ImagingSequences - MRC CBU Imaging Wiki

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CBU default imaging sequences

Introductory note

CBU_EPI

For fMRI

Description

Standard EPI sequence for fMRI

Acquisition time

2 s (per volume)

Type

2D

Slices

32

Slice gap

25%

Slice thickness

3 mm

Slice order

Descending (32,31,...,1)

FOV

192 mm x 192 mm

Matrix

64 x 64

Resolution

3 mm x 3mm

TR

2000 ms

TE

30 ms

Flip angle

78 deg

Bandwidth

2232 Hz/Px

Echo spacing

0.51 ms

Trigger pulse timing

To within a few ms, the stimulus delivery trigger pulse happens 35 ms before the acquisition of the first scan (centre of k space) of each volume. Note there is a latency of 20 ms in the visual display. The trigger pulse length is 1 ms.

CBU_MPRAGE

Description

High-resolution structural MRI

Acquisition time

4 min 16 s

Type

3D

FOV

256 mm x 240 mm x 160 mm

Matrix

256 x 240 x 160

Resolution

1 mm isotropic

TR

2250 ms

TI

900 ms

TE

2.99 ms

Flip angle

9 deg

Parallel imaging

GRAPPA BR Acceleration factor PE: 2 BR Reference lines PE: 24

CBU_TSE

Description

T2-weighted structural MRI

Acquisition time

1 min 38 s

Slices

29

Slice gap

30%

Slice thickness

4 mm

Type

2D

FOV

220 mm x 220 mm

Matrix

320 x 320

Resolution

0.7 x 0.7 mm

TR

5060 ms

TE

102 ms

Flip angle (refoc. pulse)

140 deg

Parallel imaging

GRAPPA BR Acceleration factor PE: 2 BR Reference lines PE: 26

CBU_Fieldmapping

Description

Magnetic field mapping sequence. Required for BR - undistortion of fMRI data BR - functional sensitivity mapping

Acquisition time

54 s

Type

2D

Slices

32

Slice gap

25%

Slice thickness

3 mm

FOV

192 mm x 192 mm

Matrix

64 x 64

Resolution

3 mm x 3 mm

TR

400 ms

TE

5.19 ms / 7.65 ms

Flip angle

60 deg