Non-contrast measurement of BBB permeability using an accelerated WEPCAST MRI with velocity-selective single-shot acquisition

Motivation: WEPCAST MRI was proposed for non-contrast measurement of BBB permeability, but is limited to long scan duration and sensitive to motion due to its double-subtraction scheme. Goal(s): This study aimed to design a motion-robust and accelerated WEPCAST sequence. Approach: The proposed sequence employed a velocity-selective single-shot acquisition as an alternative to the original phase-contrast for isolating the arterially-labeled spins in the vein. Sequence parameters were optimized. The validity and reproducibility were also examined. Results: VS-WEPCAST reduced scan duration from 6 to 3 minutes, while keeping a strong consistency with the original WEPCAST technique. Test-retest results indicate good reproducibility. Impact: This study proposed an accelerated velocity-selective WEPCAST technique that enables the assessment of global BBB permeability to water in nearly half the original scan time, with improved robustness to motion and cardiac pulsation.