1
|
Jorgensen LT, Traberg MS, Stuart MB, Jensen JA. Performance Assessment of Row-Column Transverse Oscillation Tensor Velocity Imaging Using Computational Fluid Dynamics Simulation of Carotid Bifurcation Flow. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:1230-1242. [PMID: 35133963 DOI: 10.1109/tuffc.2022.3150106] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In this work, the accuracy of row-column tensor velocity imaging (TVI), i.e., 3-D vector flow imaging (VFI) in 3-D space over time, is quantified on a complex, clinically relevant flow. The quantification is achieved by transferring the flow simulated using computational fluid dynamics (CFD) to a Field II simulation environment, and this allows for a direct comparison between the actual and estimated velocities. The carotid bifurcation flow simulations were performed with a peak inlet velocity of 80 cm/s, nonrigid vessel walls, and a flow cycle duration of 1.2 s. The flow was simulated from two observation angles, and it was acquired using a 3-MHz 62+62 row-column addressed array (RCA) at a pulse repetition frequency ( fprf ) of 10 and 20 kHz. The tensor velocities were obtained at a frame rate of 208.3 Hz, at fprf = 10 kHz , and the results from two velocity estimators were compared. The two estimators were the directional transverse oscillation (TO) cross correlation estimator and the proposed autocorrelation estimator. Linear regression between the actual and estimated velocity components yielded, for the cross correlation estimator, an R 2 value in the range of 0.89-0.91, 0.46-0.77, and 0.91-0.97 for the x -, y -, and z -components, and 0.87-0.89, 0.40-0.83, and 0.91-0.96 when using the autocorrelation estimator. The results demonstrate that an RCA can, with just 62 receive channels, measure complex 3-D flow fields at a high volume rate.
Collapse
|
2
|
Nguyen TQ, Traberg MS, Olesen JB, Moshavegh R, Møller-Sørensen PH, Lönn L, Jensen JA, Nielsen MB, Hansen KL. Pressure Difference Estimation in Non-stenotic Carotid Bifurcation Phantoms Using Vector Flow Imaging. ULTRASOUND IN MEDICINE & BIOLOGY 2022; 48:346-357. [PMID: 34763906 DOI: 10.1016/j.ultrasmedbio.2021.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 08/21/2021] [Accepted: 10/03/2021] [Indexed: 06/13/2023]
Abstract
Local pressure differences estimated using vector flow imaging (VFI) and direct catheterization in seven carotid bifurcation phantoms were compared with simulated pressure fields. VFI correlated strongly with simulated peak pressure differences (r = 0.99, p < 0.00001), with an average overestimation of 12.3 Pa (28.6%). The range between the lowest and highest pressure difference of VFI underestimated simulations by 4.6 Pa (8.06%; r = 0.99, p < 0.0001). The catheter method exhibited no correlation (r = -0.09, p = 0.85). Ten repeated measurements on one phantom revealed a small standard deviation (SD) for VFI (SD = 8.4%, mean estimated SD = 11.5%), but not for the catheter method (SD = 785.6%). An in vivo peak systolic pressure difference of 97.9 Pa (estimated SD = 30%) was measured using VFI in one healthy individual. This study indicates that VFI pressure difference estimation is feasible in phantoms and in vivo and realistic estimates of the SD can be attained from the data.
Collapse
Affiliation(s)
- Tin-Quoc Nguyen
- Department of Diagnostic Radiology, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
| | - Marie Sand Traberg
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | | | | | - Lars Lönn
- Department of Diagnostic Radiology, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Michael Bachmann Nielsen
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Kristoffer Lindskov Hansen
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| |
Collapse
|
3
|
Zhou X, Toulemonde M, Zhou X, Hansen-Shearer J, Senior R, Tang MX. Volumetric Flow Estimation in a Coronary Artery Phantom Using High-Frame-Rate Contrast-Enhanced Ultrasound, Speckle Decorrelation, and Doppler Flow Direction Detection. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:3299-3308. [PMID: 34133277 DOI: 10.1109/tuffc.2021.3089723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The coronary flow reserve (CFR), relating to the volumetric flow rate, is an effective functional parameter to assess the stenosis in the left anterior descending (LAD) coronary artery. We have recently proposed to use high-frame-rate (HFR) contrast-enhanced ultrasound (CEUS) to estimate the volumetric flow rate using ultrasound (US) speckle decorrelation (SDC) without any assumptions about the velocity profile. However, this method still has challenges in imaging deep and small vessels, such as LAD. In this study, we proposed to address the challenges and demonstrate the feasibility of volumetric flow rate measurement in a coronary mimicking phantom with pulsatile flow using a 1-D array cardiac probe, vector Doppler, and an optimal probe rotation/tilting for flow direction detection. Both simulations and in vitro experiments were conducted to validate the proposed method. It is shown that in-plane velocities estimated by vector Doppler under a 10° probe tilting resulted in smaller percentage error (+5.2%) in flow rate estimates than that in US imaging velocimetry (-20.2%) although their relative standard deviations were very close, being 2.6 and 2.8 ml/min, respectively. The flow rate estimated by SDC without direction detection had an error higher than 70%. A 10° tilting of the probe had the best results in flow rate estimation compared to the 5° or 15° tilting. Realistic global motions in the LAD increased the flow rate estimation error from 5.2% to 14.2%. It is concluded that it is feasible to measure the volumetric flow rate in a coronary artery flow phantom with a conventional cardiac probe, using HFR acquisition, Doppler, and SDC analysis. Potentially, this technique could also be applied to investigate the volumetric flow rate in other small vessels similar to the LAD.
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Putz FJ, Pfister K, Bergler T, Banas MC, Jung EM, Banas B, Schierling W. Sonographic 3-D Power Doppler Imaging Enhances Rapid Assessment of Morphologic and Pathologic Arteriovenous Fistula Variations. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:1484-1494. [PMID: 33757696 DOI: 10.1016/j.ultrasmedbio.2021.02.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/13/2021] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
Early detection of pathologic variations in an arteriovenous fistula (AVF) is essential for preventing fistula dysfunction in individuals undergoing hemodialysis. This study aimed to evaluate the clinical applicability of 3-D tomographic ultrasound (tUS) for rapid and simple visualization of AVF morphology and pathology. We assessed 53 AVFs in 50 consecutive patients using 3-D tUS including secondary, blinded reading. For all examinations, a high-end ultrasound (US) device was used with linear probe, attached to a tUS system to allow freehand 3-D scanning. Participants were examined by 2-D US and 3-D tUS with different raw data (B-mode, power Doppler, B-flow). Additional angiography was available for 15 participants with scheduled interventions. In all participants, 3-D tUS allowed a 3-D representation of AVFs in angiographic-like images with good image quality. The 2-D US assessment took 7.9 ± 4.0 min. A 3-D power Doppler scan required, on average, 1.4 ± 0.6 min. Diagnostic accuracy of blinded reading for pathologies was high (86.8% for aneurysms and 79.2% for stenoses). Bland-Altman plots showed an excellent correlation of 3-D tUS with 2-D US and angiography. 3-D tUS is an easily and rapidly applicable method for visualizing morphologic and pathologic AVF variations. Color-coded 3-D reconstruction of power Doppler data simplifies detection of perfused aneurysms and stenoses.
Collapse
Affiliation(s)
- Franz Josef Putz
- Department of Nephrology, University Hospital Regensburg, Regensburg, Germany.
