Premium
Simultaneous multislice spectral‐spatial excitations for reduced signal loss susceptibility artifact in BOLD functional MRI
Author(s) -
Anderson Robert J.,
Poser Benedikt A.,
Stenger V. Andrew
Publication year - 2014
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25050
Subject(s) - voxel , signal (programming language) , multislice , pulse (music) , scanner , artifact (error) , magnetic resonance imaging , biomedical engineering , materials science , nuclear magnetic resonance , medicine , nuclear medicine , optics , computer science , physics , artificial intelligence , radiology , detector , programming language
Purpose Simultaneous multislice (SMS) imaging can significantly increase image acquisition rates and improve temporal resolution and contrast in gradient‐echo blood oxygen level–dependent (BOLD) functional MRI (fMRI) experiments. Through‐plane signal loss due to B 0 inhomogeneities at air–tissue interfaces limits fMRI of structures near the nasal cavity and ear canals. This study implemented spectral–spatial (SPSP) radiofrequency pulses for reduced through‐plane signal loss across multiple simultaneously excited slices. Theory and Methods Multiband (MB) and power independent of number of slices (PINS) methods are combined with SPSP excitation for signal loss compensation in slice‐accelerated human brain imaging. Nine simultaneous slices of 5‐mm thickness and 20 mm apart were excited using standard MB radiofrequency pulses and the proposed SPSP‐SMS pulses, yielding coverage of 36 slices in four shots with 350‐ms volume pulse repetition time. The pulses were compared in breath‐hold fMRI at 3T. Results The SPSP‐SMS pulses recovered ∼45% of voxels with signal loss in standard SMS images. Activation in areas of signal recovery increased by 26.4% using a 12.6‐ms SPSP‐MB pulse and 20.3% using a 12.1‐ms SPSP‐PINS pulse. Conclusions It is demonstrated that SPSP‐SMS pulses can improve BOLD sensitivity in areas of signal loss across simultaneous multiple slices. Magn Reson Med 72:1342–1352, 2014. © 2013 Wiley Periodicals, Inc.