Susceptibility-Induced BOLD Sensitivity Variation in Breath Hold Task

Yue Zhuo¹, Bradley P. Sutton¹

Magnetic field inhomogeneity exists near the interface of air/tissue, leading to susceptibility artifacts including echo time shift. BOLD sensitivity has strong dependence on echo time, and thus is changed by the susceptibility gradients. We examined BOLD sensitivity change in a breath hold task among different subjects. The breath hold fMRI experiment analyzed to determine if susceptibility gradient induced BOLD sensitivity changes are observable within susceptibility regions in subjects. Results show a significant relationship between susceptibility gradients and BOLD signal in 81% of the subjects, which means the effect of susceptibility gradients on BOLD signal robustly exist among subjects.