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Komanek T, Rabis M, Omer S, Peters J, Frey UH. Quantification of left ventricular ejection fraction and cardiac output using a novel semi-automated echocardiographic method: a prospective observational study in coronary artery bypass patients. BMC Anesthesiol 2023; 23:65. [PMID: 36855077 PMCID: PMC9972694 DOI: 10.1186/s12871-023-02025-z] [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: 08/23/2022] [Accepted: 02/21/2023] [Indexed: 03/02/2023] Open
Abstract
BACKGROUND Echocardiographic quantification of ejection fraction (EF) by manual endocardial tracing requires training, is time-consuming and potentially user-dependent, whereas determination of cardiac output by pulmonary artery catheterization (PAC) is invasive and carries a risk of complications. Recently, a novel software for semi-automated EF and CO assessment (AutoEF) using transthoracic echocardiography (TTE) has been introduced. We hypothesized that AutoEF would provide EF values different from those obtained by the modified Simpson's method in transoesophageal echocardiography (TOE) and that AutoEF CO measurements would not agree with those obtained via VTILVOT in TOE and by thermodilution using PAC. METHODS In 167 patients undergoing coronary artery bypass graft surgery (CABG), TTE cine loops of apical 4- and 2-chamber views were recorded after anaesthesia induction under steady-state conditions. Subsequently, TOE was performed following a standardized protocol, and CO was determined by thermodilution. EF and CO were assessed by TTE AutoEF as well as TOE, using the modified Simpson's method, and Doppler measurements via velocity time integral in the LV outflow tract (VTILVOT). We determined Pearson's correlation coefficients r and carried out Bland-Altman analyses. The primary endpoints were differences in EF and CO. The secondary endpoints were differences in left ventricular volumes at end diastole (LVEDV) and end systole (LVESV). RESULTS AutoEF and the modified Simpson's method in TOE showed moderate EF correlation (r = 0.38, p < 0.01) with a bias of -12.6% (95% limits of agreement (95%LOA): -36.6 - 11.3%). AutoEF CO correlated poorly both with VTILVOT in TOE (r = 0.19, p < 0.01) and thermodilution (r = 0.28, p < 0.01). The CO bias between AutoEF and VTILVOT was 1.33 l min-1 (95%LOA: -1.72 - 4.38 l min-1) and 1.39 l min-1 (95%LOA -1.34 - 4.12 l min-1) between AutoEF and thermodilution, respectively. AutoEF yielded both significantly lower EF (EFAutoEF: 42.0% (IQR 29.0 - 55.0%) vs. EFTOE Simpson: 55.2% (IQR 40.1 - 70.3%), p < 0.01) and CO values than the reference methods (COAutoEF biplane: 2.30 l min-1 (IQR 1.30 - 3.30 l min-1) vs. COVTI LVOT: 3.64 l min-1 (IQR 2.05 - 5.23 l min-1) and COPAC: 3.90 l min-1 (IQR 2.30 - 5.50 l min-1), p < 0.01)). CONCLUSIONS AutoEF correlated moderately with TOE EF determined by the modified Simpson's method but poorly both with VTILVOT and thermodilution CO. A systematic bias was detected overestimating LV volumes and underestimating both EF and CO compared to the reference methods. TRIAL REGISTRATION German Register for Clinical Trials (DRKS-ID DRKS00010666, date of registration: 08/07/2016).
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Affiliation(s)
- Thomas Komanek
- Klinik für Anästhesiologie, operative Intensivmedizin, Schmerz- und Palliativmedizin, Marien Hospital Herne - Universitätsklinikum der Ruhr-Universität Bochum, Hölkeskampring 40, 44625, Herne, Germany.,Klinik für Anästhesiologie und Intensivmedizin, Universität Duisburg-Essen und Universitätsklinikum Essen, Essen, Germany
| | - Marco Rabis
- Klinik für Anästhesiologie und Intensivmedizin, Universität Duisburg-Essen und Universitätsklinikum Essen, Essen, Germany
| | - Saed Omer
- Klinik für Anästhesiologie, operative Intensivmedizin, Schmerz- und Palliativmedizin, Marien Hospital Herne - Universitätsklinikum der Ruhr-Universität Bochum, Hölkeskampring 40, 44625, Herne, Germany.,Klinik für Anästhesiologie und Intensivmedizin, Universität Duisburg-Essen und Universitätsklinikum Essen, Essen, Germany
| | - Jürgen Peters
- Klinik für Anästhesiologie und Intensivmedizin, Universität Duisburg-Essen und Universitätsklinikum Essen, Essen, Germany
| | - Ulrich H Frey
- Klinik für Anästhesiologie, operative Intensivmedizin, Schmerz- und Palliativmedizin, Marien Hospital Herne - Universitätsklinikum der Ruhr-Universität Bochum, Hölkeskampring 40, 44625, Herne, Germany. .,Klinik für Anästhesiologie und Intensivmedizin, Universität Duisburg-Essen und Universitätsklinikum Essen, Essen, Germany.
