Variable flip angle 3D-GRASE for high resolution fMRI at 7 tesla.

ABSTRACT:

Purpose

To evaluate the use of variable flip angle refocusing pulse trains in single-shot three-dimensional gradient and spin-echo (3D-GRASE) to reduce blurring and increase the spatial coverage for high spatial resolution T2 -weighted functional MRI at 7 Tesla.

Methods

Variable flip angle refocusing schemes in 3D-GRASE were calculated based on extended phase graph theory. The blurring along the slice (partition) direction was evaluated in simulations, as well as phantom and in vivo experiments. Furthermore, temporal stability and functional sensitivity at 0.8 mm isotropic resolution were assessed.

Results

Variable flip angle refocusing schemes yielded significantly reduced blurring compared with conventional refocusing schemes, with the full width at half maximum bei

SUBMITTER: Kemper VG 

PROVIDER: S-EPMC4801698 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature