101
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Pruitt AA, Jin N, Liu Y, Simonetti OP, Ahmad R. A method to correct background phase offset for phase-contrast MRI in the presence of steady flow and spatial wrap-around artifact. Magn Reson Med 2018; 81:2424-2438. [PMID: 30431176 DOI: 10.1002/mrm.27572] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 09/13/2018] [Accepted: 09/27/2018] [Indexed: 11/11/2022]
Abstract
PURPOSE Background phase offsets in phase-contrast MRI are often corrected using polynomial regression; however, correction performance degrades when temporally invariant outliers such as steady flow or spatial wrap-around artifact are present. We describe and validate an iterative method called automatic rejection of temporally invariant outliers (ARTO), which excludes these outliers from the fitting process. METHODS The ARTO method iteratively removes pixels with large polynomial regression errors analyzed by a Gaussian mixture model fitting of the residual distribution. A total of 150 trials of a simulated phantom (75 with wrap-around artifact) and 125 phase-contrast MRI cines from 22 healthy subjects (48 with wrap-around artifact) were used for validation. Background phase offsets were corrected using second-order weighted regularized least squares (WRLS) with and without ARTO. Flow volumes after WRLS and WRLS+ARTO corrections were compared with the known truth (phantom) and stationary phantom reference (in vivo) using Bland-Altman analysis. The ratio between the pulmonary flow and the systemic flow was also computed in a subset of 6 subjects. RESULTS In the simulated phantom, compared with WRLS and no correction, correction with WRLS+ARTO produced superior agreement in volumetric flow quantification with the known truth. In vivo, WRLS+ARTO also produced superior agreement with stationary phantom-corrected volumetric flow compared with WRLS and no correction. In data sets with wrap-around artifact, WRLS produced significantly larger variance in the pulmonary flow and systemic flow ratio than stationary phantom correction (P = .0008). CONCLUSION The proposed method provides automatic exclusion of temporally invariant outliers and produces flow quantification results comparable to stationary phantom correction.
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Affiliation(s)
- Aaron A Pruitt
- Biomedical Engineering, Ohio State University, Columbus, Ohio
| | - Ning Jin
- Cardiovascular MR R&D, Siemens Medical Solutions USA, Columbus, Ohio
| | - Yingmin Liu
- Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio
| | - Orlando P Simonetti
- Biomedical Engineering, Ohio State University, Columbus, Ohio.,Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio.,Internal Medicine, Ohio State University, Columbus, Ohio
| | - Rizwan Ahmad
- Biomedical Engineering, Ohio State University, Columbus, Ohio.,Dorothy M. Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio.,Electrical and Computer Engineering, Ohio State University, Columbus, Ohio
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102
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Walheim J, Gotschy A, Kozerke S. On the limitations of partial Fourier acquisition in phase-contrast MRI of turbulent kinetic energy. Magn Reson Med 2018; 81:514-523. [PMID: 30265753 DOI: 10.1002/mrm.27397] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 05/04/2018] [Accepted: 05/20/2018] [Indexed: 11/11/2022]
Abstract
PURPOSE To investigate limitations of partial Fourier acquisition in phase-contrast MRI of turbulent kinetic energy (TKE). METHODS To assess the validity of partial Fourier reconstruction of TKE and phase images, computational fluid dynamics data of mean and turbulent velocities in a stenotic U-bend phantom was used. Partial Fourier acquisition with 75% k-space coverage was simulated and TKE data were reconstructed using zero-filling, homodyne reconstruction, and the method of projections onto convex sets (POCS). Results were compared to data from fully sampled k-space and 75% symmetric sampling. In addition, compressed sensing (CS) reconstruction was compared for a standard variable density sampling pattern and a variable density sampling pattern combined with 75% partial Fourier. For illustration purposes, in vivo examples of velocity magnitude and TKE maps of aortic flow reconstructed with the different methods are provided. RESULTS In accordance with theory, partial Fourier reconstruction of TKE maps from phase-contrast data results in artifacts relative to fully sampled data. It is demonstrated that neither homodyne reconstruction nor POCS can improve reconstruction of TKE data with respect to zero-filling reconstruction when compared to ground-truth (RMS error: 4.70%, 4.34%, and 2.45% for homodyne, POCS, and zero-filling reconstruction of in vivo data, respectively). CS reconstruction from data acquired with partial Fourier did not recover the resolution loss incurred by partial Fourier sampling. CONCLUSION Partial Fourier reconstruction of TKE maps from phase-contrast data does not yield a benefit over zero-filling reconstruction. In consequence, symmetric sampling is preferred over partial Fourier acquisition for a given number of phase-encodes in phase-contrast MRI.
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Affiliation(s)
- Jonas Walheim
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Alexander Gotschy
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland.,Department of Cardiology, University Hospital Zurich, Zurich, Switzerland
| | - Sebastian Kozerke
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
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103
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Impact of Age and Diastolic Function on Novel, 4D flow CMR Biomarkers of Left Ventricular Blood Flow Kinetic Energy. Sci Rep 2018; 8:14436. [PMID: 30258186 PMCID: PMC6158175 DOI: 10.1038/s41598-018-32707-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 09/06/2018] [Indexed: 01/01/2023] Open
Abstract
Two-dimensional (2D) methods of assessing mitral inflow velocities are pre-load dependent, limiting their reliability for evaluating diastolic function. Left ventricular (LV) blood flow kinetic energy (KE) derived from four-dimensional flow cardiovascular magnetic resonance imaging (4D flow CMR) may offer improvements. It remains unclear whether 4D LV blood flow KE parameters are associated with physiological factors, such as age when compared to 2D mitral inflow velocities. Fifty-three healthy volunteers underwent standard CMR, plus 4D flow acquisition. LV blood flow KE parameters demonstrated good reproducibility with mean coefficient of variation of 6 ± 2% and an accuracy of 99% with a precision of 97%. The LV blood flow KEiEDV E/A ratio demonstrated good association to the 2D mitral inflow E/A ratio (r = 0.77, P < 0.01), with both decreasing progressively with advancing age (P < 0.01). Furthermore, peak E-wave KEiEDV and A-wave KEiEDV displayed a stronger association to age than the corresponding 2D metrics, peak E-wave and A-wave velocity (r = −0.51 vs −0.17 and r = 0.65 vs 0.46). Peak E-wave KEiEDV decreases whilst peak A-wave KEiEDV increases with advancing age. This study presents values for various LV blood flow KE parameters in health, as well as demonstrating that they show stronger and independent correlations to age than standard diastolic metrics.
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104
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Ferrazzi G, Bassenge JP, Wink C, Ruh A, Markl M, Moeller S, Metzger GJ, Ittermann B, Schmitter S. Autocalibrated multiband CAIPIRINHA with through‐time encoding: Proof of principle and application to cardiac tissue phase mapping. Magn Reson Med 2018; 81:1016-1030. [DOI: 10.1002/mrm.27460] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 06/30/2018] [Accepted: 07/02/2018] [Indexed: 12/27/2022]
Affiliation(s)
- Giulio Ferrazzi
- Physikalisch‐Technische Bundesanstalt (PTB) Braunschweig and Berlin Germany
| | - Jean Pierre Bassenge
- Physikalisch‐Technische Bundesanstalt (PTB) Braunschweig and Berlin Germany
- Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max‐Delbrueck Center for Molecular Medicine
| | - Clarissa Wink
- Physikalisch‐Technische Bundesanstalt (PTB) Braunschweig and Berlin Germany
| | - Alexander Ruh
- Department of Radiology, Feinberg School of Medicine Northwestern University Chicago Illinois
| | - Michael Markl
- Department of Radiology, Feinberg School of Medicine Northwestern University Chicago Illinois
- Department of Biomedical Engineering, McCormick School of Engineering Northwestern University Chicago Illinois
| | - Steen Moeller
- University of Minnesota, Center for Magnetic Resonance Research (CMRR) Minneapolis Minnesota
| | - Gregory J. Metzger
- University of Minnesota, Center for Magnetic Resonance Research (CMRR) Minneapolis Minnesota
| | - Bernd Ittermann
- Physikalisch‐Technische Bundesanstalt (PTB) Braunschweig and Berlin Germany
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105
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Jarvis K, Schnell S, Barker AJ, Rose M, Robinson JD, Rigsby CK, Markl M. Caval to pulmonary 3D flow distribution in patients with Fontan circulation and impact of potential 4D flow MRI error sources. Magn Reson Med 2018; 81:1205-1218. [PMID: 30277276 DOI: 10.1002/mrm.27455] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 06/07/2018] [Accepted: 06/26/2018] [Indexed: 11/08/2022]
Abstract
PURPOSE Uneven flow distribution in patients with Fontan circulation is suspected to lead to complications. 4D flow MRI offers evaluation using time-resolved pathlines; however, the potential error is not well understood. The aim of this study was to systematically assess variability in flow distribution caused by well-known sources of error. METHODS 4D flow MRI was acquired in 14 patients with Fontan circulation. Flow distribution was quantified by the % of caval venous flow pathlines reaching the left and right pulmonary arteries. Impact of data acquisition and data processing uncertainties were investigated by (1) probabilistic 4D blood flow tracking at varying noise levels, (2) down-sampling to mimic acquisition at different spatial resolutions, (3) pathline calculation with and without eddy current correction, and (4) varied segmentation of the Fontan geometry to mimic analysis errors. RESULTS Averaged among the cohort, uncertainties accounted for flow distribution errors from noise ≤3.2%, low spatial resolution ≤2.3% to 3.8%, eddy currents ≤6.4%, and inaccurate segmentation ≤3.9% to 9.1% (dilation and erosion, respectively). In a worst-case scenario (maximum additive errors for all 4 sources), flow distribution errors were as high as 22.5%. CONCLUSION Inaccuracies related to postprocessing (segmentation, eddy currents) resulted in the largest potential error (≤15.5% combined) whereas errors related to data acquisition (noise, low spatial resolution) had a lower impact (≤5.5%-7.0% combined). Whereas it is unlikely that these errors will be additive or affect the identification of severe asymmetry, these results illustrate the importance of eddy current correction and accurate segmentation to minimize Fontan flow distribution errors.
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Affiliation(s)
- Kelly Jarvis
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, Illinois
| | - Susanne Schnell
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Alex J Barker
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Michael Rose
- Department of Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
| | - Joshua D Robinson
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Department of Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois.,Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Division of Cardiology, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
| | - Cynthia K Rigsby
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Department of Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois.,Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Division of Cardiology, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
| | - Michael Markl
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, Illinois
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106
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In Vitro Validation of 4D Flow MRI for Local Pulse Wave Velocity Estimation. Cardiovasc Eng Technol 2018; 9:674-687. [PMID: 30218205 DOI: 10.1007/s13239-018-00377-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/04/2018] [Indexed: 12/13/2022]
Abstract
PURPOSE Arterial stiffness has predictive value for cardiovascular disease (CVD). Local artery stiffness can provide insight on CVD pathology and may be useful for diagnosis and prognosis. However, current methods are invasive, require real-time expertise for measurement, or are limited by arterial region. 4D Flow MRI can non-invasively measure local stiffness by estimating local pulse wave velocity (PWV). This technique can be applied to vascular regions, previously accessible only by invasive stiffness measurement methods. MRI PWV data can also be analyzed post-exam. However, 4D Flow MRI requires validation before it is used in vivo to measure local PWV. METHODS PWV, calculated from 4D Flow MRI and a benchtop experiment, was compared with petersons elastic modulus (PEM) of in vitro models. PEM was calculated using high-speed camera images and pressure transducers. Three transit-time algorithms were analyzed for PWV measurement accuracy and precision. RESULTS PWV from 4D Flow MRI and reference benchtop experiments show strong correlation with PEM (R2 = 0.99). The cross correlation transit-time algorithm showed the lowest percent difference between 4D Flow MRI and benchtop experiments (4-7%), and the point to point of 50% upstroke algorithm had the highest transit-time vs. distance data average R2 (0.845). CONCLUSION 4D Flow MRI is a feasible method for estimating local PWV in simple in vitro models and is a viable tool for clinical analysis. In addition, choice in transit-time algorithm depends on flow waveform shape and arterial region. This study strengthens the validity of 4D Flow MRI local PWV measurement in simple models. However, this technique requires validation in more complex models before it is used in vivo.
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107
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Garg P, Crandon S, Swoboda PP, Fent GJ, Foley JRJ, Chew PG, Brown LAE, Vijayan S, Hassell MECJ, Nijveldt R, Bissell M, Elbaz MSM, Al-Mohammad A, Westenberg JJM, Greenwood JP, van der Geest RJ, Plein S, Dall’Armellina E. Left ventricular blood flow kinetic energy after myocardial infarction - insights from 4D flow cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2018; 20:61. [PMID: 30165869 PMCID: PMC6117925 DOI: 10.1186/s12968-018-0483-6] [Citation(s) in RCA: 54] [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: 03/13/2018] [Accepted: 07/20/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Myocardial infarction (MI) leads to complex changes in left ventricular (LV) haemodynamics that are linked to clinical outcomes. We hypothesize that LV blood flow kinetic energy (KE) is altered in MI and is associated with LV function and infarct characteristics. This study aimed to investigate the intra-cavity LV blood flow KE in controls and MI patients, using cardiovascular magnetic resonance (CMR) four-dimensional (4D) flow assessment. METHODS Forty-eight patients with MI (acute-22; chronic-26) and 20 age/gender-matched healthy controls underwent CMR which included cines and whole-heart 4D flow. Patients also received late gadolinium enhancement imaging for infarct assessment. LV blood flow KE parameters were indexed to LV end-diastolic volume and include: averaged LV, minimal, systolic, diastolic, peak E-wave and peak A-wave KEiEDV. In addition, we investigated the in-plane proportion of LV KE (%) and the time difference (TD) to peak E-wave KE propagation from base to mid-ventricle was computed. Association of LV blood flow KE parameters to LV function and infarct size were investigated in all groups. RESULTS LV KEiEDV was higher in controls than in MI patients (8.5 ± 3 μJ/ml versus 6.5 ± 3 μJ/ml, P = 0.02). Additionally, systolic, minimal and diastolic peak E-wave KEiEDV were lower in MI (P < 0.05). In logistic-regression analysis, systolic KEiEDV (Beta = - 0.24, P < 0.01) demonstrated the strongest association with the presence of MI. In multiple-regression analysis, infarct size was most strongly associated with in-plane KE (r = 0.5, Beta = 1.1, P < 0.01). In patients with preserved LV ejection fraction (EF), minimal and in-plane KEiEDV were reduced (P < 0.05) and time difference to peak E-wave KE propagation during diastole increased (P < 0.05) when compared to controls with normal EF. CONCLUSIONS Reduction in LV systolic function results in reduction in systolic flow KEiEDV. Infarct size is independently associated with the proportion of in-plane LV KE. Degree of LV impairment is associated with TD of peak E-wave KE. In patient with preserved EF post MI, LV blood flow KE mapping demonstrated significant changes in the in-plane KE, the minimal KEiEDV and the TD. These three blood flow KE parameters may offer novel methods to identify and describe this patient population.
