An ellipsoidal shell model for volume estimation of the right ventricle from magnetic resonance images.
OBJECTIVE
I developed a volume estimation technique for the crescentic volume of the right ventricle (RV) of the heart. A geometric model was desired to avoid the lengthy data collection and reduction required by Simpson's rule.


METHODS
An ellipsoidal shell model was developed that requires only simple mathematics and that resembles the RV shape. RV cast volumes were obtained by water displacement and Simpson's rule and model-based calculations using magnetic resonance (MR) imaging.


RESULTS
Model-based estimates correlated well with water displacement volumes (r = 0.924), with a slope not significantly different from unity. Simpson's rule results showed a higher correlation (r = 0.994), but it required longer acquisition and processing. Geometric irregularity in the RV shape required no modification in mathematics.


CONCLUSIONS
The model provides reliable RV volume estimates from two MR image planes. The mathematics provides a simple approach to a relatively complex, crescentic shape. Short times for data acquisition and analysis suggest the potential for time savings during routine clinical measurements.
Denslow
S
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South Carolina Children's Heart Center, Medical University of South Carolina, Charleston 29425-0680, USA.
D000818:Animals; D002306:Cardiac Volume; D004285:Dogs; D006321:Heart / Q000033:anatomy & histology*; D006352:Heart Ventricles / Q000033:anatomy & histology; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000706:statistics & numerical data; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D013552:Swine