3-DIMENSIONAL RECONSTRUCTION OF MULTIPLAN E TRANSESOPHAGEAL ECHOCARDIOGRAPHIC IMAGES - REPORT ON A NEW METHOD WITH CLINICAL EXAMPLES

First experiences with the dynamic three-dimensional reconstruction of transesophageal echocardiographic images in more than 100 patients wi th various cardiac diseases are reported. Ninety different two-dimensi onal image planes were acquired for each reconstruction using a conven tional multiplanar transducer, connected to a stepper motor and contro lled by a computer-based image acquisition system with special softwar e. Acquisition time for one data set was 2.3 +/- 0.9 min, and calculat ion time to achieve three-dimensional images was 20-45 min. Several ca rdiac structures were reconstructed and analyzed qualitatively and qua ntitatively (measurements of distances and areas, volume calculation b y Simpson's rule). Image sequences showing three-dimensional depth by gray scale modification were generated. After image acquisition one ca n select any desired cut plane to achieve perspectives that cannot be obtained by two-dimensional technique. Advantages of three-dimensional echocardiography are the display and potential quantification of path omorphology of the left ventricle and mitral valve, atrial septal defe cts, intracardiac masses (i.e., myxomas, vegetations), and direct spat ial imaging of complex congenital heart diseases. In principle, three- dimensional data sets have advantages for the quantitative evaluation of irregular formed cardiac structures, since the three-dimensional da ta set is more complete than cross-sections used in conventional two-d imensional echocardiography. Currently, however, these advantages are limited by the necessity of human interaction to segment the structure s of interest.