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Brandt AH, Olesen JB, Moshavegh R, Jensen JA, Nielsen MB, Hansen KL. Common Carotid Artery Volume Flow: A Comparison Study between Ultrasound Vector Flow Imaging and Phase Contrast Magnetic Resonance Imaging. Neurol Int 2021; 13:269-278. [PMID: 34201493 PMCID: PMC8293467 DOI: 10.3390/neurolint13030028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/19/2021] [Accepted: 06/20/2021] [Indexed: 11/16/2022] Open
Abstract
Volume flow estimation in the common carotid artery (CCA) can assess the absolute hemodynamic effect of a carotid stenosis. The aim of this study was to compare a commercial vector flow imaging (VFI) setup against the reference method magnetic resonance phase contrast angiography (MRA) for volume flow estimation in the CCA. Ten healthy volunteers were scanned with VFI and MRA over the CCA. VFI had an improved precision of 19.2% compared to MRA of 31.9% (p = 0.061). VFI estimated significantly lower volume flow than MRA (mean difference: 63.2 mL/min, p = 0.017), whilst the correlation between VFI and MRA was strong (R2 = 0.81, p < 0.0001). A Bland–Altman plot indicated a systematic bias. After bias correction, the percentage error was reduced from 41.0% to 25.2%. This study indicated that a VFI setup for volume flow estimation is precise and strongly correlated to MRA volume flow estimation, and after correcting for the systematic bias, VFI and MRA become interchangeable.
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Affiliation(s)
- Andreas Hjelm Brandt
- Department of Diagnostic Radiology, Rigshospitalet, Copenhagen University Hospital, 2100 Copenhagen, Denmark; (M.B.N.); (K.L.H.)
- Correspondence:
| | | | | | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, 2800 Lyngby, Denmark;
| | - Michael Bachmann Nielsen
- Department of Diagnostic Radiology, Rigshospitalet, Copenhagen University Hospital, 2100 Copenhagen, Denmark; (M.B.N.); (K.L.H.)
- Department of Clinical Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Kristoffer Lindskov Hansen
- Department of Diagnostic Radiology, Rigshospitalet, Copenhagen University Hospital, 2100 Copenhagen, Denmark; (M.B.N.); (K.L.H.)
- Department of Clinical Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
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3
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Perrot V, Ekroll IK, Avdal J, Saxhaug LM, Dalen H, Vray D, Lovstakken L, Liebgott H. Translation of Simultaneous Vessel Wall Motion and Vectorial Blood Flow Imaging in Healthy and Diseased Carotids to the Clinic: A Pilot Study. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:558-569. [PMID: 32776877 DOI: 10.1109/tuffc.2020.3015340] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This study aims to investigate the clinical feasibility of simultaneous extraction of vessel wall motion and vectorial blood flow at high frame rates for both extraction of clinical markers and visual inspection. If available in the clinic, such a technique would allow a better estimation of plaque vulnerability and improved evaluation of the overall arterial health of patients. In this study, both healthy volunteers and patients were recruited and scanned using a planewave acquisition scheme that provided a data set of 43 carotid recordings in total. The vessel wall motion was extracted based on the complex autocorrelation of the signals received, while the vector flow was extracted using the transverse oscillation technique. Wall motion and vector flow were extracted at high frame rates, which allowed for a visual appreciation of tissue movement and blood flow simultaneously. Several clinical markers were extracted, and visual inspections of the wall motion and flow were conducted. From all the potential markers, young healthy volunteers had smaller artery diameter (7.72 mm) compared with diseased patients (9.56 mm) ( p -value ≤ 0.001), 66% of diseased patients had backflow compared with less than 10% for the other patients ( p -value ≤ 0.05), a carotid with a pulse wave velocity extracted from the wall velocity greater than 7 m/s was always a diseased vessel, and the peak wall shear rate decreased as the risk increases. Based on both the pathological markers and the visual inspection of tissue motion and vector flow, we conclude that the clinical feasibility of this approach is demonstrated. Larger and more disease-specific studies using such an approach will lead to better understanding and evaluation of vessels, which can translate to future use in the clinic.
