Quantification of left ventricular dimensions on line with biplane transesophageal echocardiography and lateral gain compensation.

Abstract

To determine the feasibility and accuracy of biplane transesophageal echocardiography (TEE) with automatic boundary detection (ABD) for the estimation of left ventricular areas, we examined 19 consecutive patients with the use of this technique. In addition, we evaluated the utility of lateral gain compensation (LGC) to improve the online tracking of the ABD algorithm on the lateral endocardial-blood boundary of the echocardiographic image. The transverse plane short-axis TEE view and the longitudinal plane two chamber TEE view were used for the analysis. A semiquantitative estimate (in degrees) of the endocardial circumference, in which the boundary was correctly identified and tracked on line, improved from a mean of 198 degrees to 360 degrees with LGC (P less than 0.001). Results of comparisons of offline and online biplane TEE cavity areas revealed excellent correlations of values for the 16 patients (84%) in whom adequate transverse plane short-axis images were obtained (r values greater than 0.9 at systole and diastole). The correlation was also excellent (r values greater than 0.9) in the nine patients in whom longitudinal plane two-chamber views adequate for ABD analysis were obtained at systole and diastole. LGC significantly improved the accuracy of endocardial detection and tracking, which otherwise would be limited due to the anisotropic properties of the myocardium. Thus, ABD during biplane TEE may be feasible in a significant number of patients and accurately reflects left ventricular areas when compared with offline methods.