| | - Karin Pfister
- Department of Vascular Surgery, University Hospital Regensburg, Regensburg, Germany
| | - Tobias Bergler
- Department of Nephrology, University Hospital Regensburg, Regensburg, Germany
| | - Miriam C Banas
- Department of Nephrology, University Hospital Regensburg, Regensburg, Germany
| | | | - Bernhard Banas
- Department of Nephrology, University Hospital Regensburg, Regensburg, Germany
| | - Wilma Schierling
- Department of Vascular Surgery, University Hospital Regensburg, Regensburg, Germany
| |
Collapse
|
6
|
From Anatomy to Functional and Molecular Biomarker Imaging and Therapy: Ultrasound Is Safe, Ultrafast, Portable, and Inexpensive. Invest Radiol 2021; 55:559-572. [PMID: 32776766 DOI: 10.1097/rli.0000000000000675] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Ultrasound is the most widely used medical imaging modality worldwide. It is abundant, extremely safe, portable, and inexpensive. In this review, we consider some of the current development trends for ultrasound imaging, which build upon its current strength and the popularity it experiences among medical imaging professional users.Ultrasound has rapidly expanded beyond traditional radiology departments and cardiology practices. Computing power and data processing capabilities of commonly available electronics put ultrasound systems in a lab coat pocket or on a user's mobile phone. Taking advantage of new contributions and discoveries in ultrasound physics, signal processing algorithms, and electronics, the performance of ultrasound systems and transducers have progressed in terms of them becoming smaller, with higher imaging performance, and having lower cost. Ultrasound operates in real time, now at ultrafast speeds; kilohertz frame rates are already achieved by many systems.Ultrasound has progressed beyond anatomical imaging and monitoring blood flow in large vessels. With clinical approval of ultrasound contrast agents (gas-filled microbubbles) that are administered in the bloodstream, tissue perfusion studies are now routine. Through the use of modern ultrasound pulse sequences, individual microbubbles, with subpicogram mass, can be detected and observed in real time, many centimeters deep in the body. Ultrasound imaging has broken the wavelength barrier; by tracking positions of microbubbles within the vasculature, superresolution imaging has been made possible. Ultrasound can now trace the smallest vessels and capillaries, and obtain blood velocity data in those vessels.Molecular ultrasound imaging has now moved closer to clinic; the use of microbubbles with a specific affinity to endothelial biomarkers allows selective accumulation and retention of ultrasound contrast in the areas of ischemic injury, inflammation, or neoangiogenesis. This will aid in noninvasive molecular imaging and may provide additional help with real-time guidance of biopsy, surgery, and ablation procedures.The ultrasound field can be tightly focused inside the body, many centimeters deep, with millimeter precision, and ablate lesions by energy deposition, with thermal or mechanical bioeffects. Some of such treatments are already in clinical use, with more indications progressing through the clinical trial stage. In conjunction with intravascular microbubbles, focused ultrasound can be used for tissue-specific drug delivery; localized triggered release of sequestered drugs from particles in the bloodstream may take time to get to clinic. A combination of intravascular microbubbles with circulating drug and low-power ultrasound allows transient opening of vascular endothelial barriers, including blood-brain barrier; this approach has reached clinical trial stage. Therefore, the drugs that normally would not be getting to the target tissue in the brain will now have an opportunity to produce therapeutic efficacy.Overall, medical ultrasound is developing at a brisk rate, even in an environment where other imaging modalities are also advancing rapidly and may be considered more lucrative. With all the current advances that we discuss, and many more to come, ultrasound may help solve many problems that modern medicine is facing.
