Lin Z, Sur S, Liu P, et al. - In this investigation involving 55 elderly participants (age = 68.4 ± 7.3 years, 26 males, 29 females), researchers sought to measure human blood-brain barrier (BBB) function in mild cognitive impairment (MCI) patients on 2 molecular scales, specifically BBB's permeability to water and albumin molecules. The sample consisted of 33 MCI patients and 22 controls. BBB permeability to water was measured with a new MRI technique, water extraction with phase-contrast arterial spin tagging. BBB in MCI patients had greater permeability to small molecules like water but was no more permeable to large molecules like albumin as compared with cognitively normal people.