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4
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Zhang Z, Zhou X, Suarez-Pierre A, Lui C, Kearney S, Yeung E, Halperin H, Choi CW, Katz J. Time-Resolved Echo-Particle Image/Tracking Velocimetry Measurement of Interactions Between Native Cardiac Output and Veno-Arterial ECMO Flows. J Biomech Eng 2021; 143:021008. [PMID: 32914854 DOI: 10.1115/1.4048424] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Indexed: 11/08/2022]
Abstract
Determination of optimal hemodynamic and pressure-volume loading conditions for patients undergoing veno-arterial extracorporeal membrane oxygenation (VA-ECMO) would benefit from understanding the impact of ECMO flow rates (QE) on the native cardiac output in the admixing zone, i.e., aortic root. This study characterizes the flow in the aortic root of a pig with severe myocardial ischemia using contrast-enhanced ultrasound particle image/tracking velocimetry (echo-PIV/PTV). New methods for data preprocessing are introduced, including autocontouring to remove surrounding tissues, followed by blind deconvolution to identify the centers of elongated bubble traces in images with low signal to noise ratio. Calibrations based on synthetic images show that this procedure increases the number of detected bubbles and reduces the error in their locations by 50%. Then, an optimized echo-PIV/PTV procedure, which integrates image enhancement with velocity measurements, is used for characterizing the time-resolved two-dimensional (2D) velocity distributions. Phase-averaged and instantaneous flow fields show that the ECMO flow rate influences the velocity and acceleration of the cardiac output during systole, and secondary flows during diastole. When QE is 3.0 L/min or higher, the cardiac ejection velocity, phase interval with open aortic valve, velocity-time integral (VTI), and mean arterial pressure (MAP) increase with decreasing QE, all indicating sufficient support. For lower QE, the MAP and VTI decrease as QE is reduced, and the deceleration during transition to diastole becomes milder. Hence, for this specific case, the optimal ECMO flow rate is 3.0 L/min.
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Affiliation(s)
- Zeng Zhang
- Department of Mechanical Engineering, Johns Hopkins University, 3400 North Charles Street, Latrobe b31, Baltimore, MD 21218
| | - Xun Zhou
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University School of Medicine, 1800 Orleans Street, Baltimore, MD 21287
| | - Alejandro Suarez-Pierre
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University School of Medicine, 1800 Orleans Street, Baltimore, MD 21287
| | - Cecillia Lui
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University School of Medicine, 1800 Orleans Street, Baltimore, MD 21287
| | - Sean Kearney
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University School of Medicine, 1800 Orleans Street, Baltimore, MD 21287
| | - Enoch Yeung
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University School of Medicine, 1800 Orleans Street, Baltimore, MD 21287; Department of Surgery, Robert Packer Hospital, 1 Guthrie Square, Sayre, PA 18840
| | - Henry Halperin
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, 1800 Orleans Street, Baltimore, MD 21287
| | - Chun Woo Choi
- Division of Cardiac Surgery, Department of Surgery, Johns Hopkins University School of Medicine, 1800 Orleans Street, Baltimore, MD 21287
| | - Joseph Katz
- Department of Mechanical Engineering, Johns Hopkins University, 3400 North Charles Street, Latrobe 122, Baltimore, MD 21218
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5
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Makouei F, Mohammadzadeh Asl B. Subspace-Based Blood Power Spectral Capon Combined with Wiener Postfilter to Provide a High-Quality Velocity Waveform with Low Mathematical Complexity. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:1783-1801. [PMID: 32387154 DOI: 10.1016/j.ultrasmedbio.2020.03.015] [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: 10/11/2019] [Revised: 01/31/2020] [Accepted: 03/18/2020] [Indexed: 06/11/2023]
Abstract
In Doppler analysis, the power spectral density (PSD), which accounts for the axial velocity distribution of the blood scatterers, is estimated. The conventional spectral estimator is Welch's method, which suffers from frequency leakage at small observation window length. The performance of adaptive techniques such as blood power Capon (BPC) has been promising at the cost of higher computation complexity. Reducing the computational complexity while retaining the benefits of BPC would be necessary for real-time implementation. The purpose of the work described here was to investigate whether it is possible to decrease the computation load in BPC and still obtain acceptable results. The computation complexity in BPC is owing primarily to the matrix inversion required for computing the PSD estimate. We here propose the subspace blood power Capon technique, which employs a data covariance matrix with reduced number of rows in estimation of the weight vector. In maximum velocity estimation in the spectra, the signal noise slope intersection envelop estimator that makes use of the integrated power spectrum is employed. The evaluations are made based on both simulated and in vivo data. The results indicate that it is possible to reduce the order of complexity to almost 12.25% at the cost of 2.31% and 2.24% increases in the relative standard deviation and relative bias of the estimates. Moreover, the Wiener post-filter as a post-weighting factor, which will be multiplied by the final weight vector of the spectral estimator, estimates the power of the desired signal and the power of the interference plus noise to improve the contrast. The proposed estimator has exhibited a promising performance at beam-to-flow angles of 45°, 60° and 75°. Furthermore, the robust performance of the proposed estimator against variation in the flow rate is also documented.
