title: Rapid sequence magnetic resonance imaging in the assessment of children with hydrocephalus.
abstract: OBJECTIVE
  Recent reports have shown the utility of rapid-acquisition magnetic resonance imaging (MRI) in the evaluation of children with hydrocephalus. Rapid sequence MRI (RS-MRI) acquires clinically useful images in seconds without exposing children to the risks of ionizing radiation or sedation. We review our experience with RS-MRI in children with shunts.
  
  
  METHODS
  Overall image quality, cost, catheter visualization, motion artifact, and ventricular size were reviewed for all RS-MRI studies obtained at Seattle Children's Hospital during a 2-year period. Image acquisition time was 12-19 seconds, with sessions usually lasting less than 3 minutes.
  
  
  RESULTS
  Image quality was very good or excellent in 94% of studies, whereas only one was graded as poor. Significant motion artifact was noted in 7%, whereas 77% had little or no motion artifact. Catheter visualization was good or excellent in 57%, poor in 36%, and misleading in 7%. Small ventricular size was correlated with poor catheter visualization (Spearman's ρ = 0.586; P < 0.00001). RS-MRI imaging cost ∼$650 more than conventional computed tomography (CT).
  
  
  CONCLUSIONS
  Our study supports that RS-MRI is an adequate substitute that allows reduced use of CT imaging and resultant exposure to ionizing radiation. Catheter position visualization remains suboptimal when ventricles are small, but shunt malfunction can be adequately determined in most cases. The cost is significantly more than CT, but the potential for lifetime reduction in radiation exposure may justify this expense in children. Limitations include the risk of valve malfunction after repeated exposure to high magnetic fields and the need for reprogramming with many types of adjustable valves.
authors.affiliation: Division of Pediatric Neurosurgery, Seattle Children's Hospital, University of Washington, Seattle, Washington, USA.
authors.forename: Brent R
authors.initials: BR
authors.lastname: O'Neill
authors.forename: Sumit
authors.initials: S
authors.lastname: Pruthi
authors.forename: Harmanjeet
authors.initials: H
authors.lastname: Bains
authors.forename: Ryan
authors.initials: R
authors.lastname: Robison
authors.forename: Keiko
authors.initials: K
authors.lastname: Weir
authors.forename: Jeff
authors.initials: J
authors.lastname: Ojemann
authors.forename: Richard
authors.initials: R
authors.lastname: Ellenbogen
authors.forename: Anthony
authors.initials: A
authors.lastname: Avellino
authors.forename: Samuel R
authors.initials: SR
authors.lastname: Browd
mesh_terms: D016477:Artifacts; D057785:Catheters; D002552:Cerebral Ventricles / Q000473:pathology; D002557:Cerebrospinal Fluid Shunts; D002648:Child; D002675:Child, Preschool; D003365:Costs and Cost Analysis; D004868:Equipment Failure; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000175:diagnosis* / Q000473:pathology* / Q000601:surgery; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D014057:Tomography, X-Ray Computed / Q000009:adverse effects
keywords: CT; Computed tomography; HASTE; HASTE MRI; Half Fourier acquisition single shot turbo spin echo; Hydrocephalus; MRI; Magnetic resonance imaging; RS-MRI; Radiation risk; Rapid acquisition MRI; Rapid-sequence magnetic resonance imaging; Repetition time; TR; Ventriculoperitoneal shunt