Hi!
Look here:
----- Message transféré de [log in to unmask] -----
Date : Sun, 20 Jan 2008 14:42:57 -0500
De : Matt Glasser <[log in to unmask]>
Répondre à : FSL - FMRIB's Software Library <[log in to unmask]>
Objet : Re: [FSL] DTI-- mean of two runs
À : [log in to unmask]
The mean will have better SNR than the individual scans. You could do
something like this to motion correct your data and get the mean:
fslmerge -t big4d <data1> <data2>
eddy_correct big4d big4d_corr 0
fslroi big4d_corr av1_corr 0 <# of volumes in a single average>
fslroi big4d_corr av2_corr <# of volumes in a single average> <# of volumes
in a single average>
fslmaths av1_corr -add av2_corr -div 2 <data>
These commands merge the two averages into a single file for motion
correction, then split out the motion corrected averages, and then get the
mean.
Peace,
Matt.
-----Original Message-----
From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On Behalf
Of Jiansong Xu
Sent: Sunday, January 20, 2008 2:31 PM
To: [log in to unmask]
Subject: [FSL] DTI-- mean of two runs
Dear Friends:
I'm using FSL (FDT) to analyze DTI data acquired with a Simens Trio 3
T scanner. Each subject had two scans with same parameters. My
question is: is the mean image of the two scans better than either
one of the two scans? If so, how to get the mean of the two images?
Best
Jiansong
----- Fin du message transféré -----
Quoting Diana Tordesillas <[log in to unmask]>:
> Dear FSL experts,
>
> I have 2 DTI adquisitions from the same subject-same session that would like
> to average. It is not clear to me if I should (and how) average before FDT
> or once I have processed both images. I am quite new to DTI processing and
> still playing around with FSL's tools for DTI.
>
> Thank you ,
>
> Diana
>
--
Dr. med. Markus Gschwind, M.D.
Laboratory for Neurology and Imaging of Cognition
Dept of Neurosciences
University Medical Center (CMU)
1 Michel-Servet - 1211 GENEVA - CH
Tel 0041 (0) 22 379 5324
Fax 0041 (0) 22 379 5402
email: [log in to unmask]
http://labnic.unige.ch
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