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Affiliation(s)
- Fatemeh Makouei
- Department of Biomedical Engineering, Tarbiat Modares University, Tehran, Iran
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6
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Ambrogio S, Walker A, Narracott A, Ferrari S, Verma P, Fenner J. A complex flow phantom for medical imaging: ring vortex phantom design and technical specification. J Med Eng Technol 2019; 43:190-201. [DOI: 10.1080/03091902.2019.1640309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Simone Ambrogio
- Department of Infection, Immunity and Cardiovascular Disease, Medical Physics, Mathematical Modelling in Medicine Group, University of Sheffield, Sheffield, UK
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, UK
- Leeds Test Objects Ltd, Boroughbridge, UK
| | | | - Andrew Narracott
- Department of Infection, Immunity and Cardiovascular Disease, Medical Physics, Mathematical Modelling in Medicine Group, University of Sheffield, Sheffield, UK
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, UK
| | - Simone Ferrari
- Department of Infection, Immunity and Cardiovascular Disease, Medical Physics, Mathematical Modelling in Medicine Group, University of Sheffield, Sheffield, UK
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, UK
| | - Prashant Verma
- Medical Imaging and Medical Physics, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - John Fenner
- Department of Infection, Immunity and Cardiovascular Disease, Medical Physics, Mathematical Modelling in Medicine Group, University of Sheffield, Sheffield, UK
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, UK
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7
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Hansen KL, Hansen PM, Ewertsen C, Lönn L, Jensen JA, Nielsen MB. Vector Flow Imaging Compared with Digital Subtraction Angiography for Stenosis Assessment in the Superficial Femoral Artery - A Study of Vector Concentration, Velocity Ratio and Stenosis Degree Percentage. Ultrasound Int Open 2019; 5:E53-E59. [PMID: 30886943 PMCID: PMC6420338 DOI: 10.1055/a-0853-2002] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/01/2018] [Accepted: 01/29/2019] [Indexed: 10/27/2022] Open
Abstract
Purpose Stenosis of the superficial femoral artery (SFA) induces complex blood flow with increased velocities. Disease assessment is performed with Doppler ultrasound and digital subtraction angiography (DSA), but Doppler ultrasound is limited by angle dependency and DSA by ionizing radiation. An alternative is the vector flow imaging method based on transverse oscillation (TO), an angle-independent vector velocity technique using ultrasound. In this study, flow complexity and velocity measured with TO were compared with DSA for the assessment of stenosis in the SFA. Materials and Methods The vector concentration, a measure of flow complexity, and the velocity ratio obtained from the stenosis and a disease-free adjacent vessel segment, were estimated with TO in 11 patients with a total of 16 stenoses of the SFA. TO data were compared with the corresponding stenosis degree percentage obtained with DSA. Results The correlation between the vector concentration and DSA was very strong (R=0.93; p<0.001; 95% confidence interval (CI): 0.81-0.98), while only moderate for velocity ratio and DSA (R=0.50; p<0.07; 95% CI: 0.00-0.80). The correlation coefficients that were found were significantly different (p<0.005) without overlapping CI. Conclusion The study indicated that flow changes in the SFA induced by stenosis can be quantified with TO, and that stenosis grading may be improved by estimation of flow complexity instead of velocity ratio. TO is a potential diagnostic tool for the assessment of atherosclerosis and peripheral arterial disease.
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Affiliation(s)
- Kristoffer Lindskov Hansen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Peter Møller Hansen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Caroline Ewertsen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Lars Lönn
- Department of Diagnostic Radiology, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Vascular Surgery, Copenhagen University Hospital, Copenhagen, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Technical University of Denmark, DTU Elektro, Kgs. Lyngby, Denmark
| | - Michael Bachmann Nielsen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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Hansen KL, Juul K, Møller-Sørensen H, Nilsson JC, Jensen JA, Nielsen MB. Pediatric Transthoracic Cardiac Vector Flow Imaging - A Preliminary Pictorial Study. Ultrasound Int Open 2019; 5:E20-E26. [PMID: 30599042 PMCID: PMC6303157 DOI: 10.1055/a-0656-5430] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/15/2018] [Accepted: 07/01/2018] [Indexed: 01/06/2023] Open
Abstract
Purpose
Conventional pediatric echocardiography is crucial for diagnosing congenital heart disease (CHD), but the technique is impaired by angle dependency. Vector flow imaging (VFI) is an angle-independent noninvasive ultrasound alternative for blood flow assessment and can assess complex flow patterns not visible on conventional Doppler ultrasound.
