Dear all,
I collect some DWI images, and I get some questions when using SPM.
MR imaging protocol
1) Information of MR imaging sequence:
T2WI(b-value=0 s/(mm^2)) and DWI(b-value=200 s/(mm^2)) were acquired alternatively.
The direction of the diffusion gradient is fixed at X axes.
So, the acquisition of the EPI series is T2WI-DXIx-T2WI-DWIx.... for the 150 excitations. (i.e, after a whole acquisition will get 75 T2WI and 75 DWI )
2) Then, I use this sequence to perform two experiments
a.
Each excitation obtained 21 axial slices covering from the cerebellum down to the angle of the jaw.
Slice thickness: 5mm
Slice gap: 0mm
TR: 2s
TE: 53.3 ms
b.
Each excitation obtained 11 axial slices covering from the cerebellum down to the angle of the jaw.
Slice thickness: 5mm
Slice gap: 5mm
TR: 1.053s
TE: 53.3 ms
Question
1) Slice timing
My data consists of T2WI images and DWI images because the sequence switches the diffusion gradient alternatively.
Should I separate my data into two group: T2WI and DWI ?
Then, how about the value of TR and TA field?
Is TR field same as my parameter (i.e TR field=2 for exp.a and TR field=1.053 for exp.b)?
Can I use TR-(TR/slice) for TA field?
And, whether slice gap influence the quality or not?
2)Realign
Because the coverage of my data is nearly neck images, not brain images. Can I use Realign in SPM for motion correction?
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