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Affiliation(s)
- Pankaj Garg
- Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT UK
| | - Saul Crandon
- Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT UK
| | - Peter P. Swoboda
- Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT UK
| | - Graham J. Fent
- Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT UK
| | - James R. J. Foley
- Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT UK
| | - Pei G. Chew
- Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT UK
| | - Louise A. E. Brown
- Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT UK
| | - Sethumadhavan Vijayan
- Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT UK
| | - Mariëlla E. C. J. Hassell
- Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Robin Nijveldt
- Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Malenka Bissell
- Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT UK
| | - Mohammed S. M. Elbaz
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Jos J. M. Westenberg
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - John P. Greenwood
- Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT UK
| | - Rob J. van der Geest
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Sven Plein
- Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT UK
| | - Erica Dall’Armellina
- Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT UK
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108
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Callaghan FM, Bannon P, Barin E, Celemajer D, Jeremy R, Figtree G, Grieve SM. Age-related changes of shape and flow dynamics in healthy adult aortas: A 4D flow MRI study. J Magn Reson Imaging 2018; 49:90-100. [PMID: 30102443 DOI: 10.1002/jmri.26210] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 05/17/2018] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Abnormal flow dynamics play an early and causative role in pathologic changes of the ascending aorta. PURPOSE To identify: 1) the changes in flow, shape, and size that occur in the ascending aorta with normal human ageing and 2) the influence of these factors on aortic flow dynamics. STUDY TYPE Retrospective. SUBJECTS In all, 247 subjects (age range 19-86 years, mean 49 ± 17.7, 169 males) free of aortic or aortic valve pathology were included in this study. Subjects were stratified by youngest (18-33 years; n = 64), highest (>60 years, n = 67), and the middle two quartiles (34-60 years, n = 116). FIELD STRENGTH/SEQUENCE Subjects underwent a cardiac MRI (3T) exam including 4D-flow MRI of the aorta. ASSESSMENT Aortic curvature, arch shape, ascending aortic angle, ascending aortic diameter, and the stroke volume normalized by the aortic volume (nSV) were measured. Velocity, vorticity, and helicity were quantified across the thoracic aorta. STATISTICAL TESTS Univariate and multivariate regressions were used to quantify continuous relationships between variables. RESULTS Aortic diameter, ascending aortic angle, shape, and curvature all increased across age while nSV decreased (all P < 0.0001). Systolic vorticity in the mid arch decreased by 50% across the age range (P < 0.0001), while peak helicity decreased by 80% (P < 0.0001). Curvature tightly governs optimal flow in the youngest quartile, with an effect size 1.5 to 4 times larger than other parameters in the descending aorta, but had a minimal influence with advancing age. In the upper quartile of age, flow dynamics were almost completely determined by nSV, exerting an effect size on velocity and vorticity >10 times that of diameter and other shape factors. DATA CONCLUSION Aortic shape influences flow dynamics in younger subjects. Flow conditions become increasingly disturbed with advancing age, and in these conditions nSV has a more dominant effect on flow patterns than shape factors. LEVEL OF EVIDENCE 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:90-100.
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Affiliation(s)
- Fraser M Callaghan
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Australia.,Sydney Medical School, University of Sydney, Camperdown, Australia
| | - Paul Bannon
- Sydney Medical School, University of Sydney, Camperdown, Australia.,Department of Cardiothoracic Surgery, Royal Prince Alfred Hospital, Camperdown, Australia.,Baird Institute, Sydney, Australia
| | - Edward Barin
- MQ Health Cardiology, Macquarie University Hospital, Macquarie Park, Australia
| | - David Celemajer
- Sydney Medical School, University of Sydney, Camperdown, Australia.,Department of Cardiology, Royal Prince Alfred Hospital, Camperdown, Australia
| | - Richmond Jeremy
- Sydney Medical School, University of Sydney, Camperdown, Australia.,Department of Cardiology, Royal Prince Alfred Hospital, Camperdown, Australia
| | - Gemma Figtree
- Sydney Medical School, University of Sydney, Camperdown, Australia.,Department of Cardiology, Royal North Shore Hospital, Camperdown, Australia
| | - Stuart M Grieve
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Australia.,Sydney Medical School, University of Sydney, Camperdown, Australia.,Department of Radiology, Royal Prince Alfred Hospital, Camperdown, Australia
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109
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Bouillot P, Brina O, Delattre BMA, Ouared R, Pellaton A, Yilmaz H, Machi P, Lovblad KO, Farhat M, Pereira VM, Vargas MI. Neurovascular stent artifacts in 3D-TOF and 3D-PCMRI: Influence of stent design on flow measurement. Magn Reson Med 2018; 81:560-572. [DOI: 10.1002/mrm.27352] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 03/22/2018] [Accepted: 04/19/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Pierre Bouillot
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
- Laboratory for Hydraulic Machines (LMH); École Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
| | - Olivier Brina
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
- Division of Neuroradiology, Department of Medical Imaging; Toronto Western Hospital, University Health Network; Toronto Ontario Canada
| | | | - Rafik Ouared
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
| | - Alain Pellaton
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
| | - Hasan Yilmaz
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
| | - Paolo Machi
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
| | - Karl-Olof Lovblad
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
| | - Mohamed Farhat
- Laboratory for Hydraulic Machines (LMH); École Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
| | - Vitor Mendes Pereira
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
- Division of Neuroradiology, Department of Medical Imaging; Toronto Western Hospital, University Health Network; Toronto Ontario Canada
- Division of Neurosurgery, Department of Surgery; Toronto Western Hospital, University Health Network; Toronto Ontario Canada
| | - Maria Isabel Vargas
- Departement of Neuroradiology; Geneva University Hospitals; Geneva Switzerland
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Watanabe T, Isoda H, Takehara Y, Terada M, Naito T, Kosugi T, Onishi Y, Tanoi C, Izumi T. Hemodynamic vascular biomarkers for initiation of paraclinoid internal carotid artery aneurysms using patient-specific computational fluid dynamic simulation based on magnetic resonance imaging. Neuroradiology 2018. [PMID: 29520642 DOI: 10.1007/s00234-018-2002-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE We performed computational fluid dynamics (CFD) for patients with and without paraclinoid internal carotid artery (ICA) aneurysms to evaluate the distribution of vascular biomarkers at the aneurysm initiation sites of the paraclinoid ICA. METHODS This study included 35 patients who were followed up for aneurysms using 3D time of flight (TOF) magnetic resonance angiography (MRA) and 3D cine phase-contrast MR imaging. Fifteen affected ICAs were included in group A with the 15 unaffected contralateral ICAs in group B. Thirty-three out of 40 paraclinoid ICAs free of aneurysms and arteriosclerotic lesions were included in group C. We deleted the aneurysms in group A based on the 3D TOF MRA dataset. We performed CFD based on MR data set and obtained wall shear stress (WSS), its derivatives, and streamlines. We qualitatively evaluated their distributions at and near the intracranial aneurysm initiation site among three groups. We also calculated and compared the normalized highest (nh-) WSS and nh-spatial WSS gradient (SWSSG) around the paraclinoid ICA among three groups. RESULTS High WSS and SWSSG distribution were observed at and near the aneurysm initiation site in group A. High WSS and SWSSG were also observed at similar locations in group B and group C. However, nh-WSS and nh-SWSSG were significantly higher in group A than in group C, and nh-SWSSG was significantly higher in group A than in group B. CONCLUSION Our findings indicated that nh-WSS and nh-SWSSG were good biomarkers for aneurysm initiation in the paraclinoid ICA.
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Affiliation(s)
- Tomoya Watanabe
- Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-20, Daikominami 1-chome, Higashi-ku, Nagoya, Aichi, 461-8673, Japan.,Division of Clinical Radiology Service, Kyoto University Hospital, 54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Haruo Isoda
- Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-20, Daikominami 1-chome, Higashi-ku, Nagoya, Aichi, 461-8673, Japan. .,Brain & Mind Research Center, Nagoya University, 1-20, Daikominami 1-chome, Higashi-ku, Nagoya, Aichi, 461-8673, Japan.
| | - Yasuo Takehara
- Department of Fundamental Development for Advanced Low Invasive Diagnostic Imaging, Nagoya University, Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan.,Department of Radiology, Hamamatsu University Hospital, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka, 431-3192, Japan
| | - Masaki Terada
- Department of Diagnostic Radiological Technology, Iwata City Hospital, 512-3 Okubo, Iwata, Shizuoka, 438-8550, Japan
| | - Takehiro Naito
- Department of Neurosurgery, Komaki City Hospital, 1-20 Jobushi, Komaki, Aichi, 485-8520, Japan.,Department of Neurosurgery, Iwata City Hospital, 512-3 Okubo, Iwata, Shizuoka, 438-8550, Japan
| | - Takafumi Kosugi
- Renaissance of Technology Corporation, 1-4-10 Shinmiyakoda Kita-ku, Hamamatsu, Shizuoka, 431-2103, Japan
| | - Yuki Onishi
- Department of Systems and Control Engineering, School of Engineering, Tokyo Institute of Technology, 2-12-1-W8-36, O-okayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Chiharu Tanoi
- Department of Neurosurgery, Iwata City Hospital, 512-3 Okubo, Iwata, Shizuoka, 438-8550, Japan
| | - Takashi Izumi
- Department of Neurosurgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan
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Bastkowski R, Weiss K, Maintz D, Giese D. Self-gated golden-angle spiral 4D flow MRI. Magn Reson Med 2018; 80:904-913. [PMID: 29344990 DOI: 10.1002/mrm.27085] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 12/07/2017] [Accepted: 12/20/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Rene Bastkowski
- Department of Radiology, University Hospital of Cologne, Cologne, Germany
| | - Kilian Weiss
- Department of Radiology, University Hospital of Cologne, Cologne, Germany
- Philips Healthcare Germany, Hamburg, Germany
| | - David Maintz
- Department of Radiology, University Hospital of Cologne, Cologne, Germany
| | - Daniel Giese
- Department of Radiology, University Hospital of Cologne, Cologne, Germany
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112
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Yamasaki Y, Kawanami S, Kamitani T, Sagiyama K, Sakamoto I, Hiasa KI, Yabuuchi H, Nagao M, Honda H. Noninvasive quantification of left-to-right shunt by phase contrast magnetic resonance imaging in secundum atrial septal defect: the effects of breath holding and comparison with invasive oximetry. Int J Cardiovasc Imaging 2018; 34:931-937. [DOI: 10.1007/s10554-018-1297-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 01/04/2018] [Indexed: 11/27/2022]
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113
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Menza M, Föll D, Hennig J, Jung B. Segmental biventricular analysis of myocardial function using high temporal and spatial resolution tissue phase mapping. MAGMA (NEW YORK, N.Y.) 2017; 31:61-73. [PMID: 29143137 DOI: 10.1007/s10334-017-0661-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 10/13/2017] [Accepted: 10/30/2017] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Myocardial dysfunction of the right ventricle (RV) is an important indicator of RV diseases, e.g. RV infarction or pulmonary hypertension. Tissue phase mapping (TPM) has been widely used to determine function of the left ventricle (LV) by analyzing myocardial velocities. The analysis of RV motion is more complicated due to the different geometry and smaller wall thickness. The aim of this work was to adapt and optimize TPM to the demands of the RV. MATERIALS AND METHODS TPM measurements were acquired in 25 healthy volunteers using a velocity-encoded phase-contrast sequence and kt-accelerated parallel imaging in combination with optimized navigator strategy and blood saturation. Post processing was extended by a 10-segment RV model and a detailed biventricular analysis of myocardial velocities was performed. RESULTS High spatio-temporal resolution (1.0 × 1.0 × 6 mm3, 21.3 ms) and the optimized blood saturation enabled good delineation of the RV and its velocities. Global and segmental velocities, as well as time to peak velocities showed significant differences between the LV and RV. Furthermore, complex timing of the RV could be demonstrated by segmental time to peak analysis. CONCLUSION High spatio-temporal resolution TPM enables a detailed biventricular analysis of myocardial motion and might provide a reliable tool for description and detection of diseases affecting left and right ventricular function.
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Affiliation(s)
- Marius Menza
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Straße 60a, 79106, Freiburg, Germany.
| | - Daniela Föll
- Department of Cardiology and Angiology I, Heart Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jürgen Hennig
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Straße 60a, 79106, Freiburg, Germany
| | - Bernd Jung
- Institute of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Bern, Switzerland
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114
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Shen X, Schnell S, Barker AJ, Suwa K, Tashakkor L, Jarvis K, Carr JC, Collins JD, Prabhakaran S, Markl M. Voxel-by-voxel 4D flow MRI-based assessment of regional reverse flow in the aorta. J Magn Reson Imaging 2017; 47:1276-1286. [PMID: 28925047 DOI: 10.1002/jmri.25862] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 09/07/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Complex and reverse flow in the aorta has been implicated in aneurysm development and stroke via retrograde embolization. PURPOSE To evaluate global and regional differences between standard 2D plane-based and volumetric voxel-based quantification of regional forward/reverse flow, and reverse flow fraction (RFF) in the aorta. STUDY TYPE Retrospective. SUBJECTS In all, 35 subjects: 10 healthy controls (age: 57 ± 7 years, nine male), nine patients without aortic valve regurgitation (AR) (age: 63 ± 10 years, seven male), six patients with mild AR (age: 66 ± 6 years, five male), and 10 with moderate or severe AR (age: 60 ± 16 years, eight male). FIELD STRENGTH/SEQUENCE 4D flow MRI (3T and 1.5T) was employed to acquire 3D blood flow velocities with entire thoracic aorta in all subjects. ASSESSMENT Data analysis included standard 2D plane-based quantification of forward/reverse flow, and RFF-plane. In addition, a new semiautomatic workflow based on 3D segmentation and extraction of an aorta centerline was developed for voxel-by-voxel visualization (forward/reverse flow and RFF-voxel maps) and quantification of regional voxel-by-voxel forward/reverse flow in the entire thoracic aorta. STATISTICAL TESTS Kruskal-Wallis tests were performed to test for differences between groups. A two-sample t-test or Wilcoxon rank sum test was used to compare voxel-based and plane-based results. RESULTS Semiautomatic plane-based analysis showed excellent agreement with standard manual plane-based analysis for net flow and RFF-plane (RFF-plane: y = 0.99x-0.0, net flow: y = 1.00x-0.21, R > 0.99, P < 0.0001). Voxel-by-voxel maps demonstrated marked regional flow reversal in the ascending aorta in all patients and RFF-voxel was significantly increased (P < 0.001) compared to RFF-plane for all four groups, with the most pronounced differences for mild AR (18.0 ± 15.2% vs. 4.7 ± 5.4%). Voxel-based flow and RFF-voxel along the aorta showed areas with marked regional flow reversal (eg, vortex flow) compared to plane-based analysis. DATA CONCLUSION Voxel-based analysis demonstrated regional flow reversal that was not detected by plane-based analysis. LEVEL OF EVIDENCE 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:1276-1286.
