Description

Brain compliance is a parameter introduced very early to describe brain homeostasis with an intracranial pressure–volume relationship based on the Monro-Kellie doctrine. The intracranial constituents (blood, cerebrospinal fluid (CSF), and brain parenchyma) create a state of volume equilibrium to maintain a normal range of intracranial pressure (ICP) for a limited change in compartmental volume. Superior to the conventional invasive monitoring, magnetic resonance (MR) motion-sensitive imaging shows strength on in-vivo and non-invasive measurements of volume arterial inflow, venous blood outflow, and CSF movement method during a cardiac cycle, and therefore allows the compartmentalization of brain compliance [4-6]. We hypothesize that the CSF and venous blood are two key buffers for maintaining the brain parenchyma and sufficient cerebral perfusion. When the deficits of cerebral venous system occur, such as the cerebral venous hypertension (CVH), the brain compliance may reduce, reflecting the altered state of brain homeostasis. Because of the limited budget, we focused on the development of quantitative flow analysis platform in this one-year project, and left the research of rat CVH disease model (which required a half to one year to be built) in the future study. We employed the motion-sensitive MR techniques on a clinical 3T scanner for healthy subjects and a 7T scanner for rat to investigate the dynamic relation between the intracranial compartments, i.e., the arterial inflow, venous outflow, and CSF movement, within a cardiac cycle to reveal the underlying physiological mechanism. We also proposed a modified computational model to improve the accuracy and repeatability of MR-based measurement of brain compliance. MR techniques in imaging edema (diffusion weighted imaging), venous dilation (susceptibility weighted imaging), and oxygen extraction fraction (OEF) using quantitative susceptibility mapping were also included in the proposed platform. Based on the current outcomes of this project, we will extend the developed analysis platform of cerebral hydrodynamics and hemodynamics to the research of brain glymphatic system and meningeal lymphatic system under different disease models.
StatusFinished
Effective start/end date8/1/157/31/16

Keywords

  • brain compliance
  • intracranial pressure
  • motion-sensitive MRI
  • flow imaging
  • cerebral venous hypertension