Including trabeculations and papillary muscles in systemic right ventricular volume analysis significantly increased measured end diastolic volume by a mean of 28.7 ml compared to excluding these structures.
Cross-Sectional (n=29)
Yes
Does including trabeculations and papillary muscles in CMR cavity delineation alter volume measurements and improve reproducibility compared to excluding them in patients with a systemic right ventricle?
In patients with a systemic right ventricle, delineating the CMR cavity by including trabeculations and papillary muscles yields significantly different volume and EF measurements, but is faster and more reproducible than excluding them.
Mean Difference: 28.7 (95% CI 24.7–32.7)
p-value: p=<0.001
BACKGROUND: The method used to delineate the boundary of the right ventricle (RV), relative to the trabeculations and papillary muscles in cardiovascular magnetic resonance (CMR) ventricular volume analysis, may matter more when these structures are hypertrophied than in individuals with normal cardiovascular anatomy. This study aimed to compare two methods of cavity delineation in patients with systemic RV. METHODS: Twenty-nine patients (mean age 34.7 +/- 12.4 years) with a systemic RV (12 with congenitally corrected transposition of the great arteries (ccTGA) and 17 with atrially switched (TGA) underwent CMR. We compared measurements of systemic RV volumes and function using two analysis protocols. The RV trabeculations and papillary muscles were either included in the calculated blood volume, the boundary drawn immediately within the apparently compacted myocardial layer, or they were manually outlined and excluded. RV stroke volume (SV) calculated using each method was compared with corresponding left ventricular (LV) SV. Additionally, we compared the differences in analysis time, and in intra- and inter-observer variability between the two methods. Paired samples t-test was used to test for differences in volumes, function and analysis time between the two methods. Differences in intra- and inter-observer reproducibility were tested using an extension of the Bland-Altman method. RESULTS: The inclusion of trabeculations and papillary muscles in the ventricular volume resulted in higher values for systemic RV end diastolic volume (mean difference 28.7 +/- 10.6 ml, p < 0.001) and for end systolic volume (mean difference 31.0 +/- 11.5 ml, p < 0.001). Values for ejection fraction were significantly lower (mean difference -7.4 +/- 3.9%, p < 0.001) if structures were included. LV SV did not differ significantly from RV SV for both analysis methods (p = NS). Including structures resulted in shorter analysis time (p < 0.001), and showed better inter-observer reproducibility for ejection fraction (p < 0.01). CONCLUSION: The choice of method for systemic RV cavity delineation significantly affected volume measurements, given the CMR acquisition and analysis systems used. We recommend delineation outside the trabeculations for routine clinical measurements of systemic RV volumes as this approach took less time and gave more reproducible measurements.
Winter et al. (2008) conducted a cross-sectional in Systemic right ventricle (n=29). Inclusion of trabeculations and papillary muscles in RV volume analysis (Method A) vs. Exclusion of trabeculations and papillary muscles (Method B) was evaluated on Systemic right ventricular end diastolic volume (EDV) (MD 28.7 ml, 95% CI 24.7-32.7, p=<0.001). Including trabeculations and papillary muscles in systemic right ventricular volume analysis significantly increased measured end diastolic volume by a mean of 28.7 ml compared to excluding these structures.