Collapse
|
7
|
Colombo A, Provenzano M, Rivoli L, Donato C, Capria M, Leonardi G, Chiarella S, Andreucci M, Fuiano G, Bolignano D, Coppolino G. Utility of Blood Flow/Resistance Index Ratio (Q x) as a Marker of Stenosis and Future Thrombotic Events in Native Arteriovenous Fistulas. Front Surg 2021; 7:604347. [PMID: 33569388 PMCID: PMC7868551 DOI: 10.3389/fsurg.2020.604347] [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: 09/09/2020] [Accepted: 12/31/2020] [Indexed: 11/21/2022] Open
Abstract
Objective: The resistance index (RI) and the blood flow volume (Qa) are the most used Doppler ultrasound (DUS) parameters to identify the presence of stenosis in arteriovenous fistula (AVF). However, the reliability of these indexes is now matter of concern, particularly in predicting subsequent thrombosis. In this study, we aimed at testing the diagnostic capacity of the Qa/RI ratio (Qx) for the early identification of AVF stenosis and for thrombosis risk stratification. Methods: From a multicentre source population of 336 HD patients, we identified 119 patients presenting at least one “alarm sign” for clinical suspicious of stenosis. Patients were therefore categorized by DUS as stenotic (n = 60) or not-stenotic (n = 59) and prospectively followed. Qa, RI, and QX, together with various clinical and laboratory parameters, were recorded. Results: Qa and Qx were significantly higher while RI was significantly lower in non-stenotic vs. stenotic patients (p < 0.001 for each comparison). At ROC analyses, Qx had the best discriminatory power in identifying the presence of stenosis as compared to Qa and RI (AUCs 0.976 vs. 0.953 and 0.804; p = 0.037 and p < 0.0001, respectively). During follow-up, we registered 30 thrombotic events with an incidence rate of 12.65 (95% CI 8.54–18.06) per 100 patients/year. In Cox-regression proportional hazard models, Qx showed a better capacity to predict thrombosis occurrence as compared to Qa (difference between c-indexes: 0.012; 95% CI 0.004–0.01). Conclusions: In chronic haemodialysis patients, Qx might represent a more reliable and valid indicator for the early identification of stenotic AVFs and for predicting the risk of following thrombosis.
Collapse
Affiliation(s)
| | | | - Laura Rivoli
- Unit of Nephrology, Department of Internal Medicine, Chivasso Hospital, Turin, Italy
| | - Cinzia Donato
- Renal Unit, "Pugliese-Ciaccio" Hospital of Catanzaro, Catanzaro, Italy
| | | | | | | | | | - Giorgio Fuiano
- Renal Unit, "Magna Graecia" University, Catanzaro, Italy
| | | | | |
Collapse
|
8
|
Nguyen TQ, Traberg MS, Olesen JB, Heerwagen ST, Brandt AH, Bechsgaard T, Pedersen BL, Moshavegh R, Lönn L, Jensen JA, Nielsen MB, Hansen KL. Flow Complexity Estimation in Dysfunctional Arteriovenous Dialysis Fistulas using Vector Flow Imaging. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:2493-2504. [PMID: 32595057 DOI: 10.1016/j.ultrasmedbio.2020.05.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 05/25/2020] [Accepted: 05/31/2020] [Indexed: 06/11/2023]
Abstract
Non-invasive assessment is preferred for monitoring arteriovenous dialysis fistulas (AVFs). Vector concentration assesses flow complexity, which may correlate with stenosis severity. We determined whether vector concentration could assess stenosis severity in dysfunctional AVFs. Vector concentration was estimated in four stenotic phantoms at different pulse repetition frequencies. Spectral Doppler peak velocity and vector concentration were measured in 12 patients with dysfunctional AVFs. Additionally, 5 patients underwent digital subtraction angiography (DSA). In phantoms, vector concentration exhibited an inverse relationship with stenosis severity and was less affected by aliasing in severe stenoses. In nine stenoses of 5 patients undergoing DSA, vector concentration correlated strongly with stenosis severity (first stenosis: r = -0.73, p = 0.04; other stenoses; r = -0.69, p = 0.02) and mid-stenotic diameter (first stenosis: r = 0.87, p = 0.006; other stenoses: r = 0.70, p = 0.02) as opposed to peak velocities (p > 0.05). Vector concentration is less affected by aliasing in severe stenoses and correlates with DSA in patients with dysfunctional AVF.