Materials and Methods
12 healthy newborns and 3 infants with CHD were examined with transthoracic cardiac VFI using a conventional ultrasound scanner and a linear array.
Results
VFI examinations revealed common cardiac flow patterns among the healthy newborns, and flow changes among the infants with CHD not previously reported with conventional echocardiography.
Conclusion
For assessment of cardiac flow in the normal and diseased pediatric heart, VFI may provide additional information compared to conventional echocardiography and become a useful diagnostic tool.
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Affiliation(s)
| | - Klaus Juul
- Department of Pediatric Cardiology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Hasse Møller-Sørensen
- Department of Cardiothoracic Anesthesiology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Jens C Nilsson
- Department of Cardiothoracic Anesthesiology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Technical University of Denmark, DTU Elektro, Lyngby, Denmark
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Bechsgaard T, Hansen KL, Brandt A, Moshavegh R, Forman JL, Føgh P, Klitfod L, Bækgaard N, Lönn L, Jensen JA, Nielsen MB. Evaluation of Peak Reflux Velocities with Vector Flow Imaging and Spectral Doppler Ultrasound in Varicose Veins. Ultrasound Int Open 2018; 4:E91-E98. [PMID: 30276359 PMCID: PMC6162191 DOI: 10.1055/a-0643-4430] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 04/24/2018] [Accepted: 05/17/2018] [Indexed: 10/29/2022] Open
Abstract
Purpose Spectral Doppler ultrasound (SDUS) is used for quantifying reflux in lower extremity varicose veins. The technique is angle-dependent opposed to the new angle-independent Vector Flow Imaging (VFI) method. The aim of this study was to compare peak reflux velocities obtained with VFI and SDUS in patients with chronic venous disease, i. e., pathological retrograde blood flow caused by incompetent venous valves. Materials and Methods 64 patients with chronic venous disease were scanned with VFI and SDUS in the great or the small saphenous vein, and reflux velocities were compared to three assessment tools for chronic venous disease. A flow rig was used to assess the accuracy and precision of the two methods. Results The mean peak reflux velocities differed significantly (VFI: 47.4 cm/s vs. SDUS: 62.0 cm/s, p<0.001). No difference in absolute precision (p=0.18) nor relative precision (p=0.79) was found. No correlation to disease severity, according to assessment tools, was found for peak reflux velocities obtained with either method. In vitro, VFI was more accurate but equally precise when compared to SDUS. Conclusion Both VFI and SDUS detected the pathologic retrograde flow in varicose veins but measured different reflux velocities with equal precision. VFI may play a role in evaluating venous disease in the future.
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Affiliation(s)
| | | | - Andreas Brandt
- Copenhagen University Hospital Rigshospitalet, Department of Diagnostic Radiology, 2100 Copenhagen Oe, Denmark
| | - Ramin Moshavegh
- The Technical University of Denmark, Department of Electrical Engineering Center for Fast Ultrasound Imaging, 2800 Kgs. Lyngby, Denmark
| | - Julie Lyng Forman
- Copenhagen University, Department of Public Health Section of Biostatistics, 1014 Copenhagen K, Denmark
| | - Pia Føgh
- Copenhagen University Hospital Rigshospitalet, Department of Vascular Surgery Herlev & Gentofte Hospital, 2900 Hellerup, Denmark
| | - Lotte Klitfod
- Copenhagen University Hospital Rigshospitalet, Department of Vascular Surgery Herlev & Gentofte Hospital, 2900 Hellerup, Denmark
| | - Niels Bækgaard
- Copenhagen University Hospital Rigshospitalet, Department of Vascular Surgery Herlev & Gentofte Hospital, 2900 Hellerup, Denmark
| | - Lars Lönn
- Rigshospitalet, Copenhagen, DK, Radiology, Copenhagen, Denmark
| | - Jørgen Arendt Jensen
- Technical University of Denmark, Department of Electrical Engineering Center for Fast Ultrasound Imaging, 2800 Kgs. Lyngby, Denmark
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10
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Bechsgaard T, Hansen KL, Brandt AH, Moshavegh R, Forman JL, Føgh P, Klitfod L, Bækgaard N, Lönn L, Nielsen MB, Jensen JA. Respiratory variability of peak velocities in the common femoral vein estimated with vector flow imaging and Doppler ultrasound. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:1941-1950. [PMID: 29960752 DOI: 10.1016/j.ultrasmedbio.2018.05.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 04/26/2018] [Accepted: 05/04/2018] [Indexed: 06/08/2023]
Abstract
Respiratory variability of peak velocities (RVPV) in the common femoral vein measured with ultrasound can reveal venous outflow obstruction. Pulse wave (PW) Doppler is the gold standard for venous velocity estimation of the lower extremities. PW Doppler measurements are angle dependent, whereas vector flow imaging (VFI) can yield angle-independent measures. The hypothesis of the present study was that VFI can provide RVPV estimations without the angle dependency of PW Doppler for an improved venous disease assessment. Sixty-seven patients with symptomatic chronic venous disease were included in the study. On average, VFI measured a lower RVPV than PW Doppler (VFI: 14.11 cm/s; PW: 17.32 cm/s, p = 0.002) with a non-significant improved precision compared with PW Doppler (VFI: 21.09%; PW: 26.49%, p = 0.08). In a flow phantom, VFI had improved accuracy (p < 0.01) and equal precision compared with PW Doppler. The study indicated that VFI can characterize the hemodynamic fluctuations in the common femoral vein.
