Quantification of the Aortic Valve Area in Three-dimensional Echocardiographic Data Sets: Analysis of Orifice Overestimation Resulting from Suboptimal Cut-plane Selection

Background: Our study was designed to determine the feasibility of three-dimensional echocardiographic (3DE) aortic valve area planimetry and to evaluate potential errors resulting from suboptimal imaging plane position.

Methods And Results: Transesophageal echocardiography with acquisition of images for 3DE was performed in 27 patients. Aortic valve orifice was planimetered in two-dimensional echocardiograms (2DE) and in two-dimensional views reconstructed from 3DE data sets optimized for the level of the cusp tips. To evaluate the errors caused by suboptimal cut-plane selection, orifice was also measured in cut-planes angulated by 10, 20, and 30 degrees or shifted by 1.5 to 7.5 mm. Planimetered orifice areas was similar in 2DE and 3DE studies: 2.09 +/- 0.97 cm2 versus 2.07 +/- 0.92 cm2. Significant overestimation was observed with cut-plane angulation (0.09, 0.19, and 0.34 cm2 at 10 degree increments) or parallel shift (0.11, 0.22, 0.33, 0.43, and 0.63 cm2 at 1.5 mm increments). Three-dimensional echocardiographic measurement reproducibility was very low and superior to that of 2DE.

Conclusions: Three-dimensional echocardiography allows accurate aortic valve area quantification with excellent reproducibility. Relatively small inaccuracy in cut-plane adjustment is a major source of errors in aortic valve area planimetry.