress curves observed large peaks in the presence of even the lowest degree stenosis (20%). CONCLUSIONS Doppler ultrasound could potentially be utilised to diagnose low degree stenoses in a clinical setting. Doppler ultrasound in conjunction with wall shear stress analysis in particular has significant potential in the diagnosis of renal artery stenosis.
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Affiliation(s)
- Andrew Malone
- School of Physics and Clinical & Optometric Sciences, College of Science and Health, Technological University Dublin, Dublin, Ireland.
| | - Deepa Chari
- STEM Transformation Institute, Florida International University, Miami, USA
| | | | - Izabela Naydenova
- School of Physics and Clinical & Optometric Sciences, College of Science and Health, Technological University Dublin, Dublin, Ireland
| | - Andrew Fagan
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | - Jacinta Browne
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
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Browne JE, King D, Fagan AJ, Chari D, Moran CM. An investigation of the detection capability of pulsed wave duplex Doppler of low grade stenosis using ultrasound contrast agent microbubbles - An in-vitro study. ULTRASONICS 2019; 96:48-54. [PMID: 31004864 DOI: 10.1016/j.ultras.2019.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 03/11/2019] [Accepted: 04/02/2019] [Indexed: 06/09/2023]
Abstract
OBJECTIVE The objective of the study was to investigate whether clinically used ultrasonic contrast agents improved the accuracy of spectral Doppler ultrasound in the detection of low grade (<50%) renal artery stenosis. Low grade stenoses in the renal artery are notoriously difficult to reliably detect using Doppler ultrasound due to difficulties such as overlying fat and bowel gas. METHODS A range of anatomically-realistic renal artery phantoms with varying low degrees of stenosis (0, 30 and 50%) were constructed and peak velocity data was measured from within the pre-stenotic and mid-stenotic regions in each phantom, for both unenhanced and contrast-enhanced spectral Doppler data acquisitions. The effect of a 20 mm overlying fat layer on the ultrasound beam distortion and phase aberration, and hence on the measured peak velocity data, was also investigated. RESULTS The overlying fat layer produced a statistically significant underestimation (p < 0.01) in both the peak velocity and peak velocity ratio [Stenotic Region(Vmax)/Pre-stenotic Region(Vmax)] for the 0% and 30% stenosis models, but not the 50% model. A statistically significant increase (p < 0.01) in the peak velocity was found in the contrast-enhanced Doppler spectra; however, no significant difference was found between the unenhanced and contrast enhanced peak velocity ratio data, which suggests that the ratio metric has better diagnostic accuracy. The peak velocity ratios determined for each of the contrast-enhanced phantoms correctly predicted if the phantom had a stenosis and furthermore correctly classified the degree of stenosis. CONCLUSION Contrast-enhanced Doppler ultrasound could significantly assist in the early detection of renal artery disease.
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Affiliation(s)
- Jacinta E Browne
- Medical Ultrasound Physics and Technology Group, School of Physics & FOCAS, Technical University Dublin - Kevin Street Campus, Dublin 6, Ireland; Department of Radiology, Mayo Clinic, Rochester, 55901 MN, USA.
| | - Deirdre King
- Medical Physics, Blackrock Clinic, Dublin, Ireland
| | - Andrew J Fagan
- Department of Radiology, Mayo Clinic, Rochester, 55901 MN, USA
| | - Deepa Chari
- Medical Ultrasound Physics and Technology Group, School of Physics & FOCAS, Technical University Dublin - Kevin Street Campus, Dublin 6, Ireland
| | - Carmel M Moran
- Medical Physics, Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, UK
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Yiu BYS, Yu ACH. Spiral Flow Phantom for Ultrasound Flow Imaging Experimentation. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2017; 64:1840-1848. [PMID: 29035216 DOI: 10.1109/tuffc.2017.2762860] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
As new ultrasound flow imaging methods are being developed, there is a growing need to devise appropriate flow phantoms that can holistically assess the accuracy of the derived flow estimates. In this paper, we present a novel spiral flow phantom design whose Archimedean spiral lumen naturally gives rise to multi-directional flow over all possible angles (i.e., from 0° to 360°). Developed using lost-core casting principles, the phantom geometry comprised a three-loop spiral (4-mm diameter and 5-mm pitch), and it was set to operate in steady flow mode (3 mL/s flow rate). After characterizing the flow pattern within the spiral vessel using computational fluid dynamics (CFD) simulations, the phantom was applied to evaluate the performance of color flow imaging (CFI) and high-frame-rate vector flow imaging. Significant spurious coloring artifacts were found when using CFI to visualize flow in the spiral phantom. In contrast, using vector flow imaging (least-squares multi-angle Doppler based on a three-transmit and three-receive configuration), we observed consistent depiction of flow velocity magnitude and direction within the spiral vessel lumen. The spiral flow phantom was also found to be a useful tool in facilitating demonstration of dynamic flow visualization based on vector projectile imaging. Overall, these results demonstrate the spiral flow phantom's practical value in analyzing the efficacy of ultrasound flow estimation methods.
