Test-retest reliability of Cerebral Blood Flow and Cerebrovascular Reactivity using novel M2-PCASL sequence in healthy adults.

Motivation: Cerebrovascular parameters may contribute to Alzheimer's Disease and could function as early biomarkers. It is critical to establish noninvasive and reliable methods for measuring these parameters. Goal(s): We aim to assess the reliability of vascular parameters obtained with a novel multiband M2-PCASL sequence that simultaneously measures CBF and BOLD and to examine factors influencing their reliability. Approach: We use the M2-PCASL sequence and in-house pipelines to quantify perfusion and cerebrovascular reactivity in a test-retest study to determine the reliability of our method and factors influencing reliability. Results: Our method reliably estimates perfusion and CVR. Motion was a significant source of parameter variability. Impact: Reliable estimation of cerebrovascular parameters is essential for scientists and clinicians to study these parameters in neurodegenerative diseases such as Alzheimer's Disease and will enable the discovery of disease biomarkers and potential drug targets for therapeutics.