Aaron Benjamin Simon1, Richard Buxton2
1Department of Bioengineering, University of California San Diego, La Jolla, CA, United States; 2Department of Radiology, University of California San Diego, La Jolla, CA, United States
We analyzed a novel method of quantitatively measuring CBF fluctuations during complex behavior without knowledge of stimulus dynamics, based on the combined measurement of BOLD and CBF time series. We hypothesized that projection of the ASL time series onto the BOLD time series would separate ASL fluctuations due to CBF from those due to noise. This method was tested on data from a visual stimulus experiment and was found to significantly remove noise from the ASL data, although it produced a small underestimate of CBF fluctuations due to the presence of noise in the BOLD signal.