title: MRI Measurement of the hemodynamics of the pulmonary and systemic arterial circulation: influence of breathing maneuvers.
abstract: OBJECTIVE
  The purpose of this study was to use phase-contrast MRI to evaluate the influence of various breathing maneuvers on the hemodynamics of the pulmonary and systemic arterial circulation.
  
  
  METHODS
  Twenty-five volunteers were examined with phase-contrast MRI. Flow measurements were acquired in the aorta, pulmonary trunk, and left and right pulmonary arteries during deep, large-volume inspiratory breath-hold, expiratory breath-hold, and smooth respiration (no breath-hold). Parameters assessed were peak velocity, blood flow, velocity gradient, and acceleration time.
  
  
  RESULTS
  Pulmonary blood flow and peak velocity were significantly reduced during inspiratory breath-hold and expiratory breath-hold compared with no breath-hold (p < 0.01). Pulmonary velocity gradient in inspiratory breath-hold was significantly (p </= 0.01) lower than in expiratory breath-hold and no breath-hold. There was no difference in velocity gradient between expiratory breath-hold and no breath-hold. Peak velocity in the aorta was lowest with no breath-hold. Velocity gradient was highest in expiratory breath-hold, and no breath-hold had the smallest SD. Acceleration time in the pulmonary trunk showed no difference between inspiratory breath-hold, expiratory breath-hold, and no breath-hold. Blood flow distribution to the left (45-47%) and to the right (53-55%) lung was not influenced by breathing maneuver.
  
  
  CONCLUSIONS
  Measurements during smooth respiration showed the smallest SD. Therefore, no-breath-hold measurements should be considered for assessment of hemodynamics in clinical practice.
authors.affiliation: Department of Radiology (E010), German Cancer Research Center, (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. ley@gmx.de
authors.forename: Sebastian
authors.initials: S
authors.lastname: Ley
authors.forename: Christian
authors.initials: C
authors.lastname: Fink
authors.forename: Michael
authors.initials: M
authors.lastname: Puderbach
authors.forename: Julia
authors.initials: J
authors.lastname: Zaporozhan
authors.forename: Christian
authors.initials: C
authors.lastname: Plathow
authors.forename: Monika
authors.initials: M
authors.lastname: Eichinger
authors.forename: Waldemar
authors.initials: W
authors.lastname: Hosch
authors.forename: Karl-Friedrich
authors.initials: KF
authors.lastname: Kreitner
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
mesh_terms: D000328:Adult; D001775:Blood Circulation / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011652:Pulmonary Circulation / Q000502:physiology*; D012119:Respiration