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Affiliation(s)
- Thor Bechsgaard
- Department of Diagnostic Radiology, Rigshospitalet - Copenhagen University Hospital, Copenhagen Ø, Denmark.
| | - Kristoffer Lindskov Hansen
- Department of Diagnostic Radiology, Rigshospitalet - Copenhagen University Hospital, Copenhagen Ø, Denmark
| | - Andreas Hjelm Brandt
- Department of Diagnostic Radiology, Rigshospitalet - Copenhagen University Hospital, Copenhagen Ø, Denmark
| | - Ramin Moshavegh
- Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Julie Lyng Forman
- Section of Biostatistics, Department of Public Health, Copenhagen University, Copenhagen K, Denmark
| | - Pia Føgh
- Department of Vascular Surgery, Rigshospitalet & Gentofte Hospital - Copenhagen University Hospital, Hellerup, Denmark
| | - Lotte Klitfod
- Department of Vascular Surgery, Rigshospitalet & Gentofte Hospital - Copenhagen University Hospital, Hellerup, Denmark
| | - Niels Bækgaard
- Department of Vascular Surgery, Rigshospitalet & Gentofte Hospital - Copenhagen University Hospital, Hellerup, Denmark
| | - Lars Lönn
- Department of Diagnostic Radiology, Rigshospitalet - Copenhagen University Hospital, Copenhagen Ø, Denmark
| | - Michael Bachmann Nielsen
- Department of Diagnostic Radiology, Rigshospitalet - Copenhagen University Hospital, Copenhagen Ø, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
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11
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Brandt AH, Hansen KL, Ewertsen C, Holbek S, Olesen JB, Moshavegh R, Thomsen C, Jensen JA, Nielsen MB. A Comparison Study of Vector Velocity, Spectral Doppler and Magnetic Resonance of Blood Flow in the Common Carotid Artery. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:1751-1761. [PMID: 29804906 DOI: 10.1016/j.ultrasmedbio.2018.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 04/26/2018] [Accepted: 05/01/2018] [Indexed: 06/08/2023]
Abstract
Magnetic resonance phase contrast angiography (MRA) is the gold standard for blood flow evaluation. Spectral Doppler ultrasound (SDU) is the first clinical choice, although the method is angle dependent. Vector flow imaging (VFI) is an angle-independent ultrasound method. The aim of the study was to compare VFI- and SDU-estimated peak systolic velocities (PSV) of the common carotid artery (CCA) with PSV obtained by MRA. Furthermore, intra- and inter-observer agreement was determined. MRA estimates were significantly different from SDU estimates (left CCA: p < 0.001, right CCA: p < 0.001), but not from VFI estimates (left CCA: p = 0.28, right CCA: p = 0.18). VFI measured lower PSV in both CCAs compared with SDU (p < 0.001) with improved precision (VFI: left: 24%, right: 18%; SDU: left 38%, right: 23%). Intra- and inter-observer agreement was almost perfect for VFI and SDU (inter-observer correlation coefficient: VFI 0.88, SDU 0.91; intra-observer correlation coefficient: VFI 0.96, SDU 0.97). VFI is more accurate than SDU in evaluating PSV compared with MRA.
