Greatly improved diagnosis and investigation of fetal central nervous system abnormalities is the result
of impressive technologic advances in ultrasonographic imaging. This applies as well to the study of spinal and
facial abnormalities that are associated with central nervous system anomalies. More attention has been paid to
midbrain structural defects, such as agenesis of the corpus callosum and abnormalities of the cerebellum, with the
introduction of three- and four- dimensional ultrasound. Notwithstanding all these recent rapid technologic
advances, many professionals --- except for a few pioneers --- have difficulty keeping up-to-date. The purpose of
this review of basic principles and various applications of three-dimensional ultrasound to the fetal central nervous
system evaluation is to inform professionals working in obstetric ultrasound of those advances. We will focus
primarily on normal findings of three-dimensional sonography of the fetal central nervous system. We will also
discuss a range of topics from methods of real-time scanning and software manipulation to the application of these
techniques to each section of the fetal nervous system.
