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Nicolas N, de Tilly A, Roux E. Blood shear stress during the cardiac cycle and endothelial cell orientation and polarity in the carotid artery of male and female mice. Front Physiol 2024; 15:1386151. [PMID: 39072218 PMCID: PMC11272658 DOI: 10.3389/fphys.2024.1386151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 06/17/2024] [Indexed: 07/30/2024] Open
Abstract
Introduction: Blood flow produces fluid shear stress (SS), a frictional force parallel to the blood flow, on the endothelial cell (EC) layer of the lumen of the vessels. ECs themselves are sensitive to this frictional force in terms of directionality and intensity. The aim of this study was to determine the physiological shear stress value during the cardiac cycle and EC polarity and orientation from blood flow in healthy male and female mouse carotid artery. Methods: Experimentation is done on anesthetized male and female 8-week-old C5BL/6J mice. In vivo measurements of maximum blood velocity and vessel diameter in diastole and systole were performed on the right common carotid artery by Doppler ultrasound imaging. Blood viscosity (total and plasmatic) and hematocrit were determined on blood samples. For SS calculation, we developed a new method assuming heterogenous blood flow, i.e., a red cell central plug flow surrounded by a peripheral plasma sheath flow, and computing SS from vessel diameter and hemodynamical measurements (maximal blood velocity, hematocrit and plasmatic viscosity). Results: Results were compared with the classical method assuming a homogenous blood flow with constant apparent total blood viscosity. EC polarity and orientation were determined ex vivo on the carotid endothelium by confocal imaging after labeling of the EC nucleus and Golgi apparatus. Diastolic and systolic SS were 6 ± 2.5 Pa and 30 ± 6.5 Pa, respectively. Total blood and plasmatic viscosity was 4 ± 0.5 cP and 1.27 cP, respectively. ECs were polarized and significantly oriented against blood flow. No sex difference was identified.
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Affiliation(s)
- Nabil Nicolas
- Biologie des Maladies Cardiovasculaires, INSERM, U1034, University of Bordeaux, Pessac, France
| | | | - Etienne Roux
- Biologie des Maladies Cardiovasculaires, INSERM, U1034, University of Bordeaux, Pessac, France
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Kocaaga B, Inan T, Yasar Nİ, Yalcin CE, Sungur FA, Kurkcuoglu O, Demiroz A, Komurcu H, Kizilkilic O, Aydin SY, Aydin Ulgen O, Güner FS, Arslan H. Innovative Use of an Injectable, Self-Healing Drug-Loaded Pectin-Based Hydrogel for Micro- and Supermicro-Vascular Anastomoses. Biomacromolecules 2024; 25:3959-3975. [PMID: 38934558 PMCID: PMC11238333 DOI: 10.1021/acs.biomac.4c00102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 05/30/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024]
Abstract
Microvascular surgery plays a crucial role in reconnecting micrometer-scale vessel ends. Suturing remains the gold standard technique for small vessels; however, suturing the collapsed lumen of microvessels is challenging and time-consuming, with the risk of misplaced sutures leading to failure. Although multiple solutions have been reported, the emphasis has predominantly been on resolving challenges related to arteries rather than veins, and none has proven superior. In this study, we introduce an innovative solution to address these challenges through the development of an injectable lidocaine-loaded pectin hydrogel by using computational and experimental methods. To understand the extent of interactions between the drug and the pectin chain, molecular dynamics (MD) simulations and quantum mechanics (QM) calculations were conducted in the first step of the research. Then, a series of experimental studies were designed to prepare lidocaine-loaded injectable pectin-based hydrogels, and their characterization was performed by using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and rheological analysis. After all the results were evaluated, the drug-loaded pectin-based hydrogel exhibiting self-healing properties was selected as a potential candidate for in vivo studies to determine its performance during operation. In this context, the hydrogel was injected into the divided vessel ends and perivascular area, allowing for direct suturing through the gel matrix. While our hydrogel effectively prevented vasospasm and facilitated micro- and supermicro-vascular anastomoses, it was noted that it did not cause significant changes in late-stage imaging and histopathological analysis up to 6 months. We strongly believe that pectin-based hydrogel potentially enhanced microlevel arterial, lymphatic, and particularly venous anastomoses.
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Affiliation(s)
- Banu Kocaaga
- Department
of Chemical Engineering, Istanbul Technical
University, Maslak, 34469 Istanbul, Turkey
| | - Tugce Inan
- Department
of Chemical Engineering, Istanbul Technical
University, Maslak, 34469 Istanbul, Turkey
| | - Nesrin İsil Yasar
- Informatics
Institute, Computational Science and Engineering Division, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey
| | - Can Ege Yalcin
- Cerrahpasa
Medical Faculty, Department of Plastic, Reconstructive and Aesthetic
Surgery, Istanbul University-Cerrahpasa, Istanbul 34089, Turkey
| | - Fethiye Aylin Sungur
- Informatics
Institute, Computational Science and Engineering Division, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey
| | - Ozge Kurkcuoglu
- Department
of Chemical Engineering, Istanbul Technical
University, Maslak, 34469 Istanbul, Turkey
| | - Anil Demiroz
- Cerrahpasa
Medical Faculty, Department of Plastic, Reconstructive and Aesthetic
Surgery, Istanbul University-Cerrahpasa, Istanbul 34089, Turkey
| | - Hasan Komurcu
- Department
of Plastic, Reconstructive and Aesthetic Surgery, Balat Or-Ahayim Hastanesi, Istanbul 34087, Turkey
| | - Osman Kizilkilic
- Cerrahpasa
Medical Faculty, Department of Interventional Radiology, Istanbul University-Cerrahpasa, Istanbul 34098, Turkey
| | - Servet Yekta Aydin
- Cerrahpasa
Medical Faculty, Department of Plastic, Reconstructive and Aesthetic
Surgery, Istanbul University-Cerrahpasa, Istanbul 34089, Turkey
| | - Ovgu Aydin Ulgen
- Cerrahpasa
Medical Faculty, Department of Pathology, Istanbul University-Cerrahpasa, Istanbul 34098, Turkey
| | - Fatma Seniha Güner
- Department
of Chemical Engineering, Istanbul Technical
University, Maslak, 34469 Istanbul, Turkey
- Sabancı
University Nanotechnology Research and Application Center, Istanbul 34956, Turkey
| | - Hakan Arslan
- Cerrahpasa
Medical Faculty, Department of Plastic, Reconstructive and Aesthetic
Surgery, Istanbul University-Cerrahpasa, Istanbul 34089, Turkey
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3
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Mynard JP, Kowalski R, Harrington HA, Kondiboyina A, Smolich JJ, Cheung MMH. Superiority of a Representative MRI Flow Waveform over Doppler Ultrasound for Aortic Wave Reflection Assessment in Children and Adolescents With/Without a History of Heart Disease. Ann Biomed Eng 2023; 51:2772-2784. [PMID: 37561232 PMCID: PMC10632254 DOI: 10.1007/s10439-023-03339-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 07/29/2023] [Indexed: 08/11/2023]
Abstract
Wave separation analysis (WSA) reveals the impact of forward- and backward-running waves on the arterial pressure pulse, but the calculations require a flow waveform. This study investigated (1) the variability of the ascending aortic flow waveform in children and adolescents with/without a childhood heart disease history (CHD); (2) the accuracy of WSA obtained with a representative flow waveform (RepFlow), compared with the triangulation method and published ultrasound-derived adult representative flow; (3) the impact of limitations in Doppler ultrasound on WSA; and (4) generalizability of results to adults with a history of CHD. Phase contrast MRI was performed in youth without (n = 45, Group 1, 10-19 years) and with CHD (n = 79, Group 2, 7-18 years), and adults with CHD history (n = 29, Group 3, 19-59 years). Segmented aortic cross-sectional area was used as a surrogate for the central pressure waveform in WSA. A subject-specific virtual Doppler ultrasound was performed on MRI data by extracting velocities from a sample volume. Time/amplitude-normalized ascending aortic flow waveforms were highly consistent amongst all groups. WSA with RepFlow therefore yielded errors < 10% in all groups for reflected wave magnitude and return time. Absolute errors were typically 1.5-3 times greater with other methods, including subject-specific (best-case/virtual) Doppler ultrasound, for which velocity profile skewing introduced waveform errors. Our data suggest that RepFlow is the optimal approach for pressure-only WSA in children and adolescents with/without CHD, as well as adults with CHD history, and may even be more accurate than subject-specific Doppler ultrasound in the ascending aorta.
