TR and TE Dependence on Low Frequency BOLD Fluctuations

Matthew Evan Magnuson¹, Wenju Pan¹, Waqas Majeed¹, Garth Thompson¹, Shella Keilholz¹

Low freqnecy fluctuations in resting state BOLD data have often been used to map functional connectivity in the rat brain. These low frequency BOLD fluctuations contain contributions from CBF, CBV, and CMRO2. Each of these components have unique physiological time signatures and effective echo times; therefore, modification of the TR and TE used in resting state scans should result in altered contributions from each BOLD component. In this study we examine the dependence of the selection of the TR and TE variables on low frequency resting state data.