title: Magnetic resonance-based estimation of intracranial pressure correlates with ventriculoperitoneal shunt valve opening pressure setting in children with hydrocephalus.
abstract: OBJECTIVE
  The aim of this study was to investigate the relationship between the pressure setting of the ventriculoperitoneal (VP) shunt valve and a magnetic resonance (MR)-based estimate of intracranial pressure (ICP) in children with shunt-treated hydrocephalus without clinical signs of shunt malfunction.
  
  
  METHODS
  Institutional review board approval was obtained before the study, and all subjects and/or their legal guardians provided written informed consent. In this prospective study, 15 consecutive patients (median age, 8.25 years; range, 2.2-18.4 years; 6 girls and 9 boys) with shunt-treated hydrocephalus without signs of shunt malfunction were examined with retrospectively gated phase contrast sequences to quantify arterial inflow, venous outflow, and cerebrospinal fluid (CSF) flow to and from the cranial vault. The ratio of the maximal intracranial volume change and the pulse pressure gradient change was used to derive MR-ICP. Spearman ρ was used to test for the association of setting of the shunt valve opening pressure and MR-ICP.
  
  
  RESULTS
  Shunt valve opening pressure settings and MR-ICP were positively correlated (Spearman ρ = 0.64, P < 0.01). Median MR-ICP was 8.67 mm Hg (interquartile range [IQR], 1.59 mm Hg) and median setting of the VP-shunt valve was 6.62 mm Hg (IQR, 1.47 mm Hg). The median MR-ICP was 1.9 mm Hg (IQR, 0.73 mm Hg) higher than the setting of the shunt valve.
  
  
  CONCLUSIONS
  There is a positive correlation between MR-ICP and VP shunt valve opening pressure setting. The systematically higher assessment of MR-ICP is most likely a result of outflow resistance within the shunt tubing system and well within the known fluctuation rates of VP shunt systems.
authors.affiliation: Institute for Clinical Radiology, University of Munich, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Muehlmann
authors.forename: Inga K
authors.initials: IK
authors.lastname: Koerte
authors.forename: Ruediger P
authors.initials: RP
authors.lastname: Laubender
authors.forename: Denise
authors.initials: D
authors.lastname: Steffinger
authors.forename: Markus
authors.initials: M
authors.lastname: Lehner
authors.forename: Aurelia
authors.initials: A
authors.lastname: Peraud
authors.forename: Florian
authors.initials: F
authors.lastname: Heinen
authors.forename: Michael
authors.initials: M
authors.lastname: Kiefer
authors.forename: Maximilian
authors.initials: M
authors.lastname: Reiser
authors.forename: Birgit
authors.initials: B
authors.lastname: Ertl-Wagner
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D019586:Intracranial Hypertension / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*; D007427:Intracranial Pressure; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008365:Manometry / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D016896:Treatment Outcome; D017287:Ventriculoperitoneal Shunt