Echo time dependence of basal ganglia activation at 3T during motor task
Van de Moortele P, Ugurbil K, Lehericy S
University of Minnesota
It is generally accepted that BOLD response should be higher when the echo time (TE) matches the T2* of the structure. Therefore, adapting the TE of BOLD gradient echo fMRI time series to T2* may improve signal detection in the globus pallidus, where ferromagnetic particles deposit normally with age, leading to reduced T2*. Activation volume did not change significantly at TE = 42 ms (T2* of the putamen) compared to TE = 28 ms (T2* of the globus pallidus) in these two structures. Therefore, there was no gain in decreasing the TE to match the T2* of the globus pallidus.