title: Real-time phase contrast magnetic resonance imaging for assessment of haemodynamics: from phantom to patients.
abstract: OBJECTIVE
  Assessment of haemodynamics is crucial in many cardiac diseases. Phase contrast MRI (PC-MRI) can accurately access it. Arrhythmia is a major limitation in conventional segmented PC-MRI (SEG). A real-time PC-MRI sequence (RT) could overcome this. We validated RT by comparing to SEG.
  
  
  METHODS
  A prototype RT using shared velocity encoding was tested against SEG at 1.5 T in a flow phantom and consecutively included patients with (n = 55) or without (n = 59) aortic valve disease. In patients with atrial fibrillation (Afib, n = 15), only RT was applied. Phantom: PC images were acquired in front of and behind an interchangeable aortic-stenosis-like inlay. Mean velocity and flow were quantified.
  
  
  METHODS
  PC images were acquired in the ascending aorta, pulmonary trunk and superior caval vein. Peak velocity, stroke volume and regurgitant fraction were quantified.
  
  
  RESULTS
  Phantom: Mean velocities (11 ± 1 to 207 ± 10 cm/s) and flow correlated closely between SEG and RT (r ≥ 0.99, ICC ≥ 0.98, p < 0.0005). Patients without AVD or with aortic regurgitation: Concordance of SEG and RT was excellent regarding peak velocities, stroke volumes (r ≥ 0.91, ICC ≥ 0.94, p < 0.0005) and regurgitant fractions (r = 0.95, ICC = 0.95, p < 0.0005). RT was feasible in all patients with Afib.
  
  
  CONCLUSIONS
  The real-time sequence is accurate compared to conventional segmented PC-MRI. Its applicability in Afib was shown. Real-time PC-MRI might become a valuable tool in arrhythmia.
  
  
  CONCLUSIONS
  • Assessment of haemodynamics is crucial in many cardiac diseases. • Arrhythmias are a major limitation of conventional techniques in cardiac magnetic resonance. • A real-time technique, which allows application in arrhythmia, was validated. • This real-time technique might become a valuable tool in arrhythmic patients.
authors.affiliation: Department of Cardiology and Nephrology, Working Group on Cardiovascular Magnetic Resonance Imaging, Experimental and Clinical Research Center, Max-Delbrück-Centrum and Charité -Medical University Berlin and HELIOS Klinikum Berlin-Buch, Schwanebecker Chaussee 50, 13125, Berlin, Germany. julius.traber@charite.de.
authors.forename: Julius
authors.identifier: http://orcid.org/0000-0003-3501-3568
authors.initials: J
authors.lastname: Traber
authors.affiliation: Department of Cardiology and Nephrology, Working Group on Cardiovascular Magnetic Resonance Imaging, Experimental and Clinical Research Center, Max-Delbrück-Centrum and Charité -Medical University Berlin and HELIOS Klinikum Berlin-Buch, Schwanebecker Chaussee 50, 13125, Berlin, Germany. lennart.wurche@charite.de.
authors.forename: Lennart
authors.initials: L
authors.lastname: Wurche
authors.affiliation: Department of Cardiology and Nephrology, Working Group on Cardiovascular Magnetic Resonance Imaging, Experimental and Clinical Research Center, Max-Delbrück-Centrum and Charité -Medical University Berlin and HELIOS Klinikum Berlin-Buch, Schwanebecker Chaussee 50, 13125, Berlin, Germany. matthias.dieringer@charite.de.
authors.forename: Matthias A
authors.initials: MA
authors.lastname: Dieringer
authors.affiliation: Department of Cardiology and Nephrology, Working Group on Cardiovascular Magnetic Resonance Imaging, Experimental and Clinical Research Center, Max-Delbrück-Centrum and Charité -Medical University Berlin and HELIOS Klinikum Berlin-Buch, Schwanebecker Chaussee 50, 13125, Berlin, Germany. wolfgang.utz@charite.de.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Utz
authors.affiliation: Department of Cardiology and Nephrology, Working Group on Cardiovascular Magnetic Resonance Imaging, Experimental and Clinical Research Center, Max-Delbrück-Centrum and Charité -Medical University Berlin and HELIOS Klinikum Berlin-Buch, Schwanebecker Chaussee 50, 13125, Berlin, Germany. Florian.Von-Knobelsdorff@charite.de.
authors.forename: Florian
authors.initials: F
authors.lastname: von Knobelsdorff-Brenkenhoff
authors.affiliation: Siemens AG Healthcare Sector, Erlangen, Germany. andreas.greiser@siemens.com.
authors.forename: Andreas
authors.initials: A
authors.lastname: Greiser
authors.affiliation: Siemens Medical Solutions USA, Inc., Columbus, OH, USA. ning.jin@siemens.com.
authors.forename: Ning
authors.initials: N
authors.lastname: Jin
authors.affiliation: Department of Cardiology and Nephrology, Working Group on Cardiovascular Magnetic Resonance Imaging, Experimental and Clinical Research Center, Max-Delbrück-Centrum and Charité -Medical University Berlin and HELIOS Klinikum Berlin-Buch, Schwanebecker Chaussee 50, 13125, Berlin, Germany. jeanette.schulz-menger@charite.de.
authors.forename: Jeanette
authors.initials: J
authors.lastname: Schulz-Menger
mesh_terms: D000368:Aged; D001011:Aorta / Q000502:physiology; D001021:Aortic Valve / Q000503:physiopathology; D001022:Aortic Valve Insufficiency / Q000503:physiopathology; D001024:Aortic Valve Stenosis / Q000503:physiopathology; D001281:Atrial Fibrillation / Q000503:physiopathology*; D000082882:Bicuspid Aortic Valve Disease; D001783:Blood Flow Velocity / Q000502:physiology; D005260:Female; D006330:Heart Defects, Congenital / Q000503:physiopathology; D006349:Heart Valve Diseases / Q000503:physiopathology; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000295:instrumentation / Q000379:methods; D008297:Male; D008858:Microscopy, Phase-Contrast / Q000295:instrumentation / Q000379:methods; D008875:Middle Aged; D019047:Phantoms, Imaging; D011651:Pulmonary Artery / Q000502:physiology; D013318:Stroke Volume / Q000502:physiology
keywords: Aortic valve insufficiency; Atrial fibrillation; Blood flow velocity; Magnetic resonance imaging; Phantoms, Imaging