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Affiliation(s)
- Jonathan P Mynard
- Heart Research, Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC, 3052, Australia.
- Department of Paediatrics, University of Melbourne, Parkville VIC, Australia.
- Department of Biomedical Engineering, University of Melbourne, Parkville VIC, Australia.
| | - Remi Kowalski
- Heart Research, Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC, 3052, Australia
- Department of Paediatrics, University of Melbourne, Parkville VIC, Australia
- Department of Cardiology, Royal Children's Hospital, Parkville VIC, Australia
| | - Hilary A Harrington
- Heart Research, Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC, 3052, Australia
| | - Avinash Kondiboyina
- Heart Research, Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC, 3052, Australia
- Department of Paediatrics, University of Melbourne, Parkville VIC, Australia
| | - Joseph J Smolich
- Heart Research, Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC, 3052, Australia
- Department of Paediatrics, University of Melbourne, Parkville VIC, Australia
| | - Michael M H Cheung
- Heart Research, Murdoch Children's Research Institute, 50 Flemington Road, Parkville, VIC, 3052, Australia
- Department of Paediatrics, University of Melbourne, Parkville VIC, Australia
- Department of Cardiology, Royal Children's Hospital, Parkville VIC, Australia
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Barnhart BK, Kan T, Srivastava A, Wessner CE, Waters J, Ambelil M, Eisenbrey JR, Hoek JB, Vadigepalli R. Longitudinal ultrasound imaging and network modeling in rats reveal sex-dependent suppression of liver regeneration after resection in alcoholic liver disease. Front Physiol 2023; 14:1102393. [PMID: 36969577 PMCID: PMC10033530 DOI: 10.3389/fphys.2023.1102393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 02/28/2023] [Indexed: 03/11/2023] Open
Abstract
Liver resection is an important surgical technique in the treatment of cancers and transplantation. We used ultrasound imaging to study the dynamics of liver regeneration following two-thirds partial hepatectomy (PHx) in male and female rats fed via Lieber-deCarli liquid diet protocol of ethanol or isocaloric control or chow for 5–7 weeks. Ethanol-fed male rats did not recover liver volume to the pre-surgery levels over the course of 2 weeks after surgery. By contrast, ethanol-fed female rats as well as controls of both sexes showed normal volume recovery. Contrary to expectations, transient increases in both portal and hepatic artery blood flow rates were seen in most animals, with ethanol-fed males showing higher peak portal flow than any other experimental group. A computational model of liver regeneration was used to evaluate the contribution of physiological stimuli and estimate the animal-specific parameter intervals. The results implicate lower metabolic load, over a wide range of cell death sensitivity, in matching the model simulations to experimental data of ethanol-fed male rats. However, in the ethanol-fed female rats and controls of both sexes, metabolic load was higher and in combination with cell death sensitivity matched the observed volume recovery dynamics. We conclude that adaptation to chronic ethanol intake has a sex-dependent impact on liver volume recovery following liver resection, likely mediated by differences in the physiological stimuli or cell death responses that govern the regeneration process. Immunohistochemical analysis of pre- and post-resection liver tissue validated the results of computational modeling by associating lack of sensitivity to cell death with lower rates of cell death in ethanol-fed male rats. Our results illustrate the potential for non-invasive ultrasound imaging to assess liver volume recovery towards supporting development of clinically relevant computational models of liver regeneration.
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Affiliation(s)
- Benjamin K. Barnhart
- Daniel Baugh Institute for Functional Genomics/Computational Biology, Department of Pathology and Genomic Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Toshiki Kan
- Daniel Baugh Institute for Functional Genomics/Computational Biology, Department of Pathology and Genomic Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Ankita Srivastava
- Daniel Baugh Institute for Functional Genomics/Computational Biology, Department of Pathology and Genomic Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Corinne E. Wessner
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - John Waters
- Daniel Baugh Institute for Functional Genomics/Computational Biology, Department of Pathology and Genomic Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Manju Ambelil
- Daniel Baugh Institute for Functional Genomics/Computational Biology, Department of Pathology and Genomic Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - John R. Eisenbrey
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Jan B. Hoek
- Daniel Baugh Institute for Functional Genomics/Computational Biology, Department of Pathology and Genomic Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Rajanikanth Vadigepalli
- Daniel Baugh Institute for Functional Genomics/Computational Biology, Department of Pathology and Genomic Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
- *Correspondence: Rajanikanth Vadigepalli,
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Suriani I, van Houte J, de Boer EC, van Knippenberg L, Manzari S, Mischi M, Bouwman RA. Carotid Doppler ultrasound for non-invasive haemodynamic monitoring: a narrative review. Physiol Meas 2023; 43. [PMID: 36179705 DOI: 10.1088/1361-6579/ac96cb] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 09/30/2022] [Indexed: 11/11/2022]
Abstract
Objective.Accurate haemodynamic monitoring is the cornerstone in the management of critically ill patients. It guides the optimization of tissue and organ perfusion in order to prevent multiple organ failure. In the past decades, carotid Doppler ultrasound (CDU) has been explored as a non-invasive alternative for long-established invasive haemodynamic monitoring techniques. Considering the large heterogeneity in reported studies, we conducted a review of the literature to clarify the current status of CDU as a haemodynamic monitoring tool.Approach.In this article, firstly an overview is given of the equipment and workflow required to perform a CDU exam in clinical practice, the limitations and technical challenges potentially faced by the CDU sonographer, and the cerebrovascular mechanisms that may influence CDU measurement outcomes. The following chapter describes alternative techniques for non-invasive haemodynamic monitoring, detailing advantages and limitations compared to CDU. Next, a comprehensive review of the literature regarding the use of CDU for haemodynamic monitoring is presented. Furthermore, feasibility aspects, training requirements and technical developments of CDU are addressed.Main results.Based on the outcomes of these studies, we assess the applicability of CDU-derived parameters within three clinical domains (cardiac output, volume status, and fluid responsiveness), and amongst different patient groups. Finally, recommendations are provided to improve the quality and standardization of future research and clinical practice in this field.Significance.Although CDU is not yet interchangeable with invasive 'gold standard' cardiac output monitoring, the present work shows that certain CDU-derived parameters prove promising in the context of functional haemodynamic monitoring.
