Hi Anastasia, Thank you for your response. I think I figured out what was the problem: The delimiter for the 3 column .bvec file MUST be SPACE/TAB, otherwise the program fails to reshape it correctly. In my case the delimiter was "," and the program was reading only the 1st column of it.
I have one more question: I know that FA values might differ from study to study and from MRI to MRI, but what is a reasonable range for that after analysis with Tracula? In your study (20011) the range was ~ 0.3-0.6. But for in elderly population the average is around 0.2 higher. Does it sound normal to you? I was not able to find any study using your method in elderly population for comparison. Thank you, Ali ________________________________________ From: Anastasia Yendiki [ayend...@nmr.mgh.harvard.edu] Sent: Tuesday, April 30, 2013 3:11 PM To: Ali Ezzati Cc: freesurfer@nmr.mgh.harvard.edu Subject: Re: [Freesurfer] TRACULA outputs out of expected range Hi Ali - This is unusual. It may have something to do with system settings. Can you send an example of the two versions of the bvecs files that have the different values? Thanks, a.y On Mon, 29 Apr 2013, Ali Ezzati wrote: > Hello Experts, > I would be grateful if you could help me with this problem: > > I was able to run all steps of TRACULA on several subjects without any error > message, but all the final > outcomes (FA,MD,RD,AD values) are out of the expected range (i.e average FA > values for all tracts are >1). > > I tried to identify the source of this problem... clearly FA values in > "dmri/dtifit_FA", which is an output > of "prep" step are all out of range. The only source of error that I can > think of is .bvecs file. My input > .bvecs files are in 3 columns, exactly as described in the manual. > > There are two .bvecs file in the "dmri" folder. one is > "dwi_orig.mghdti.bvecs" which is exactly the same as > my input .bvecs file and the other one's name is just "bvecs", which has > completely different values. Could > this be the source of my problem? or something else is causing this. > > Thank you, > Ali > > > > 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. _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
