Wietske van der Zwaag1, 2, Mayur Narsude1, Joo Jorge3, Jos Pedro Marques1, 2, Rolf Gruetter1, 2
1Universit de Lausanne, Lausanne, VD, Switzerland; 2LIFMET, EPFL, Lausanne, VD, Switzerland; 3Instituto Superior Tcnico, Lisbonne, Switzerland
Physiological noise can prohibit the detection of BOLD signal variations. The movement of the brainstem during the cardiac cycle amplifies this problem locally. In this study, the effect of (1) temporal resolution of a 3D-EPI acquisition and (2) physiological noise removal on BOLD detection in primary auditory cortex AI and the brainstem were investigated. Physiological noise removal was essential for BOLD signal detection in the brainstem at the axial slice orientation used. In addition, higher temporal resolution increased the number of active voxels significantly. Increases in BOLD sensitivity with shorter TR and physiological noise removal were also found in AI.