3-DIMENSIONAL MEASUREMENT OF THE MITRAL ANNULUS BY MULTIPLANE TRANSESOPHAGEAL ECHOCARDIOGRAPHY - IN-VITRO VALIDATION AND IN-VIVO DEMONSTRATION

Ten phantoms were scanned with a multiplane transesophageal echocardio graphic probe in a water bath to assess a new method for three-dimensi onal modeling of the mitral annulus. The annulus was reconstructed fro m manually outlined borders with Fourier series in each of the three s patial coordinates. Comparisons with direct measurements by least-squa res linear regression gave coefficients of determination of 0.99 for a nnular height, area, and circumference. Expressed as a percent age of their true values, the mean +/- SD of the errors were -0.1% +/- 3.0% f or annular height, -2.8% +/- 3.1% for area, and -0.2% +/- 1.7% for cir cumference. The mean residual error length for phantoms was 0.64 mm co mpared with 1.21 mm in nine patients studied during general anesthesia . This method gives accurate and precise measurements of the mitral an nulus in vitro and should be valuable for studying its morphology and dynamics in vivo.