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Neurulation anomaly: Embryology and MR imaging of spinal dysraphism 2012

General Spine

Birva, Patel, M.D.
Hasit, Mehta, M.D., Non ASSR Member

Poster

Purpose

Spinal dysraphism encompasses a wide range of skin-covered spinal column and neuraxis anomalies resulting from defective closure of the neural tube early in fetal development. The open form of spinal dysraphism, known as spina bifida aperta, includes the familiar myelomeningocele. Myelomeningocele results from nondysjunction of cutaneous neural ectoderm and lack of closure of the neural tube. The closed form of spinal dysraphism, known as spina bifida occulta, is lack of closure of the vertebral arch, without the spinal cord or meninges being involved; the overlying skin is intact. Our learning objective is to review normal embryologic development of the spinal cord and identify neurulation errors resulting in spina bifida and highlight key MR features of spinal dysraphisms.

Methods & Materials

Descriptive review of a series of patients with spinal MR imaging which demonstrate the various forms of spinal dysraphism. Pathology correlation is provided for those patients who have been surgically corrected. Presentation of literature review of embryologic development of the spinal cord and neurulation error.

Results

MRI, pathology and surgical findings depicting the range of spinal dysraphism will be presented. An overview of the embryologic development with pictorial overview. Key MR imaging points and features will be discussed, including technical points salient to optimizing imaging of the pediatric spine. Patients with tethered cord and spina bifida aperta were operated on. In one case, associated anomaly included Chiari II malformation.

Conclusion

MR imaging is the preferred modality for accurate evaluation of the spinal neural elements and spinal dysraphism including spina bifida aperta and occulta. Early spinal MR imaging can delineate the extent of spinal dysmorphology and is a critical component in presurgical planning.

References/Financial Disclosures

References: Larsen W. Human Embryology, 3rd ed. Philadelphia, PA: Churchill Livingstone, 2001. Lowe L, Johanek A, Moore C. Sonography of the neonatal spine: part I, normal anatomy, imaging pitfalls and variations that may simulate disorders. AJR. Amer J Roentgen 2007; 188:733-38. Ross J, Brant-Zawadzki M, Moore K, et al. Diagnostic Imaging: Spine, 1st ed. Salt Lake City, UT: Amirsys, 2004. Sadler T. Langman's Medical Embryology, 5th ed. Baltimore, MD:Lippincott Williams & Wilkins, 1985:335. No financial disclosures.

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