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Ho CK, Chee AJY, Yiu BYS, Tsang ACO, Chow KW, Yu ACH. Wall-Less Flow Phantoms With Tortuous Vascular Geometries: Design Principles and a Patient-Specific Model Fabrication Example. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2017; 64:25-38. [PMID: 27959808 DOI: 10.1109/tuffc.2016.2636129] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Flow phantoms with anatomically realistic geometry and high acoustic compatibility are valuable investigative tools in vascular ultrasound studies. Here, we present a new framework to fabricate ultrasound-compatible flow phantoms to replicate human vasculature that is tortuous, nonplanar, and branching in nature. This framework is based upon the integration of rapid prototyping and investment casting principles. A pedagogical walkthrough of our engineering protocol is presented in this paper using a patient-specific cerebral aneurysm model as an exemplar demonstration. The procedure for constructing the flow circuit component of the phantoms is also presented, including the design of a programmable flow pump system, the fabrication of blood mimicking fluid, and flow rate calibration. Using polyvinyl alcohol cryogel as the tissue mimicking material, phantoms developed with the presented protocol exhibited physiologically relevant acoustic properties [attenuation coefficient: 0.229±0.032 dB/( [Formula: see text]) and acoustic speed: 1535±2.4 m/s], and their pulsatile flow dynamics closely resembled the flow profile input. As a first application of our developed phantoms, the flow pattern of the patient-specific aneurysm model was visualized by performing high-frame-rate color-encoded speckle imaging over multiple time-synchronized scan planes. Persistent recirculation was observed, and the vortex center was found to shift in position over a cardiac cycle, indicating the 3-D nature of flow recirculation inside an aneurysm. These findings suggest that phantoms produced from our reported protocol can serve well as acoustically compatible test beds for vascular ultrasound studies, including 3-D flow imaging.
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Chee AJY, Ho CK, Yiu BYS, Yu ACH. Walled Carotid Bifurcation Phantoms for Imaging Investigations of Vessel Wall Motion and Blood Flow Dynamics. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2016; 63:1852-1864. [PMID: 27429436 DOI: 10.1109/tuffc.2016.2591946] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
As a major application domain of vascular ultrasound, the carotid artery has long been the subject of anthropomorphic phantom design. It is nevertheless not trivial to develop walled carotid phantoms that are compatible for use in integrative imaging of carotid wall motion and flow dynamics. In this paper, we present a novel phantom design protocol that can enable efficient fabrication of walled carotid bifurcation phantoms with: (i) high acoustic compatibility, (ii) artery-like vessel elasticity, and (iii) stenotic narrowing feature. Our protocol first involved direct fabrication of the vessel core and an outer mold using computer-aided design tools and 3-D printing technology; these built parts were then used to construct an elastic vessel tube through investment casting of a polyvinyl alcohol containing mixture, and an agar-gelatin tissue mimicking slab was formed around the vessel tube. For demonstration, we applied our protocol to develop a set of healthy and stenosed (25%, 50%, 75%) carotid bifurcation phantoms. Plane wave imaging experiments were performed on these phantoms using an ultrasound scanner with channel-level configurability. Results show that the wall motion dynamics of our phantoms agreed with pulse wave propagation in an elastic vessel (pulse wave velocity of 4.67±0.71 m/s measured at the common carotid artery), and their flow dynamics matched the expected ones in healthy and stenosed bifurcation (recirculation and flow jet formation observed). Integrative imaging of vessel wall motion and blood flow dynamics in our phantoms was also demonstrated, from which we observed fluid-structure interaction differences between healthy and diseased bifurcation phantoms. These findings show that the walled bifurcation phantoms developed with our new protocol are useful in vascular imaging studies that individually or jointly assess wall motion and flow dynamics.
