Correcting dynamic distortions in 7T echo planar imaging using a jittered echo time sequence.

ABSTRACT:

Purpose

To develop a distortion correction method for echo planar imaging (EPI) that is able to measure dynamic changes in B₀ .

Theory and methods

The approach we propose is based on single-echo EPI with a jittering of the echo time between two values for alternate time points. Field maps are calculated between phase images from adjacent volumes and are used to remove distortion from corresponding magnitude images. The performance of our approach was optimized using an analytical model and by comparison with field maps from dual-echo EPI. The method was tested in functional MRI experiments at 7T with motor tasks and compared with the conventional static approach.

Results

Unwarping using our method was accurate even for head rotations up to 8.2°, where the s

SUBMITTER: Dymerska B 

PROVIDER: S-EPMC5082535 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature