[Imaging techniques in cardiology: three-dimensional echocardiography].

UNLABELLED: Three-dimensional echocardiography offers new opportunities for clinical cardiology and the solution of scientific questions. Data acquisition is possible using different techniques: (1) Realtime 3D echocardiography with matrix-array transducers is the most promising approach, but is still limited by several difficulties; (2) 3D reconstruction is based on a number of sequentially acquired 2D image planes (like in multiplane TEE), which are put together afterwards. There are 2 ways of data analysis. 1. Morphological analysis. Surface rendering of the endocardial border can create perspectives not achievable with conventional methods such as the "en face" view of atrial septal defects or the atrial view of the mitral valve. Prolapsing leaflets and the spatial relationship can be identified much easier than using 2D methods. In complex congenital heart disease 3D echo may provide better spatial orientation and easier communication with the cardiothoracic surgeons. 2. Quantitative analysis of volumes, masses, and surfaces is only possible after manual contour tracing with several cut planes generated from the 3D data set. This procedure is time consuming and limits the use in clinical routine, even though validation studies demonstrated that 3D echo determination of masses and volumes is superior to one- or two-dimensional techniques which are based on geometric assumptions. Furthermore, quantitative 3D analysis has a unique pre- and postinterventional diagnostic potential.

FUTURE PERSPECTIVES: Combination with color Doppler data may lead to a more precise quantitation of valve regurgitations. Improvements of hard- and software will allow faster acquisition, reconstruction, and quantitative analysis. Assessment of regional myocardial perfusion may be possible in combination with left heart contrast agents.

CONCLUSION: 3D echocardiography allows perspectives not achievable conventionally and has a great potential for precise quantitative and reproducible analysis of cardiac morphology which overcomes the limitations of 2D echocardiography.