Accurate Measurement of Mitral Annular Dimensions by Echocardiography: Importance of Correctly Aligned Imaging Planes and Anatomic Landmarks

Background: Mitral annular (MA) dimensions obtained by traditional two-dimensional echocardiography are poorly standardized and do not adhere to anatomic principles. Correct anatomic imaging planes of the anterior-posterior (AP) and commissure-commissure (CC) axes of the mitral annulus were compared with the traditional method and correlated with cardiac computed tomography (CT). Methods: Seventeen subjects underwent traditional and correct anatomic imaging planes echocardiography and cardiac CT. The traditional method was obtained in the parasternal long-axis and apical 4-chamber views. Correct anatomic imaging planes were obtained in the apical long-axis view. The traditional and correct anatomic images planes methods were correlated with cardiac CT. Results: The traditional method of MA measurement correlated poorly with cardiac CT (AP axis: r=0.13; CC axis: r=0.02). The correct anatomic imaging planes method of MA measurement correlated very well with cardiac CT (AP axis: r=0.96; CC axis: r=0.91) (P<.05). Conclusions: The correct anatomic imaging planes method provides accurate measurement of the AP and CC axes of the mitral annulus by adhering to geometric and anatomic principles. (J Am Soc Echocardiogr 2009; 22: 458-463.)