Blood‐CSF barrier permeability to water and contrast agent in neurodegenerative dementias

Motivation: Blood-CSF barrier (BCSFB) plays a vital role in neurodegenerative dementias, whereas its dysfunction is less explored. Goal(s): We aimed to propose a novel tracer kinetic model enabling a comprehensive investigation of BCSFB permeability to both water and contrast agents. Approach: We compared the BCSFB permeability across different diagnostic groups based on the proposed model, and further analyzed these results in relation to blood-brain barrier (BBB) permeability and cognitive performance. Results: We found that Alzheimer's dementia patients exhibited significantly reduced BCSFB permeability to water, but not to contrast agent. Additionally, BCSFB permeability emerged later in the progression of neurodegenerative dementia compared to BBB permeability. Impact: BCSFB permeability metrics derived from our novel tracer kinetic model, demonstrated significant correlations with BBB permeability and cognitive function. These findings suggest that BCSFB permeability could serve as a valuable imaging biomarker for comprehensive diagnostic metric together with BBB permeability.