Hanzhang Lu1, Joanna Hutchison2, Feng Xu1, Bart Rypma2
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Center for BrainHealth, University of Texas at Dallas, Dallas, TX, United States
The calibrated fMRI technique requires a hypercapnia or hyperoxia calibration experiment in order to estimate the factor M. It would be desirable to be able to obtain the M value without the need of a gas challenge calibration. According to the analytical expression of M, it is a function of two baseline physiologic parameters, baseline CBF and baseline venous oxygenation, both of which have recently been shown to be significant modulators of fMRI signal. Here we studied the relationship among M, baseline CBF and baseline venous oxygenation, and assessed the possibility of estimating M from the baseline physiologic parameters.