Assessment of the aortic valve annular geometry by real-time three-dimensional transthoracic echocardiography: comparison with two-dimensional transthoracic echocardiography and multidetector computed tomography

Background Real-time three-dimensional transthoracic echocardiography (3DTTE) has been developed and provides detailed 3D information, noninvasively. However, the accuracy and usefulness of 3DTTE in the evaluation of aortic root geometry are still not clear. Methods 2DTTE and 3DTTE were performed in 161 patients with various cardiac diseases. Multidetector computed tomography (MDCT) was performed in 35 of the 161 patients. The diameters and areas of the aortic annulus were evaluated by these three methods and compared. To evaluate the shape of the aortic annuli, eccentricity index (EI) (1 − minimum diameter/long-axis diameter) were calculated. Results Maximum dimensions of the aortic annulus measured by MDCT were significantly larger than those by 3DTTE and 2DTTE. The aortic annular areas measured by MDCT and 3DTTE were significantly larger than areas by 2DTTE. A good correlation ( r = 0.85) was observed between the areas obtained by 3DTTE and MDCT; however, the correlation between the values by 2DTTE and MDCT was rough ( r = 0.44). EI values in 46 % of the patients were greater than 0.1, i.e., the aortic annulus was elliptical. Conclusion The images obtained by 3DTTE provided accurate values of the aortic annular area, which were equal to the values measured by MDCT. 3DTTE is a useful method to evaluate the aortic annular geometry.