Comparison of right ventricular volume measurements between axial and short axis orientation using steady-state free precession magnetic resonance imaging

Purpose: To compare right ventricular (RV) volume measurements and their, reproducibility between axial and short axis orientation acquisition-techniques. Materials and 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 deft 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 +/- 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). Conclusion: There is,a significant systematic difference. between volumes measured using the two different orientations. The axial orientation resulted in better inter- and intraobserver reproducibility.