[Evaluation of valvular lesions by three-dimensional echocardiography]

A recently developed, on-line image processing system (Tomtec EchoScan) for three-dimensional (3D) echocardiography was compared with conventional two-dimensional examination and our own off-line 3D system. Transesophageal echocardiography was performed in 10 cardiac patients using an omniplane transducer which was automatically rotated under the control of the 3D system. At each angle of the transducer, the respiration-gated image of one cardiac cycle was acquired and transferred into the computer, where the dynamic 3D images of mitral and/or aortic valve were reconstructed. The EchoScan system enabled 3D recognition of the structural and dynamic abnormalities of the valves, such as mitral valve prolapse, although tissue information, which is expressed as a gray scale in the conventional echocardiography, cannot be evaluated from the 3D image. Average times were 5.4 min for the data acquisition, 11.8 min for the 3D processing and 5.7 min for the rendering. Although it seems necessary to improve the efficacy of data acquisition, to shorten the calculation time and to minimize the artifacts, this system enables assessment of 3D cardiac structures at the bedside and to fully recognize valvular lesions preoperatively in patients with valvular heart disease.