During a resting-state fMRI scan, both structural imaging and gradient-echo
echo-planar imaging T2* weighted sequences are taken to measure to brain activity (8).
The development of
echo-planar imaging (fast gradient echo sequence), a fast magnetic resonance imaging (MRI) method, eliminated prolonged imaging time and associated artifacts observed with conventional sequences and allowed use of DWI for evaluation of abdominal organs (2).
Different pulse sequences were applied: 2D axial and coronal T2-weighted turbo spin echo (TSE) sequences, 2D axial
echo-planar imaging (EPI) sequence at different b values (b: 0, 500, 800 s/[mm.sup.2]), and 2D T1-weighted axial dual fastfield-echo (FFE) breath-hold sequence.
Parameters were as follows: transverse view T1 Weighted Image (T1WI) (time of repetition (TE): 300 ~ 500 ms; time of echo (TE): 8 ~ 12 ms), Fast Spin Echo (FSE) (TR: 2500 ~ 5000 ms; TE 90 ~ 102 ms), fluid attenuated inversion recovery (FLAIR) (TR: 8002 ms; TE: 104 ms),
echo-planar imaging - diffusion weighted imaging (EPI-DWI) (TR: 7100 ms; TE: 129 ms); sagittal view spin echo T1WI (TR: 300 ~ 500 ms; TE: 8 ~ 12 ms); coronal view FSE T2WI (TR: 2500 ~ 5000 ms; TE: 90 ~ 102 ms).
These include single-shot
echo-planar imaging (SS-EPI), sagittal spin-echo SS-EPI (SE-SS-EPI), single-shot fast spin-echo (SS-FSE), and FSE.
Diffusion-weighted images were acquired in the transverse plane using a spin-echo
echo-planar imaging sequence with diffusion-gradient encoding in three orthogonal directions.
DWI is
echo-planar imaging that measures brownian motion of water molecules (i.e.
(18,19) These are referred to as a spin-and gradient-echo
echo-planar imaging (SAGE EPI) MRI.
Scientists from the University of Nottingham used an ultra-fast MRI scanning technique called
echo-planar imaging to image the volunteers' stomachs in real time until they looked empty.
Functional MRI data were acquired on a 3-Tesla scanner using a 2D gradient
echo-planar imaging sequence during two modified Stroop paradigms.