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Blackwood S, Mix D, Chandra A, Dietzek AM. A model to demonstrate that endotension is a nonvisualized type I endoleak. J Vasc Surg 2016. [DOI: 10.1016/j.jvs.2015.04.422] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Nikitichev DI, Barburas A, McPherson K, Mari JM, West SJ, Desjardins AE. Construction of 3-Dimensional Printed Ultrasound Phantoms With Wall-less Vessels. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2016; 35:1333-9. [PMID: 27162278 DOI: 10.7863/ultra.15.06012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 09/15/2015] [Indexed: 05/08/2023]
Abstract
Ultrasound phantoms are invaluable as training tools for vascular access procedures. We developed ultrasound phantoms with wall-less vessels using 3-dimensional printed chambers. Agar was used as a soft tissue-mimicking material, and the wall-less vessels were created with rods that were retracted after the agar was set. The chambers had integrated luer connectors to allow for fluid injections with clinical syringes. Several variations on this design are presented, which include branched and stenotic vessels. The results show that 3-dimensional printing can be well suited to the construction of wall-less ultrasound phantoms, with designs that can be readily customized and shared electronically.
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Affiliation(s)
- Daniil I Nikitichev
- Department of Medical Physics and Biomedical Engineering, University College London, London, England
| | - Anamaria Barburas
- Department of Medical Physics and Biomedical Engineering, University College London, London, England
| | | | - Jean-Martial Mari
- Department of Medical Physics and Biomedical Engineering, University College London, London, EnglandUniversity of French Polynesia, Tahiti, French Polynesia
| | | | - Adrien E Desjardins
- Department of Medical Physics and Biomedical Engineering, University College London, London, England
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Browne JE. A review of Doppler ultrasound quality assurance protocols and test devices. Phys Med 2014; 30:742-51. [PMID: 25212384 DOI: 10.1016/j.ejmp.2014.08.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 08/13/2014] [Accepted: 08/14/2014] [Indexed: 02/07/2023] Open
Abstract
In this paper, an overview of Doppler ultrasound quality assurance (QA) testing will be presented in three sections. The first section will review the different Doppler ultrasound parameters recommended by professional bodies for use in QA protocols. The second section will include an evaluation and critique of the main test devices used to assess Doppler performance, while the final section of this paper will discuss which of the wide range of test devices have been found to be most suitable for inclusion in Doppler QA programmes. Pulsed Wave Spectral Doppler, Colour Doppler Imaging QA test protocols have been recommended over the years by various professional bodies, including the UK's Institute of Physics and Engineering in Medicine (IPEM), the American Institute for Ultrasound in Medicine (AIUM), and the International Electrotechnical Commission (IEC). However, despite the existence of such recommended test protocols, very few commercial or research test devices exist which can measure the full range of both PW Doppler ultrasound and colour Doppler imaging performance parameters, particularly quality control measurements such as: (i) Doppler sensitivity (ii) colour Doppler spatial resolution (iii) colour Doppler temporal resolution (iv) colour Doppler velocity resolution (v) clutter filter performance and (vi) tissue movement artefact suppression. In this review, the merits of the various commercial and research test devices will be considered and a summary of results obtained from published studies which have made use of some of these Doppler test devices, such as the flow, string, rotating and belt phantom, will be presented.
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Affiliation(s)
- Jacinta E Browne
- Medical Ultrasound Group, School of Physics and IEO, FOCAS Institute, Dublin Institute of Technology, Kevin Street, Dublin 8, Ireland.
