Reproducibility and feasibility of optic nerve diffusion MRI techniques: single-shot echo-planar imaging (EPI), readout-segmented EPI, and reduced field-of-view diffusion-weighted imaging

Table 1 Magnetic resonance imaging sequence parameters

	T2w imaging	rs-EPI DWI	rFOV DWI	ss-EPI DWI
TR (ms)	4400	4650	3500	3700
TE (ms)	99	68	65	80
FOV (mm²)	180 × 180	180 × 108	120 × 98	210 × 210
Voxel size (mm²)	0.5 × 0.5 × 2.5	1.1 × 1.1 × 2.5	1.3 × 1.3 × 2.5	1.8 × 1.8 × 2.5
b-value (s/mm²)	–	0, 1000	0, 1000	0, 1000
Diffusion directions	–	3	3	3
Averages per b-value	–	2,2	2,10	2,10
PAT mode	GRAPPA	GRAPPA	GRAPPA	GRAPPA
Acceleration factor PE	2	2	2	2
In-plane resolution (mm²)	0.5 × 0.5	1.1 × 1.1	1.3 × 1.3	1.8 × 1.8
Slice thickness (mm)	2.5	2.5	2.5	2.5
Base resolution	384	160	96	120
Echo spacing (mm)	11.0	0.36	0.99	0.76
Bandwidth (Hz/px)	250	679	1158	1488
EPI factor	–	96	78	120
B0 Shim mode	Standard	Standard	Standard	Standard
TA (min)	1:47	3:12	2:03	2:11

rs-EPI DWI, readout-segmented echo-planar imaging diffusion-weighted imaging; rFOV, reduced field-of-view; ss-EPI, single-shot echo-planar imaging; TE, echo time; TR, repetition time, TA, acquisition time, GRAPPA: generalized autocalibrating partially parallel acquisitions

ISSN: 1471-2342