Single-PLD ASL with 1800 msec PLD demonstrated the best balance of reliability and agreement with 15Owater PET, suggesting it may be an effective choice for studying CBF in aging and AD populations. While multiple-PLD ASL offered comparable performance, it did not confer notable benefits compared with the best-performing single-PLD under similar acquisition time constraints. These findings underscore the importance of PLD selection in ASL protocols in older or cognitively impaired cohorts and highlight the value of assessing intermediate-term reliability in longitudinal studies.
Fu et al. (Thu,) studied this question.