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Affiliation(s)
- Xin Shen
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, Illinois, USA
| | - Susanne Schnell
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Alex J Barker
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Kenichiro Suwa
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Lingzi Tashakkor
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, Illinois, USA
| | - Kelly Jarvis
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, Illinois, USA
| | - James C Carr
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Jeremy D Collins
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Shyam Prabhakaran
- Department of Neurology, Northwestern University, Chicago, Illinois, USA
| | - Michael Markl
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, Illinois, USA.,Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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Giese D, Weiss K, Baeßler B, Madershahian N, Choi YH, Maintz D, Bunck AC. In vitro evaluation of flow patterns and turbulent kinetic energy in trans-catheter aortic valve prostheses. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2017; 31:165-172. [DOI: 10.1007/s10334-017-0651-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 09/04/2017] [Accepted: 09/05/2017] [Indexed: 11/24/2022]
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116
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Ragunathan S, Pipe JG. Radiofrequency saturation induced bias in aqueductal cerebrospinal fluid flow quantification obtained using two-dimensional cine phase contrast magnetic resonance imaging. Magn Reson Med 2017; 79:2067-2076. [PMID: 28833454 DOI: 10.1002/mrm.26883] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 07/28/2017] [Accepted: 07/31/2017] [Indexed: 12/31/2022]
Abstract
PURPOSE To explore the extent of bias in cerebrospinal fluid flow estimates due to radiofrequency saturation, and its possible impact on the use of two-dimensional cine phase contrast magnetic resonance imaging in the diagnosis and characterization of normal pressure hydrocephalus in patients. THEORY AND METHODS Theoretical signal equations were generated to describe saturation dependence on velocity. An experimental set of phase contrast magnetic resonance imaging scans with two different flip angles was used to show bias in flow estimates in a flow phantom, and in six different healthy volunteers. The cerebral aqueduct was targeted as the flow region of interest. RESULTS Data from a constant flow phantom showed a spatial distribution of voxels with significant bias in flow at the periphery of the flow region. The velocity difference (bias) maps of the cerebral aqueduct correlated with the spatial velocity gradients around peak systole and peak diastole, and high correlation with temporal velocity gradients during transition between systole and diastole. The aqueductal stroke volume for θ = 30° were found to be significantly higher than for θ = 10° using a Wilcoxon signed rank test. CONCLUSION This work shows the extent of bias in cerebrospinal fluid flow quantification due to radiofrequency saturation effects. This clinical relevance of this error was presented with respect to shunt responsiveness among normal pressure hydrocephalus patients. Magn Reson Med 79:2067-2076, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
| | - James G Pipe
- Barrow Neurological Institute, Imaging Research, Phoenix, Arizona, USA
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117
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Frydrychowicz A, Roldan-Alzate A, Winslow E, Consigny D, Campo CA, Motosugi U, Johnson KM, Wieben O, Reeder SB. Comparison of radial 4D Flow-MRI with perivascular ultrasound to quantify blood flow in the abdomen and introduction of a porcine model of pre-hepatic portal hypertension. Eur Radiol 2017; 27:5316-5324. [PMID: 28656461 DOI: 10.1007/s00330-017-4862-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 03/22/2017] [Accepted: 04/20/2017] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Objectives of this study were to compare radial time-resolved phase contrast magnetic resonance imaging (4D Flow-MRI) with perivascular ultrasound (pvUS) and to explore a porcine model of acute pre-hepatic portal hypertension (PHTN). METHODS Abdominal 4D Flow-MRI and pvUS in portal and splenic vein, hepatic and both renal arteries were performed in 13 pigs of approximately 60 kg. In six pigs, measurements were repeated after partial portal vein (PV) ligature. Inter- and intra-reader comparisons and statistical analysis including Bland-Altman (BA) comparison, paired Student's t tests and linear regression were performed. RESULTS PvUS and 4D Flow-MRI measurements agreed well; flow before partial PV ligature was 322 ± 30 ml/min in pvUS and 297 ± 27 ml/min in MRI (p = 0.294), and average BA difference was 25 ml/min [-322; 372]. Inter- and intra-reader results differed very little, revealed excellent correlation (R 2 = 0.98 and 0.99, respectively) and resulted in BA differences of -5 ml/min [-161; 150] and -2 ml/min [-28; 25], respectively. After PV ligature, PV flow decreased from 356 ± 50 to 298 ± 61 ml/min (p = 0.02), and hepatic arterial flow increased from 277 ± 36 to 331 ± 65 ml/min (p = n.s.). CONCLUSION The successful in vivo comparison of radial 4D Flow-MRI to perivascular ultrasound revealed good agreement of abdominal blood flow although with considerable spread of results. A model of pre-hepatic PHTN was successfully introduced and acute responses monitored. KEY POINTS • Radial 4D Flow-MRI in the abdomen was successfully compared to perivascular ultrasound. • Inter- and intra-reader testing demonstrated excellent reproducibility of upper abdominal 4D Flow-MRI. • A porcine model of acute pre-hepatic portal hypertension was successfully introduced. • 4D Flow-MRI successfully monitored acute changes in a model of portal hypertension.
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Affiliation(s)
- A Frydrychowicz
- Department of Radiology, School of Medicine and Public Health, E3/366 Clinical Science Center, University of Wisconsin - Madison, 600 Highland Avenue, Madison, WI, 53792-3252, USA.
- Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.
- University of Lübeck, Lübeck, Germany.
| | - A Roldan-Alzate
- Department of Radiology, School of Medicine and Public Health, E3/366 Clinical Science Center, University of Wisconsin - Madison, 600 Highland Avenue, Madison, WI, 53792-3252, USA
- Department of Mechanical Engineering, University of Wisconsin, Madison, USA
| | - E Winslow
- Department of Surgery, University of Wisconsin, Madison, USA
| | - D Consigny
- Department of Radiology, School of Medicine and Public Health, E3/366 Clinical Science Center, University of Wisconsin - Madison, 600 Highland Avenue, Madison, WI, 53792-3252, USA
| | - C A Campo
- Department of Radiology, School of Medicine and Public Health, E3/366 Clinical Science Center, University of Wisconsin - Madison, 600 Highland Avenue, Madison, WI, 53792-3252, USA
| | - U Motosugi
- Department of Radiology, School of Medicine and Public Health, E3/366 Clinical Science Center, University of Wisconsin - Madison, 600 Highland Avenue, Madison, WI, 53792-3252, USA
| | - K M Johnson
- Department of Medical Physics, University of Wisconsin, Madison, USA
| | - O Wieben
- Department of Radiology, School of Medicine and Public Health, E3/366 Clinical Science Center, University of Wisconsin - Madison, 600 Highland Avenue, Madison, WI, 53792-3252, USA
- Department of Medical Physics, University of Wisconsin, Madison, USA
| | - S B Reeder
- Department of Radiology, School of Medicine and Public Health, E3/366 Clinical Science Center, University of Wisconsin - Madison, 600 Highland Avenue, Madison, WI, 53792-3252, USA
- Department of Medical Physics, University of Wisconsin, Madison, USA
- Department of Biomedical Engineering, University of Wisconsin, Madison, USA
- Department of Medicine, University of Wisconsin, Madison, USA
- Department of Emergency Medicine, University of Wisconsin, Madison, USA
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Binter C, Gotschy A, Sündermann SH, Frank M, Tanner FC, Lüscher TF, Manka R, Kozerke S. Turbulent Kinetic Energy Assessed by Multipoint 4-Dimensional Flow Magnetic Resonance Imaging Provides Additional Information Relative to Echocardiography for the Determination of Aortic Stenosis Severity. Circ Cardiovasc Imaging 2017; 10:CIRCIMAGING.116.005486. [PMID: 28611119 DOI: 10.1161/circimaging.116.005486] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 04/21/2017] [Indexed: 12/25/2022]
Affiliation(s)
- Christian Binter
- From the Institute for Biomedical Engineering, University and ETH Zurich, Switzerland (C.B., A.G., S.K.); Department of Cardiology, University Heart Center (A.G., M.F., F.C.T., T.F.L., R.M.), Division of Internal Medicine (A.G.), and Institute of Diagnostic and Interventional Radiology (R.M.), University Hospital Zurich, Switzerland; Department of Cardiothoracic and Vascular Surgery, Deutsches Herzzentrum Berlin, Germany (S.H.S.); and Imaging Sciences and Biomedical Engineering, King’s College
| | - Alexander Gotschy
- From the Institute for Biomedical Engineering, University and ETH Zurich, Switzerland (C.B., A.G., S.K.); Department of Cardiology, University Heart Center (A.G., M.F., F.C.T., T.F.L., R.M.), Division of Internal Medicine (A.G.), and Institute of Diagnostic and Interventional Radiology (R.M.), University Hospital Zurich, Switzerland; Department of Cardiothoracic and Vascular Surgery, Deutsches Herzzentrum Berlin, Germany (S.H.S.); and Imaging Sciences and Biomedical Engineering, King’s College
| | - Simon H. Sündermann
- From the Institute for Biomedical Engineering, University and ETH Zurich, Switzerland (C.B., A.G., S.K.); Department of Cardiology, University Heart Center (A.G., M.F., F.C.T., T.F.L., R.M.), Division of Internal Medicine (A.G.), and Institute of Diagnostic and Interventional Radiology (R.M.), University Hospital Zurich, Switzerland; Department of Cardiothoracic and Vascular Surgery, Deutsches Herzzentrum Berlin, Germany (S.H.S.); and Imaging Sciences and Biomedical Engineering, King’s College
| | - Michelle Frank
- From the Institute for Biomedical Engineering, University and ETH Zurich, Switzerland (C.B., A.G., S.K.); Department of Cardiology, University Heart Center (A.G., M.F., F.C.T., T.F.L., R.M.), Division of Internal Medicine (A.G.), and Institute of Diagnostic and Interventional Radiology (R.M.), University Hospital Zurich, Switzerland; Department of Cardiothoracic and Vascular Surgery, Deutsches Herzzentrum Berlin, Germany (S.H.S.); and Imaging Sciences and Biomedical Engineering, King’s College
| | - Felix C. Tanner
- From the Institute for Biomedical Engineering, University and ETH Zurich, Switzerland (C.B., A.G., S.K.); Department of Cardiology, University Heart Center (A.G., M.F., F.C.T., T.F.L., R.M.), Division of Internal Medicine (A.G.), and Institute of Diagnostic and Interventional Radiology (R.M.), University Hospital Zurich, Switzerland; Department of Cardiothoracic and Vascular Surgery, Deutsches Herzzentrum Berlin, Germany (S.H.S.); and Imaging Sciences and Biomedical Engineering, King’s College
| | - Thomas F. Lüscher
- From the Institute for Biomedical Engineering, University and ETH Zurich, Switzerland (C.B., A.G., S.K.); Department of Cardiology, University Heart Center (A.G., M.F., F.C.T., T.F.L., R.M.), Division of Internal Medicine (A.G.), and Institute of Diagnostic and Interventional Radiology (R.M.), University Hospital Zurich, Switzerland; Department of Cardiothoracic and Vascular Surgery, Deutsches Herzzentrum Berlin, Germany (S.H.S.); and Imaging Sciences and Biomedical Engineering, King’s College
| | - Robert Manka
- From the Institute for Biomedical Engineering, University and ETH Zurich, Switzerland (C.B., A.G., S.K.); Department of Cardiology, University Heart Center (A.G., M.F., F.C.T., T.F.L., R.M.), Division of Internal Medicine (A.G.), and Institute of Diagnostic and Interventional Radiology (R.M.), University Hospital Zurich, Switzerland; Department of Cardiothoracic and Vascular Surgery, Deutsches Herzzentrum Berlin, Germany (S.H.S.); and Imaging Sciences and Biomedical Engineering, King’s College
| | - Sebastian Kozerke
- From the Institute for Biomedical Engineering, University and ETH Zurich, Switzerland (C.B., A.G., S.K.); Department of Cardiology, University Heart Center (A.G., M.F., F.C.T., T.F.L., R.M.), Division of Internal Medicine (A.G.), and Institute of Diagnostic and Interventional Radiology (R.M.), University Hospital Zurich, Switzerland; Department of Cardiothoracic and Vascular Surgery, Deutsches Herzzentrum Berlin, Germany (S.H.S.); and Imaging Sciences and Biomedical Engineering, King’s College
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119
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Markl M, Lee DC, Furiasse N, Carr M, Foucar C, Ng J, Carr J, Goldberger JJ. Left Atrial and Left Atrial Appendage 4D Blood Flow Dynamics in Atrial Fibrillation. Circ Cardiovasc Imaging 2017; 9:e004984. [PMID: 27613699 DOI: 10.1161/circimaging.116.004984] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 07/21/2016] [Indexed: 11/16/2022]
Abstract
BACKGROUND Atrial 4D flow magnetic resonance imaging was used for the characterization of left atrial (LA) and left atrial appendage (LAA) flow dynamics in patients with atrial fibrillation (AF). METHODS AND RESULTS 4D flow magnetic resonance imaging measured in vivo 3D blood flow velocities in 60 AF patients and 15 controls. Anatomic maps of LA and LAA stasis and velocity were calculated to quantify atrial peak velocity, mean velocity, and stasis (velocities <0.1 m/s). In a substudy with 30 AF patients, 4D flow metrics were compared with Doppler transesophageal echocardiography. For all 15 controls, LAA mean and peak velocities were consistently lower (by 21%/12%; P<0.001) while LAA stasis was higher (by 58%; P<0.001) compared with the LA. In contrast, lower LAA velocity and increased LAA stasis were only found in a fraction (38 of 60) of AF patients. In AF patients, increased CHA2DS2-VASc score was associated with significantly (P<0.043) reduced LA velocities and elevated stasis. There was a heterogeneous expression of atrial flow dynamics, and 25% to 68% of AF patients demonstrated flow in the normal range: 25%/68% for LA/LAA stasis and 38%/60% for LA/LAA peak velocities. Transesophageal echocardiography velocities modestly but significantly (P<0.05) correlated with 4D flow-based LA velocities (r=0.41) and stasis (r=-0.39). CONCLUSIONS AF resulted in overall impaired but individually variable flow dynamics in both the LA and LAA. AF patients demonstrated atrial flow in the normal range, despite elevated CHA2DS2-VASc score.
