Real-time three-dimensional transesophageal echocardiography--an initial experience.

Introduction: Echocardiography (echo) has gained increasing importance in cardiology as technological developments have enabled progression from one-dimensional to two-dimensional imaging and the inclusion of physiological information with the Doppler principle. Although three-dimensional (3D) echo is not a new concept, its use has been limited by image artifacts and the need for time-consuming offline processing. Despite several improvements since its introduction in the 1990s, real-time 3D echo was until 2007 limited to transthoracic studies, but a real-time 3D transesophageal (TE) echo probe has recently become commercially available. The objective of this article is to describe our initial experience with this probe, to assess its ability to visualize different cardiac structures and to discuss its advantages and shortcomings. Methods: We performed 103 transesophageal studies between 08/05/2008 and 10/31/2009 using an iE33 ultrasound system with an X7-2t probe (Philips Medical Systems, Andover, Massachusetts, USA). Successful intubation was achieved in all patients. The 3D images obtained were exported to a workstation equipped with QLAB version 6.0 software for review and post-processing. Results: Three-dimensional images were obtained in 73 studies, mostly for pre- or post-closure evaluation of atrial septal defects (ASD; 31.5%) and assessment of mitral valve disease or mitral prostheses (30%). Most of the images were acquired using 3D zoom mode. The additional information provided by 3D study was very useful for evaluation of mitral valve disease and mitral valve prostheses, enabling quick and reliable recognition of the cardiac anatomy and the pathological processes involved in each case. The interatrial septum was clearly visualized and the anatomical relations of defects were identified in most exams, in spite of the presence of dropouts in some cases. Imaging of more anterior cardiac structures, particularly the aortic, pulmonary and tricuspid valves, is generally suboptimal with this technique and good-quality images were obtained in only a few studies. Conclusion: After a relatively short training period and without prolonging the study time significantly, we were able to visualize the various components of the mitral valve clearly and identify its anatomical relations; in our initial experience, this was the major advantage of the technique, which will probably become the gold standard for preoperative evaluation of mitral valve disease. Programming and guiding ASD closure is another promising area for 3D TE echo. On the other hand, imaging of anterior cardiac structures is poor and needs refinement.