Joe S. Cheng1, 2, Iris Y. Zhou1, 2, Patrick P. Gao1, 2, Russell W. Chan1, 2, Ed X. Wu1, 2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, Hong Kong; 2Department of Electrical and Electronic Engineering, Hong Kong, Hong Kong
Resting-state functional MRI (rsfMRI) utilizing blood-oxygen-level-dependent (BOLD) contrast has increasingly used to map inter and intra-hemispheric connectivity in normal and diseased brains. However BOLD is a complex function of changes in oxygen metabolism, cerebral blood flow (CBF), and cerebral blood volume (CBV). While the effect of various gas inspirations including hypoxia on baseline and stimulus-evoked BOLD signal have been documented, how BOLD synchronization or rsfMRI can be affected by hypoxia has not been investigated. This study aims to assess the effect of graded hypoxia on BOLD rsfMRI connectivity in an animal model and shows that both mild and severe hypoxia suppressed BOLD rsfMRI connectivity significantly.