S Linge

Publications (7)5.86 Total impact

• Article: Patient-Specific 3D Simulation of Cyclic CSF Flow at the Craniocervical Region.

  G Rutkowska, V Haughton, S Linge, K-A Mardal
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  ABSTRACT: Flow simulations in patient-specific models of the subarachnoid space characterize CSF flow in more detail than MR flow imaging. We extended previous simulation studies by including cyclic CSF flow and patient-specific models in multiple patients with Chiari I. We compared simulation results with MR flow measurements. Volumetric high resolution image sets acquired in 7 patients with Chiari I, 3 patients who had previous craniovertebral decompression, and 3 controls were segmented and converted to mathematical models of the subarachnoid space. CSF flow velocities and pressures were calculated with high spatial and temporal resolution during simulated oscillatory flow in each model with the Navier-Stokes equations. Pressures, velocities, and bidirectional flow were compared in the groups (with Student t test). Peak velocities in the simulations were compared with peak velocities measured in vivo with PCMR. Flow visualization for patients and volunteers demonstrated nonuniform reversing patterns resembling those observed with PCMR. Velocities in the 13 subjects were greater between C2 and C5 than in the foramen magnum. Chiari patients had significantly greater peak systolic and diastolic velocities, synchronous bidirectional flow, and pressure gradients than controls. Peak velocities measured in PCMR correlated significantly (P = .003; regression analysis) despite differences between them. In simulations of CSF, patients with Chiari I had significantly greater peak systolic and diastolic velocities, synchronous bidirectional flow, and pressure gradients than controls.
  American Journal of Neuroradiology 04/2012; 33(9):1756-62. · 2.93 Impact Factor
• Article: Characterization of cyclic CSF flow in the foramen magnum and upper cervical spinal canal with MR flow imaging and computational fluid dynamics.

  S Hentschel, K-A Mardal, A E Løvgren, S Linge, V Haughton
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  ABSTRACT: CSF flow has been shown to exhibit complex patterns in MR images in both healthy subjects and in patients with Chiari I. Abnormal CSF flow oscillations, according to prevailing opinion, cause syringomyelia and other clinical manifestations that affect some patients with the Chiari I malformation. For this article, we reviewed the literature on PC MR of CSF flow, collected the published CFD studies relevant to CSF flow, and performed flow simulations. PC MR creates cine and still images of CSF flow and measurements of flow velocities. CFD, a technique used to compute flow and pressure in liquid systems, simulates the CSF flow patterns that occur in a specific geometry or anatomy of the SAS and a specific volume of flow. Published PC MR studies show greater peak CSF velocities and more complex flow patterns in patients with Chiari I than in healthy subjects, with synchronous bidirectional flow one of the characteristic markers of pathologic flow. In mathematic models of the SAS created from high-resolution MR images, CFD displays complex CSF flow patterns similar to those shown in PC MR in patients. CFD shows that the pressure and flow patterns vary from level to level in the upper spinal canal and differ between patients with Chiari and healthy volunteers. In models in which elasticity and motion are incorporated, CFD displays CSF pressure waves in the SAS. PC MR and CFD studies to date demonstrate significant alterations of CSF flow and pressure patterns in patients with Chiari I. CSF flow has nonlaminar complex spatial and temporal variations and associated pressure waves and pressure gradients. Additional simulations of CSF flow supplemented by PC MR will lead to better measures for distinguishing pathologic flow abnormalities that cause syringomyelia, headaches, and other clinical manifestations in Chiari I malformations.
  American Journal of Neuroradiology 03/2010; 31(6):997-1002. · 2.93 Impact Factor
• Conference Proceeding: Effect of Tonsilar Position on Cerebrospinal Fluid Flow in the Spinal Subarachnoid Space Studied with Computational Fluid Dynamics

  S Linge, E Løvgren, K -A Mardal, V Haughton, H P Langtangen
  Proceedings of the ASNR 47th Annual Meeting, Vancouver, Canada;
• Article: Effect of tonsilar herniation on cyclic CSF flow studied with computational flow analysis

  S Linge, V Haughton, A E Løvgren, K -A Mardal, Anders Helgeland, H P Langtangen
  American Journal of Neuroradiology.
• Conference Proceeding: CFD Analysis of Cerebrospinal Fluid Flow in the Cranio-Cervical Region

  A E Løvgren, S Linge, K -A Mardal, V Haughton, H P Langtangen
  Proceedings from the 21st Nordic Seminar on Computational Mechanics (NSCM-21);
• Conference Proceeding: Cyclic Cerebrospinal Fluid Flow (I): Towards the Understanding of Cerebrospinal Fluid Flow Dynamics in Chiari I Malformation

  S Linge, V Haughton, A E Løvgren, K -A Mardal, A Helgeland, H P Langtangen, K -H Støverud
  ASNR 49th Annual Meeting and the Foundation of the ASNR Symposium;
• Article: CSF Flow Dynamics at the Cranio-Vertebral Junction Studied with an Idealized Model of the Subarachnoid Space and Computational Flow Analysis

  S Linge, A E Løvgren, K -A Mardal, V Haughton, H P Langtangen
  American Journal of Neuroradiology. 31:185–192.