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Affiliation(s)
- Michael Markl
- From the Department of Radiology, Feinberg School of Medicine (M.M., D.C.L., M.C., J.C.), Department of Biomedical Engineering, McCormick School of Engineering (M.M.), Division of Cardiology, Feinberg School of Medicine (D.C.L., N.F., C.F., J.N., J.J.G.), and Feinberg Cardiovascular Research Institute (D.C.L., J.N., J.J.G.), Northwestern University, Chicago, IL; and Division of Cardiology, Department of Medicine, University of Miami Miller School of Medicine, FL (J.J.G.).
| | - Daniel C Lee
- From the Department of Radiology, Feinberg School of Medicine (M.M., D.C.L., M.C., J.C.), Department of Biomedical Engineering, McCormick School of Engineering (M.M.), Division of Cardiology, Feinberg School of Medicine (D.C.L., N.F., C.F., J.N., J.J.G.), and Feinberg Cardiovascular Research Institute (D.C.L., J.N., J.J.G.), Northwestern University, Chicago, IL; and Division of Cardiology, Department of Medicine, University of Miami Miller School of Medicine, FL (J.J.G.)
| | - Nicholas Furiasse
- From the Department of Radiology, Feinberg School of Medicine (M.M., D.C.L., M.C., J.C.), Department of Biomedical Engineering, McCormick School of Engineering (M.M.), Division of Cardiology, Feinberg School of Medicine (D.C.L., N.F., C.F., J.N., J.J.G.), and Feinberg Cardiovascular Research Institute (D.C.L., J.N., J.J.G.), Northwestern University, Chicago, IL; and Division of Cardiology, Department of Medicine, University of Miami Miller School of Medicine, FL (J.J.G.)
| | - Maria Carr
- From the Department of Radiology, Feinberg School of Medicine (M.M., D.C.L., M.C., J.C.), Department of Biomedical Engineering, McCormick School of Engineering (M.M.), Division of Cardiology, Feinberg School of Medicine (D.C.L., N.F., C.F., J.N., J.J.G.), and Feinberg Cardiovascular Research Institute (D.C.L., J.N., J.J.G.), Northwestern University, Chicago, IL; and Division of Cardiology, Department of Medicine, University of Miami Miller School of Medicine, FL (J.J.G.)
| | - Charles Foucar
- From the Department of Radiology, Feinberg School of Medicine (M.M., D.C.L., M.C., J.C.), Department of Biomedical Engineering, McCormick School of Engineering (M.M.), Division of Cardiology, Feinberg School of Medicine (D.C.L., N.F., C.F., J.N., J.J.G.), and Feinberg Cardiovascular Research Institute (D.C.L., J.N., J.J.G.), Northwestern University, Chicago, IL; and Division of Cardiology, Department of Medicine, University of Miami Miller School of Medicine, FL (J.J.G.)
| | - Jason Ng
- From the Department of Radiology, Feinberg School of Medicine (M.M., D.C.L., M.C., J.C.), Department of Biomedical Engineering, McCormick School of Engineering (M.M.), Division of Cardiology, Feinberg School of Medicine (D.C.L., N.F., C.F., J.N., J.J.G.), and Feinberg Cardiovascular Research Institute (D.C.L., J.N., J.J.G.), Northwestern University, Chicago, IL; and Division of Cardiology, Department of Medicine, University of Miami Miller School of Medicine, FL (J.J.G.)
| | - James Carr
- From the Department of Radiology, Feinberg School of Medicine (M.M., D.C.L., M.C., J.C.), Department of Biomedical Engineering, McCormick School of Engineering (M.M.), Division of Cardiology, Feinberg School of Medicine (D.C.L., N.F., C.F., J.N., J.J.G.), and Feinberg Cardiovascular Research Institute (D.C.L., J.N., J.J.G.), Northwestern University, Chicago, IL; and Division of Cardiology, Department of Medicine, University of Miami Miller School of Medicine, FL (J.J.G.)
| | - Jeffrey J Goldberger
- From the Department of Radiology, Feinberg School of Medicine (M.M., D.C.L., M.C., J.C.), Department of Biomedical Engineering, McCormick School of Engineering (M.M.), Division of Cardiology, Feinberg School of Medicine (D.C.L., N.F., C.F., J.N., J.J.G.), and Feinberg Cardiovascular Research Institute (D.C.L., J.N., J.J.G.), Northwestern University, Chicago, IL; and Division of Cardiology, Department of Medicine, University of Miami Miller School of Medicine, FL (J.J.G.)
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Chan BT, Yeoh HK, Liew YM, Aziz YFA, Sridhar GS, Hamilton-Craig C, Platts D, Lim E. Left ventricular flow propagation velocity measurement: Is it cast in stone? Med Biol Eng Comput 2017; 55:1883-1893. [PMID: 28321684 DOI: 10.1007/s11517-017-1639-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 03/13/2017] [Indexed: 10/19/2022]
Abstract
This study aims to investigate the measurement of left ventricular flow propagation velocity, V p, using phase contrast magnetic resonance imaging and to assess the discrepancies resulting from inflow jet direction and individual left ventricular size. Three V p measuring techniques, namely non-adaptive (NA), adaptive positions (AP) and adaptive vectors (AV) method, were suggested and compared. We performed the comparison on nine healthy volunteers and nine post-infarct patients at four measurement positions, respectively, at one-third, one-half, two-thirds and the conventional 4 cm distances from the mitral valve leaflet into the left ventricle. We found that the V p measurement was affected by both the inflow jet direction and measurement positions. Both NA and AP methods overestimated V p, especially in dilated left ventricles, while the AV method showed the strongest correlation with the isovolumic relaxation myocardial strain rate (r = 0.53, p < 0.05). Using the AV method, notable difference in mean V p was also observed between healthy volunteers and post-infarct patients at positions of: one-half (81 ± 31 vs. 58 ± 25 cm/s), two-thirds (89 ± 32 vs. 45 ± 15 cm/s) and 4 cm (98 ± 23 vs. 47 ± 13 cm/s) distances. The use of AV method and measurement position at one-half distance was found to be the most suitable method for assessing diastolic dysfunction given varying left ventricular sizes and inflow jet directions.
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Affiliation(s)
- Bee Ting Chan
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Hak Koon Yeoh
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia.,Seri Kembangan Engineering Sdn. Bhd., 61-1, Jalan Anggerik Vanilla T, Kota Kemuning, 40460, Shah Alam, Malaysia
| | - Yih Miin Liew
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Yang Faridah Abdul Aziz
- Department of Biomedical Imaging, University Malaya Research Imaging Centre, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | | | - Christian Hamilton-Craig
- Heart and Lung Institute, The Prince Charles Hospital, Chermside, QLD, 4032, Australia.,School of Medicine, University of Queensland, Brisbane, QLD, 4006, Australia
| | - David Platts
- School of Medicine, University of Queensland, Brisbane, QLD, 4006, Australia.,Department of Echocardiography, The Prince Charles Hospital, Chermside, QLD, 4032, Australia
| | - Einly Lim
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia.
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Keller EJ, Collins JD, Rigsby C, Carr JC, Markl M, Schnell S. Superior Abdominal 4D Flow MRI Data Consistency with Adjusted Preprocessing Workflow and Noncontrast Acquisitions. Acad Radiol 2017; 24:350-358. [PMID: 27940231 DOI: 10.1016/j.acra.2016.10.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 10/13/2016] [Accepted: 10/19/2016] [Indexed: 02/07/2023]
Abstract
RATIONALE AND OBJECTIVES To assess the impact of an alternative preprocessing workflow on noncontrast- and contrast-enhanced abdominal four-dimensional flow magnetic resonance imaging (4D flow MRI) data consistency. MATERIALS AND METHODS Twenty patients with cirrhosis and portal hypertension (5 women; 53 ± 10 years old) underwent 4D flow MRI at 3.0T before and after administration of 0.03 mmol/kg of gadofosveset trisodium with velocity sensitivities of 100 and 50 cm/s for arterial and venous flow quantifications, respectively. 4D flow MRI data were preprocessed using the conventional workflow (workflow 1), applying noise filters prior to eddy current correction, and an alternative workflow (workflow 2), first correcting for eddy currents and using noise filtering only if needed for anti-aliasing. Vessel segmentation quality was ranked by independent reviewers and compared via Wilcoxon signed-rank tests. Flow quantification and conservation of mass at two portal and one arterial branch points were compared via paired t tests. RESULTS Segmentation quality was significantly higher for workflow 2 (P < 0.05) with excellent interobserver agreement (κ = 0.92). Workflow 2 resulted in larger flow values (P < 0.05) with improved conservation of mass (7.3 ± 6.1% vs. 27.7 ± 25.0%, P < 0.001 [portal]; 10.7 ± 9.0% vs. 21.7 ± 21.6%, P = 0.02 [arterial]). Peak velocities and abdominal aortic flow were similar (P > 0.05). Noncontrast acquisitions yielded significantly smaller portal flow values (P < 0.05) with improved conservation of mass (5.8 ± 4.7% vs. 8.7 ± 6.9%, P = 0.05 [portal]; 6.2 ± 4.5% vs. 13.7 ± 10.2%, P = 0.03 [arterial]). CONCLUSIONS Superior abdominal 4D flow MRI data consistency was obtained by applying eddy current correction before any other data manipulation, using noise masking and velocity anti-aliasing cautiously, and using noncontrast acquisitions.
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Bouillot P, Delattre BMA, Brina O, Ouared R, Farhat M, Chnafa C, Steinman DA, Lovblad KO, Pereira VM, Vargas MI. 3D phase contrast MRI: Partial volume correction for robust blood flow quantification in small intracranial vessels. Magn Reson Med 2017; 79:129-140. [PMID: 28244132 DOI: 10.1002/mrm.26637] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/19/2017] [Accepted: 01/19/2017] [Indexed: 11/11/2022]
Abstract
PURPOSE Recent advances in 3D-PCMRI (phase contrast MRI) sequences allow for measuring the complex hemodynamics in cerebral arteries. However, the small size of these vessels vs spatial resolution can lead to non-negligible partial volume artifacts, which must be taken into account when computing blood flow rates. For this purpose, we combined the velocity information provided by 3D-PCMRI with vessel geometry measured with 3DTOF (time of flight MRI) or 3DRA (3D rotational angiography) to correct the partial volume effects in flow rate assessments. METHODS The proposed methodology was first tested in vitro on cylindrical and patient specific vessels subject to fully controlled pulsatile flows. Both 2D- and 3D-PCMRI measurements using various spatial resolutions ranging from 20 to 1.3 voxels per vessel diameter were analyzed and compared with flowmeter baseline. Second, 3DTOF, 2D- and 3D-PCMRI measurements were performed in vivo on 35 patients harboring internal carotid artery (ICA) aneurysms indicated for endovascular treatments requiring 3DRA imaging. RESULTS The in vitro 2D- and 3D-PCMRI mean flow rates assessed with partial volume correction showed very low sensitivity to the acquisition resolution above ≈2 voxels per vessel diameter while uncorrected flow rates deviated critically when decreasing the spatial resolution. 3D-PCMRI flow rates measured in vivo in ICA agreed very well with 2D-PCMRI data and a good flow conservation was observed at the C7 bifurcation. Globally, partial volume correction led to 10-15% lower flow rates than uncorrected values as those reported in most of the published studies on intracranial flows. CONCLUSION Partial volume correction may improve the accuracy of PCMRI flow rate measurements especially in small vessels such as intracranial arteries. Magn Reson Med 79:129-140, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Pierre Bouillot
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Laboratory for Hydraulic Machines (LMH), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Bénédicte M A Delattre
- Division of Radiology, Geneva University Hospitals, University of Geneva, Geneva, Switzerland
| | - Olivier Brina
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Rafik Ouared
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Mohamed Farhat
- Laboratory for Hydraulic Machines (LMH), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Christophe Chnafa
- Biomedical Simulation Laboratory, Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Canada
| | - David A Steinman
- Biomedical Simulation Laboratory, Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Canada
| | - Karl-Olof Lovblad
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Vitor M Pereira
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Canada.,Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Maria I Vargas
- Division of Neuroradiology, Geneva University Hospitals & Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Schaffner D, von Elverfeldt D, Deibert P, Lazaro A, Merfort I, Lutz L, Neubauer J, Baumstark MW, Kreisel W, Reichardt W. Phase-contrast MR flow imaging: A tool to determine hepatic hemodynamics in rats with a healthy, fibrotic, or cirrhotic liver. J Magn Reson Imaging 2017; 46:1526-1534. [PMID: 28240794 DOI: 10.1002/jmri.25677] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 02/01/2017] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To test a magnetic resonance (MR) scanning protocol as a noninvasive tool to determine hepatic hemodynamics and to assess the degree of liver fibrosis in an animal model of liver fibrosis and cirrhosis. MATERIALS AND METHODS Fifty-four male Wistar rats were studied. Thirty-nine received thioacetamide (TAA) in their drinking water for either 12 or 16 weeks. MR measurements were performed using flow-sensitive 2D phase-contrast MRI and a 9.4T preclinical scanner. The following hemodynamic parameters were investigated: portal cross-sectional area, mean portal flow velocity, and portal and aortic flow volume rate. Therefore, rats (n = 46) were divided into three groups: CON (control, n = 13), FIB (fibrosis, n = 25), and CIR (cirrhosis, n = 8). Furthermore, the degree of liver fibrosis was assessed by a self-established MR score and verified by a standardized histological score (n = 48). RESULTS Portal and aortic flow parameters could be reliably detected. A significant decrease in portal flow velocity was found in FIB (FIB vs. CON: -21%, P = 0.006 and CIR vs. CON: -17%, P = 0.105) and in portal flow volume rate in FIB and CIR (FIB vs. CON: -20%, P = 0.009 and CIR vs. CON: -25%, P = 0.024). If the histological score is taken as standard, the self-established MR score enabled discrimination between healthy and diseased livers (sensitivity to identify diseased livers: 89% and specificity to identify healthy livers: 100%). CONCLUSION This MR scanning protocol presents a noninvasive tool to determine hepatic hemodynamics in healthy and diseased rats. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1526-1534.
