Evidence of Incoherent Cerebrospinal Fluid Flow in the Human Brain From Multidimensional MRI.

Area of Science:

• Neuroimaging
• Fluid Dynamics
• Biomedical Engineering

Background:

• The brain contains diverse fluid types, including blood, cerebrospinal fluid (CSF), and tissue water.
• Intravoxel incoherent motion (IVIM) imaging is established for microvascular perfusion assessment.
• Emerging evidence suggests IVIM may also detect incoherent CSF flows.

Purpose of the Study:

• To develop novel in vivo multidimensional MRI methods.
• To investigate the potential contributions of CSF in the IVIM regime.
• To characterize incoherent CSF dynamics in the human brain.

Main Methods:

• Acquired T1-Diffusion (T1-D) and T2-Diffusion (T2-D) MRI data from 10 healthy subjects.
• Investigated relaxivity and diffusion signatures of incoherent fluid flows.
• Developed T1/T2 selective IVIM protocols based on T1-D and T2-D findings.

Main Results:

• T1-D and T2-D MRI successfully detected incoherent CSF flow in the brain's subarachnoid space.
• Four distinct relaxation-selective IVIM methods corroborated the presence of incoherent CSF flows.
• Demonstrated feasibility of T1-D and T2-D MRI in the low b-value regime.

Conclusions:

• Established the feasibility of using T1-D and T2-D MRI to probe IVIM flow components.
• Developed relaxation-selective 1D IVIM acquisition within clinically feasible timeframes.
• Advanced the understanding of CSF dynamics using advanced MRI techniques.