Qihong Zou1,2, JiongJiong Wang3, Hong Gu1, Yufeng Zang2, Yihong Yang1
1Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States; 2State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China; 3Center for Functional Neuroimaging and Department of Radiology and Neurology, School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
Amplitude of low-frequency fluctuations (ALFF) has been used to quantify the strength of spontaneous fluctuations of fMRI signal in the resting state. However, its underlying physiological/biophysical mechanisms are unknown. In this study, the relationship between BOLD fluctuation amplitude and resting-state cerebral blood flow (CBF) were investigated. Our results showed that ALFF of BOLD and CBF were positively correlated within multiple cortical and subcortical networks. These findings provided first evidences that ALFF is related to baseline CBF and likely reflects the level of spontaneous neuronal activity.