Brain Clearance Assessment Using the DTI-ALPS Index and Intrathecal Contrast Enhanced Magnetic Resonance Imaging

Motivation: To investigate if DTI-ALPS as a non-invasive method compared to intrathecal contrast enhanced magnetic resonance (gMRI) imaging can be used for evaluating human brain clearance function. Goal(s): To investigate whether or not DTI-ALPS can be used as a non-invasive alternative to gMRI. Approach: This study compared the ALPS index with brain clearance parameters derived from gMRI in a reference group (REF). Results: No significant relationships were found between the ALPS index and change in normalized T1w signal intensity from the gMRI data in both the distribution phase and clearance phase. Impact: The proposed DTI-ALPS index may not be a valid marker of glymphatic function.