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Affiliation(s)
- Andreas Hjelm Brandt
- Department of Radiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
| | | | - Caroline Ewertsen
- Department of Radiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Simon Holbek
- Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Jacob Bjerring Olesen
- Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Ramin Moshavegh
- Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Carsten Thomsen
- Department of Radiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark; Department of Radiology, Zealand University Hospital Roskilde, Roskilde, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
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12
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Brandt AH, Moshavegh R, Hansen KL, Bechsgaard T, Lönn L, Jensen JA, Nielsen MB. Vector Flow Imaging Compared with Pulse Wave Doppler for Estimation of Peak Velocity in the Portal Vein. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:593-601. [PMID: 29223701 DOI: 10.1016/j.ultrasmedbio.2017.10.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 10/25/2017] [Accepted: 10/30/2017] [Indexed: 06/07/2023]
Abstract
The study described here investigated whether angle-independent vector flow imaging (VFI) technique estimates peak velocities in the portal vein comparably to pulsed wave Doppler (PWD). Furthermore, intra- and inter-observer agreement was assessed in a substudy. VFI and PWD peak velocities were estimated with from intercostal and subcostal views for 32 healthy volunteers, and precision analyses were conducted. Blinded to estimates, three physicians rescanned 10 volunteers for intra- and inter-observer agreement analyses. The precision of VFI and PWD was 18% and 28% from an intercostal view and 23% and 77% from a subcostal view, respectively. Bias between VFI and PWD was 0.57 cm/s (p = 0.38) with an intercostal view and 9.89 cm/s (p <0.001) with a subcostal view. Intra- and inter-observer agreement was highest for VFI (inter-observer intra-class correlation coefficient: VFI 0.80, PWD 0.3; intra-observer intra-class correlation coefficient: VFI 0.90, PWD 0.69). Regardless of scan view, VFI was more precise than PWD.
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Affiliation(s)
- Andreas Hjelm Brandt
- Department of Radiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
| | - Ramin Moshavegh
- Center for Fast Ultrasound Imaging, Technical University of Denmark, Lyngby, Denmark
| | | | - Thor Bechsgaard
- Department of Radiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Lars Lönn
- Department of Radiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Technical University of Denmark, Lyngby, Denmark
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13
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Bechsgaard T, Hansen KL, Brandt AH, Holbek S, Forman JL, Strandberg C, Lönn L, Bækgaard N, Jensen JA, Nielsen MB. Vector and Doppler Ultrasound Velocities Evaluated in a Flow Phantom and the Femoropopliteal Vein. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:2477-2487. [PMID: 28750944 DOI: 10.1016/j.ultrasmedbio.2017.06.020] [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: 12/13/2016] [Revised: 06/16/2017] [Accepted: 06/19/2017] [Indexed: 06/07/2023]
Abstract
Ultrasound is used for evaluating the veins of the lower extremities. Operator and angle dependency limit spectral Doppler ultrasound (SDUS). The aim of the study was to compare peak velocity measurements in a flow phantom and the femoropopliteal vein of 20 volunteers with the angle-independent vector velocity technique vector flow imaging (VFI) and SDUS. In the flow phantom, VFI underestimated velocity (p = 0.01), with a lower accuracy of 5.5% (p = 0.01) and with no difference in precision, that is, error factor, compared with SDUS (VFI: 1.02 vs. SDUS: 1.02, p = 0.58). In vivo, VFI estimated lower velocities (femoral: p = 0.001; popliteal: p = 0.001) with no difference in precision compared with SDUS (femoral: VFI 1.09 vs. SDUS 1.14, p = 0.37; popliteal: VFI 1.13 vs. SDUS 1.06, p = 0.09). In conclusion, the precise VFI technique can be used to characterize venous hemodynamics of the lower extremities despite its underestimation of velocities.
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Affiliation(s)
- Thor Bechsgaard
- Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark.
| | | | - Andreas Hjelm Brandt
- Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Simon Holbek
- Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Julie Lyng Forman
- Section of Biostatistics, Department of Public Health, Copenhagen University, Copenhagen, Denmark
| | - Charlotte Strandberg
- Department of Radiology, University Hospital of Copenhagen, Herlev & Gentofte Hospital, Hellerup, Denmark
| | - Lars Lönn
- Department of Radiology, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Niels Bækgaard
- Department of Vascular Surgery, University Hospital of Copenhagen, Rigshospitalet & Gentofte Hospital, Hellerup, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
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14
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Holbek S, Hansen KL, Bouzari H, Ewertsen C, Stuart MB, Thomsen C, Nielsen MB, Jensen JA. Common Carotid Artery Flow Measured by 3-D Ultrasonic Vector Flow Imaging and Validated with Magnetic Resonance Imaging. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:2213-2220. [PMID: 28711283 DOI: 10.1016/j.ultrasmedbio.2017.06.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 05/22/2017] [Accepted: 06/05/2017] [Indexed: 06/07/2023]
Abstract
Ultrasound (US) examination of the common carotid artery was compared with a through-plane magnetic resonance imaging (MRI) sequence to validate a recently proposed technique for 3-D US vector flow imaging. Data from the first volunteer examined were used as the training set, before volume flow and peak velocities were calculated for the remaining eight volunteers. Peak systolic velocities (PSVs) and volume flow obtained with 3-D US were, on average, 34% higher and 24% lower than those obtained with MRI, respectively. A high correlation was observed for PSV (r = 0.79), whereas a lower correlation was observed for volume flow (r = 0.43). The overall standard deviations were ±5.7% and ±5.7% for volume flow and PSV with 3-D US, compared with ±2.7% and ±3.2% for MRI. Finally, the data were re-processed with a change in the parameter settings for the echo-canceling filter to investigate its influence on overall performance. PSV was less affected by the re-processing, whereas the difference in volume flow between 3-D vector flow imaging and MRI was reduced to -9%, and with an improved overall standard deviation of ±4.7%. The results illustrate the feasibility of using 3-D US for precise and angle-independent volume flow and PSV estimation in vivo.
