Three-dimensional ultrasound of the fetal spine

Objective: To describe normal fetal spinal anatomy displayed by three-dimensional ultrasound and to determine whether three-dimensional ultrasound improves visualization of specific spinal defects. Methods: Fetuses (n = 28) (16 normal and 12 abnormal) were examined on standard two- and three-dimensional sonographic equipment. Results: In 15 of 16 normal fetuses, the spine tvas visualized at least from the upper thoracic area to the lower sacrum in a single three-dimensional image, and in 14 normal fetuses continuity of the ribs and spine was depicted. Neural tube defects were identified on both two- and three-dimensional ultrasounds; however, three-dimensional ultrasound displayed the level of the defect more accurately in three of the five cases. Scoliosis was recognized easily on a single three-dimensional rendered image, whereas several two-dimensional images were needed for the examiner mentally to reconstruct the scoliosis. Conclusion: Three-dimensional ultrasound may become an important tool for imaging of the fetal spine. Additional studies are necessary to determine the efficacy and cost effectiveness of this technology. However, our preliminary data suggest that presentation of the spine as a continuous structure rather than in independent two-dimensional views makes visualization of the spatial relationship of the spinal anatomy and adjacent structures easier. The ability to review the volume data using techniques not available on two-dimensional ultrasound may enable physicians to determine the extent of neural tube defects with more accuracy. Copyright (C) 1997 by The American College of Obstetricians and Gynecologists.