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Affiliation(s)
- Irene Suriani
- Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands
| | - Joris van Houte
- Catharina Hospital Michelangelolaan 2, 5623 EJ Eindhoven, The Netherlands
| | - Esmée C de Boer
- Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands
| | - Luuk van Knippenberg
- Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands
| | - Sabina Manzari
- Philips Research High Tech Campus 34, 5656 AE Eindhoven, The Netherlands
| | - Massimo Mischi
- Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands
| | - R Arthur Bouwman
- Eindhoven University of Technology, Groene Loper 3, 5612 AE Eindhoven, The Netherlands.,Catharina Hospital Michelangelolaan 2, 5623 EJ Eindhoven, The Netherlands
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6
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Shaikh F, Kenny JE, Awan O, Markovic D, Friedman O, He T, Singh S, Yan P, Qadir N, Barjaktarevic I. Measuring the accuracy of cardiac output using POCUS: the introduction of artificial intelligence into routine care. Ultrasound J 2022; 14:47. [DOI: 10.1186/s13089-022-00301-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 12/07/2022] [Indexed: 12/15/2022] Open
Abstract
Abstract
Background
Shock management requires quick and reliable means to monitor the hemodynamic effects of fluid resuscitation. Point-of-care ultrasound (POCUS) is a relatively quick and non-invasive imaging technique capable of capturing cardiac output (CO) variations in acute settings. However, POCUS is plagued by variable operator skill and interpretation. Artificial intelligence may assist healthcare professionals obtain more objective and precise measurements during ultrasound imaging, thus increasing usability among users with varying experience. In this feasibility study, we compared the performance of novice POCUS users in measuring CO with manual techniques to a novel automation-assisted technique that provides real-time feedback to correct image acquisition for optimal aortic outflow velocity measurement.
Methods
28 junior critical care trainees with limited experience in POCUS performed manual and automation-assisted CO measurements on a single healthy volunteer. CO measurements were obtained using left ventricular outflow tract (LVOT) velocity time integral (VTI) and LVOT diameter. Measurements obtained by study subjects were compared to those taken by board-certified echocardiographers. Comparative analyses were performed using Spearman’s rank correlation and Bland–Altman matched-pairs analysis.
Results
Adequate image acquisition was 100% feasible. The correlation between manual and automated VTI values was not significant (p = 0.11) and means from both groups underestimated the mean values obtained by board-certified echocardiographers. Automated measurements of VTI in the trainee cohort were found to have more reproducibility, narrower measurement range (6.2 vs. 10.3 cm), and reduced standard deviation (1.98 vs. 2.33 cm) compared to manual measurements. The coefficient of variation across raters was 11.5%, 13.6% and 15.4% for board-certified echocardiographers, automated, and manual VTI tracing, respectively.
Conclusions
Our study demonstrates that novel automation-assisted VTI is feasible and can decrease variability while increasing precision in CO measurement. These results support the use of artificial intelligence-augmented image acquisition in routine critical care ultrasound and may have a role for evaluating the response of CO to hemodynamic interventions. Further investigations into artificial intelligence-assisted ultrasound systems in clinical settings are warranted.
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Riemer K, Rowland EM, Broughton-Venner J, Leow CH, Tang M, Weinberg PD. Contrast Agent-Free Assessment of Blood Flow and Wall Shear Stress in the Rabbit Aorta using Ultrasound Image Velocimetry. ULTRASOUND IN MEDICINE & BIOLOGY 2022; 48:437-449. [PMID: 34876322 PMCID: PMC8843088 DOI: 10.1016/j.ultrasmedbio.2021.10.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 10/07/2021] [Accepted: 10/10/2021] [Indexed: 06/13/2023]
Abstract
Blood flow velocity and wall shear stress (WSS) influence and are influenced by vascular disease. Their measurement is consequently useful in the laboratory and clinic. Contrast-enhanced ultrasound image velocimetry (UIV) can estimate them accurately but the need to inject contrast agents limits utility. Singular value decomposition and high-frame-rate imaging may render contrast agents dispensable. Here we determined whether contrast agent-free UIV can measure flow and WSS. In simulation, accurate measurements were achieved with a signal-to-noise ratio of 13.5 dB or higher. Signal intensity in the rabbit aorta increased monotonically with mechanical index; it was lowest during stagnant flow and uneven across the vessel. In vivo measurements with contrast-free and contrast-enhanced UIV differed by 4.4% and 1.9% for velocity magnitude and angle and by 9.47% for WSS. Bland-Altman analysis of waveforms revealed good agreement between contrast-free and contrast-enhanced UIV. In five rabbits, the root-mean-square errors were as low as 0.022 m/s (0.81%) and 0.11 Pa (1.7%). This study indicates that with an optimised protocol, UIV can assess flow and WSS without contrast agents. Unlike contrast-enhanced UIV, contrast-free UIV could be routinely employed.
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Affiliation(s)
- Kai Riemer
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Ethan M Rowland
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | | | - Chee Hau Leow
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Mengxing Tang
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - P D Weinberg
- Department of Bioengineering, Imperial College London, London, United Kingdom.
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Ambrogio S, Ansell J, Gabriel E, Aneju G, Newman B, Negoita M, Fedele F, Ramnarine KV. Pulsed Wave Doppler Measurements of Maximum Velocity: Dependence on Sample Volume Size. ULTRASOUND IN MEDICINE & BIOLOGY 2022; 48:68-77. [PMID: 34607758 DOI: 10.1016/j.ultrasmedbio.2021.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 08/20/2021] [Accepted: 09/04/2021] [Indexed: 06/13/2023]
Abstract
Pulsed wave (PW) Doppler ultrasound is routinely used in the clinic to assess blood flow. Our annual Doppler quality assurance tests revealed unexpectedly large errors in measurement of maximum velocity, exceeding our tolerance (error >20%), when using certain scanners with small Doppler sample volume dimensions. The aim of this study was to assess the dependence of maximum velocity estimates on PW Doppler sample volume size. A flow phantom with known steady flow was used to acquire maximum velocity estimates (maximum velocities of 24, 39 and 85 cm/s and sample volume range of 0.3-20 mm) with a variety of transducers and scanners in clinical use (51 probes from 4 manufacturers). Selected acoustic outputs were characterized using free-field hydrophone measurements. All maximum velocity estimates were within our tolerance for sample volume sizes ≥1.5 mm, although maximum velocity estimates typically increased with decreasing sample volume size. Errors exceeding our tolerance were commonly found for one manufacturer when using smaller sample volumes, resulting in up to 75% overestimation. Although intrinsic spectral broadening based on transit time considerations may help explain our findings, the sample volume dependence raises potential clinical concerns that users should be aware of and which manufacturers should consider addressing.
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Affiliation(s)
- Simone Ambrogio
- Medical Physics Department, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
| | - Jane Ansell
- Medical Physics Department, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
| | - Elizabeth Gabriel
- Medical Physics Department, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
| | - Grace Aneju
- Medical Physics Department, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
| | - Benedict Newman
- Medical Physics Department, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
| | - Madalina Negoita
- Medical Physics Department, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
| | - Fiammetta Fedele
- Medical Physics Department, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
| | - Kumar V Ramnarine
- Medical Physics Department, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom.
