The purpose of this paper is to review how 3D/4D echocardiographic images can be manipulated to
maximize the information regarding cardiac structure to improve the diagnostic yield of congenital heart defects. The
following topics are discussed: (1) the differences between 3D and 4D ultrasound; (2) basic imaging principles of fourdimensional
ultrasound when using spatial-temporal image correlation, real-time volume display, and matrix array
technology; (3) analysis of acquired volumes using X,Y and Z rotation, the transverse sweep, the spin technique,
tomographic imaging, rendering, inversion, and B-flow. The conclusion is that while the 3D and 4D volumes are easy to
acquire, the user must understand the number of tools available to enhance the examination of the fetal heart.
Keywords: 4D ultrasound, Fetal echocardiography, Cardiac volumes, Methodology
