Accuracy of Left Ventricular Cavity Volume and Ejection Fraction for Conventional Estimation Methods and 3D Surface Fitting.

Background While left ventricular cavity volume ( LVV ) and ejection fraction ( LVEF ) are used routinely for clinical decision-making, the errors in LVV and LVEF estimates in the clinic have yet to be rigorously quantified and are perhaps underappreciated. Methods and Results The goal of this study was to quantify the accuracy and precision of several common geometric-model-based methods for estimating LVV and LVEF using a highly sampled, high-resolution magnetic resonance imaging data set and an independent ground truth. The effect on LVV and LVEF accuracy of slice number and orientation was also studied. When using the common geometric assumptions and limited short- and/or long-axis views, the expected LVEF measurement uncertainty can be as high as 49%. The composite midpoint rule applied to a stack of short-axis slices can achieve LVEF error <3% and LVV error of ≈10%, but in the clinic an additional ≈8% uncertainty is expected. An analogous approach applied to a series of radially prescribed long-axis slices can achieve higher LVEF accuracy, up to 3.9% with 12 slices, and more reliable LVV measurements than methods based solely on short-axis images. Using a mathematical 3-dimensional surface model that incorporates anatomic information from multiple views achieves superior accuracy, with LVEF error <4% and LVV error <2.5% when using 6 slices in each short- and long-axis view. Conclusions Combining anatomical information from multiple views into a conformal 3-dimensional surface model greatly reduces errors in LVV and LVEF estimates, with potential clinical benefit via improved early detection of cardiac disease.