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Al-harosh M, Yangirov M, Kolesnikov D, Shchukin S. Bio-Impedance Sensor for Real-Time Artery Diameter Waveform Assessment. SENSORS 2021; 21:s21248438. [PMID: 34960542 PMCID: PMC8709432 DOI: 10.3390/s21248438] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/08/2021] [Accepted: 12/15/2021] [Indexed: 01/21/2023]
Abstract
The real-time artery diameter waveform assessment during cardio cycle can allow the measurement of beat-to-beat pressure change and the long-term blood pressure monitoring. The aim of this study is to develop a self-calibrated bio-impedance-based sensor, which can provide regular measurement of the blood-pressure-dependence time variable parameters such as the artery diameter waveform and the elasticity. This paper proposes an algorithm based on analytical models which need prior geometrical and physiological patient parameters for more appropriate electrode system selection and hence location to provide accurate blood pressure measurement. As a result of this study, the red cell orientation effect contribution was estimated and removed from the bio-impedance signal obtained from the artery to keep monitoring the diameter waveform correspondence to the change of blood pressure.
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10
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Kenny JÉS, Clarke G, Myers M, Elfarnawany M, Eibl AM, Eibl JK, Nalla B, Atoui R. A Wireless Wearable Doppler Ultrasound Detects Changing Stroke Volume: Proof-of-Principle Comparison with Trans-Esophageal Echocardiography during Coronary Bypass Surgery. Bioengineering (Basel) 2021; 8:203. [PMID: 34940356 PMCID: PMC8698882 DOI: 10.3390/bioengineering8120203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/30/2021] [Accepted: 12/07/2021] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND A novel, wireless, ultrasound biosensor that adheres to the neck and measures real-time Doppler of the carotid artery may be a useful functional hemodynamic monitor. A unique experimental set-up during elective coronary artery bypass surgery is described as a means to compare the wearable Doppler to trans-esophageal echocardiography (TEE). METHODS A total of two representative patients were studied at baseline and during Trendelenburg position. Carotid Doppler spectra from the wearable ultrasound and TEE were synchronously captured. Areas under the receiver operator curve (AUROC) were performed to assess the accuracy of changing common carotid artery velocity time integral (ccVTI∆) at detecting a clinically significant change in stroke volume (SV∆). RESULTS Synchronously measuring and comparing Doppler spectra from the wearable ultrasound and TEE is feasible during Trendelenburg positioning. In two representative cardiac surgical patients, the ccVTI∆ accurately detected a clinically significant SV∆ with AUROCs of 0.89, 0.91, and 0.95 when single-beat, 3-consecutive beat and 10-consecutive beat averages were assessed, respectively. CONCLUSION In this proof-of-principle research communication, a wearable Doppler ultrasound system is successfully compared to TEE. Preliminary data suggests that the diagnostic accuracy of carotid Doppler ultrasonography at detecting clinically significant SV∆ is enhanced by averaging more cardiac cycles.
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Affiliation(s)
- Jon-Émile Stuart Kenny
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (G.C.); (A.M.E.); (J.K.E.); (B.N.); (R.A.)
- Flosonics Medical, 325 Front Street, Toronto, ON M5V 2Y1, Canada; (M.M.); (M.E.)
| | - Geoffrey Clarke
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (G.C.); (A.M.E.); (J.K.E.); (B.N.); (R.A.)
- Flosonics Medical, 325 Front Street, Toronto, ON M5V 2Y1, Canada; (M.M.); (M.E.)
| | - Matt Myers
- Flosonics Medical, 325 Front Street, Toronto, ON M5V 2Y1, Canada; (M.M.); (M.E.)
| | - Mai Elfarnawany
- Flosonics Medical, 325 Front Street, Toronto, ON M5V 2Y1, Canada; (M.M.); (M.E.)
| | - Andrew M. Eibl
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (G.C.); (A.M.E.); (J.K.E.); (B.N.); (R.A.)
- Flosonics Medical, 325 Front Street, Toronto, ON M5V 2Y1, Canada; (M.M.); (M.E.)
| | - Joseph K. Eibl
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (G.C.); (A.M.E.); (J.K.E.); (B.N.); (R.A.)
- Flosonics Medical, 325 Front Street, Toronto, ON M5V 2Y1, Canada; (M.M.); (M.E.)
- Northern Ontario School of Medicine, Sudbury, ON P3E 2C6, Canada
| | - Bhanu Nalla
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (G.C.); (A.M.E.); (J.K.E.); (B.N.); (R.A.)
- Northern Ontario School of Medicine, Sudbury, ON P3E 2C6, Canada
| | - Rony Atoui
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (G.C.); (A.M.E.); (J.K.E.); (B.N.); (R.A.)
- Northern Ontario School of Medicine, Sudbury, ON P3E 2C6, Canada
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Kim S, Jing B, Lindsey BD. Forward-viewing estimation of 3D blood flow velocity fields by intravascular ultrasound: Influence of the catheter on velocity estimation in stenoses. ULTRASONICS 2021; 117:106558. [PMID: 34461527 PMCID: PMC8448960 DOI: 10.1016/j.ultras.2021.106558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/02/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Coronary artery disease is the most common type of cardiovascular disease, affecting > 18 million adults, and is responsible for > 365 k deaths per year in the U.S. alone. Wall shear stress (WSS) is an emerging indicator of likelihood of plaque rupture in coronary artery disease, however, non-invasive estimation of 3-D blood flow velocity and WSS is challenging due to the requirement for high spatial resolution at deep penetration depths in the presence of significant cardiac motion. Thus we propose minimally-invasive imaging with a catheter-based, 3-D intravascular forward-viewing ultrasound (FV US) transducer and present experiments to quantify the effect of the catheter on flow disturbance in stenotic vessel phantoms with realistic velocities and luminal diameters for both peripheral (6.33 mm) and coronary (4.74 mm) arteries. An external linear array ultrasound transducer was used to quantify 2-D velocity fields in vessel phantoms under various conditions of catheter geometry, luminal diameter, and position of the catheter relative to the stenosis at a frame rate of 5000 frames per second via a particle imaging velocimetry (PIV) approach. While a solid catheter introduced an underestimation of velocity measurement by > 20% relative to the case without a catheter, the hollow catheter introduced < 10% velocity overestimation, indicating that a hollow catheter design allowing internal blood flow reduces hemodynamic disturbance. In addition, for both peripheral and coronary arteries, the hollow catheter introduced < 3% deviation in flow velocity at the minimum luminal area compared to the control case. Finally, an initial comparison was made between velocity measurements acquired using a low frequency, catheter-based, 3-D intravascular FV US transducer and external linear array measurements, with relative error < 12% throughout the region of interest for a flow rate of 150 mL/min. While further system development is required, results suggest intravascular ultrasound characterization of blood flow velocity fields in stenotic vessels could be feasible with appropriate catheter design.
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Affiliation(s)
- Saeyoung Kim
- Georgia Institute of Technology, George W. Woodruff School of Mechanical Engineering, 801 Ferst Dr., Atlanta, GA 30332, USA; Georgia Institute of Technology, Interdisciplinary BioEngineering Graduate Program, 315 Ferst Dr., Atlanta, GA 30332, USA
| | - Bowen Jing
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, 313 Ferst Dr NW, Atlanta, GA 30332, USA
| | - Brooks D Lindsey
- Georgia Institute of Technology, Interdisciplinary BioEngineering Graduate Program, 315 Ferst Dr., Atlanta, GA 30332, USA; Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, 313 Ferst Dr NW, Atlanta, GA 30332, USA.
