3-DIMENSIONAL ULTRASOUND OF THE FETAL SPINE

Objective: To describe normal fetal spinal anatomy displayed by three- dimensional ultrasound and to determine whether three-dimensional ultr asound improves visualization of specific spinal defects. Methods: Fet uses (n = 28) (16 normal and 12 abnormal) were examined on standard tw o- and three-dimensional sonographic equipment. Results: In 15 of 16 n ormal fetuses, the spine tvas visualized at least from the upper thora cic area to the lower sacrum in a single three-dimensional image, and in 14 normal fetuses continuity of the ribs and spine was depicted. Ne ural tube defects were identified on both two- and three-dimensional u ltrasounds; however, three-dimensional ultrasound displayed the level of the defect more accurately in three of the five cases. Scoliosis wa s recognized easily on a single three-dimensional rendered image, wher eas several two-dimensional images were needed for the examiner mental ly to reconstruct the scoliosis. Conclusion: Three-dimensional ultraso und may become an important tool for imaging of the fetal spine. Addit ional studies are necessary to determine the efficacy and cost effecti veness of this technology. However, our preliminary data suggest that presentation of the spine as a continuous structure rather than in ind ependent two-dimensional views makes visualization of the spatial rela tionship of the spinal anatomy and adjacent structures easier. The abi lity to review the volume data using techniques not available on two-d imensional ultrasound may enable physicians to determine the extent of neural tube defects with more accuracy. Copyright (C) 1997 by The Ame rican College of Obstetricians and Gynecologists.