Three- and four-dimensional fetal echocardiography.

The rapid continuing development of 3-dimensional ultrasound imaging technologies has extended capabilities of fetal cardiac scanning beyond 2-dimensional imaging technologies and now provides a wide array of analytic possibilities. The acquisition of the 3D volume information is based on initial application of 2-dimensional imaging techniques including grey scale, Doppler, Power Doppler and B-flow modalities. Once the cardiac volume is obtained a combination of postprocessing tools such as surface mode, minimal mode, transverse rendering, inversion and glass body modes allow preferential display of various features of the fetal heart. Motion display modes including cine-loop and spatiotemporal image correlation in combination with automated and semiautomated display of examination planes opens a whole new array of diagnostic possibilities in clinical practice.