ABSTRACT
Three-and four-dimensional (3D and 4D) sonographic imaging is based on computer data processing of classic two-dimensional (2D) images. Numerous improvements in data processing capacity in the past two decades now enable the rapid synthesis of multiple adjacent sections and extraction of important data. The resultant images provided by this technology are so highly processed that a single 3D image, either surface-rendered or transparent, is as informative as several planar images obtained from different sections. Furthermore, multiplanar imaging overcomes previous limitations of unobtainable sections due to unfavorable fetal position. In other words, no fetal position makes it impossible to obtain a desired section. At present, the only limiting factor in modern sonography for visualization of a desired structure is the amount of adjacent amniotic fluid.
