Multi-band SWIFT enables quiet and artefact-free EEG-fMRI and awake fMRI studies in rat

Publication date: Available online 12 November 2019Source: NeuroImageAuthor(s): Jaakko Paasonen, Hanne Laakso, Tiina Pirttimäki, Petteri Stenroos, Raimo A. Salo, Ekaterina Zhurakovskaya, Lauri J. Lehto, Heikki Tanila, Michael Garwood, Shalom Michaeli, Djaudat Idiyatullin, Silvia Mangia, Olli GröhnAbstractFunctional magnetic resonance imaging (fMRI) studies in animal models provide invaluable information regarding normal and abnormal brain function, especially when combined with complementary stimulation and recording techniques. The echo planar imaging (EPI) pulse sequence is the most common choice for fMRI investigations, but it has several shortcomings. EPI is one of the loudest sequences and very prone to movement and susceptibility-induced artefacts, making it suboptimal for awake imaging. Additionally, the fast gradient-switching of EPI induces disrupting currents in simultaneous electrophysiological recordings. Therefore, we investigated whether the unique features of Multi-Band SWeep Imaging with Fourier Transformation (MB-SWIFT) overcome these issues at a high 9.4 T magnetic field, making it a potential alternative to EPI. MB-SWIFT had 32-dB and 20-dB lower peak and average sound pressure levels, respectively, than EPI with typical fMRI parameters. Body movements had little to no effect on MB-SWIFT images or functional connectivity analyses, whereas they severely affected EPI data. The minimal gradient steps of MB-SWIFT induced significantly lower currents in simu...
Source: NeuroImage - Category: Neuroscience Source Type: research