Neuroradiology

, Volume 34, Issue 5, pp 370–380

Pulsatile brain movement and associated hydrodynamics studied by magnetic resonance phase imaging

The Monro-Kellie doctrine revisited

Authors

  • D. Greitz
    • Department of NeuroradiologyKarolinska Hospital
  • R. Wirestam
    • Department of Radiation PhysicsLund University Hospital
    • Danish Research Centre of Magnetic ResonanceHvidovre Hospital
  • A. Franck
    • Department of Radiation PhysicsKarolinska Hospital
  • B. Nordell
    • Department of Hospital PhysicsKarolinska Hospital
  • C. Thomsen
    • Danish Research Centre of Magnetic ResonanceHvidovre Hospital
  • F. Ståhlberg
    • Department of Radiation PhysicsLund University Hospital
    • Danish Research Centre of Magnetic ResonanceHvidovre Hospital
Diagnostic Neuroradiology

DOI: 10.1007/BF00596493

Cite this article as:
Greitz, D., Wirestam, R., Franck, A. et al. Neuroradiology (1992) 34: 370. doi:10.1007/BF00596493

Summary

Brain tissue movements were studied in axial, sagittal and coronal planes in 15 healthy volunteers, using a gated spin echo MRI sequence. All movements had characteristics different from those of perfusion and diffusion. The highest velocities occurred during systole in the basal ganglia (maximum 1.0 mm/s) and brain stem (maximum 1.5 mm/s). The movements were directed caudally, medially and posteriorly in the basal ganglia, and caudally-anteriorly in the pons. Caudad and anterior motion increased towards the foramen magnum and towards the midline. The resultant movement occurred in a funnelshaped fashion as if the brain were pulled by the spinal cord. This may be explained by venting of brain and cerebrospinal fluid (CSF) through the tentorial notch and foramen magnum. The intracranial volume is assumed to be always constant by the Monro-Kellie doctrine. The intracranial dynamics can be viewed as an interplay between the spatial requirements of four main components: arterial blood, capillary blood (brain volume), venous blood and CSF. These components could be characterized, and the expansion of the arteries and the brain differentiated, by applying the Monro-Kellie doctrine to every moment of the cardiac cycle. The arterial expansion causes a remoulding of the brain that enables its piston-like action. The arterial expansion creates the prerequisites for the expansion of the brain by venting CSF to the spinal canal. The expansion of the brain is, in turn, responsible for compression of the ventricular system and hence for the intraventricular flow of CSF.

Key words

Magnetic resonance imagingBrain motionBrain volumeArterial expansionPulsation

Copyright information

© Springer-Verlag 1992