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Affiliation(s)
- Denise Schaffner
- Institute for Exercise- und Occupational Medicine, Medical Center, University of Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Germany.,Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Germany
| | - Dominik von Elverfeldt
- Faculty of Medicine, University of Freiburg, Germany.,Department of Radiology, Medical Physics, Medical Center, University of Freiburg, Germany
| | - Peter Deibert
- Institute for Exercise- und Occupational Medicine, Medical Center, University of Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Germany
| | - Adhara Lazaro
- Institute for Exercise- und Occupational Medicine, Medical Center, University of Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Germany
| | - Irmgard Merfort
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Germany
| | - Lisa Lutz
- Faculty of Medicine, University of Freiburg, Germany.,Institute of Clinical Pathology, Medical Center, University of Freiburg, Germany
| | - Jakob Neubauer
- Faculty of Medicine, University of Freiburg, Germany.,Department of Radiology, Medical Center, University of Freiburg, Germany
| | - Manfred W Baumstark
- Institute for Exercise- und Occupational Medicine, Medical Center, University of Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Germany
| | - Wolfgang Kreisel
- Faculty of Medicine, University of Freiburg, Germany.,Department of Medicine II, Gastroenterology, Hepatology, Endocrinology and Infectious Diseases, Medical Center, University of Freiburg, Germany
| | - Wilfried Reichardt
- Faculty of Medicine, University of Freiburg, Germany.,Department of Radiology, Medical Physics, Medical Center, University of Freiburg, Germany.,German Cancer Consortium (DKTK), Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
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124
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Busch J, Giese D, Kozerke S. Image-based background phase error correction in 4D flow MRI revisited. J Magn Reson Imaging 2017; 46:1516-1525. [PMID: 28225577 DOI: 10.1002/jmri.25668] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 01/26/2017] [Indexed: 11/07/2022] Open
Affiliation(s)
- Julia Busch
- Institute for Biomedical Engineering; University of Zurich and ETH Zurich; Zurich Switzerland
| | - Daniel Giese
- Department of Radiology; University Hospital Cologne; Cologne Germany
| | - Sebastian Kozerke
- Institute for Biomedical Engineering; University of Zurich and ETH Zurich; Zurich Switzerland
- Division of Imaging Science and Biomedical Engineering; King's College London; London UK
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125
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Stevens MC, Callaghan FM, Forrest P, Bannon PG, Grieve SM. Flow mixing during peripheral veno-arterial extra corporeal membrane oxygenation - A simulation study. J Biomech 2017; 55:64-70. [PMID: 28262284 DOI: 10.1016/j.jbiomech.2017.02.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 01/17/2017] [Accepted: 02/11/2017] [Indexed: 11/15/2022]
Abstract
Peripheral veno-arterial extra-corporeal membrane oxygenation (ECMO) is an artificial circulation that supports patients with severe cardiac and respiratory failure. Differential hypoxia during ECMO support has been reported, and it has been suggested that it is due to the mixing of well-perfused retrograde ECMO flow and poorly-perfused antegrade left ventricle (LV) flow in the aorta. This study aims to quantify the relationship between ECMO support level and location of the mixing zone (MZ) of the ECMO and LV flows. Steady-state and transient computational fluid dynamics (CFD) simulations were performed using a patient-specific geometrical model of the aorta. A range of ECMO support levels (from 5% to 95% of total cardiac output) were evaluated. For ECMO support levels above 70%, the MZ was located in the aortic arch, resulting in perfusion of the arch branches with poorly perfused LV flow. The MZ location was stable over the cardiac cycle for high ECMO flows (>70%), but moved 5cm between systole and diastole for ECMO support level of 60%. This CFD approach has potential to improve individual patient care and ECMO design.
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Affiliation(s)
- M C Stevens
- Sydney Medical School, University of Sydney, Sydney, Australia; Graduate School of Biomedical Engineering, University of New South Wales Sydney, Australia; Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Camperdown, Australia.
| | - F M Callaghan
- Sydney Medical School, University of Sydney, Sydney, Australia; Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Camperdown, Australia
| | - P Forrest
- Sydney Medical School, University of Sydney, Sydney, Australia; Department of Anaesthetics, Royal Prince Alfred Hospital, Sydney, Australia
| | - P G Bannon
- Sydney Medical School, University of Sydney, Sydney, Australia; Department of Anaesthetics, Royal Prince Alfred Hospital, Sydney, Australia; Institute of Academic Surgery, Royal Prince Alfred Hospital, Sydney, Australia; The Baird Institute, Sydney, Australia
| | - S M Grieve
- Sydney Medical School, University of Sydney, Sydney, Australia; Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Camperdown, Australia; Department of Radiology, Royal Prince Alfred Hospital, Sydney, Australia
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126
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Sun A, Zhao B, Li Y, He Q, Li R, Yuan C. Real-time phase-contrast flow cardiovascular magnetic resonance with low-rank modeling and parallel imaging. J Cardiovasc Magn Reson 2017; 19:19. [PMID: 28183320 PMCID: PMC5301411 DOI: 10.1186/s12968-017-0330-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 01/19/2017] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Conventional phase-contrast cardiovascular magnetic resonance (PC-CMR) employs cine-based acquisitions to assess blood flow condition, in which electro-cardiogram (ECG) gating and respiration control are generally required. This often results in lower acquisition efficiency, and limited utility in the presence of cardiovascular pathology (e.g., cardiac arrhythmia). Real-time PC-CMR, without ECG gating and respiration control, is a promising alternative that could overcome limitations of the conventional approach. But real-time PC-CMR involves image reconstruction from highly undersampled (k, t)-space data, which is very challenging. In this study, we present a novel model-based imaging method to enable high-resolution real-time PC-CMR with sparse sampling. METHODS The proposed method captures spatiotemporal correlation among flow-compensated and flow-encoded image sequences with a novel low-rank model. The image reconstruction problem is then formulated as a low-rank matrix recovery problem. With proper temporal subspace modeling, it results in a convex optimization formulation. We further integrate this formulation with the SENSE-based parallel imaging model to handle multichannel acquisitions. The performance of the proposed method was systematically evaluated in 2D real-time PC-CMR with flow phantom experiments and in vivo experiments (with healthy subjects). Additionally, we performed a feasibility study of the proposed method on patients with cardiac arrhythmia. RESULTS The proposed method achieves a spatial resolution of 1.8 mm and a temporal resolution of 18 ms for 2D real-time PC-CMR with one directional flow encoding. For the flow phantom experiments, both regular and irregular flow patterns were accurately captured. For the in vivo experiments with healthy subjects, flow dynamics obtained from the proposed method correlated well with those from the cine-based acquisitions. For the experiments with the arrhythmic patients, the proposed method demonstrated excellent capability of resolving the beat-by-beat flow variations, which cannot be obtained from the conventional cine-based method. CONCLUSION The proposed method enables high-resolution real-time PC-CMR at 2D without ECG gating and respiration control. It accurately resolves beat-by-beat flow variations, which holds great promise for studying patients with irregular heartbeats.
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Affiliation(s)
- Aiqi Sun
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Haidian District, Beijing, China
| | - Bo Zhao
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Chalestown, MA, USA
- Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Yunduo Li
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Haidian District, Beijing, China
| | - Qiong He
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Haidian District, Beijing, China
| | - Rui Li
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Haidian District, Beijing, China.
| | - Chun Yuan
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Haidian District, Beijing, China
- Vascular Imaging Lab, Department of Radiology, University of Washington, Seattle, WA, USA
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Schnell S, Ansari SA, Wu C, Garcia J, Murphy IG, Rahman OA, Rahsepar AA, Aristova M, Collins JD, Carr JC, Markl M. Accelerated dual-venc 4D flow MRI for neurovascular applications. J Magn Reson Imaging 2017; 46:102-114. [PMID: 28152256 DOI: 10.1002/jmri.25595] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/28/2016] [Indexed: 12/28/2022] Open
Abstract
PURPOSE To improve velocity-to-noise ratio (VNR) and dynamic velocity range of 4D flow magnetic resonance imaging (MRI) by using dual-velocity encoding (dual-venc) with k-t generalized autocalibrating partially parallel acquisition (GRAPPA) acceleration. MATERIALS AND METHODS A dual-venc 4D flow MRI sequence with k-t GRAPPA acceleration was developed using a shared reference scan followed by three-directional low- and high-venc scans (repetition time / echo time / flip angle = 6.1 msec / 3.4 msec / 15°, temporal/spatial resolution = 43.0 msec/1.2 × 1.2 × 1.2 mm3 ). The high-venc data were used to correct for aliasing in the low-venc data, resulting in a single dataset with the favorable VNR of the low-venc but without velocity aliasing. The sequence was validated with a 3T MRI scanner in phantom experiments and applied in 16 volunteers to investigate its feasibility for assessing intracranial hemodynamics (net flow and peak velocity) at the major intracranial vessels. In addition, image quality and image noise were assessed in the in vivo acquisitions. RESULTS All 4D flow MRI scans were acquired successfully with an acquisition time of 20 ± 4 minutes. The shared reference scan reduced the total acquisition time by 12.5% compared to two separate scans. Phantom experiments showed 51.4% reduced noise for dual-venc compared to high-venc and an excellent agreement of velocities (ρ = 0.8, P < 0.001). The volunteer data showed decreased noise in dual-venc data (54.6% lower) compared to high-venc, and improved image quality, as graded by two observers: fewer artifacts (P < 0.0001), improved vessel conspicuity (P < 0.0001), and reduced noise (P < 0.0001). CONCLUSION Dual-venc 4D flow MRI exhibits the superior VNR of the low-venc acquisition and reliably incorporates low- and high-velocity fields simultaneously. In vitro and in vivo data demonstrate improved flow visualization, image quality, and image noise. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:102-114.
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Affiliation(s)
- Susanne Schnell
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Sameer A Ansari
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.,Department of Neurosurgery, Northwestern University, Chicago, Illinois, USA
| | - Can Wu
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.,Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, Illinois, USA
| | - Julio Garcia
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.,Department of Cardiac Sciences - Stephenson Cardiac Imaging Centre, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Ian G Murphy
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Ozair A Rahman
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Amir A Rahsepar
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Maria Aristova
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Jeremy D Collins
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - James C Carr
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Michael Markl
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.,Department of Neurosurgery, Northwestern University, Chicago, Illinois, USA
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128
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Fukuyama A, Isoda H, Morita K, Mori M, Watanabe T, Ishiguro K, Komori Y, Kosugi T. Influence of Spatial Resolution in Three-dimensional Cine Phase Contrast Magnetic Resonance Imaging on the Accuracy of Hemodynamic Analysis. Magn Reson Med Sci 2017; 16:311-316. [PMID: 28132996 PMCID: PMC5743522 DOI: 10.2463/mrms.mp.2016-0060] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Introduction: We aim to elucidate the effect of spatial resolution of three-dimensional cine phase contrast magnetic resonance (3D cine PC MR) imaging on the accuracy of the blood flow analysis, and examine the optimal setting for spatial resolution using flow phantoms. Materials and Methods: The flow phantom has five types of acrylic pipes that represent human blood vessels (inner diameters: 15, 12, 9, 6, and 3 mm). The pipes were fixed with 1% agarose containing 0.025 mol/L gadolinium contrast agent. A blood-mimicking fluid with human blood property values was circulated through the pipes at a steady flow. Magnetic resonance (MR) images (three-directional phase images with speed information and magnitude images for information of shape) were acquired using the 3-Tesla MR system and receiving coil. Temporal changes in spatially-averaged velocity and maximum velocity were calculated using hemodynamic analysis software. We calculated the error rates of the flow velocities based on the volume flow rates measured with a flowmeter and examined measurement accuracy. Results: When the acrylic pipe was the size of the thoracicoabdominal or cervical artery and the ratio of pixel size for the pipe was set at 30% or lower, spatially-averaged velocity measurements were highly accurate. When the pixel size ratio was set at 10% or lower, maximum velocity could be measured with high accuracy. It was difficult to accurately measure maximum velocity of the 3-mm pipe, which was the size of an intracranial major artery, but the error for spatially-averaged velocity was 20% or less. Conclusions: Flow velocity measurement accuracy of 3D cine PC MR imaging for pipes with inner sizes equivalent to vessels in the cervical and thoracicoabdominal arteries is good. The flow velocity accuracy for the pipe with a 3-mm-diameter that is equivalent to major intracranial arteries is poor for maximum velocity, but it is relatively good for spatially-averaged velocity.
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Affiliation(s)
- Atsushi Fukuyama
- Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine
| | - Haruo Isoda
- Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine.,Brain & Mind Research Center, Nagoya University
| | | | | | | | - Kenta Ishiguro
- Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine
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Rutkowski DR, Reeder SB, Fernandez LA, Roldán-Alzate A. Surgical planning for living donor liver transplant using 4D flow MRI, computational fluid dynamics and in vitro experiments. COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING-IMAGING AND VISUALIZATION 2017; 6:545-555. [PMID: 30094106 DOI: 10.1080/21681163.2017.1278619] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This study used magnetic resonance imaging (MRI), computational fluid dynamics (CFD) modeling, and in vitro experiments to predict patient-specific alterations in hepatic hemodynamics in response to partial hepatectomy in living liver donors. 4D Flow MRI was performed on three donors before and after hepatectomy and models of the portal venous system were created. Virtual surgery was performed to simulate (1) surgical resection and (2) post-surgery vessel dilation. CFD simulations were conducted using in vivo flow data for boundary conditions. CFD results showed good agreement with in vivo data, and in vitro experimental values agreed well with imaging and simulation results. The post-surgery models predicted an increase in all measured hemodynamic parameters, and the dilated virtual surgery model predicted post-surgery conditions better than the model that only simulated resection. The methods used in this study have potential significant value for the surgical planning process for the liver and other vascular territories.
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Affiliation(s)
- David R Rutkowski
- Mechanical Engineering, University of Wisconsin-Madison Madison, WI, United States.,Radiology, University of Wisconsin-Madison Madison, WI, United States
| | - Scott B Reeder
- Radiology, University of Wisconsin-Madison Madison, WI, United States.,Medical Physics, University of Wisconsin-Madison Madison, WI, United States.,Biomedical Engineering, University of Wisconsin-Madison Madison, WI, United States.,Medicine, University of Wisconsin-Madison Madison, WI, United States.,Emergency Medicine, University of Wisconsin-Madison Madison, WI, United States
| | | | - Alejandro Roldán-Alzate
- Mechanical Engineering, University of Wisconsin-Madison Madison, WI, United States.,Radiology, University of Wisconsin-Madison Madison, WI, United States.,Biomedical Engineering, University of Wisconsin-Madison Madison, WI, United States
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Qualitative grading of aortic regurgitation: a pilot study comparing CMR 4D flow and echocardiography. Int J Cardiovasc Imaging 2016; 32:301-307. [PMID: 26498478 PMCID: PMC4737795 DOI: 10.1007/s10554-015-0779-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 09/25/2015] [Indexed: 11/21/2022]
Abstract
Over the past 10 years there has been intense research in the development of volumetric visualization of intracardiac flow by cardiac magnetic resonance (CMR). This volumetric time resolved technique called CMR 4D flow imaging has several advantages over standard CMR. It offers anatomical, functional and flow information in a single free-breathing, ten-minute acquisition. However, the data obtained is large and its processing requires dedicated software. We evaluated a cloud-based application package that combines volumetric data correction and visualization of CMR 4D flow data, and assessed its accuracy for the detection and grading of aortic valve regurgitation using transthoracic echocardiography as reference. Between June 2014 and January 2015, patients planned for clinical CMR were consecutively approached to undergo the supplementary CMR 4D flow acquisition. Fifty four patients (median age 39 years, 32 males) were included. Detection and grading of the aortic valve regurgitation using CMR 4D flow imaging were evaluated against transthoracic echocardiography. The agreement between 4D flow CMR and transthoracic echocardiography for grading of aortic valve regurgitation was good (κ = 0.73). To identify relevant, more than mild aortic valve regurgitation, CMR 4D flow imaging had a sensitivity of 100 % and specificity of 98 %. Aortic regurgitation can be well visualized, in a similar manner as transthoracic echocardiography, when using CMR 4D flow imaging.