Collapse
Affiliation(s)
- Tin-Quoc Nguyen
- Department of Diagnostic Radiology, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
| | - Marie Sand Traberg
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, Lyngby, Denmark
| | - Jacob Bjerring Olesen
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, Lyngby, Denmark; BK Medical, Herlev, Denmark
| | | | | | - Thor Bechsgaard
- Department of Radiology, Odense University Hospital, Odense C, Denmark
| | | | - Ramin Moshavegh
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, Lyngby, Denmark; BK Medical, Herlev, Denmark
| | - Lars Lönn
- Department of Diagnostic Radiology, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Department of Health Technology, Technical University of Denmark, Lyngby, Denmark
| | - Michael Bachmann Nielsen
- Department of Diagnostic Radiology, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Kristoffer Lindskov Hansen
- Department of Diagnostic Radiology, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
9
|
Saris AECM, Hansen HHG, Fekkes S, Menssen J, Nillesen MM, de Korte CL. In Vivo Blood Velocity Vector Imaging Using Adaptive Velocity Compounding in the Carotid Artery Bifurcation. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:1691-1707. [PMID: 31079874 DOI: 10.1016/j.ultrasmedbio.2019.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 03/06/2019] [Accepted: 03/10/2019] [Indexed: 06/09/2023]
Abstract
Visualization and quantification of blood flow are considered important for early detection of atherosclerosis and patient-specific diagnosis and intervention. As conventional Doppler imaging is limited to 1-D velocity estimates, 2-D and 3-D techniques are being developed. We introduce an adaptive velocity compounding technique that estimates the 2-D velocity vector field using predominantly axial displacements estimated by speckle tracking from dual-angle plane wave acquisitions. Straight-vessel experiments with a 7.8-MHz linear array transducer connected to a Verasonics Vantage ultrasound system revealed that the technique performed with a maximum velocity magnitude bias and angle bias of -3.7% (2.8% standard deviation) and -0.16° (0.41° standard deviation), respectively. In vivo, complex flow patterns were visualized in two healthy and three diseased carotid arteries and quantified using a vector complexity measure that increased with increasing wall irregularity. This measure could potentially be a relevant clinical parameter which might aid in early detection of atherosclerosis.
Collapse
Affiliation(s)
- Anne E C M Saris
- Medical Ultrasound Imaging Centre (MUSIC), Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Hendrik H G Hansen
- Medical Ultrasound Imaging Centre (MUSIC), Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Stein Fekkes
- Medical Ultrasound Imaging Centre (MUSIC), Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jan Menssen
- Medical Ultrasound Imaging Centre (MUSIC), Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maartje M Nillesen
- Medical Ultrasound Imaging Centre (MUSIC), Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Chris L de Korte
- Medical Ultrasound Imaging Centre (MUSIC), Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands; Physics of Fluid Group, MESA+ Institute for Nanotechnology, and MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| |
Collapse
|
10
|
Abstract
Sonography is increasingly being used by nephrologists and the field of dialysis access is no exception. Advances in technology have allowed the addition of this universally available, portable, non-invasive tool to the nephrologist's armamentarium, which provides information on both morphology and physiology without the need for contrast or radiation. Ultrasound may be used across the spectrum of dialysis access, including central venous catheter placements, vascular mapping, regional anesthesia, creation, maintenance and assessment of hemodialysis access as well as assessment of the abdominal wall and peritoneal dialysis catheter placements. However, the lack of exposure in most training programs limits incorporation of routine use of ultrasounds in nephrology practice. As our specialty embarks on the ultrasound revolution, a two-pronged approach is essential to provide ample training opportunities while ensuring establishment of basic standards for training and competency.
Collapse
Affiliation(s)
- Vandana Dua Niyyar
- Division of Nephrology, Department of Medicine, Emory University, Atlanta, GA, USA
| |
Collapse
|
11
|
Hansen PM, Hansen KL, Pedersen MM, Lange T, Lönn L, Jensen JA, Nielsen MB. Atherosclerotic Lesions in the Superficial Femoral Artery (SFA) Characterized with Velocity Ratios using Vector Velocity Ultrasound. Ultrasound Int Open 2018; 4:E79-E84. [PMID: 30250942 PMCID: PMC6143374 DOI: 10.1055/a-0637-2437] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 04/13/2018] [Accepted: 05/12/2018] [Indexed: 12/19/2022] Open
Abstract
Purpose Atherosclerotic arteries are challenging to evaluate quantitatively using spectral Doppler ultrasound because of the turbulent flow conditions that occur in relation to the atherosclerotic stenoses. Vector velocity ultrasound is angle independent and provides flow information, which could potentially improve the diagnosis of arterial stenoses. The purpose of the study is to distinguish significant stenoses in the superficial femoral artery (> 50% diameter reduction) from non-significant stenoses based on velocity ratios derived from the commercially available vector velocity ultrasound technique Vector Flow Imaging (VFI). Materials and Methods Velocity ratios (intrastenotic blood flow velocity divided by pre- or poststenotic velocity) from a total of 16 atherosclerotic stenoses and plaques in the superficial femoral artery of 11 patients were obtained using VFI. The stenosis degree, expressed as percentage diameter reduction of the artery, was determined from digital subtraction angiography and compared to the velocity ratios. Results A velocity ratio of 2.5 was found to distinguish clinically relevant stenoses with>50% diameter reduction from clinically non-relevant stenoses with<50% diameter reduction and the difference was statistically significant. Conclusion The study indicates that VFI is a potential future tool for the evaluation of arterial stenoses.
