Multiband multislice GE‐EPI at 7 tesla, with 16‐fold acceleration using partial parallel imaging with application to high spatial and temporal whole‐brain fMRI

TLDR

The study applied multiband radiofrequency excitation with reduced k‑space coverage to human gradient‑echo fMRI at 7 T to increase volumetric coverage and achieve concurrent high spatial and temporal resolution. Using simultaneous acquisition of four coronal slices separated by 44 mm and 4‑fold phase‑encoding undersampling, the authors achieved 16‑fold acceleration, enabling whole‑brain functional mapping at 7 T with 2 × 2 × 2 mm (TR 1.25 s) and 1 × 1 × 2 mm (TR 1.5 s) resolutions. Multiband fMRI produced task‑induced signal changes and temporal behavior comparable to standard single‑band excitation, and demonstrated robust whole‑brain functional mapping at 7 T with high spatial and temporal resolution. Published in Magn Reson Med 63:1144–1153 (2010); © 2010 Wiley‑.

Abstract

Abstract Parallel imaging in the form of multiband radiofrequency excitation, together with reduced k ‐space coverage in the phase‐encode direction, was applied to human gradient echo functional MRI at 7 T for increased volumetric coverage and concurrent high spatial and temporal resolution. Echo planar imaging with simultaneous acquisition of four coronal slices separated by 44mm and simultaneous 4‐fold phase‐encoding undersampling, resulting in 16‐fold acceleration and up to 16‐fold maximal aliasing, was investigated. Task/stimulus‐induced signal changes and temporal signal behavior under basal conditions were comparable for multiband and standard single‐band excitation and longer pulse repetition times. Robust, whole‐brain functional mapping at 7 T, with 2 × 2 × 2mm 3 (pulse repetition time 1.25 sec) and 1 × 1 × 2mm 3 (pulse repetition time 1.5 sec) resolutions, covering fields of view of 256 × 256 × 176mm 3 and 192 × 172 × 176mm 3 , respectively, was demonstrated with current gradient performance. Magn Reson Med 63:1144–1153, 2010. © 2010 Wiley‐Liss, Inc.