Journal of Ultrasound in Medicine, Vol 6, Issue 11 631-636, Copyright © 1987 by American Institute of Ultrasound in Medicine
Fetal spine morphology and maturation during the second trimester. Sonographic evaluation
R. A. Filly, G. F. Simpson and G. Linkowski
Department of Radiology, University of California School of Medicine, San Francisco 94143.
We reviewed high-resolution real-time sonographic images (especially
selected for a lack of technical artifacts) of the fetal spine of 46 normal
fetuses between 18-27 menstrual weeks of development. The degree of visible
posterior neural arch ossification was graded and compared with the
gestational age. Recognizable early ossification of the laminae was seen in
the cervical region of all fetuses studied. Similar ossification followed
sequentially in the thoracic, lumbar, and sacral regions; however,
sonographically recognizable ossification of the laminae in the lumbar
spine was delayed until 22-24 weeks and in the sacral spine until 25 weeks
or more. Awareness of these features will help to prevent false-positive
diagnoses of dysraphism and, conversely, hopefully augment our ability to
detect such lesions.
