Noncontrast assessment of blood-brain barrier permeability to water: Shorter acquisition, test-retest reproducibility, and comparison with contrast-based method.

Single-delay WEPCAST MRI can measure BBB permeability to water within 5 min with an intrasession, intersession, and inter-vendor test-retest reproducibility of 6% to 9%. This method may provide a useful marker of BBB breakdown in clinical studies.