title: Comparison of right ventricular volume measurements between axial and short axis orientation using steady-state free precession magnetic resonance imaging.
abstract: OBJECTIVE
  To compare right ventricular (RV) volume measurements and their reproducibility between axial and short axis orientation acquisition techniques.
  
  
  METHODS
  Measurements of RV volumes from data sets acquired in axial and short axis orientations were compared in 20 normal subjects. The observer variabilities were assessed and the left ventricle (LV) and RV stroke volumes (SV) were compared.
  
  
  RESULTS
  There was a significant and systematic difference in the EDV and ESV volumes between the axial and short axis methods. The latter method resulted in larger volumes (mean bias EDV 7.5 +/- 13.2, 4.7% difference; ESV 7.2 +/- 8.6, 10.7% difference). The axial method had lower intra- and interobserver variability than the short axis method. The standard deviation of the difference (SDD) and the limits of agreement were consistently lower for the axial method. The mean differences between LV and RV stroke volumes expressed as mean +/- 1 SD (r(2) =correlation coefficient) were: axial 7.6 +/- 9.1 (r(2) = 0.93); and short axis 7.4 +/- 10.8 (r(2) = 0.90).
  
  
  CONCLUSIONS
  There is a significant systematic difference between volumes measured using the two different orientations. The axial orientation resulted in better inter- and intraobserver reproducibility.
authors.affiliation: BHF Cardiac MRI Unit, Leeds General Infirmary, UK. Khaled.Alfakih@leedsth.nhs.uk
authors.forename: Khaled
authors.initials: K
authors.lastname: Alfakih
authors.forename: Sven
authors.initials: S
authors.lastname: Plein
authors.forename: Tim
authors.initials: T
authors.lastname: Bloomer
authors.forename: Tim
authors.initials: T
authors.lastname: Jones
authors.forename: John
authors.initials: J
authors.lastname: Ridgway
authors.forename: Mohan
authors.initials: M
authors.lastname: Sivananthan
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D013318:Stroke Volume / Q000502:physiology*; D016278:Ventricular Function, Right / Q000502:physiology*