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Affiliation(s)
- Simon Holbek
- Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark.
| | | | - Hamed Bouzari
- Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Caroline Ewertsen
- Department of Radiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Matthias Bo Stuart
- Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Carsten Thomsen
- Department of Radiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | | | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
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15
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Hansen KL, Møller-Sørensen H, Kjaergaard J, Jensen MB, Jensen JA, Nielsen MB. Aortic Valve Stenosis Increases Helical Flow and Flow Complexity: A Study of Intra-Operative Cardiac Vector Flow Imaging. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:1607-1617. [PMID: 28495300 DOI: 10.1016/j.ultrasmedbio.2017.03.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 03/21/2017] [Accepted: 03/27/2017] [Indexed: 06/07/2023]
Abstract
Aortic valve stenosis alters blood flow in the ascending aorta. Using intra-operative vector flow imaging on the ascending aorta, secondary helical flow during peak systole and diastole, as well as flow complexity of primary flow during systole, were investigated in patients with normal, stenotic and replaced aortic valves. Peak systolic helical flow, diastolic helical flow and flow complexity during systole differed between the groups (p < 0.0001), and correlated to peak systolic velocity (R = 0.94, 0.87 and 0.88, respectively). The study indicates that aortic valve stenosis increases helical flow and flow complexity, which are measurable with vector flow imaging. For assessment of aortic stenosis and optimization of valve surgery, vector flow imaging may be useful.
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Affiliation(s)
| | | | | | | | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, DTU Elektro, Technical University of Denmark, Denmark
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16
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Hansen KL, Nielsen MB, Jensen JA. Vector velocity estimation of blood flow - A new application in medical ultrasound. ULTRASOUND : JOURNAL OF THE BRITISH MEDICAL ULTRASOUND SOCIETY 2017; 25:189-199. [PMID: 29163655 DOI: 10.1177/1742271x17713353] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/24/2017] [Indexed: 11/15/2022]
Abstract
Vector flow techniques in the field of ultrasound encompass different pulse emission and estimation strategies. Numerous techniques have been introduced over the years, and recently commercial implementations usable in the clinic have been made. A number of clinical papers using different vector velocity approaches have been published. This review will give an overview of the most significant in vivo results achieved with ultrasound vector flow techniques, and will outline some of the possible clinical applications for vector velocity estimation in the future.
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Affiliation(s)
| | | | - Jørgen Arendt Jensen
- Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
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17
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Jensen JA, Nikolov SI, Yu ACH, Garcia D. Ultrasound Vector Flow Imaging-Part I: Sequential Systems. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2016; 63:1704-1721. [PMID: 27824555 DOI: 10.1109/tuffc.2016.2600763] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This paper gives a review of the most important methods for blood velocity vector flow imaging (VFI) for conventional sequential data acquisition. This includes multibeam methods, speckle tracking, transverse oscillation, color flow mapping derived VFI, directional beamforming, and variants of these. The review covers both 2-D and 3-D velocity estimation and gives a historical perspective on the development along with a summary of various vector flow visualization algorithms. The current state of the art is explained along with an overview of clinical studies conducted and methods for presenting and using VFI. A number of examples of VFI images are presented, and the current limitations and potential solutions are discussed.
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18
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Wetterslev M, Møller-Sørensen H, Johansen RR, Perner A. Systematic review of cardiac output measurements by echocardiography vs. thermodilution: the techniques are not interchangeable. Intensive Care Med 2016; 42:1223-33. [DOI: 10.1007/s00134-016-4258-y] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 02/01/2016] [Indexed: 11/29/2022]
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