Robust Detection of Functional Activation in the Superior Colliculus Without ECG-Triggering

Ute Goerke¹, Kamil Ugurbil¹

In fMRI, high spatial resolution is usually achieved by segmenting the echo-planar imaging (EPI) acquisition scheme. However, such images are susceptible to ghosting due to pulsatile flow of blood and cerebrospinal fluid (CSF), especially in regions near the brain stem. We propose a novel post processing technique, the spectral side band analysis (SSBA), to detect activation in deep brain structures without the need of ECG-triggering. This is demonstrated in a high resolution fMRI study of the superior colliculus stimulated with a visual paradigm.