Development and evaluation of alternative methods for functional magnetic resonance imaging at 7 Tesla

Abstract

Within the last decade, magnetic resonance imaging (MRI) scanners with ultra-high magnetic field strengths of 7 Tesla and above have become available. While high magnetic fields provide theoretical improvements in the nuclear magnetic resonance signal-to-noise ratio (SNR) and in the blood-oxygenation-level dependent (BOLD) contrast used for functional brain imaging, they also introduce technical issues such as increased bulk magnetic susceptibility effects and increased physiological noise in human data. Acquiring MRI data with multiple receiver coils in parallel can alleviate some of these issues at a cost to SNR and BOLD sensitivity that depends on several experiment-specific factors. This work attempts to address some of the issues surrounding high field fMRI in the context of parallel imaging and suggests methods for realizing the theoretical benefits of functional MRI with high magnetic fields.