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Wei L, Williams R, Loupas T, Helfield B, Burns PN. Lateral Position-Dependent Velocity Estimation Error in Plane-Wave Doppler Ultrasound Systems. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:2456-2466. [PMID: 34006440 DOI: 10.1016/j.ultrasmedbio.2021.03.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/27/2021] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
Doppler ultrasound has become a standard method used to diagnose and grade vascular diseases and monitor their progression. Conventional focused-beam color Doppler imaging is routinely used in clinical practice, but suffers from inherent trade-offs between spatial, temporal and velocity resolution. Newer, plane-wave Doppler imaging offers rapid simultaneous acquisition of B-mode, color and spectral Doppler information across large fields of view, making it a potentially useful method for quantitative estimation of blood flow velocities in the clinic. However, plane-wave imaging can lead to a substantial error in velocity estimation, which is dependent on the lateral location within the image. This is seen in both clinical and experimental plane-wave systems. In the work described in this article, we quantified this velocity error under different geometric and beamforming conditions using numerical simulation and experimental phantoms. We found that the lateral-dependent velocity errors are caused by asymmetrical geometric spectral broadening, and outline a correction algorithm that can mitigate these errors.
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Affiliation(s)
- Luxi Wei
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Ross Williams
- Sunnybrook Research Institute, Toronto, Ontario, Canada
| | | | | | - Peter N Burns
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Sunnybrook Research Institute, Toronto, Ontario, Canada.
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Carotid Doppler Measurement Variability in Functional Hemodynamic Monitoring: An Analysis of 17,822 Cardiac Cycles. Crit Care Explor 2021; 3:e0439. [PMID: 34136821 PMCID: PMC8202589 DOI: 10.1097/cce.0000000000000439] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Carotid Doppler ultrasound is used as a measure of fluid responsiveness, however, assessing change with statistical confidence requires an adequate beat sample size. The coefficient of variation helps quantify the number of cardiac cycles needed to adequately detect change during functional hemodynamic monitoring. DESIGN Prospective, observational, human model of hemorrhage and resuscitation. SETTING Human physiology laboratory at Mayo Clinic. SUBJECTS Healthy volunteers. INTERVENTIONS Lower body negative pressure. MEASUREMENTS AND MAIN RESULTS We measured the coefficient of variation of the carotid artery velocity time integral and corrected flow time during significant cardiac preload changes. Seventeen-thousand eight-hundred twenty-two cardiac cycles were analyzed. The median coefficient of variation of the carotid velocity time integral was 8.7% at baseline and 11.9% during lowest-tolerated lower body negative pressure stage. These values were 3.6% and 4.6%, respectively, for the corrected flow time. CONCLUSIONS The median coefficient of variation values measured in this large dataset indicates that at least 6 cardiac cycles should be averaged before and after an intervention when using the carotid artery as a functional hemodynamic measure.
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14
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Is Doppler Echocardiography Adequate for Surgical Planning of Single Ventricle Patients? Cardiovasc Eng Technol 2021; 12:606-617. [PMID: 33931807 DOI: 10.1007/s13239-021-00533-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 03/12/2021] [Indexed: 12/13/2022]
Abstract
PURPOSE Surgical planning has shown great potential for optimizing outcomes for patients affected by single ventricle (SV) malformations. Phase-contrast magnetic resonance imaging (PC-MRI) is the routine technique used for flow acquisition in the surgical planning paradigm. However, PC-MRI may suffer from possible artifacts in certain cases; furthermore, this technology may not be readily available for patients in low and lower-middle-income countries. Therefore, this study aims to investigate the effectiveness of using Doppler echocardiography (echo-Doppler) for flow acquisitions of SV surgical planning. METHODS This study included eight patients whose blood flow data was acquired by both PC-MRI and echo-Doppler. A virtual surgery platform was used to generate two surgical options for each patient: (1) a traditional Fontan conduit and (2) a Y-graft. Computational fluid dynamics (CFD) simulations were conducted using the two flow acquisitions to assess clinically relevant hemodynamic metrics: indexed power loss (iPL) and hepatic flow distribution (HFD). RESULTS Differences exist in flow data acquired by PC-MRI and echo-Doppler, but no statistical significance was obtained. Flow fields, therefore, exhibit discrepancies between simulations using flow acquisitions by PC-MRI and echo-Doppler. In virtual surgery, the two surgical options were ranked based on these metrics. No difference was observed in the ranking of surgical options between using different flow acquisitions. CONCLUSION Doppler echocardiography is an adequate alternative approach to acquire flow data for SV surgical planning. This finding encourages broader usage of SV surgical planning with echo-Doppler when MRI may present artifacts or is not available, especially in low and lower-middle-income countries.
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Kenny JÉS, Munding CE, Eibl JK, Eibl AM, Long BF, Boyes A, Yin J, Verrecchia P, Parrotta M, Gatzke R, Magnin PA, Burns PN, Foster FS, Demore CEM. A novel, hands-free ultrasound patch for continuous monitoring of quantitative Doppler in the carotid artery. Sci Rep 2021; 11:7780. [PMID: 33833288 PMCID: PMC8032670 DOI: 10.1038/s41598-021-87116-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 03/22/2021] [Indexed: 12/19/2022] Open
Abstract
Quantitative Doppler ultrasound of the carotid artery has been proposed as an instantaneous surrogate for monitoring rapid changes in left ventricular output. Tracking immediate changes in the arterial Doppler spectrogram has value in acute care settings such as the emergency department, operating room and critical care units. We report a novel, hands-free, continuous-wave Doppler ultrasound patch that adheres to the neck and tracks Doppler blood flow metrics in the common carotid artery using an automated algorithm. String and blood-mimicking test objects demonstrated that changes in velocity were accurately measured using both manually and automatically traced Doppler velocity waveforms. In a small usability study with 22 volunteer users (17 clinical, 5 lay), all users were able to locate the carotid Doppler signal on a volunteer subject, and, in a subsequent survey, agreed that the device was easy to use. To illustrate potential clinical applications of the device, the Doppler ultrasound patch was used on a healthy volunteer undergoing a passive leg raise (PLR) as well as on a congestive heart failure patient at resting baseline. The wearable carotid Doppler patch holds promise because of its ease-of-use, velocity measurement accuracy, and ability to continuously record Doppler spectrograms over many cardiac and respiratory cycles.
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Affiliation(s)
- Jon-Émile S Kenny
- Health Sciences North Research Institute and the Northern Ontario School of Medicine, Sudbury, ON, Canada.
- Flosonics Medical, Sudbury, ON, Canada.
| | | | - Joseph K Eibl
- Health Sciences North Research Institute and the Northern Ontario School of Medicine, Sudbury, ON, Canada
- Flosonics Medical, Sudbury, ON, Canada
| | | | - Bradley F Long
- Health Sciences North Research Institute and the Northern Ontario School of Medicine, Sudbury, ON, Canada
| | - Aaron Boyes
- Sunnybrook Research Institute, Sunnybrook Health Sciences Center, Toronto, ON, Canada
| | - Jianhua Yin
- Sunnybrook Research Institute, Sunnybrook Health Sciences Center, Toronto, ON, Canada
| | | | | | | | | | - Peter N Burns
- Sunnybrook Research Institute, Sunnybrook Health Sciences Center, Toronto, ON, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - F Stuart Foster
- Sunnybrook Research Institute, Sunnybrook Health Sciences Center, Toronto, ON, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Christine E M Demore
- Sunnybrook Research Institute, Sunnybrook Health Sciences Center, Toronto, ON, Canada.
