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Abstract #0662

Towards T2 Weighted fMRI of the Whole Brain at Ultra-High Fields

Ritter J, van de Moortele P, Ugurbil K, Goerke U
University of Minnesota

Spin Echo (SE) BOLD based Functional Magnetic Resonance Imaging (fMRI) is less sensitive to the extra vascular response from larger vessels and, at ultra-high magnetic fields, is less sensitive to blood contributions to functional mapping signals. Hence, SE fMRI is less contaminated by contributions which may originate far from the actual site of neuronal activation than Gradient-recalled Echo (GE) fMRI. A major disadvantage of SE fMRI signals is that the mapping signals are inherently weak. However, they increase supralinearly with magnetic field and attain usable magnitudes at ~7 Tesla or above. Thus, SE fMRI at ultra-high magnetic fields provide a high contrast-to-noise ratio (CNR) and high spatial accuracy method for functional mapping (see for instance [1], [2]). Specific absorption rate (SAR) considerations, however, have been a limiting factor in pursuing multi slice SE Echo-Planar Imaging (EPI) at ultra high field strengths. In this study, a slab wise T2 magnetization preparation followed by a multis