Sonography of the fetal spine: technique, imaging findings, and clinical implications.

Sonographic evaluation of the fetal spine is an essential part of any fetal survey, and it is included in the current American Institute of Ultrasound in Medicine/American College of Radiology and American College of Obstetrics and Gynecology guidelines for obstetric sonography [1, 2]. In this paper, we review the current knowledge of anatomy of the normal fetal spine and the sonographic findings associated with spinal anomalies, with special emphasis on neural tube defects. Important cranial clues to a spine abnormality initially may be more obvious at sonography than the spine abnormality itself, and the general significance of these clues is provided. The expanding role of prenatal maternal serum and amniotic fluid testing is explored, as are the benefits and modifications these bring to sonographic evaluations. Finally, the potential benefits of the rapidly advancing technology of three-dimensional sonography are introduced.