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.
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Kenny JES, Cannesson M, Barjaktarevic I. Minimizing Measurement Variability in Carotid Ultrasound Evaluations. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2021; 40:855-856. [PMID: 32833264 PMCID: PMC7902729 DOI: 10.1002/jum.15445] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Affiliation(s)
- Jon-Emile S Kenny
- Health Sciences North Research Institute, Sudbury, Ontario, Canada
- Flosonics Medical, Sudbury, Ontario, Canada
| | - Maxime Cannesson
- Department of Anesthesiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Igor Barjaktarevic
- Division of Pulmonary and Critical Care, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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Kenny JÉS. Functional Hemodynamic Monitoring With a Wireless Ultrasound Patch. J Cardiothorac Vasc Anesth 2021; 35:1509-1515. [PMID: 33597088 DOI: 10.1053/j.jvca.2021.01.040] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 01/19/2021] [Indexed: 02/07/2023]
Abstract
In this Emerging Technology Review, a novel, wireless, wearable Doppler ultrasound patch is described as a tool for resuscitation. The device is designed, foremost, as a functional hemodynamic monitor-a simple, fast, and consistent method for measuring hemodynamic change with preload variation. More generally, functional hemodynamic monitoring is a paradigm that helps predict stroke volume response to additional intravenous volume. Because Doppler ultrasound of the left ventricular outflow tract noninvasively measures stroke volume in realtime, it increasingly is deployed for this purpose. Nevertheless, Doppler ultrasound in this manner is cumbersome, especially when repeat assessments are needed. Accordingly, peripheral arteries have been studied and various measures from the common carotid artery Doppler signal act as windows to the left ventricle. Yet, handheld Doppler ultrasound of a peripheral artery is susceptible to human measurement error and statistical limitations from inadequate beat sample size. Therefore, a wearable Doppler ultrasound capable of continuous assessment minimizes measurement inconsistencies and smooths inherent physiologic variation by sampling many more cardiac cycles. Reaffirming clinical studies, the ultrasound patch tracks immediate SV change with excellent accuracy in healthy volunteers when cardiac preload is altered by various maneuvers. The wearable ultrasound also follows jugular venous Doppler, which qualitatively trends right atrial pressure. With further clinical research and the application of artificial intelligence, the monitoring modalities with this new technology are manifold.
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18
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Kenny JÉS, Barjaktarevic I. Timing and Measurement Variability Are Critical When Using Carotid Doppler to Infer Hemodynamics. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:3485-3486. [PMID: 32988668 DOI: 10.1016/j.ultrasmedbio.2020.08.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 08/14/2020] [Indexed: 06/11/2023]
Affiliation(s)
- Jon-Émile S Kenny
- Health Sciences North Research Institute, Sudbury, ON, Canada; Flosonics Medical, Sudbury, ON, Canada.
| | - Igor Barjaktarevic
- Division of Pulmonary and Critical Care, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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19
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Mynard JP, Kondiboyina A, Kowalski R, Cheung MMH, Smolich JJ. Measurement, Analysis and Interpretation of Pressure/Flow Waves in Blood Vessels. Front Physiol 2020; 11:1085. [PMID: 32973569 PMCID: PMC7481457 DOI: 10.3389/fphys.2020.01085] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 08/06/2020] [Indexed: 01/10/2023] Open
Abstract
The optimal performance of the cardiovascular system, as well as the break-down of this performance with disease, both involve complex biomechanical interactions between the heart, conduit vascular networks and microvascular beds. ‘Wave analysis’ refers to a group of techniques that provide valuable insight into these interactions by scrutinizing the shape of blood pressure and flow/velocity waveforms. The aim of this review paper is to provide a comprehensive introduction to wave analysis, with a focus on key concepts and practical application rather than mathematical derivations. We begin with an overview of invasive and non-invasive measurement techniques that can be used to obtain the signals required for wave analysis. We then review the most widely used wave analysis techniques—pulse wave analysis, wave separation and wave intensity analysis—and associated methods for estimating local wave speed or characteristic impedance that are required for decomposing waveforms into forward and backward wave components. This is followed by a discussion of the biomechanical phenomena that generate waves and the processes that modulate wave amplitude, both of which are critical for interpreting measured wave patterns. Finally, we provide a brief update on several emerging techniques/concepts in the wave analysis field, namely wave potential and the reservoir-excess pressure approach.
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Affiliation(s)
- Jonathan P Mynard
- Heart Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia.,Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia.,Department of Biomedical Engineering, The University of Melbourne, Melbourne, VIC, Australia.,Department of Cardiology, The Royal Children's Hospital, Parkville, VIC, Australia
| | - Avinash Kondiboyina
- Heart Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia.,Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia
| | - Remi Kowalski
- Heart Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia.,Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia.,Department of Cardiology, The Royal Children's Hospital, Parkville, VIC, Australia
| | - Michael M H Cheung
- Heart Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia.,Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia.,Department of Cardiology, The Royal Children's Hospital, Parkville, VIC, Australia
| | - Joseph J Smolich
- Heart Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia.,Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia
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Kowalski R, Mynard JP, Smolich JJ, Cheung MMH. Comparison of invasive and non-invasive aortic wave intensity and wave power analyses in sheep. Physiol Meas 2019; 40:015005. [PMID: 30625426 DOI: 10.1088/1361-6579/aafcc4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Wave intensity (WI) and wave power (WP) analyses are powerful approaches for assessing ventricular-vascular interactions and arterial dynamics using invasive and non-invasive methods. However, in vivo comparison of these methods for large arteries is lacking. This study assessed agreement, correlation and relative changes in wave size in invasive and non-invasive aortic WI/WP analyses, and associated sources of error. APPROACH The proximal descending thoracic aorta (DTA) of nine wethers was instrumented with a micromanometer and perivascular transit-time flow probe to measure high-fidelity blood pressure (P) and flow (Q) for invasive WI/WP analyses at baseline and during haemodynamic perturbations produced by cardiac pacing, distal DTA constriction and dobutamine-induced inotropic stimulation. In 212 experimental runs, concurrent echocardiographic DTA diameter and velocity (U) data were acquired for non-invasive WI/WP analyses, with measurement of forward compression wave (FCW), backward compression wave (BCW) and forward decompression wave (FDW) cumulative intensity (CI), cumulative power (CP) and wave-related pressure changes (ΔP). MAIN RESULTS Although agreement between invasive and non-invasive FCW, BCW and FDW CI/CP measures was variable (bias -84% to +7%), correlation was good (R = 0.66-0.84), with lower bias and higher correlation for ΔP variables and similar relative changes in FCW and BCW CI/ΔP during haemodynamic perturbations. Main error sources were overestimation of invasive U due to assumed fixed vessel diameter, inaccuracies in non-invasive Q, and non-invasive underestimation of peak P/U and Q rates of change. SIGNIFICANCE Despite variable agreement, non-invasive CI/CP indices correlate well with invasive measurements, and detect relative changes in major waves induced by haemodynamic perturbations.
