Assessment of sedated pediatric brain with 3D-FLAIR sequence at 3T MRI

Brain Dev. 2015 May;37(5):495-500. doi: 10.1016/j.braindev.2014.08.008. Epub 2014 Oct 2.


Background and purpose: In sedated pediatric brains, 2D-FLAIR causes increased signal intensity of the cerebrospinal fluid (CSF) leading to false-positive diagnoses. Our aim is to determine whether increased CSF signal intensity is observed on 3D-FLAIR images.

Methods: In this institutional review board-approved study, a 2-year retrospective analysis of our MRI database was conducted which revealed 48 sedated pediatric patients with normal cranial MRI findings and 3D-FLAIR sequence. One adult volunteer was imaged before and after O2 inhalation with 2D and 3D-FLAIR sequences. The hyperintensity in the subarachnoid spaces and basal cisterns were quantified as follows: 0: artifact free; 1: homogeneous minimal CSF signal; 2: abnormal CSF signal. Inter-observer agreement was assessed with kappa agreement analysis.

Results: Grade 0 and grade 1 signals were observed at inferior to Liliequist membrane (LLQ) in 48/48 and 0/48 cases; prepontine cistern 47/48 and 1/48; superior to LLQ 26/48 and 22/48; 4th ventricle 16/48 and 32/48; 3rd ventricle 34/48 and 14/48; lateral ventricle 3/48 and 45/48; subarachnoid space 36/48 and 12/48, respectively. No patients showed grade 2 signal. Inter-observer agreement was 0.81-1. In the volunteer, after O2 inhalation, grade 2 signal intensity was evident on 2D-FLAIR however; 3D-FLAIR did not show any signal increase.

Conclusions: In sedated pediatric brains, 3D-FLAIR suppresses CSF signal, and enables reliable assessment free from CSF artifacts.

Keywords: Brain; Cerebrospinal fluid; FLAIR; Magnetic resonance imaging.

MeSH terms

  • Anesthesia, General / methods
  • Brain / pathology
  • Brain / physiology*
  • Cerebrospinal Fluid / physiology
  • Child
  • Child, Preschool
  • Humans
  • Hypnotics and Sedatives / administration & dosage*
  • Imaging, Three-Dimensional / methods
  • Infant
  • Infant, Newborn
  • Magnetic Resonance Imaging / methods*
  • Male
  • Observer Variation
  • Retrospective Studies


  • Hypnotics and Sedatives