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Boote EJ. Phantoms for Ultrasound Experimentation and Quality Control. THE PHANTOMS OF MEDICAL AND HEALTH PHYSICS 2014. [DOI: 10.1007/978-1-4614-8304-5_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Lai SSM, Yiu BYS, Poon AKK, Yu ACH. Design of anthropomorphic flow phantoms based on rapid prototyping of compliant vessel geometries. ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:1654-1664. [PMID: 23791354 DOI: 10.1016/j.ultrasmedbio.2013.03.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 02/25/2013] [Accepted: 03/09/2013] [Indexed: 06/02/2023]
Abstract
Anatomically realistic flow phantoms are essential experimental tools for vascular ultrasound. Here we describe how these flow phantoms can be efficiently developed via a rapid prototyping (RP) framework that involves direct fabrication of compliant vessel geometries. In this framework, anthropomorphic vessel models were drafted in computer-aided design software, and they were fabricated using stereolithography (one type of RP). To produce elastic vessels, a compliant photopolymer was used for stereolithography. We fabricated a series of compliant, diseased carotid bifurcation models with eccentric stenosis (50%) and plaque ulceration (types I and III), and they were used to form thin-walled flow phantoms by coupling the vessels to an agar-based tissue-mimicking material. These phantoms were found to yield Doppler spectrograms with significant spectral broadening and color flow images with mosaic patterns, as typical of disturbed flow under stenosed and ulcerated disease conditions. Also, their wall distension behavior was found to be similar to that observed in vivo, and this corresponded with the vessel wall's average elastic modulus (391 kPa), which was within the nominal range for human arteries. The vessel material's acoustic properties were found to be sub-optimal: the estimated average acoustic speed was 1801 m/s, and the attenuation coefficient was 1.58 dB/(mm·MHz(n)) with a power-law coefficient of 0.97. Such an acoustic mismatch nevertheless did not notably affect our Doppler spectrograms and color flow image results. These findings suggest that phantoms produced from our design framework have the potential to serve as ultrasound-compatible test beds that can simulate complex flow dynamics similar to those observed in real vasculature.
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Affiliation(s)
- Simon S M Lai
- Medical Engineering Program, University of Hong Kong, Pokfulam, Hong Kong SAR, China
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16
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Current world literature. Curr Opin Cardiol 2011; 26:576-83. [PMID: 21988836 DOI: 10.1097/hco.0b013e32834d3850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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King DM, Moran CM, McNamara JD, Fagan AJ, Browne JE. Development of a vessel-mimicking material for use in anatomically realistic Doppler flow phantoms. ULTRASOUND IN MEDICINE & BIOLOGY 2011; 37:813-826. [PMID: 21497719 DOI: 10.1016/j.ultrasmedbio.2011.02.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 02/17/2011] [Accepted: 02/19/2011] [Indexed: 05/30/2023]
Abstract
Polyvinyl alcohol cryogel (PVA-C) is presented as a vessel-mimicking material for use in anatomically realistic Doppler flow phantoms. Three different batches of 10% wt PVA-C containing (i) PVA-C alone, (ii) PVA-C with antibacterial agent and (iii) PVA-C with silicon carbide particles were produced, each with 1-6 freeze-thaw cycles. The resulting PVA-C samples were characterized acoustically (over a range 2.65 to 10.5 MHz) and mechanically to determine the optimum mixture and preparation for mimicking the properties of healthy and diseased arteries found in vivo. This optimum mix was reached with the PVA-C with antibacterial agent sample, prepared after two freeze/thaw cycles, which achieved a speed of sound of 1538 ± 5 m s(-1) and a Young's elastic modulus of 79 ± 11 kPa. This material was used to make a range of anatomically realistic flow phantoms with varying degrees of stenoses, and subsequent flow experiments revealed that higher degrees of stenoses and higher velocities could be achieved without phantom rupturing compared with a phantom containing conventional wall-less vessels.
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Affiliation(s)
- Deirdre M King
- Medical Ultrasound Physics and Technology Group, School of Physics and FOCAS Institute, Dublin Institute of Technology, Dublin, Ireland
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King DM, Fagan AJ, Moran CM, Browne JE. Comparative imaging study in ultrasound, MRI, CT, and DSA using a multimodality renal artery phantom. Med Phys 2011; 38:565-73. [DOI: 10.1118/1.3533674] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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