title: Fetal magnetic resonance imaging of normal spinal cord: evaluating cord visualization and conus medullaris position by T2-weighted sequences.
abstract: BACKGROUND
  Prenatal magnetic resonance (MR) imaging demonstration of the normal spinal cord and the conus medullaris location has not been well studied. We compared balanced fast field echo (bFFE) with single-shot turbo spin-echo (SSh-TSE) MR sequences for visualizing the normal spinal cord and position of conus medullaris in fetuses.
  
  
  METHODS
  This retrospective study was approved by the Institutional Review Board of Chang Gung Medical Foundation. We reviewed the MR images of 141 fetuses aged between 16 and 39 gestational weeks, to determine the position of the conus and visualize the spinal cord by using a signal intensity ratio of cerebral spinal fluid (CSF) to the spinal cord.
  
  
  RESULTS
  Of the 75 subjects having normal spinal cord and being examined by both bFFE and SSh-TSE studies, the signal intensity ratio of CSF/cord was greater on bFFE images (2.18 ± 0.53) than that on SSh-TSE images (1.21 ± 0.13) (p < 0.05). The conus level identified in the 50 subjects, in whom the lumbosacral spine was appropriately imaged, was located from L1 to L5 levels. The ascendance of the conus correlated moderately with gestational age.
  
  
  CONCLUSIONS
  With greater signal contrast ratio of CSF to spinal cord, bFFE sequence, when compared with SSh-TSE sequence, provides better visualization of normal spinal cord. The fetal conus medullaris ascends from L5 to L1 levels as the gestational age increases.
authors.forename: Yen-Ling
authors.initials: YL
authors.lastname: Huang
authors.affiliation: Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Keelung and Linkou, Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Alex M
authors.initials: AM
authors.lastname: Wong
authors.forename: Ho-Ling
authors.initials: HL
authors.lastname: Liu
authors.forename: Yung-Liang
authors.initials: YL
authors.lastname: Wan
authors.forename: Yu-Chun
authors.initials: YC
authors.lastname: Lin
authors.forename: An-Shine
authors.initials: AS
authors.lastname: Chao
authors.forename: Yao-Lung
authors.initials: YL
authors.lastname: Chang
mesh_terms: D003287:Contrast Media; D005260:Female; D005333:Fetus; D005865:Gestational Age; D006801:Humans; D008161:Lumbosacral Region; D008279:Magnetic Resonance Imaging; D012189:Retrospective Studies; D013116:Spinal Cord / Q000166:cytology*
chemical_list: D003287:Contrast Media