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Affiliation(s)
- Remi Kowalski
- Murdoch Children's Research Institute, University of Melbourne, Melbourne, Australia. Department of Cardiology, Royal Children's Hospital, University of Melbourne, Melbourne, Australia. Departments of Paediatrics, University of Melbourne, Melbourne, Australia
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21
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Negoita M, Hughes AD, Parker KH, Khir AW. A method for determining local pulse wave velocity in human ascending aorta from sequential ultrasound measurements of diameter and velocity. Physiol Meas 2018; 39:114009. [PMID: 30475745 PMCID: PMC6254752 DOI: 10.1088/1361-6579/aae8a0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 10/11/2018] [Accepted: 10/16/2018] [Indexed: 01/09/2023]
Abstract
BACKGROUND Pulse wave velocity (PWV) is an indicator of arterial stiffness, and predicts cardiovascular events independently of blood pressure. Currently, PWV is commonly measured by the foot-to-foot technique thus giving a global estimate of large arterial stiffness. However, and despite its importance, methods to measure the stiffness of the ascending aorta are limited. OBJECTIVE To introduce a method for calculating local PWV in the human ascending aorta using non-invasive ultrasound measurements of its diameter (D) and flow velocity (U). APPROACH Ten participants (four females) were recruited from Brunel University students. Ascending aortic diameter and velocity were recorded with a GE Vivid E95 equipped with a 1.5-4.5 MHz phased array transducer using M-mode in the parasternal long axis view and pulse wave Doppler in the apical five chamber view respectively. Groups of six consecutive heartbeats were selected from each 20 s run based on the most similar cycle length resulting in three groups for D and three for U each with six waveforms. Each D waveform was paired with each U waveform to calculate PWV using ln(D)U-loop method. MAIN RESULTS The diastolic portions of the diameters or velocities waveforms were truncated to allow the pairs to have equal length and were used to construct ln(D)U-loops. The trimmed average, excluding 10% of extreme values, resulting from the 324 loops was considered representative for each participant. Overall mean local PWV for all participants was 4.1(SD = 0.9) m s-1. SIGNIFICANCE Local PWV can be measured non-invasively in the ascending aorta using ultrasound measurements of diameter and flow velocity This should facilitate more widespread assessment of ascending aortic stiffness in larger studies.
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Affiliation(s)
- Madalina Negoita
- Brunel Institute of Bioengineering, Brunel University London, London, United Kingdom
| | - Alun D Hughes
- Institute of Cardiovascular Science, University College London, London, United Kingdom
- MRC Unit for Lifelong Health and Ageing at UCL, London, United Kingdom
| | - Kim H Parker
- Department of Bioengineering, Imperial College, London, United Kingdom
| | - Ashraf W Khir
- Brunel Institute of Bioengineering, Brunel University London, London, United Kingdom
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22
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Kowalski R, Beare R, Willemet M, Alastruey J, Smolich JJ, Cheung MMH, Mynard JP. Robust and practical non-invasive estimation of local arterial wave speed and mean blood velocity waveforms. Physiol Meas 2017; 38:2081-2099. [DOI: 10.1088/1361-6579/aa8de3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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23
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Zhou X, Hoskins PR. Testing a new surfactant in a widely-used blood mimic for ultrasound flow imaging. ULTRASOUND : JOURNAL OF THE BRITISH MEDICAL ULTRASOUND SOCIETY 2017; 25:239-244. [PMID: 29163660 DOI: 10.1177/1742271x17733299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 09/04/2017] [Indexed: 11/15/2022]
Abstract
Background A blood-mimicking fluid developed by Ramnarine et al. has been widely used in flow phantoms for ultrasound flow imaging research, and it has also been cited by IEC 61685 as a reference for making blood-mimicking fluid.However, the surfactant material Synperonic N in this blood-mimicking fluid recipe is phased out from the European market due to environmental issues. The aim of this study is to test whether Synperonic N can be substituted by biodegradable Synperonic A7 in making blood-mimicking fluid for ultrasound flow imaging research. Methods and materials A flow phantom was fabricated to test the blood-mimicking fluid with Synperonic N and Synperonic A7 as surfactants separately. Doppler images and velocity data were collected using a clinical ultrasound scanner under constant and pulsatile flows; and images and measured velocities were compared. Results It was found that both blood mimics can provide exactly the same images under spectral Doppler ultrasound and colour Doppler ultrasound in terms of their image qualities. The maximum velocities under constant flow were measured by the spectral Doppler ultrasound as 0.4714 ± 0.001 m.s-1 and 0.4644 ± 0.001 m.s-1 for blood-mimicking fluid with Synperonic N and blood-mimicking fluid with Synperonic A7, respectively. Measured velocities using the two different blood-mimicking fluids were statistically different (p < 0.001), but this difference was less than 2%. The Synperonic A7 can be used as a substitute for Synperonic N as a surfactant material in making the blood-mimicking fluid for ultrasound flow imaging research.
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Affiliation(s)
- Xiaowei Zhou
- School of Engineering, University of Dundee, Dundee, UK
| | - Peter R Hoskins
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
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Zhou X, Xia C, Stephen G, Khan F, Corner GA, Hoskins PR, Huang Z. Investigation of Ultrasound-Measured Flow Velocity, Flow Rate and Wall Shear Rate in Radial and Ulnar Arteries Using Simulation. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:981-992. [PMID: 28236532 DOI: 10.1016/j.ultrasmedbio.2016.12.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Revised: 12/02/2016] [Accepted: 12/31/2016] [Indexed: 06/06/2023]
Abstract
Parameters of blood flow measured by ultrasound in radial and ulnar arteries, such as flow velocity, flow rate and wall shear rate, are widely used in clinical practice and clinical research. Investigation of these measurements is useful for evaluating accuracy and providing knowledge of error sources. A method for simulating the spectral Doppler ultrasound measurement process was developed with computational fluid dynamics providing flow-field data. Specific scanning factors were adjusted to investigate their influence on estimation of the maximum velocity waveform, and flow rate and wall shear rate were derived using the Womersley equation. The overestimation in maximum velocity increases greatly (peak systolic from about 10% to 30%, time-averaged from about 30% to 50%) when the beam-vessel angle is changed from 30° to 70°. The Womersley equation was able to estimate flow rate in both arteries with less than 3% error, but performed better in the radial artery (2.3% overestimation) than the ulnar artery (15.4% underestimation) in estimating wall shear rate. It is concluded that measurements of flow parameters in the radial and ulnar arteries with clinical ultrasound scanners are prone to clinically significant errors.
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Affiliation(s)
- Xiaowei Zhou
- School of Science and Engineering, University of Dundee, Dundee, United Kingdom
| | - Chunming Xia
- School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China; NHS Tayside Medical Physics, Ninewells Hospital, Dundee, United Kingdom
| | - Gandy Stephen
- School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China; NHS Tayside Medical Physics, Ninewells Hospital, Dundee, United Kingdom
| | - Faisel Khan
- Cardiovascular and Diabetes Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom
| | - George A Corner
- School of Science and Engineering, University of Dundee, Dundee, United Kingdom
| | - Peter R Hoskins
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
| | - Zhihong Huang
- School of Science and Engineering, University of Dundee, Dundee, United Kingdom.
