title: A study to determine the contribution to right ventricle stroke volume from pulmonary and tricuspid valve displacement volumes.
abstract: BACKGROUND
  Describing the systolic function of the right ventricle (RV) is a difficult task due to the complex shape and orientation of the RV. The purpose of this study was to investigate the extent to which the volumes encompassed by the pulmonary and tricuspid valve displacements contribute to the total right ventricle stroke volume (RVSV).
  
  
  METHODS
  Twelve healthy volunteers were examined using cardiac magnetic resonance (CMR). Two series of time-resolved axially rotated MR images were acquired that encompassed the tricuspid valve and the pulmonary valve, respectively. The volume related to each valve movement, the tricuspid plane displacement (TPD) and the pulmonary plane displacement (PPD), was determined by delineation in diastole and systole. These volumes, RVSV(TPD) and RVSV(PPD) , were compared to the stroke volume to determine the contributions to the total stroke volume from the TPD and the PPD. The remaining volume of the total RVSV was referred to as RVSV(Other) . An initial in vitro study was carried out to validate the accuracy of volume measurements using axially rotated images.
  
  
  RESULTS
  In vitro measurements indicated that the method for volumetric measurements using axially rotated images was a very accurate one, with a mean difference of 0·04 ± 0·10 ml. The in vivo measurements of RVSV(TPD) , RVSV(PPD) and RVSVOther were 45 ± 10%, 13 ± 2% and 42 ± 11%, respectively.
  
  
  CONCLUSIONS
  Right ventricle stroke volume is determined by different individual volume changes as follows: RVSV(TPD) together with RVSVOther contributes to almost the entire RVSV in nearly equal proportions, while RVSV(PPD) contributes only a small amount and is approximately 30% of either RVSV(TPD) or RVSV(Other) .
authors.affiliation: School of Health and Medical Sciences, Örebro University, Örebro, Sweden.
authors.forename: Stina
authors.initials: S
authors.lastname: Jorstig
authors.affiliation: School of Health and Medical Sciences, Örebro University, Örebro, Sweden.|Department of Clinical Physiology, Örebro University Hospital, Örebro, Sweden.
authors.forename: Kent
authors.initials: K
authors.lastname: Emilsson
authors.affiliation: School of Health and Medical Sciences, Örebro University, Örebro, Sweden.|Department of Radiology, Örebro University Hospital, Örebro, Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Lidén
authors.affiliation: School of Health and Medical Sciences, Örebro University, Örebro, Sweden.|Department of Medical Physics, Örebro University Hospital, Örebro, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Thunberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003198:Computer Simulation; D005260:Female; D006352:Heart Ventricles / Q000033:anatomy & histology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D009929:Organ Size / Q000502:physiology; D011664:Pulmonary Valve / Q000033:anatomy & histology / Q000502:physiology*; D013318:Stroke Volume / Q000502:physiology*; D014261:Tricuspid Valve / Q000033:anatomy & histology / Q000502:physiology*; D016278:Ventricular Function, Right / Q000502:physiology*; D055815:Young Adult
keywords: magnetic resonance imaging; pulmonary valve; right ventricle; stroke volume; tricuspid valve