title: Clinical Significance of Prenatal and Postnatal Heavily T2-Weighted Magnetic Resonance Images in Patients with Myelomeningocele.
abstract: OBJECTIVE
  To compare the utility and limitations of prenatal magnetic resonance (MR) imaging using half-Fourier acquisition single-shot turbo spin-echo (HASTE) with postnatal heavily T2-weighted imaging (hT2WI) for the evaluation of central nervous system abnormalities associated with myelomeningocele (MMC).
  
  
  METHODS
  Sixteen patients with MMC who had undergone pre- and postnatal MR imaging were included in this study. MR imaging, including HASTE, was undertaken in the 3rd trimester, and hT2WI was performed immediately after delivery. The precision with which each could distinguish MMC, hindbrain herniation and ventriculomegaly was compared retrospectively.
  
  
  RESULTS
  The skin defects and MMC sacs were clearly visible on prenatal HASTE images, although it was difficult to identify precisely the level of MMC compared with postnatal hT2WI, in which the detailed anatomical relationships of the spinal cord, neural placode and ventral nerve roots were evident in every case. Hindbrain herniation could be visualized on prenatal HASTE images, although its severity was difficult to evaluate because of the small size of the structures and neck flexion; again, the resolution was superior on postnatal hT2WI. For hydrocephalus, there were no significant differences in the diagnostic precision and ability to grade the severity between pre- and postnatal imaging.
  
  
  CONCLUSIONS
  Prenatal HASTE imaging permits the diagnosis and understanding of the gross anatomy of MMC and associated hindbrain herniation and ventriculomegaly, but postnatal hT2WI is superior for evaluating detailed anatomy.
authors.forename: Kimiaki
authors.initials: K
authors.lastname: Hashiguchi
authors.forename: Takato
authors.initials: T
authors.lastname: Morioka
authors.forename: Nobuya
authors.initials: N
authors.lastname: Murakami
authors.forename: Koji
authors.initials: K
authors.lastname: Yamashita
authors.forename: Akio
authors.initials: A
authors.lastname: Hiwatashi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ochiai
authors.forename: Seiichi
authors.initials: S
authors.lastname: Morokuma
authors.forename: Koji
authors.initials: K
authors.lastname: Iihara
mesh_terms: D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008297:Male; D008591:Meningomyelocele / Q000175:diagnosis* / Q000473:pathology; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis / Q000379:methods* / Q000592:standards