Diffusion magnetic resonance imaging study of a rat hippocampal slice model for acute brain injury (2003)

Author(s): Shepherd TM, Thelwall PE, Blackband SJ, Pike BR, Hayes RL, Wirth ED III

    Abstract: Diffusion magnetic resonance imaging (MRI) provides a surrogate marker of acute brain pathology, yet few studies have resolved the evolution of water diffusion changes during the first 8 hours after acute injury, a critical period for therapeutic intervention. To characterize this early period, this study used a 17.6-T wide-bore magnet to measure multicomponent water diffusion at high b-values (7 to 8,080 s/mm(2)) for rat hippocampal slices at baseline and serially for 8 hours after treatment with the calcium ionophore A23187. The mean fast diffusing water fraction (Ffast) progressively decreased for slices treated with 10-microM/L A23187 (-20.9 +/- 6.3% at 8 hours). Slices treated with 50-micromol/L A23187 had significantly reduced Ffast 80 minutes earlier than slices treated with 10-microM/L A23187 (P < 0.05), but otherwise, the two doses had equivalent effects on the diffusion properties of tissue water. Correlative histologic analysis showed dose-related selective vulnerability of hippocampal pyramidal neurons (CA1 > CA3) to pathologic swelling induced by A23187, confirming that particular intravoxel cell populations may contribute disproportionately to water diffusion changes observed by MRI after acute brain injury. These data suggest diffusion-weighted images at high b-values and the diffusion parameter Ffast may be highly sensitive correlates of cell swelling in nervous issue after acute injury.

      • Date: 01-12-2003
      • Journal: Journal of Cerebral Blood Flow & Metabolism
      • Volume: 23
      • Issue: 12
      • Pages: 1461-1470
      • Publisher: Nature Publishing Group
      • Publication type: Article
      • Bibliographic status: Published

      Keywords: Acute Disease Animals Brain Injuries/*pathology Brain Ischemia/*pathology Calcimycin/pharmacology Diffusion *Diffusion Magnetic Resonance Imaging Disease Models, Animal Edema/pathology Hippocampus/*injuries/*pathology Ionophores/pharmacology Male Neurons/drug effects/pathology Organ Culture Techniques Rats Rats, Long-Evans Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S.


      Dr Peter Thelwall
      William Leech Reader in Magnetic Resonance Physics