Changwei Wesley Wu1,2, Jyh-Horng Chen1, Elliot A. Stein2, Yihong Yang2
1Electrical Engineering, National Taiwan University, Taipei, Taiwan; 2Neuroimaging Research Branch, National Institute on Drug Abuse, Baltimore, MD, USA
The contrast-to-noise ratio of the spontaneous fMRI signal fluctuations remains inconclusive. In this work, a multiple gradient-echo sequence was applied to evaluate and optimize the echo time on functional connectivity targeting at the so-called default mode network. Results show that both spatial and spectral features of the spontaneous fluctuation would be modulated by the echo time, and an optimal echo time can be retrieved for maximal connectivity strength at 3T.