Dynamic three-dimensional echocardiography: a new era in ultrasound technology

The use of noninvasive methods to visualise the heart has had an extraordinary development over the last decade, with echocardiography demonstrating a particularly fast growth. Despite its unquestionable role in the diagnosis of heart disease and in the management of cardiac patients, it does have some limitations, both in the morphological visualisation, as well as in the functional assessment of the heart, such as blood flow, quantification of intracardiac volumes, etc. The recent development of dynamic three-dimensional (3D) echocardiography from two dimensional images has opened new perspectives in the study of cardiac pathophysiology. There are basically two methods of displaying three dimensional data sets: (1) a two-dimensional display from individual selected cut planes (any-plane echocardiography) or from parallel short axis cuts; (2) a volume rendered technique: from any defined cut plane, different algorithms are applied to represent the information in space. There are several potential clinical applications of 3D such as the measurement and serial follow-up of left ventricular volumes; in valvular heart disease (the abnormalities can be delineated more precisely and in greater detail than conventional imaging, including a detailed definition of mitral apparatus in mitral stenosis), in mitral valve prolapse both leaflets can be seen from the left atrial view and in endocarditis it can aid in deciding when and how to intervene; in complex congenital heart disease, such as reconstruction of double outlet right ventricle, left-sided obstructive and regurgitant lesions and subaortic obstructive cases, in atrial and ventricular septal defects, displaying size, geometry and relationships to other structures; another expression of cardiac disorders are blood flow disturbances (visualisation of flows in 3D could allow a better qualitative and quantitative assessment of their size and severity; the pictures so far generated allow a good perception of the size and shape of mitral, aortic and tricuspid regurgitation jets, by examining them from a new perspective, it also has the potential to display the flow convergence zone and quantify the regurgitant volume). Recent studies have clearly demonstrated the feasibility of performing three-dimensional imaging in a variety of cardiac diseases, but continued development of ultrasound technology must be made to improve better image resolution. The prolonged acquisition time is the most important limiting factor that currently restricts the routine use of 3D echocardiography. The development of faster computers will shorten the time needed for image acquisition, postprocessing, and data analysis, contributing to the goal of easy access and wide use. With improvements in computer technology and production of interactive software, 3D echocardiography will provide a dynamic view of the surgical anatomy of the heart. Thus, the three-dimensional reconstruction concept has the potential to and diagnostic assessment of cardiac pathology in every facet.