title: Micro-computed tomography assessment of vertebral column defects in retinoic acid-induced rat model of myelomeningocele.
abstract: BACKGROUND
  Myelomeningocele (MMC) is a common congenital malformation and the most severe form of spina bifida characterized by the protrusion of spinal cord and meninges through the spinal defect. Our objective was to improve the assessment of congenital vertebral defects in animal models of MMC using three-dimensional high resolution micro-computed tomography (micro-CT) imaging and quantitative digital analyses methods.
  
  
  METHODS
  Lumbosacral MMC was induced in fetal rats by exposure of pregnant mothers at embryonic day 10 (E10) to all-trans retinoic acid, and rats were examined at term (embryonic day 22). The axial skeleton was examined in an MMC model for the first time using ex vivo micro-CT at 10 μm voxel resolution to allow high resolution two-dimensional and three-dimensional characterization of anomalies in lumbosacral vertebrae, and quantitative assessment of distances between dorsal vertebral arches in lumbosacral regions in MMC rats, compared with normal controls.
  
  
  RESULTS
  We observed, in detail, skeletal defects in lumbosacral vertebra of MMC rats, including in the morphology of individual dorsal vertebral arches. Use of high resolution micro-CT has also enabled us to identify the delayed (nonfused) or absent ossification in vertebral bodies, increased fusion of adjacent lateral vertebral elements, and quantify the extent of dorsal arch widening. Distances between dorsal vertebral arches showed statistically significant increases from L5 through S4 in MMC rats, compared with normal controls.
  
  
  CONCLUSIONS
  High-resolution micro-CT combined with digital quantification methods is a powerful technique ideally suited for precise assessment of complex congenital skeletal abnormalities such as examined in this rodent model of MMC.
authors: Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania.
authors: Mary F
authors: MF
authors: Barbe
authors: Radhika
authors: R
authors: Adiga
authors: Oleg
authors: O
authors: Gordiienko
authors: Nancy
authors: N
authors: Pleshko
authors: Michael E
authors: ME
authors: Selzer
authors: Barbara
authors: B
authors: Krynska
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005333:Fetus; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008161:Lumbosacral Region; D008591:Meningomyelocele / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000196:embryology / Q000473:pathology*; D011247:Pregnancy; D051381:Rats; D013131:Spine / Q000000981:diagnostic imaging / Q000196:embryology / Q000473:pathology*; D014212:Tretinoin; D055114:X-Ray Microtomography
chemical_list: D014212:Tretinoin
keywords: birth defects; bone defects; myelomeningocele; retinoic acid; spina bifida