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131
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Kamphuis VP, Westenberg JJM, van der Palen RLF, Blom NA, de Roos A, van der Geest R, Elbaz MSM, Roest AAW. Unravelling cardiovascular disease using four dimensional flow cardiovascular magnetic resonance. Int J Cardiovasc Imaging 2016; 33:1069-1081. [PMID: 27888419 PMCID: PMC5489572 DOI: 10.1007/s10554-016-1031-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/21/2016] [Indexed: 11/29/2022]
Abstract
Knowledge of normal and abnormal flow patterns in the human cardiovascular system increases our understanding of normal physiology and may help unravel the complex pathophysiological mechanisms leading to cardiovascular disease. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) has emerged as a suitable technique that enables visualization of in vivo blood flow patterns and quantification of parameters that could potentially be of prognostic value in the disease process. In this review, current image processing tools that are used for comprehensive visualization and quantification of blood flow and energy distribution in the heart and great vessels will be discussed. Also, imaging biomarkers extracted from 4D flow CMR will be reviewed that have been shown to distinguish between normal and abnormal flow patterns. Furthermore, current applications of 4D flow CMR in the heart and great vessels will be discussed, showing its potential as an additional diagnostic modality which could aid in disease management and timing of surgical intervention.
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Affiliation(s)
- Vivian P Kamphuis
- Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.,Netherlands Heart Institute, Utrecht, The Netherlands
| | - Jos J M Westenberg
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
| | - Roel L F van der Palen
- Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Nico A Blom
- Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Albert de Roos
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Rob van der Geest
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Mohammed S M Elbaz
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Arno A W Roest
- Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
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132
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Callaghan FM, Grieve SM. Spatial resolution and velocity field improvement of 4D-flow MRI. Magn Reson Med 2016; 78:1959-1968. [DOI: 10.1002/mrm.26557] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 09/27/2016] [Accepted: 10/28/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Fraser M. Callaghan
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre; University of Sydney; Sydney Australia
- Sydney Medical School; University of Sydney; Camperdown Australia
| | - Stuart M. Grieve
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre; University of Sydney; Sydney Australia
- Sydney Medical School; University of Sydney; Camperdown Australia
- Department of Radiology; Royal Prince Alfred Hospital; Camperdown Australia
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133
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Heidari Pahlavian S, Bunck AC, Thyagaraj S, Giese D, Loth F, Hedderich DM, Kröger JR, Martin BA. Accuracy of 4D Flow Measurement of Cerebrospinal Fluid Dynamics in the Cervical Spine: An In Vitro Verification Against Numerical Simulation. Ann Biomed Eng 2016; 44:3202-3214. [PMID: 27043214 PMCID: PMC5050060 DOI: 10.1007/s10439-016-1602-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 03/29/2016] [Indexed: 11/30/2022]
Abstract
Abnormal alterations in cerebrospinal fluid (CSF) flow are thought to play an important role in pathophysiology of various craniospinal disorders such as hydrocephalus and Chiari malformation. Three directional phase contrast MRI (4D Flow) has been proposed as one method for quantification of the CSF dynamics in healthy and disease states, but prior to further implementation of this technique, its accuracy in measuring CSF velocity magnitude and distribution must be evaluated. In this study, an MR-compatible experimental platform was developed based on an anatomically detailed 3D printed model of the cervical subarachnoid space and subject specific flow boundary conditions. Accuracy of 4D Flow measurements was assessed by comparison of CSF velocities obtained within the in vitro model with the numerically predicted velocities calculated from a spatially averaged computational fluid dynamics (CFD) model based on the same geometry and flow boundary conditions. Good agreement was observed between CFD and 4D Flow in terms of spatial distribution and peak magnitude of through-plane velocities with an average difference of 7.5 and 10.6% for peak systolic and diastolic velocities, respectively. Regression analysis showed lower accuracy of 4D Flow measurement at the timeframes corresponding to low CSF flow rate and poor correlation between CFD and 4D Flow in-plane velocities.
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Affiliation(s)
- Soroush Heidari Pahlavian
- Conquer Chiari Research Center, The University of Akron, Akron, OH, USA
- Department of Mechanical Engineering, The University of Akron, Akron, OH, USA
| | - Alexander C Bunck
- Department of Radiology, University Hospital of Cologne, Cologne, Germany
- Department of Radiology, University Hospital of Muenster, Muenster, Germany
| | - Suraj Thyagaraj
- Conquer Chiari Research Center, The University of Akron, Akron, OH, USA
- Department of Mechanical Engineering, The University of Akron, Akron, OH, USA
| | - Daniel Giese
- Department of Radiology, University Hospital of Cologne, Cologne, Germany
| | - Francis Loth
- Conquer Chiari Research Center, The University of Akron, Akron, OH, USA
- Department of Mechanical Engineering, The University of Akron, Akron, OH, USA
| | - Dennis M Hedderich
- Department of Radiology, University Hospital of Cologne, Cologne, Germany
| | - Jan Robert Kröger
- Department of Radiology, University Hospital of Muenster, Muenster, Germany
| | - Bryn A Martin
- Department of Biological Engineering, The University of Idaho, 875 Perimeter Drive MS 0904, Moscow, ID, 83844-0904, USA.
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134
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Valvano G, Martini N, Huber A, Santelli C, Binter C, Chiappino D, Landini L, Kozerke S. Accelerating 4D flow MRI by exploiting low-rank matrix structure and hadamard sparsity. Magn Reson Med 2016; 78:1330-1341. [PMID: 27787911 DOI: 10.1002/mrm.26508] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 09/23/2016] [Accepted: 09/23/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Giuseppe Valvano
- Department of Information Engineering; University of Pisa; Pisa Italy
- Fondazione G. Monasterio CNR-Regione Toscana; Massa Italy
| | - Nicola Martini
- Fondazione G. Monasterio CNR-Regione Toscana; Massa Italy
| | - Adrian Huber
- Institute for Biomedical Engineering; University and ETH Zurich; Zurich Switzerland
| | - Claudio Santelli
- Institute for Biomedical Engineering; University and ETH Zurich; Zurich Switzerland
| | - Christian Binter
- Institute for Biomedical Engineering; University and ETH Zurich; Zurich Switzerland
| | | | - Luigi Landini
- Department of Information Engineering; University of Pisa; Pisa Italy
- Fondazione G. Monasterio CNR-Regione Toscana; Massa Italy
| | - Sebastian Kozerke
- Institute for Biomedical Engineering; University and ETH Zurich; Zurich Switzerland
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135
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Left Atrial 4-Dimensional Flow Magnetic Resonance Imaging: Stasis and Velocity Mapping in Patients With Atrial Fibrillation. Invest Radiol 2016; 51:147-54. [PMID: 26488375 DOI: 10.1097/rli.0000000000000219] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Left atrial (LA) 4-dimensional flow magnetic resonance imaging (MRI) was used to derive anatomic maps of LA stasis, peak velocity, and time-to-peak (TTP) velocity in patients with atrial fibrillation (AF) and to identify relationships between LA flow with LA volume and patient characteristics. MATERIALS AND METHODS Four-dimensional flow MRI for the in vivo assessment of time-resolved 3-dimensional LA blood flow velocities was performed in 111 subjects: 42 patients with a history of AF and in sinus rhythm (AF-sinus), 39 patients with persistent AF (AF-afib), 10 young healthy volunteers (HVs), and 20 age-appropriate controls (CTRL). Data analysis included the 3-dimensional segmentation of the LA and the calculation of LA stasis, peak velocity, and TTP maps. Regional LA flow dynamics were quantified by calculating mean stasis, peak velocity, and TTP in the LA center region and the region adjacent to the LA wall. RESULTS A sensitivity analysis identified thresholds for global LA stasis (<0.1 m/s) and peak velocity (top 5% LA velocities), which detected significant differences between AF patients and controls for global LA stasis (HV, 25% ± 5%; CTRL, 29% ± 10%; AF-sinus, 41% ± 13%; AF-afib, 52% ± 17%) and peak velocity (HV, 0.43 ± 0.02 m/s; CTRL, 0.37 ± 0.04 m/s; AF-sinus, 0.33 ± 0.05 m/s; AF-afib, 0.30 ± 0.05 m/s). Regional analysis revealed significantly increased stasis at both LA center and wall for AF patients compared with age-appropriate controls (29%-84% difference, P < 0.006) and for AF-afib versus AF-sinus patients (22%-30% difference, P < 0.004). In addition, stasis close to the LA wall was significantly elevated (P < 0.001) compared with the LA center for all subject groups. Multiple regressions revealed significant (RAdj = 0.45-0.50, P < 0.001) relationships between impaired global LA flow (reduced velocity and increased stasis) with age (|β| = 0.27-0.50, P < 0.002) and LA volume (|β| = 0.26-0.50, P < 0.003). CONCLUSIONS Atrial 4-dimensional flow MRI detected changes in global and regional LA flow dynamics associated with AF, age, and LA volume. Longitudinal studies are needed to test the diagnostic value of LA flow metrics as potential risk factors for thromboembolic events.
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136
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Jarvis K, Schnell S, Barker AJ, Garcia J, Lorenz R, Rose M, Chowdhary V, Carr J, Robinson JD, Rigsby CK, Markl M. Evaluation of blood flow distribution asymmetry and vascular geometry in patients with Fontan circulation using 4-D flow MRI. Pediatr Radiol 2016; 46:1507-19. [PMID: 27350377 PMCID: PMC5039076 DOI: 10.1007/s00247-016-3654-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/04/2016] [Accepted: 06/02/2016] [Indexed: 11/26/2022]
Abstract
BACKGROUND Asymmetrical caval to pulmonary blood flow is suspected to cause complications in patients with Fontan circulation. The aim of this study was to test the feasibility of 4-D flow MRI for characterizing the relationship between 3-D blood flow distribution and vascular geometry. OBJECTIVE We hypothesized that both flow distribution and geometry can be calculated with low interobserver variability and will detect a direct relationship between flow distribution and Fontan geometry. MATERIALS AND METHODS Four-dimensional flow MRI was acquired in 10 Fontan patients (age: 16 ± 4 years [mean ± standard deviation], range: 9-21 years). The Fontan connection was isolated by 3-D segmentation to evaluate flow distribution from the inferior vena cava (IVC) and superior vena cava (SVC) to the left and right pulmonary arteries (LPA, RPA) and to characterize geometry (cross-sectional area, caval offset, vessel angle). RESULTS Flow distribution results indicated SVC flow tended toward the RPA while IVC flow was more evenly distributed (SVC to RPA: 78% ± 28 [9-100], IVC to LPA: 54% ± 28 [4-98]). There was a significant relationship between pulmonary artery cross-sectional area and flow distribution (IVC to RPA: R(2)=0.50, P=0.02; SVC to LPA: R(2)=0.81, P=0.0004). Good agreement was found between observers and for flow distribution when compared to net flow values. CONCLUSION Four-dimensional flow MRI was able to detect relationships between flow distribution and vessel geometry. Future studies are warranted to investigate the potential of patient specific hemodynamic analysis to improve diagnostic capability.
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Affiliation(s)
- Kelly Jarvis
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA.
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL, USA.
| | - Susanne Schnell
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
| | - Alex J Barker
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
| | - Julio Garcia
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
| | - Ramona Lorenz
- Department of Radiology, University Medical Center Freiburg, Freiburg, Germany
| | - Michael Rose
- Department of Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Varun Chowdhary
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
| | - James Carr
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
| | - Joshua D Robinson
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
- Division of Cardiology, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Cynthia K Rigsby
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
- Department of Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Michael Markl
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL, USA
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137
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Jarvis K, Vonder M, Barker AJ, Schnell S, Rose M, Carr J, Robinson JD, Markl M, Rigsby CK. Hemodynamic evaluation in patients with transposition of the great arteries after the arterial switch operation: 4D flow and 2D phase contrast cardiovascular magnetic resonance compared with Doppler echocardiography. J Cardiovasc Magn Reson 2016; 18:59. [PMID: 27659876 PMCID: PMC5034650 DOI: 10.1186/s12968-016-0276-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 08/24/2016] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Peak velocity measurements are used to evaluate the significance of stenosis in patients with transposition of the great arteries after the arterial switch operation (TGA after ASO). 4D flow cardiovascular magnetic resonance (CMR) provides 3-directional velocity encoding and full volumetric coverage of the great arteries and may thus improve the hemodynamic evaluation in these patients. The aim of this study was to compare peak velocities measured by 4D flow CMR with 2D phase contrast (PC) CMR and the gold standard Doppler echocardiography (echo) in patients with TGA after ASO. METHODS Nineteen patients (mean age 13 ± 9 years, range 1-25 years) with TGA after ASO who underwent 2D PC CMR and 4D flow CMR were included in this study. Peak velocities were measured with 4D flow CMR in the aorta and pulmonary arteries and compared to peak velocities measured with 2D PC CMR and Doppler echo. 2D PC CMR data were available in the ascending aorta, main, right and left pulmonary arteries (AAO/MPA/RPA/LPA) for 19/18/17/17 scans, respectively, and Doppler echo data were available for 13/9/6/6 scans, respectively. Peak velocities were measured with: 1) a single cross section for 2D PC CMR, 2) velocity maximum intensity projections (MIPs) for 4D flow CMR and 3) Doppler echo. RESULTS Significantly higher peak velocities were found with 4D flow CMR than 2D PC CMR in the AAO (p = 0.003), MPA (p = 0.002) and RPA (p = 0.005) but not in the LPA (p = 0.200). No difference in peak velocity was found between 4D flow CMR and Doppler echo (p > 0.46) or 2D PC CMR and echo (p > 0.11) for all analyzed vessel segments. CONCLUSIONS 4D flow CMR evaluation of patients with TGA after ASO detected higher peak velocities than 2D PC CMR, indicating the potential of 4D flow CMR to provide improved stenosis assessment in these patients.
