Diffusion-weighted Imaging¶

Acquisition parameters¶

Three types of diffusion sequences were employed in three different sessions, respectively:

High-resolution (1.3mm isotropic, 60 directions) acquisitions with \(B=1500\) or \(B=3000\).

Acquisition parameters for high-resolution diffusion imaging.¶
Parameter	Value
Sequence	diff_dw60_TE76
TR	7000 ms
TE	76 ms
Flip angle	90 deg
Refocusing flip angle	180 deg
FOV	240 mm
Slice thickness	1.30 mm
Number of slices	112 slices
GRAPPA iPAT	2
Multiband accel. factor	2
Echo spacing	0.71 ms
BW	1598 Hz/Px
Phase partial Fourier	6/8
b-values	[1500, 3000] s/mm²

Multi-shell (1.3mm isotropic, 20 directions) acquisitions for multiple B-values ranging from 300 to 3000 in steps of 300.

Acquisition parameters for multi-shell diffusion imaging.¶
Parameter	Value
Sequence	diff_dw26_TE76
TR	7000 ms
TE	76 ms
Flip angle	90 deg
Refocusing flip angle	180 deg
FOV	240 x 240 mm
Matrix	128 x 128
Slice thickness	1.30 mm, 112 slices, 1.30 mm isotropic
Multiband accel. factor	2
Echo spacing	0.71 ms
BW	1598 Hz/Px
Phase partial Fourier	6/8
b-values	[0, 300, 600, 900, 1200, 1500,
	1800, 2100, 1400, 2700, 3000] s/mm²

Two low-resolution acquisitions (2mm, 20 directions) used for screening.

Acquisition parameters for screening.¶
Parameter	Value
Sequence	diff_screening_2mmiso
TR	9000 ms
TE	66,00 ms
Flip angle	90 deg
Refocusing flip angle	180 deg
FOV	240 x 240 mm
Matrix	128 x 128
Slice thickness	2 mm isotropic, 70 slices
Multiband accel. factor	1
Echo spacing	0,54 ms
BW	2192 Hz/Px
Phase partial Fourier	6/8
b-values	0, 1500 s/mm²

Parameter	Value
Sequence	diff_dw20_MB
TR	5700 ms
TE	79,40 ms
Flip angle	90 deg
Refocusing flip angle	180 deg
FOV	240 x 240 mm
Matrix	160 x 160
Slice thickness	1,5 mm isotropic, 94 slices
Multiband accel. factor	2
Echo spacing	0,65 ms
BW	1838 Hz/Px
Phase partial Fourier	6/8
b-values	0, 1500 s/mm²