 |
 |
Hi Sandra, I had a quick look at the different code versions since October 2008. Regarding dtifit and the FA calculation nothing has changed, I suspect the changes you observe do not reflect differences in the FA values, but differences in the min/max values in fslview that define contrast/brightness. If not, please let us know. Regarding bedpostx, there have been some changes, the major ones have to do with the initialization of the MCMC. These were incorporated in FSL 4.1.5 and in later versions. Cheers, Stam On 9 Sep 2011, at 21:18, Woodman, Sandra wrote: > Hi all, > > We have encountered something with our DTI data and are wondering if > anyone else has seen the same thing and if it has an impact on our data. > We have been working on a DTI analysis dataset for a few years (a lot of > methods development work went into this particular study), and we have > recently noticed that the FA maps that were unpacked and preprocessed in > October 2008 look, to the bare eye, brighter overall than those processed > in October 2009 and later. We tried loading them into the freesurfer > tkmedit tool and we did not see much of a difference, so we are wondering > if this is simply a visualization issue. We realize that there may have > been changes in the version of FSL during this time and/or the software > programs themselves, and want to be sure that the data analyzed earlier > has been treated in the same way as that which was analyzed later. > > In addition, we have run tractography on this dataset, and there seem to > be more log files in the bedpostx log directory in the sessions that were > run more recently. So we are also wondering if something has changed in > the bedpostx program between October 2008 and October 2009 that affects > the tractography data. > > Thank you! > > > > > > Sandra > > > > > 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. >