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Ricci S, Swillens A, Ramalli A, Segers P, Tortoli P. Wall Shear Rate Measurement: Validation of a New Method Through Multiphysics Simulations. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2017; 64:66-77. [PMID: 28092504 DOI: 10.1109/tuffc.2016.2608442] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Wall shear stress is known to affect the vessel endothelial function and to be related to important pathologies like the development of atherosclerosis. It is defined as the product of the blood viscosity by the blood velocity gradient at the wall position, i.e., the wall shear rate (WSR). The WSR measurement is particularly challenging in important cardiovascular sites, like the carotid bifurcation, because of the related complex flow configurations characterized by high spatial and temporal gradients, wall movement, and clutter noise. Moreover, accuracy of any method for WSR measurement can be effectively tested only if reliable gold standard WSR values, considering all the aforementioned disturbing effects, are available. Unfortunately, these requirements are difficult to achieve in a physical phantom, so that the accuracy test of the novel WSR measurement methods was so far limited to straight pipes and/or similar idealistic configurations. In this paper, we propose a new method for WSR measurement and its validation based on a mathematical model of the carotid bifurcation, which, exploiting fluid-structure simulations, is capable of reproducing realistic flow configuration, wall movement, and clutter noise. In particular, the profile near the wall, not directly measurable because affected by clutter, is estimated through a power-law fitting and compared with the gold standard provided by the model. In this condition, the WSR measurements featured an accuracy of ±20 %. A preliminary test on a volunteer confirmed the feasibility of the WSR method for in vivo application.
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Zhou X, Xia C, Khan F, Corner GA, Huang Z, Hoskins PR. Investigation of Ultrasound-Measured Flow Rate and Wall Shear Rate in Wrist Arteries Using Flow Phantoms. ULTRASOUND IN MEDICINE & BIOLOGY 2016; 42:815-823. [PMID: 26742894 DOI: 10.1016/j.ultrasmedbio.2015.10.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 09/15/2015] [Accepted: 10/18/2015] [Indexed: 06/05/2023]
Abstract
The aim of this study was to evaluate the errors in measurement of volumetric flow rate and wall shear rate measured in radial and ulnar arteries using a commercial ultrasound scanning system. The Womersley equations were used to estimate the flow rate and wall shear rate waveforms, based on the measured vessel diameter and centerline velocity waveform. In the experiments, each variable (vessel depth, diameter, flow rate, beam-vessel angle and different waveform) in the phantom was investigated in turn, and its value was varied within a normal range while others were fixed at their typical values. The outcomes revealed that flow rate and wall shear rate were overestimated in all cases, from around 13% to nearly 50%. It is concluded that measurements of flow rate and wall shear rate in radial and ulnar arteries with a clinical ultrasound scanner are vulnerable to overestimation.
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Affiliation(s)
- Xiaowei Zhou
- School of Engineering, Physics & Mathematics, University of Dundee, Dundee, United Kingdom
| | - Chunming Xia
- School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China.
| | - Faisel Khan
- Cardiovascular and Diabetes Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, United Kingdom
| | - George A Corner
- School of Engineering, Physics & Mathematics, University of Dundee, Dundee, United Kingdom
| | - Zhihong Huang
- School of Engineering, Physics & Mathematics, University of Dundee, Dundee, United Kingdom.
| | - Peter R Hoskins
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom
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Kenwright DA, Sadhoo N, Rajagopal S, Anderson T, Moran CM, Hadoke PW, Gray GA, Zeqiri B, Hoskins PR. acoustic assessment of a konjac–carrageenan tissue-mimicking material aT 5–60 MHZ. ULTRASOUND IN MEDICINE & BIOLOGY 2014; 40:2895-902. [PMID: 25438864 PMCID: PMC4259902 DOI: 10.1016/j.ultrasmedbio.2014.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 07/03/2014] [Accepted: 07/11/2014] [Indexed: 05/10/2023]
Abstract
The acoustic properties of a robust tissue-mimicking material based on konjac–carrageenan at ultrasound frequencies in the range 5–60 MHz are described. Acoustic properties were characterized using two methods: a broadband reflection substitution technique using a commercially available preclinical ultrasound scanner (Vevo 770, FUJIFILM VisualSonics, Toronto, ON, Canada), and a dedicated high-frequency ultrasound facility developed at the National Physical Laboratory (NPL, Teddington, UK), which employed a broadband through-transmission substitution technique. The mean speed of sound across the measured frequencies was found to be 1551.7 ± 12.7 and 1547.7 ± 3.3 m s21, respectively. The attenuation exhibited a non-linear dependence on frequency, f (MHz), in the form of a polynomial function: 0.009787f2 1 0.2671f and 0.01024f2 1 0.3639f, respectively. The characterization of this tissue-mimicking material will provide reference data for designing phantoms for preclinical systems, which may, in certain applications such as flow phantoms, require a physically more robust tissuemimicking material than is currently available.
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Affiliation(s)
- David A Kenwright
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom.
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Cournane S, Fagan A, Browne J. An audit of a hospital-based Doppler ultrasound quality control protocol using a commercial string Doppler phantom. Phys Med 2014; 30:380-4. [DOI: 10.1016/j.ejmp.2013.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 08/30/2013] [Accepted: 10/02/2013] [Indexed: 11/27/2022] Open
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Mynard JP, Steinman DA. Effect of velocity profile skewing on blood velocity and volume flow waveforms derived from maximum Doppler spectral velocity. ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:870-881. [PMID: 23453373 DOI: 10.1016/j.ultrasmedbio.2012.11.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 10/19/2012] [Accepted: 11/05/2012] [Indexed: 06/01/2023]
Abstract
Given evidence that fully developed axisymmetric flow may be the exception rather than the rule, even in nominally straight arteries, maximum velocity (V(max)) can lie outside the Doppler sample volume (SV). The link between V(max) and derived quantities, such as volume flow (Q), may therefore be more complex than commonly thought. We performed idealized virtual Doppler ultrasound on data from image-based computational fluid dynamics (CFD) models of the normal human carotid artery and investigated how velocity profile skewing and choice of sample volume affected V(max) waveforms and derived Q variables, considering common assumptions about velocity profile shape (i.e., Poiseuille or Womersley). Severe velocity profile skewing caused substantial errors in V(max) waveforms when using a small, centered SV, although peak V(max) was reliably detected; errors with a long SV covering the vessel diameter were orientation dependent but lower overall. Cycle-averaged Q calculated from V(max) was typically within ±15%, although substantial skewing and use of a small SV caused 10%-25% underestimation. Peak Q derived from Womersley's theory was generally accurate to within ±10%. V(max) pulsatility and resistance indexes differed from Q-based values, although the Q-based resistance index could be predicted reliably. Skewing introduced significant error into V(max)-derived Q waveforms, particularly during mid-to-late systole. Our findings suggest that errors in the V(max) and Q waveforms related to velocity profile skewing and use of a small SV, or orientation-dependent errors for a long SV, could limit their use in wave analysis or for constructing characteristic or patient-specific flow boundary conditions for model studies.
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Affiliation(s)
- Jonathan P Mynard
- Biomedical Simulation Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto, Canada
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Bonnefous O, Pereira VM, Ouared R, Brina O, Aerts H, Hermans R, van Nijnatten F, Stawiaski J, Ruijters D. Quantification of arterial flow using digital subtraction angiography. Med Phys 2012; 39:6264-75. [DOI: 10.1118/1.4754299] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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