Optimising the imaging plane for right ventricular magnetic resonance volume analysis in adult patients referred for assessment of right ventricular structure and function

INTRODUCTION: Our aim was to evaluate the reproducibility and accuracy of using short-axis and axial (transaxial) plane for magnetic resonance imaging analysis in adult patients referred for assessment of right ventricular (RV) structure and function.

METHODS: Twenty consecutive subjects (10 male, 10 female, mean age 32.2 ± 14.8 years) who were referred for RV assessment and had cardiac magnetic resonance imaging were retrospectively selected. Axial and short-axis manual contouring was performed using cine steady-state free precession sequences by three experienced imaging specialists. The reproducibility of end diastolic volumes, end systolic volumes and ejection fraction was assessed with intraclass correlation coefficients (ICCs) and paired t-tests. Left ventricular stroke volume (LVSV) and RV stroke volumes (RVSV) were compared with concordance correlation coefficients (CCCs) and t-tests to determine accuracy.

RESULTS: The concordance between the RVSV and LVSV was good using both methods (axial RVSV CCC = 0.93, short-axis RVSV CCC = 0.86). Paired t-test and analysis of variance showed that the LV/RV stroke volume differences were not significant (p = 0.17). There was slight improvement in interobserver reliability with end systolic volume measurements (axial ICC = 0.92, short-axis ICC = 0.81) but this failed to reach statistical significance (p = 0.37). There was excellent intraobserver variability (ICC > 0.9).

CONCLUSION: This study shows that there is no statistically significant difference in reproducibility or accuracy using the short-axis or axial orientations in RV volume analysis in adult patients being referred for RV assessment.