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Hi Paul, How different are the TE's? Because if you have different TE value's then you have data from two different spin ensembles. There is no algorithm (that I know of anyway) that can compensate for the measurement being made on different sets of spins that will allow these data to be combined in the sense of them being equivalent in the processing. If it's a 1ms difference you are probably ok, but if it's 10ms, I think you are going to have to try a different approach other than simple combination. regards, Karl > Dear all > If these two DTI dataset have different TE value, could I use the simple > concatenation approach to analyze this dataset or need to consider some > "adjustment" approach for this dataset ? > >> Date: Fri, 13 Jun 2014 00:21:06 +0200 >> From: [log in to unmask] >> Subject: Re: [FSL] combining multiple dti acquisitions before running >> dtifit >> To: [log in to unmask] >> >> Hi, >> if you do >> bet nodif nodif_brain -m >> >> you can spare >> fslmaths nodif_brain -bin nodif_brain_mask >> >> Otherwise it looks good. >> Cheers, >> Andreas >> >> Am 12.06.14 21:57 schrieb "Sarah Wyn" unter <[log in to unmask]>: >> >> >Hello, >> > >> >I have two sets of diffusion data for each of my participants (each >> set >> >is 32 directions). If I want to combine them before running dtifit is >> >the following code correct? In particular, do I need to do anything >> in >> >between running eddy_correct and bet to somehow average the two >> >acquisitions?? >> > >> >fslmerge -t combo.nii.gz data1.nii.gz data2.nii.gz >> > >> >eddy_correct combo 0 >> > >> >fslroi data nodif 0 1 >> >bet nodif nodif_brain >> >slicer nodif nodif_brain -a nodif_overlay.png >> >fslmaths nodif_brain -bin nodif_brain_mask >> > >> >dtifit --data=data --out=dti --mask=nodif_brain_mask --bvecs=bvecs >> >--bvals=bvals >> > >> >Any and all help greatly appreciated!! >> > >> >Best, >> > >> >Sarah > -- Karl Helmer, PhD Athinoula A Martinos Center for Biomedical Imaging Massachusetts General Hospital 149 - 13th St Room 2301 Charlestown, MA 02129 (p) 617.726.8636 (f) 617.726.7422 [log in to unmask] The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.