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Affiliation(s)
- Kelly Jarvis
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 North Michigan Avenue Suite 1600, Chicago, IL 60611 USA
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, USA
| | - Marleen Vonder
- Center for Medical Imaging-North East Netherlands, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Alex J. Barker
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 North Michigan Avenue Suite 1600, Chicago, IL 60611 USA
| | - Susanne Schnell
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 North Michigan Avenue Suite 1600, Chicago, IL 60611 USA
| | - Michael Rose
- Department of Medical Imaging, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, USA
| | - James Carr
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 North Michigan Avenue Suite 1600, Chicago, IL 60611 USA
| | - Joshua D. Robinson
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 North Michigan Avenue Suite 1600, Chicago, IL 60611 USA
- Department of Medical Imaging, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, USA
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, USA
- Division of Cardiology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, USA
| | - Michael Markl
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 North Michigan Avenue Suite 1600, Chicago, IL 60611 USA
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, USA
| | - Cynthia K. Rigsby
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 North Michigan Avenue Suite 1600, Chicago, IL 60611 USA
- Department of Medical Imaging, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, USA
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, USA
- Division of Cardiology, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, USA
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138
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Schnell S, Smith DA, Barker AJ, Entezari P, Honarmand AR, Carr ML, Malaisrie SC, McCarthy PM, Collins J, Carr JC, Markl M. Altered aortic shape in bicuspid aortic valve relatives influences blood flow patterns. Eur Heart J Cardiovasc Imaging 2016; 17:1239-1247. [PMID: 27461208 DOI: 10.1093/ehjci/jew149] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 06/23/2016] [Indexed: 12/25/2022] Open
Abstract
AIMS Bicuspid aortic valve (BAV) is known to exhibit familial inheritance and is associated with aortopathy and altered aortic haemodynamics. However, it remains unclear whether BAV-related aortopathy can be inherited independently of valve morphology. METHODS AND RESULTS Four-dimensional flow magnetic resonance imaging for the in vivo assessment of thoracic aortic 3D blood flow was performed in 24 BAV relatives with trileaflet aortic valves (age = 40 ± 14 years) and 15 healthy controls (age = 37 ± 10 years). Data analysis included aortic dimensions, shape (round/gothic/cubic), and 3D blood flow characteristics (semi-quantitative vortex/helix grading and peak velocities). Cubic and gothic aortic shapes were markedly more prevalent in BAV relatives compared with controls (38 vs. 7%). Ascending aorta (AAo) vortex flow in BAV relatives was significantly increased compared with controls (grading = 1.5 ± 1.0 vs. 0.6 ± 0.9, P = 0.015). Aortic haemodynamics were influenced by aortic shape: peak velocities were reduced for gothic aortas vs. round aortas (P = 0.003); vortex flow was increased for cubic aortas in the AAo (P < 0.001) and aortic arch (P = 0.004); vortex and helix flows were elevated for gothic aortas in the AAo and descending aorta (P = 0.003, P = 0.029). Logistic regression demonstrated significant associations of shape with severity of vortex flow in AAo (P < 0.001) and aortic arch (P = 0.016) in BAV relatives. CONCLUSION BAV relatives expressed altered aortic shape and increased vortex flow despite the absence of valvular disease or aortic dilatation. These data suggest a heritable component of BAV-related aortopathy affecting aortic shape and aberrant blood flow, independent of valve morphology.
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Affiliation(s)
- Susanne Schnell
- Department of Radiology, Northwestern University, 737 N. Michigan Avenue, Suite 1600, Chicago, IL 60611, USA
| | - Danielle A Smith
- Division of Cardiac Surgery, Northwestern University, 201 E. Huron Street, Galter 11-140, Chicago, IL 60611, USA
| | - Alex J Barker
- Department of Radiology, Northwestern University, 737 N. Michigan Avenue, Suite 1600, Chicago, IL 60611, USA
| | - Pegah Entezari
- Department of Radiology, Northwestern University, 737 N. Michigan Avenue, Suite 1600, Chicago, IL 60611, USA
| | - Amir R Honarmand
- Department of Radiology, Northwestern University, 737 N. Michigan Avenue, Suite 1600, Chicago, IL 60611, USA
| | - Maria L Carr
- Department of Radiology, Northwestern University, 737 N. Michigan Avenue, Suite 1600, Chicago, IL 60611, USA
| | - S Chris Malaisrie
- Division of Cardiac Surgery, Northwestern University, 201 E. Huron Street, Galter 11-140, Chicago, IL 60611, USA
| | - Patrick M McCarthy
- Division of Cardiac Surgery, Northwestern University, 201 E. Huron Street, Galter 11-140, Chicago, IL 60611, USA
| | - Jeremy Collins
- Department of Radiology, Northwestern University, 737 N. Michigan Avenue, Suite 1600, Chicago, IL 60611, USA
| | - James C Carr
- Department of Radiology, Northwestern University, 737 N. Michigan Avenue, Suite 1600, Chicago, IL 60611, USA
| | - Michael Markl
- Department of Radiology, Northwestern University, 737 N. Michigan Avenue, Suite 1600, Chicago, IL 60611, USA.,Department Biomedical Engineering, McCormick School of Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
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139
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Bollache E, van Ooij P, Powell A, Carr J, Markl M, Barker AJ. Comparison of 4D flow and 2D velocity-encoded phase contrast MRI sequences for the evaluation of aortic hemodynamics. Int J Cardiovasc Imaging 2016; 32:1529-41. [PMID: 27435230 DOI: 10.1007/s10554-016-0938-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 07/09/2016] [Indexed: 01/08/2023]
Abstract
The purpose of this study was to compare aortic flow and velocity quantification using 4D flow MRI and 2D CINE phase-contrast (PC)-MRI with either one-directional (2D-1dir) or three-directional (2D-3dir) velocity encoding. 15 healthy volunteers (51 ± 19 years) underwent MRI including (1) breath-holding 2D-1dir and (2) free breathing 2D-3dir PC-MRI in planes orthogonal to the ascending (AA) and descending (DA) aorta, as well as (3) free breathing 4D flow MRI with full thoracic aorta coverage. Flow quantification included the co-registration of the 2D PC acquisition planes with 4D flow MRI data, AA and DA segmentation, and calculation of AA and DA peak systolic velocity, peak flow and net flow volume for all sequences. Additionally, the 2D-3dir velocity taking into account the through-plane component only was used to obtain results analogous to a free breathing 2D-1dir acquisition. Good agreement was found between 4D flow and 2D-3dir peak velocity (differences = -3 to 6 %), peak flow (-7 %) and net volume (-14 to -9 %). In contrast, breath-holding 2D-1dir measurements exhibited indices significantly lower than free breathing 2D-3dir and 2D-1dir (differences = -35 to -7 %, p < 0.05). Finally, high correlations (r ≥ 0.97) were obtained for indices estimated with or without eddy current correction, with the lowest correlation observed for net volume. 4D flow and 2D-3dir aortic hemodynamic indices were in concordance. However, differences between respiration state and 2D-1dir and 2D-3dir measurements indicate that reference values should be established according to the PC-MRI sequence, especially for the widely used net flow (e.g. stroke volume in the AA).
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Affiliation(s)
- Emilie Bollache
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N Michigan ave-Suite 1600, Chicago, IL, 60611, USA.
| | - Pim van Ooij
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N Michigan ave-Suite 1600, Chicago, IL, 60611, USA
| | - Alex Powell
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N Michigan ave-Suite 1600, Chicago, IL, 60611, USA
| | - James Carr
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N Michigan ave-Suite 1600, Chicago, IL, 60611, USA
| | - Michael Markl
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N Michigan ave-Suite 1600, Chicago, IL, 60611, USA.,Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL, USA
| | - Alex J Barker
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N Michigan ave-Suite 1600, Chicago, IL, 60611, USA
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140
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Ha H, Kim GB, Kweon J, Lee SJ, Kim YH, Lee DH, Yang DH, Kim N. Hemodynamic Measurement Using Four-Dimensional Phase-Contrast MRI: Quantification of Hemodynamic Parameters and Clinical Applications. Korean J Radiol 2016; 17:445-62. [PMID: 27390537 PMCID: PMC4936168 DOI: 10.3348/kjr.2016.17.4.445] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/22/2016] [Indexed: 11/21/2022] Open
Abstract
Recent improvements have been made to the use of time-resolved, three-dimensional phase-contrast (PC) magnetic resonance imaging (MRI), which is also named four-dimensional (4D) PC-MRI or 4D flow MRI, in the investigation of spatial and temporal variations in hemodynamic features in cardiovascular blood flow. The present article reviews the principle and analytical procedures of 4D PC-MRI. Various fluid dynamic biomarkers for possible clinical usage are also described, including wall shear stress, turbulent kinetic energy, and relative pressure. Lastly, this article provides an overview of the clinical applications of 4D PC-MRI in various cardiovascular regions.
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Affiliation(s)
- Hojin Ha
- POSTECH Biotech Center, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Guk Bae Kim
- Asan Institute of Life Science, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Jihoon Kweon
- Department of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Sang Joon Lee
- POSTECH Biotech Center, Pohang University of Science and Technology, Pohang 37673, Korea.; Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Young-Hak Kim
- Department of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Deok Hee Lee
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Dong Hyun Yang
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Namkug Kim
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea.; Department of Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
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141
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van der Geest RJ, Garg P. Advanced Analysis Techniques for Intra-cardiac Flow Evaluation from 4D Flow MRI. CURRENT RADIOLOGY REPORTS 2016; 4:38. [PMID: 27390626 PMCID: PMC4875115 DOI: 10.1007/s40134-016-0167-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE OF THE REVIEW Time-resolved 3D velocity-encoded MR imaging with velocity encoding in three directions (4D Flow) has emerged as a novel MR acquisition technique providing detailed information on flow in the cardiovascular system. In contrast to other clinically available imaging techniques such as echo-Doppler, 4D Flow MRI provides the 3D Flow velocity field within a volumetric region of interest over the cardiac cycle. This work reviews the most recent advances in the development and application of dedicated image analysis techniques for the assessment of intra-cardiac flow features from 4D Flow MRI. RECENT FINDINGS Novel image analysis techniques have been developed for extraction of relevant intra-cardiac flow features from 4D Flow MRI, which have been successfully applied in various patient cohorts and volunteer studies. Disturbed flow patterns have been linked with valvular abnormalities and ventricular dysfunction. Recent technical advances have resulted in reduced scan times and improvements in image quality, increasing the potential clinical applicability of 4D Flow MRI. SUMMARY 4D Flow MRI provides unique capabilities for 3D visualization and quantification of intra-cardiac blood flow. Contemporary knowledge on 4D Flow MRI shows promise for further exploration of the potential use of the technique in research and clinical applications.
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Affiliation(s)
- Rob J. van der Geest
- />Division of Image Processing, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Pankaj Garg
- />Division of Biomedical Imaging, Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT UK
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Parekh K, Markl M, Rose M, Schnell S, Popescu A, Rigsby CK. 4D flow MR imaging of the portal venous system: a feasibility study in children. Eur Radiol 2016; 27:832-840. [PMID: 27193778 DOI: 10.1007/s00330-016-4396-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 03/28/2016] [Accepted: 05/02/2016] [Indexed: 12/26/2022]
Abstract
OBJECTIVES To determine the feasibility of 4D flow MRI for visualization and quantification of the portal venous haemodynamics in children and young adults. METHODS 4D flow was performed in 28 paediatric patients (median age, 8.5 years; interquartile range, 5.2-16.5), 15 with non-operated native portal system and 13 with surgically created portal shunt. Image quality assessment for 3D flow visualization and flow pattern analyses was performed. Regional 4D flow peak velocity and net flow were compared with 2D-cine phase contrast MRI (2D-PC MR) in the post-surgical patients. RESULTS Mean 3D flow visualization quality score was excellent (mean ± SD, 4.2 ± 0.9) with good inter-rater agreement (κ,0.67). Image quality in children aged >10 years was better than children ≤10 years (p < 0.05). Flow pattern was defined for portal, superior mesenteric, splenic veins and splenic artery in all patients. 4D flow and 2D-PC MR peak velocity and net flow were similar with good correlation (peak velocity: 4D flow 22.2 ± 9.1 cm/s and 2D-PC MR 25.2 ± 11.2 cm/s, p = 0.46; r = 0.92, p < 0.0001; net flow: 4D flow 9.5 ± 7.4 ml/s and 2D-PC MR 10.1 ± 7.3 ml/s, p = 0.65; r = 0.81, p = 0.0007). CONCLUSIONS 4D flow MRI is feasible and holds promise for the comprehensive 3D visualization and quantification of portal venous flow dynamics in children and young adults. KEY POINTS • 4D flow MRI is feasible in children and young adults. • 4D flow MRI has the ability to non-invasively characterize portal haemodynamics. • Image quality of 4D flow MRI is better is older children. • 4D flow MRI can accurately quantify portal flow compared to 2D-cine PC MRI.
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Affiliation(s)
- Keyur Parekh
- Department of Medical Imaging, Ann and Robert H. Lurie Children's Hospital of Chicago, 225 E. Chicago Ave., Chicago, IL, 60611, USA. .,Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
| | - Michael Markl
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.,Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL, USA
| | - Michael Rose
- Department of Medical Imaging, Ann and Robert H. Lurie Children's Hospital of Chicago, 225 E. Chicago Ave., Chicago, IL, 60611, USA.,Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Susanne Schnell
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Andrada Popescu
- Department of Medical Imaging, Ann and Robert H. Lurie Children's Hospital of Chicago, 225 E. Chicago Ave., Chicago, IL, 60611, USA.,Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Cynthia K Rigsby
- Department of Medical Imaging, Ann and Robert H. Lurie Children's Hospital of Chicago, 225 E. Chicago Ave., Chicago, IL, 60611, USA.,Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
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Abstract
OBJECTIVE Comprehensive assessment of abdominal hemodynamics is crucial for many clinical diagnoses but is challenged by a tremendous complexity of anatomy, normal physiology, and a wide variety of pathologic abnormalities. This article introduces 4D flow MRI as a powerful technique for noninvasive assessment of the hemodynamics of abdominal vascular territories. CONCLUSION Four-dimensional flow MRI provides clinicians with a more extensive and straightforward approach to evaluate disorders that affect blood flow in the abdomen. This review presents a series of clinical cases to illustrate the utility of 4D flow MRI in the comprehensive assessment of the abdominal circulation.
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Improved Semiautomated 4D Flow MRI Analysis in the Aorta in Patients With Congenital Aortic Valve Anomalies Versus Tricuspid Aortic Valves. J Comput Assist Tomogr 2016; 40:102-8. [PMID: 26466113 DOI: 10.1097/rct.0000000000000312] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The aim of this study was to systematically investigate a newly developed semiautomated workflow for the analysis of aortic 4-dimensional flow MRI and its ability to detect hemodynamic differences in patients with congenitally altered aortic valve (bicuspid or quadricuspid valves) compared with tricuspid aortic valves. METHODS Four-dimensional flow MRI data were acquired in 20 patients with aortic dilatation (9 tricuspid aortic valves, 11 congenitally altered aortic valves). A semiautomated workflow was evaluated regarding interobserver variability, accuracy of net flow, regurgitant fraction and peak systolic velocity, and the ability to detect differences between cohorts. Results were compared with manual segmentation of vessel contours. RESULTS Despite the significantly reduced analysis time, a good interobserver agreement was found for net flow and peak systolic velocity, and a moderate agreement was found for regurgitation. Significant differences in peak velocities in the descending aorta (P = 0.014) could be detected. CONCLUSIONS Four-dimensional flow MRI-based semiautomated analysis of aortic hemodynamics can be performed with good reproducibility and accuracy.
