title: Computational Investigation of Cerebrospinal Fluid Dynamics in the Posterior Cranial Fossa and Cervical Subarachnoid Space in Patients with Chiari I Malformation.
abstract: OBJECTIVE
  Previous computational fluid dynamics (CFD) studies have demonstrated that the Chiari malformation is associated with abnormal cerebrospinal fluid (CSF) flow in the cervical part of the subarachnoid space (SAS), but the flow in the SAS of the posterior cranial fossa has received little attention. This study extends previous modelling efforts by including the cerebellomedullary cistern, pontine cistern, and 4th ventricle in addition to the cervical subarachnoid space.
  
  
  METHODS
  The study included one healthy control, Con1, and two patients with Chiari I malformation, P1 and P2. Meshes were constructed by segmenting images obtained from T2-weighted turbo spin-echo sequences. CFD simulations were performed with a previously verified and validated code. Patient-specific flow conditions in the aqueduct and the cervical SAS were used. Two patients with the Chiari malformation and one control were modelled.
  
  
  RESULTS
  The results demonstrated increased maximal flow velocities in the Chiari patients, ranging from factor 5 in P1 to 14.8 in P2, when compared to Con1 at the level of Foramen Magnum (FM). Maximal velocities in the cervical SAS varied by a factor 2.3, while the maximal flow in the aqueduct varied by a factor 3.5. The pressure drop from the pontine cistern to the cervical SAS was similar in Con1 and P1, but a factor two higher in P2. The pressure drop between the aqueduct and the cervical SAS varied by a factor 9.4 where P1 was the one with the lowest pressure jump and P2 and Con1 differed only by a factor 1.6.
  
  
  CONCLUSIONS
  This pilot study demonstrates that including the posterior cranial fossa is feasible and suggests that previously found flow differences between Chiari I patients and healthy individuals in the cervical SAS may be present also in the SAS of the posterior cranial fossa.
authors.affiliation: Center for Biomedical Computing, Simula Research Laboratory and Department of Informatics, University of Oslo, Oslo, Norway.
authors.forename: Karen-Helene
authors.initials: KH
authors.lastname: Støverud
authors.affiliation: Center for Biomedical Computing, Simula Research Laboratory and Department of Informatics, University of Oslo, Oslo, Norway.
authors.forename: Hans Petter
authors.initials: HP
authors.lastname: Langtangen
authors.affiliation: Department of Radiology and Nuclear Medicine, Oslo University Hospital- Rikshospitalet, University of Oslo, Oslo, Norway.
authors.forename: Geir Andre
authors.initials: GA
authors.lastname: Ringstad
authors.affiliation: Department of Neurosurgery, Oslo University Hospital- Rikshospitalet, Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: Per Kristian
authors.initials: PK
authors.lastname: Eide
authors.affiliation: Center for Biomedical Computing, Simula Research Laboratory and Department of Informatics, University of Oslo, Oslo, Norway.|Department of Mathematics, University of Oslo, Oslo, Norway.
authors.forename: Kent-Andre
authors.initials: KA
authors.lastname: Mardal
mesh_terms: D000328:Adult; D000465:Algorithms; D001139:Arnold-Chiari Malformation / Q000134:cerebrospinal fluid / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002555:Cerebrospinal Fluid / Q000502:physiology*; D003388:Cranial Fossa, Posterior / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D006801:Humans; D057446:Hydrodynamics; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D010865:Pilot Projects; D011312:Pressure; D013346:Subarachnoid Space / Q000000981:diagnostic imaging / Q000502:physiology*