title: Magnetic resonance imaging of neonatal encephalopathy at 4.7 tesla: initial experiences.
abstract: OBJECTIVE
  The goals were to develop safe 4.7-T MRI examination protocols for newborn infants and to explore the advantages of this field strength in neonatal encephalopathy.
  
  
  METHODS
  Nine ventilated newborn infants with moderate or severe encephalopathy were studied at 4.7 T, with ethical approval and informed parental consent. The custom-made, 4.7-T-compatible, neonatal patient management system included acoustic noise protection and physiologic monitoring. An adult head coil was used. Acquisition parameters for T2-weighted fast spin echo MRI and a variety of T1-weighted methods were adapted for MRI of neonatal brain at 4.7 T. The pulse sequences used had a radiofrequency specific absorption rate of <2 W/kg.
  
  
  RESULTS
  Physiologic measures were normal throughout each scan. T2-weighted fast spin echo imaging provided better anatomic resolution and gray/white matter contrast than typically obtained at 1.5 T; T1-weighted images were less impressive.
  
  
  CONCLUSIONS
  With appropriate safety precautions, MRI of newborn infants undergoing intensive care is as feasible at 4.7 T as it is at 1.5 T; our initial studies produced T2-weighted fast spin echo images with more detail than commonly obtained at 1.5 T. Although T1-weighted images were not adequately informative, additional pulse sequence optimization may be advantageous. A smaller neonatal head coil should also permit greater flexibility in acquisition parameters and even more anatomic resolution and tissue contrast. In neonatal encephalopathy, interpretation of the T2-weighted pathologic detail in combination with comprehensive neurodevelopmental follow-up should improve prognostic accuracy and enable more patient-specific therapeutic interventions. In addition, more precise relationships between structural changes and functional impairment may be defined.
authors.affiliation: Department of Medical Physics and Bio-Engineering, Elizabeth Garrett Anderson Hospital, University College London Hospitals National Health Service Foundation Trust, London, United Kingdom.
authors.forename: Enrico
authors.initials: E
authors.lastname: De Vita
authors.forename: Alan
authors.initials: A
authors.lastname: Bainbridge
authors.forename: Jeanie L Y
authors.initials: JL
authors.lastname: Cheong
authors.forename: Cornelia
authors.initials: C
authors.lastname: Hagmann
authors.forename: Rosarie
authors.initials: R
authors.lastname: Lombard
authors.forename: Wui K
authors.initials: WK
authors.lastname: Chong
authors.forename: John S
authors.initials: JS
authors.lastname: Wyatt
authors.forename: Ernest B
authors.initials: EB
authors.lastname: Cady
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Ordidge
authors.forename: Nicola J
authors.initials: NJ
authors.lastname: Robertson
mesh_terms: D001927:Brain Diseases / Q000175:diagnosis*; D006801:Humans; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods*; D012720:Severity of Illness Index