3D echocardiography: Technical toy in search of a clinical application or logical evolution of a diagnostic tool?

In recent years, 3D echocardiographic reconstruction and real time 3D echocardiography have been developed. Reconstruction techniques are based on one of two principles: acoustic or electromagnetic location devices that identify the spatial position of the transducer during imaging, or transducers that image from a fixed position varying the sector orientation in a predefined way. Animated, dynamic recontructions of cardiac structures are possible, and the 3D data set can be sliced and viewed in any desired way after acquisition. The mitral annulus and congenital malformations of the heart have been imaged and studied successfully by 3D echo. Mass and volume calculations based on 3D data sets have been shown to be extraordinarily accurate by several investigators working with different techniques. Since the 3D data set is more comprehensive than any set of 2D images, such calculations are fundamentally superior to 2D or M-mode derived parameters. Color Doppler data can also be recontructed into 3D data sets, with possible applications to proximal convergence zone calculations. However, broad implementation of 3D echo in clinical practice is hampered to date by cumbersome manual tracing to derive quantitative parameters and sometimes by insufficient image quality. Nevertheless, the rapid technical evolution, now including real-time 3D echo, ensures an important role for 3D echo in future echocardiography.