A Novel Approach to Estimate Whole-Brain Dynamic Cerebral Autoregulation using Task-fMRI

The limitation of estimating Dynamic Cerebral Autoregulation (dCA) using Transcranial Doppler ultrasound is the lack of whole-brain estimation capabilities. In this study, the data acquisition of whole-brain task-fMRI scan during a novel Passive Cyclical Leg Raise (PCLR) task allows us to induce blood pressure (BP) changes. A surrogate BP signal was acquired from the brain stem and depicts expected fluctuations based on the PCLR-task design. The whole-brain dCA was estimated using voxel-wise TFA to obtain the transfer gain, coherence, and phase-offset. These results show similar significant brain regions but with distinct values based on the participant’s varying level of constitution.