Reliability of BBB water exchange rate assessed by diffusion‐prepared pseudo‐continuous ASL (DP‐pCASL): Preliminary results from the Cognitive Recovery After Elective Surgery (CREATES) Study

Impaired blood‐brain barrier (BBB) function is hypothesized to be an important mechanism in the development of perioperative neurocognitive disorders (postoperative delirium and postoperative cognitive impairment), as well as in the onset and progression of Alzheimer’s (AD) and cerebrovascular disease. Non‐contrast neuroimaging methods have shown promise for detecting subtle alterations in BBB permeability; however, test‐retest reliability has not been well‐established. Here we report preliminary results for BBB water exchange rate (kw ) values from a novel diffusion‐prepared 3D pseudo‐continuous arterial spin labeling (DP‐pCASL) protocol with two different post‐labeling delays (PLD), and compared test‐retest reliability results with the original approach with a single PLD.