Right ventricular volume measurement with single-plane Simpsonʹs method based on a new half-circle model

Background: The complexity of right ventricular (RV) shape makes it more difficult for measuring its volume. However, the short-axis view of the right ventricle usually is crescent and might be assumed as half of a circle. This hypothesis can be applied to calculate RV volume by using the single-plane Simpsonʹs method, but the final RV volume should be about half of the original calculated value. The aim of this study was to test the accuracy of RV volume measurement based on this new assumption in human RV casts. Methods: Fifteen human RV casts were scanned with multislice helical CT and RV sagittal image that corresponds to right anterior oblique view were reconstructed. Single-plane Simpsonʹs method was used to calculate RV volumes. The calculated RV volume was defined as the original calculated value divided by 2. The true RV cast volume was determined by water displacement. Results: The true RV volume was 64.23±24.51 ml; the calculated volume was 53.18±26.22 ml. The calculated RV correlated closely with true volume with a regression equation of RV actual VOLUME=21.04 0.406×RV calculated volume (r=0.869, P<0.001), but significantly underestimated the actual volume by 11.05±13.09 ml (P<0.006). Conclusion: Right ventricular volume could be calculated with single-plane Simpsonʹs method based on the new proposed half-circle model.