In comparison to transthoracic echocardiography (TTE) transesophageal echocardiography (TEE) enables an acquisition of images with better spatial resolution due to the use of higher ultrasound frequencies. Thus, the morphology and function of cardiac structures can principally be analyzed better and more accurately with TEE than with TTE. In addition, using three-dimensional (3D) TEE data sets standardized sectional planes can be constructed by post-processing, which enables quantitative assessment of the target structures. The size and function of the left ventricle can objectively and reproducibly be measured. End diastolic left ventricular volume and total stroke volume of the left ventricle can be accurately determined in patients with heart valve disease. Furthermore, particular cardiac structures that cannot be totally evaluated by two-dimensional (2D) echocardiography, can be completely analyzed by 3D TEE. In 2D images for example, only analyses of the right coronary cusp of the aortic valve are possible because only the center of the right coronary cusp can be visualized using conventional sectional level presentation. Using 3D TEE the non-coronary cusp and the left coronary cusp can also be visualized in the mid-sectional plane by post-processing of the 3D data set. Additional important structures of 3D TEE analysis are the left atrial auricle, the interatrial septum and the mitral valve. Planimetry of valvular and regurgitation orifices as well as the monitoring of interventions for treatment of structural heart diseases are further fields of application of clinically established 3D TEE diagnostics.
Keywords: Three-dimensional imaging; Transesophageal echocardiography; Transthoracic echocardiography; Valvular heart diseases; Volume analysis.