title: 4D flow cardiovascular magnetic resonance consensus statement.
abstract: Pulsatile blood flow through the cavities of the heart and great vessels is time-varying and multidirectional. Access to all regions, phases and directions of cardiovascular flows has formerly been limited. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) has enabled more comprehensive access to such flows, with typical spatial resolution of 1.5×1.5×1.5 - 3×3×3 mm(3), typical temporal resolution of 30-40 ms, and acquisition times in the order of 5 to 25 min. This consensus paper is the work of physicists, physicians and biomedical engineers, active in the development and implementation of 4D Flow CMR, who have repeatedly met to share experience and ideas. The paper aims to assist understanding of acquisition and analysis methods, and their potential clinical applications with a focus on the heart and greater vessels. We describe that 4D Flow CMR can be clinically advantageous because placement of a single acquisition volume is straightforward and enables flow through any plane across it to be calculated retrospectively and with good accuracy. We also specify research and development goals that have yet to be satisfactorily achieved. Derived flow parameters, generally needing further development or validation for clinical use, include measurements of wall shear stress, pressure difference, turbulent kinetic energy, and intracardiac flow components. The dependence of measurement accuracy on acquisition parameters is considered, as are the uses of different visualization strategies for appropriate representation of time-varying multidirectional flow fields. Finally, we offer suggestions for more consistent, user-friendly implementation of 4D Flow CMR acquisition and data handling with a view to multicenter studies and more widespread adoption of the approach in routine clinical investigations.
authors.affiliation: Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. petter.dyverfeldt@liu.se.|Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden. petter.dyverfeldt@liu.se.
authors.forename: Petter
authors.initials: P
authors.lastname: Dyverfeldt
authors.affiliation: Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research, Oxford, UK. malenka.bissell@cardiov.ox.ac.uk.
authors.forename: Malenka
authors.initials: M
authors.lastname: Bissell
authors.affiliation: Department of Radiology, Northwestern University, Chicago, USA. alex.barker@northwestern.edu.
authors.forename: Alex J
authors.initials: AJ
authors.lastname: Barker
authors.affiliation: Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. abolger@medsfgh.ucsf.edu.|Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden. abolger@medsfgh.ucsf.edu.|Department of Medicine, University of California San Francisco, San Francisco, CA, United States. abolger@medsfgh.ucsf.edu.
authors.forename: Ann F
authors.initials: AF
authors.lastname: Bolger
authors.affiliation: Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. carljohan.carlhall@liu.se.|Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden. carljohan.carlhall@liu.se.|Department of Clinical Physiology, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. carljohan.carlhall@liu.se.
authors.forename: Carl-Johan
authors.initials: CJ
authors.lastname: Carlhäll
authors.affiliation: Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. tino.ebbers@liu.se.|Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden. tino.ebbers@liu.se.
authors.forename: Tino
authors.initials: T
authors.lastname: Ebbers
authors.affiliation: Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA. cfrancois@uwhealth.org.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Francios
authors.affiliation: Klinik für Radiologie und Nuklearmedizin, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany. alex.frydrychowicz@uksh.de.
authors.forename: Alex
authors.initials: A
authors.lastname: Frydrychowicz
authors.affiliation: Department of Radiology, University Children's Hospital Zurich, Zurich, Switzerland. julia.geiger@kispi.uzh.ch.
authors.forename: Julia
authors.initials: J
authors.lastname: Geiger
authors.affiliation: Department of Radiology, University Hospital of Cologne, Cologne, Germany. daniel.giese@uk-koeln.de.
authors.forename: Daniel
authors.initials: D
authors.lastname: Giese
authors.affiliation: Department of Radiology, University of California San Francisco, San Francisco, CA, United States. mdhope@stanfordalumni.org.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Hope
authors.affiliation: NIHR Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, National Heart and Lung Institute, Imperial College, London, UK. p.kilner@rbht.nhs.uk.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Kilner
authors.affiliation: Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland. kozerke@biomed.ee.ethz.ch.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kozerke
authors.affiliation: Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research, Oxford, UK. saul.myerson@cardiov.ox.ac.uk.
authors.forename: Saul
authors.initials: S
authors.lastname: Myerson
authors.affiliation: Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research, Oxford, UK. stefan.neubauer@cardiov.ox.ac.uk.
authors.forename: Stefan
authors.initials: S
authors.lastname: Neubauer
authors.affiliation: Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA. owieben@wisc.edu.|Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA. owieben@wisc.edu.
authors.forename: Oliver
authors.initials: O
authors.lastname: Wieben
authors.affiliation: Department of Radiology, Northwestern University, Chicago, USA. mmarkl@northwestern.edu.|Department of Biomedical Engineering, Northwestern University, Chicago, IL, USA. mmarkl@northwestern.edu.
authors.forename: Michael
authors.initials: M
authors.lastname: Markl
mesh_terms: D001011:Aorta / Q000503:physiopathology; D001783:Blood Flow Velocity; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D002319:Cardiovascular System / Q000473:pathology / Q000503:physiopathology*; D032921:Consensus; D003326:Coronary Circulation; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods / Q000592:standards*; D018810:Magnetic Resonance Angiography / Q000379:methods / Q000592:standards*; D055414:Myocardial Perfusion Imaging / Q000379:methods / Q000592:standards*; D011237:Predictive Value of Tests; D011673:Pulsatile Flow; D013997:Time Factors