Conventional echocardiography is the most commonly used imaging technique in clinical cardiology. However, the complex cardiac anatomy and the sophisticated functional mechanisms of the cardiac structures require a transition from a two dimensional (2D) to a three dimensional (3D) approach. In fact, conventional 2D echocardiography makes significant geometric assumptions for the quantification of cardiac size, and only permits cross-sectional views for interpretation of cardiac pathologies. Real-time 3D echocardiography (RT3DE) may overcome most of these limitations and is now readily available as a clinically applicable imaging technique.^w1

Early approaches to 3D echocardiography were based on off-line and time consuming reconstructions of a series of 2D images obtained by either freehand scanning or a mechanically driven rotating transducer.^w2 Current generation 3D echo transducers consist of a fully sampled matrix array of more than 3000 simultaneously active ultrasound elements that provide real-time volumetric scanning with rapid post-processing. Recently, this novel technology has also been applied to a new generation of transoesophageal probes, broadening the possibility of clinical applications.^{w3 w4}

The main advantages of a 3D echocardiographic approach are summarised in table 1. In this article, the role of RT3DE for the assessment of cardiac chambers size and function and for the evaluation of valvular and congenital heart diseases will be reviewed. In addition, the potential future applications of RT3DE will be discussed.