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Bannas P, Roldán-Alzate A, Johnson KM, Woods MA, Ozkan O, Motosugi U, Wieben O, Reeder SB, Kramer H. Longitudinal Monitoring of Hepatic Blood Flow before and after TIPS by Using 4D-Flow MR Imaging. Radiology 2016; 281:574-582. [PMID: 27171019 DOI: 10.1148/radiol.2016152247] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Purpose To demonstrate the feasibility of four-dimensional (4D)-flow magnetic resonance (MR) imaging for noninvasive longitudinal hemodynamic monitoring of hepatic blood flow before and after transjugular intrahepatic portosystemic shunt (TIPS) placement. Materials and Methods The institutional review board approved this prospective Health Insurance Portability and Accountability Act compliant study with written informed consent. Four-dimensional-flow MR imaging was performed in seven patients with portal hypertension and refractory ascites before and 2 and 12 weeks after TIPS placement by using a time-resolved three-dimensional radial phase-contrast acquisition. Flow and peak velocity measurements were obtained in the superior mesenteric vein (SMV), splenic vein (SV), portal vein (PV), and the TIPS. Flow volumes and peak velocities in each vessel, as well as the ratio of in-stent to PV flow, were compared before and after TIPS placement by using analysis of variance. Results Flow volumes significantly increased in the SMV (0.24 L/min; 95% confidence interval [CI]: 0.07, 0.41), SV (0.31 L/min; 95% CI: 0.07, 0.54), and PV (0.88 L/min; 95% CI: 0.06, 1.70) after TIPS placement (all P < .05), with no significant difference between the first and second post-TIPS placement acquisitions (all P > .11). Ascites resolved in six of seven patients. In those with resolved ascites, the TIPS-to-PV flow ratio was 0.8 ± 0.2 and 0.9 ± 0.2 at the two post-TIPS time points, respectively, while the observed ratios were 4.6 and 4.3 in the patient with refractory ascites at the two post-TIPS time points, respectively. In this patient, 4D-flow MR imaging demonstrated arterio-portal-venous shunting, with draining into the TIPS. Conclusion Four-dimensional-flow MR imaging is feasible for noninvasive longitudinal hemodynamic monitoring of hepatic blood flow before and after TIPS placement. © RSNA, 2016 Online supplemental material is available for this article.
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Affiliation(s)
- Peter Bannas
- From the Departments of Radiology (P.B., A.R.A., M.A.W., O.O., U.M., O.W., S.B.R., H.K.), Medical Physics (K.M.J., O.W., S.B.R.), Biomedical Engineering (S.B.R.), Medicine (S.B.R.), Emergency Medicine (S.B.R.), and Mechanical Engineering (A.R.A.) University of Wisconsin-Madison, Madison, Wis
| | - Alejandro Roldán-Alzate
- From the Departments of Radiology (P.B., A.R.A., M.A.W., O.O., U.M., O.W., S.B.R., H.K.), Medical Physics (K.M.J., O.W., S.B.R.), Biomedical Engineering (S.B.R.), Medicine (S.B.R.), Emergency Medicine (S.B.R.), and Mechanical Engineering (A.R.A.) University of Wisconsin-Madison, Madison, Wis
| | - Kevin M Johnson
- From the Departments of Radiology (P.B., A.R.A., M.A.W., O.O., U.M., O.W., S.B.R., H.K.), Medical Physics (K.M.J., O.W., S.B.R.), Biomedical Engineering (S.B.R.), Medicine (S.B.R.), Emergency Medicine (S.B.R.), and Mechanical Engineering (A.R.A.) University of Wisconsin-Madison, Madison, Wis
| | - Michael A Woods
- From the Departments of Radiology (P.B., A.R.A., M.A.W., O.O., U.M., O.W., S.B.R., H.K.), Medical Physics (K.M.J., O.W., S.B.R.), Biomedical Engineering (S.B.R.), Medicine (S.B.R.), Emergency Medicine (S.B.R.), and Mechanical Engineering (A.R.A.) University of Wisconsin-Madison, Madison, Wis
| | - Orhan Ozkan
- From the Departments of Radiology (P.B., A.R.A., M.A.W., O.O., U.M., O.W., S.B.R., H.K.), Medical Physics (K.M.J., O.W., S.B.R.), Biomedical Engineering (S.B.R.), Medicine (S.B.R.), Emergency Medicine (S.B.R.), and Mechanical Engineering (A.R.A.) University of Wisconsin-Madison, Madison, Wis
| | - Utaroh Motosugi
- From the Departments of Radiology (P.B., A.R.A., M.A.W., O.O., U.M., O.W., S.B.R., H.K.), Medical Physics (K.M.J., O.W., S.B.R.), Biomedical Engineering (S.B.R.), Medicine (S.B.R.), Emergency Medicine (S.B.R.), and Mechanical Engineering (A.R.A.) University of Wisconsin-Madison, Madison, Wis
| | - Oliver Wieben
- From the Departments of Radiology (P.B., A.R.A., M.A.W., O.O., U.M., O.W., S.B.R., H.K.), Medical Physics (K.M.J., O.W., S.B.R.), Biomedical Engineering (S.B.R.), Medicine (S.B.R.), Emergency Medicine (S.B.R.), and Mechanical Engineering (A.R.A.) University of Wisconsin-Madison, Madison, Wis
| | - Scott B Reeder
- From the Departments of Radiology (P.B., A.R.A., M.A.W., O.O., U.M., O.W., S.B.R., H.K.), Medical Physics (K.M.J., O.W., S.B.R.), Biomedical Engineering (S.B.R.), Medicine (S.B.R.), Emergency Medicine (S.B.R.), and Mechanical Engineering (A.R.A.) University of Wisconsin-Madison, Madison, Wis
| | - Harald Kramer
- From the Departments of Radiology (P.B., A.R.A., M.A.W., O.O., U.M., O.W., S.B.R., H.K.), Medical Physics (K.M.J., O.W., S.B.R.), Biomedical Engineering (S.B.R.), Medicine (S.B.R.), Emergency Medicine (S.B.R.), and Mechanical Engineering (A.R.A.) University of Wisconsin-Madison, Madison, Wis
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Paul J, Wundrak S, Hombach V, Rottbauer W, Rasche V. On the influence of respiratory motion in radial tissue phase mapping cardiac MRI. J Magn Reson Imaging 2016; 44:1218-1228. [PMID: 27086896 DOI: 10.1002/jmri.25286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 03/31/2016] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To investigate the impact of respiratory motion on radial tissue phase mapping (TPM) measurements, and to improve image quality and scan efficiency without compromising velocity fidelity by increasing the respiratory acceptance window with and without motion correction. MATERIALS AND METHODS A radial golden angle TPM sequence was measured in 10 healthy volunteers in three short axis slices at 3T. Ungated ( CFREE), self-gated with a single acceptance window ( CREF), motion-corrected averaging using all ( CMCall), or selected ( CMC) data reconstructions were compared by means of various image quality measures and resulting velocities. RESULTS Using all data ( CFREE) resulted in significantly higher perceived signal-to-noise ratio (SNR) (P < 0.001), but significantly reduced sharpness (P < 0.001) and contrast (P = 0.02), when compared to CREF. Coefficient of variation (CV) and perceived sharpness were not significantly different (P > 0.05). With motion-correction, perceived sharpness could be significantly improved ( CMC: P = 0.002; CMCall: P = 0.002) in comparison to CFREE. Velocity peaks of CFREE were significantly reduced compared to CREF (all peaks: P < 0.001; except the longitudinal "E" peak: P = 0.03). The peak velocities in CMC and CMCall were not significantly different from CREF (all peaks: P > 0.08; except longitudinal "E"/"A" peaks: P > 0.01). CONCLUSION Free-breathing reconstruction results in good perceived image sharpness and velocity information with slightly, but significantly, reduced peak velocities. For achieving velocities and image quality comparable to data from a single acceptance window, but higher gating efficiency, selected motion-corrected TPM (CMC) can be applied. J. Magn. Reson. Imaging 2016;44:1218-1228.
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Affiliation(s)
- Jan Paul
- Department of Internal Medicine II, University Hospital of Ulm, Germany.
| | - Stefan Wundrak
- Department of Internal Medicine II, University Hospital of Ulm, Germany
| | - Vinzenz Hombach
- Department of Internal Medicine II, University Hospital of Ulm, Germany
| | | | - Volker Rasche
- Department of Internal Medicine II, University Hospital of Ulm, Germany
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Sun A, Zhao B, Ma K, Zhou Z, He L, Li R, Yuan C. Accelerated phase contrast flow imaging with direct complex difference reconstruction. Magn Reson Med 2016; 77:1036-1048. [PMID: 27016025 DOI: 10.1002/mrm.26184] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 01/31/2016] [Accepted: 02/05/2016] [Indexed: 11/09/2022]
Abstract
PURPOSE To propose and evaluate a new model-based reconstruction method for highly accelerated phase-contrast magnetic resonance imaging (PC-MRI) with sparse sampling. THEORY AND METHODS This work presents a new constrained reconstruction method based on low-rank and sparsity constraints to accelerate PC-MRI. More specifically, we formulate the image reconstruction problem into separate reconstructions of flow-reference image sequence and complex differences. We then utilize the joint partial separability and sparsity constraints to enable high quality reconstruction from highly undersampled (k,t)-space data. We further integrate the proposed method with ESPIRiT based parallel imaging model to effectively handle multichannel acquisition. RESULTS The proposed method was evaluated with in vivo data acquired from both 2D and 3D PC flow imaging experiments, and compared with several state-of-the-art methods. Experimental results demonstrate that the proposed method leads to more accurate velocity reconstruction from highly undersampled (k,t)-space data, and particularly superior capability of capturing the peak velocity of blood flow. In terms of flow visualization, blood flow patterns obtained from the proposed reconstruction also exhibit better agreement with those obtained from the fully sampled reference. CONCLUSION The proposed method achieves improved accuracy over several state-of-the-art methods for velocity reconstruction with highly accelerated (k,t)-space data. Magn Reson Med 77:1036-1048, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Aiqi Sun
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Bo Zhao
- Department of Electrical and Computer Engineering and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Ke Ma
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Zechen Zhou
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Le He
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Rui Li
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Chun Yuan
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China.,Vascular Imaging Lab, Department of Radiology, University of Washington, Seattle, Washington, USA
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Advanced flow MRI: emerging techniques and applications. Clin Radiol 2016; 71:779-95. [PMID: 26944696 DOI: 10.1016/j.crad.2016.01.011] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 12/10/2015] [Accepted: 01/10/2016] [Indexed: 12/12/2022]
Abstract
Magnetic resonance imaging (MRI) techniques provide non-invasive and non-ionising methods for the highly accurate anatomical depiction of the heart and vessels throughout the cardiac cycle. In addition, the intrinsic sensitivity of MRI to motion offers the unique ability to acquire spatially registered blood flow simultaneously with the morphological data, within a single measurement. In clinical routine, flow MRI is typically accomplished using methods that resolve two spatial dimensions in individual planes and encode the time-resolved velocity in one principal direction, typically oriented perpendicular to the two-dimensional (2D) section. This review describes recently developed advanced MRI flow techniques, which allow for more comprehensive evaluation of blood flow characteristics, such as real-time flow imaging, 2D multiple-venc phase contrast MRI, four-dimensional (4D) flow MRI, quantification of complex haemodynamic properties, and highly accelerated flow imaging. Emerging techniques and novel applications are explored. In addition, applications of these new techniques for the improved evaluation of cardiovascular (aorta, pulmonary arteries, congenital heart disease, atrial fibrillation, coronary arteries) as well as cerebrovascular disease (intra-cranial arteries and veins) are presented.
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149
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Phase Error Correction in Time-Averaged 3D Phase Contrast Magnetic Resonance Imaging of the Cerebral Vasculature. PLoS One 2016; 11:e0149930. [PMID: 26910600 PMCID: PMC4765993 DOI: 10.1371/journal.pone.0149930] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 02/05/2016] [Indexed: 11/19/2022] Open
Abstract
Purpose Volume flow rate (VFR) measurements based on phase contrast (PC)-magnetic resonance (MR) imaging datasets have spatially varying bias due to eddy current induced phase errors. The purpose of this study was to assess the impact of phase errors in time averaged PC-MR imaging of the cerebral vasculature and explore the effects of three common correction schemes (local bias correction (LBC), local polynomial correction (LPC), and whole brain polynomial correction (WBPC)). Methods Measurements of the eddy current induced phase error from a static phantom were first obtained. In thirty healthy human subjects, the methods were then assessed in background tissue to determine if local phase offsets could be removed. Finally, the techniques were used to correct VFR measurements in cerebral vessels and compared statistically. Results In the phantom, phase error was measured to be <2.1 ml/s per pixel and the bias was reduced with the correction schemes. In background tissue, the bias was significantly reduced, by 65.6% (LBC), 58.4% (LPC) and 47.7% (WBPC) (p < 0.001 across all schemes). Correction did not lead to significantly different VFR measurements in the vessels (p = 0.997). In the vessel measurements, the three correction schemes led to flow measurement differences of -0.04 ± 0.05 ml/s, 0.09 ± 0.16 ml/s, and -0.02 ± 0.06 ml/s. Although there was an improvement in background measurements with correction, there was no statistical difference between the three correction schemes (p = 0.242 in background and p = 0.738 in vessels). Conclusions While eddy current induced phase errors can vary between hardware and sequence configurations, our results showed that the impact is small in a typical brain PC-MR protocol and does not have a significant effect on VFR measurements in cerebral vessels.
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Wang HH, Chiu HH, Tseng WYI, Peng HH. Does altered aortic flow in marfan syndrome relate to aortic root dilatation? J Magn Reson Imaging 2016; 44:500-8. [PMID: 26854646 PMCID: PMC5132207 DOI: 10.1002/jmri.25174] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 01/19/2016] [Indexed: 01/24/2023] Open
Abstract
Purpose To examine possible hemodynamic alterations in adolescent to adult Marfan syndrome (MFS) patients with aortic root dilatation. Materials and Methods Four‐dimensional flow MRI was performed in 20 MFS patients and 12 age‐matched normal subjects with a 3T system. The cross‐sectional areas of 10 planes along the aorta were segmented for calculating the axial and circumferential wall shear stress (WSSaxial, WSScirc), oscillatory shear index (OSIaxial, OSIcirc), and the nonroundness (NR), presenting the asymmetry of segmental WSS. Pearson's correlation analysis was performed to present the correlations between the quantified indices and the body surface area (BSA), aortic root diameter (ARD), and Z score of the ARD. P < 0.05 indicated statistical significance. Results Patients exhibited lower WSSaxial in the aortic root and the WSScirc in the arch (P < 0.05–0.001). MFS patients exhibited higher OSIaxial and OSIcirc in the sinotubular junction and arch, but lower OSIcirc in the descending aorta (all P < 0.05). The NR values were lower in patients (P < 0.05). The WSSaxial or WSScirc exhibited moderate to strong correlations with BSA, ARD, or Z score (R2 = 0.50–0.72) in MFS patients. Conclusion The significant differences in the quantified indices, which were associated with BSA, ARD, or Z score, in MFS were opposite to previous reports for younger MFS patients, indicating that altered flows in MFS patients may depend on the disease progress. The possible time dependency of hemodynamic alterations in MFS patients strongly suggests that longitudinal follow‐up of 4D Flow is needed to comprehend disease progress. J. Magn. Reson. Imaging 2016;44:500–508.
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Affiliation(s)
- Hung-Hsuan Wang
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Hsin-Hui Chiu
- Department of Pediatrics, Taipei Medical University Hospital and School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Wen-Yih Isaac Tseng
- Institute of Medical Device and Imaging, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Hsu-Hsia Peng
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
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