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In vivo Measurement of Intra- and Extracellular Space of Brain Tissue by Electrical Impedance Method

  • Sadao Suga
  • S. Mitani
  • Y. Shimamoto
  • T. Kawase
  • S. Toya
  • K. Sakamoto
  • H. Kanai
  • M. Fukui
  • N. Takeneka
Conference paper
Part of the Acta Neurochirurgica book series (NEUROCHIRURGICA, volume 51)

Summary

An impedance method was applied to evaluate transcellular fluid shifts in ischaemic brain oedema. The admittances (apparent electrical conductivities) of tissues were measured at varied frequencies based on a simple model of an electrical equivalent circuit for tissues, which consisted of Re (resistivity of extracellular fluid), Ri (resistivity of intracellular fluid) and Cm (capacitance of cell membrane). Calculated were Re, Ri, Rinf (resistivity of total fluid), Re/Ri and alpha (Cole-Cole distribution index) of brain tissue by Cole-Cole an arc of a circle. During ischaemia induced by cat middle cerebral artery occlusion (MCAO), the parameters were examined continuously.

After MCAO, cerebral blood flow (CBF) decreased to under 10 m1/100 g/min. Then Re and Re/Ri increased, but Ri decreased. These results indicated that fluid shift from extracellular (EC) to intracellular (IC) space occurred after ischaemic insult. Rinf showed no changes during ischaemia of 30 min, which demonstrated no changes of total fluid volume.

Using this impedance technique, fluid accumulation and shift may be examined by changes of Re, Ri, Re/Ri and Rinf in various types of brain oedema in vivo.

Keywords

Cerebral Blood Flow Middle Cerebral Artery Occlusion Brain Oedema Electrical Impedance Impedance Method 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

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Copyright information

© Springer-Verlag 1990

Authors and Affiliations

  • Sadao Suga
    • 5
  • S. Mitani
    • 1
  • Y. Shimamoto
    • 1
  • T. Kawase
    • 1
  • S. Toya
    • 1
  • K. Sakamoto
    • 2
  • H. Kanai
    • 2
  • M. Fukui
    • 3
  • N. Takeneka
    • 4
  1. 1.Department of Neurosurgery, School of MedicineKeio UniversityTokyoJapan
  2. 2.Faculty of Science and TechnologySophia UniversityBulgaria
  3. 3.Faculty of Science and EngineeringTokyo Denki UniversityTokyoJapan
  4. 4.Department of NeurosurgeryAshigkaga Red Cross HospitalTokyoJapan
  5. 5.Department of Neurosurgery, School of MedicineKeio UniversityShinjuku-ku, Tokyo 160Japan

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