Collapse
Affiliation(s)
- Peter Møller Hansen
- Department of Radiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | | | - Mads Møller Pedersen
- Department of Radiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Theis Lange
- Section of Biostatistics, University of Copenhagen, Copenhagen, Denmark.,Center for Statistical Sciences, Peking University, Beijing, China
| | - Lars Lönn
- Department of Radiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.,Department of Vascular Surgery, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, Dept. of Elec. Eng., Technical University of Denmark, Lyngby, Denmark
| | | |
Collapse
|
12
|
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.
Collapse
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
| | | |
Collapse
|
13
|
Goddi A, Fanizza M, Bortolotto C, Raciti MV, Fiorina I, He X, Du Y, Calliada F. Vector flow imaging techniques: An innovative ultrasonographic technique for the study of blood flow. JOURNAL OF CLINICAL ULTRASOUND : JCU 2017; 45:582-588. [PMID: 28734035 DOI: 10.1002/jcu.22519] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Revised: 06/03/2017] [Accepted: 06/09/2017] [Indexed: 06/07/2023]
Abstract
Doppler ultrasonography is routinely used to identify abnormal blood flow. Nevertheless, conventional Doppler can be used to determine only the axial component of blood flow velocity and is angle dependent. A new method of multidimensional angle-independent estimation of flow velocity, called Vector Flow Imaging (VFI), has been proposed. It quantitatively evaluates the true velocity vector's amplitude and direction at any location into a vessel and displays a more intuitive depiction of the flow movements. High frame rate VFI, based on plane wave imaging, allows a detailed dynamic visualization of complex flow by showing even transient events, otherwise undetectable. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:582-588, 2017.
Collapse
Affiliation(s)
- Alfredo Goddi
- Centro Medico SME-Diagnostica per Immagini, Varese, Italy
| | - Marianna Fanizza
- Radiology Department, Fondazione IRCCS Policlinico San Matteo, Via Oberdan 21, Pavia, 27100, Italy
| | - Chandra Bortolotto
- Radiology Department, Fondazione IRCCS Policlinico San Matteo, Via Oberdan 21, Pavia, 27100, Italy
| | - Maria Vittoria Raciti
- Radiology Department, Fondazione IRCCS Policlinico San Matteo, Via Oberdan 21, Pavia, 27100, Italy
| | - Ilaria Fiorina
- Radiology Department, Fondazione IRCCS Policlinico San Matteo, Via Oberdan 21, Pavia, 27100, Italy
| | - Xujin He
- Ultrasound R&D Department, Shenzhen Mindray Bio-Medical Electronics Co., Ltd., Shenzhen, China
| | - Yigang Du
- Ultrasound R&D Department, Shenzhen Mindray Bio-Medical Electronics Co., Ltd., Shenzhen, China
| | - Fabrizio Calliada
- Radiology Department, Fondazione IRCCS Policlinico San Matteo, Via Oberdan 21, Pavia, 27100, Italy
| |
Collapse
|
14
|
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.
Collapse
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
| | | |
Collapse
|
15
|
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.
Collapse
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
| |
Collapse
|
16
|
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.
Collapse
Affiliation(s)
| | | | - Jørgen Arendt Jensen
- Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
| |
Collapse
|
17
|
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.
Collapse
|