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Hi! I realise that there maybe outliers present in my data at the edge of the brain and therefore the intensity ranges of my non FA data are not accurate. As these intensity ranges have to be specified for the first step of analysis for non FA data, do you know what the 'recommended' or 'normal' intensity ranges are for RD, MD and AD? Would it be possible to specify these 'normal' ranges for my analysis? If not, then perhaps I should re-process my data using dtifit. I greatly appreciate any advice on this issue, Thank you! Sinead On 2 January 2013 17:40, Saad Jbabdi <[log in to unmask]> wrote: > Hi - I would suggest that you analyse the data using dtifit! > > Saad > > On 2 Jan 2013, at 17:37, Sinead Kelly wrote: > >> Hi Saad, >> >> I used ExploreDTI to preprocess my data and also used this software to >> convert the DTI *.mat files to the RD,MD and AD *.nii files. >> >> I have 15 direction data with a b-value of 800 but I haven't looked at >> the bvals for this subject - do you know how I could check this? >> Should I look at the b-matrix? Do you know what the normal intensity >> ranges for non_FA data should be? I could exclude this subject from >> analysis. However, the intensity ranges for my FA data is normal for >> all of my subjects (0:1). >> >> Thank you for your help! >> >> Sinead >> >> On 2 January 2013 16:39, Saad Jbabdi <[log in to unmask]> wrote: >>> Hi - this looks strange. >>> - Did you run dtifit to get the RD values? Or is it from a different software? >>> - Did you check that the bvals are correct for that subject? >>> >>> Cheers >>> Saad >>> >>> >>> On 2 Jan 2013, at 16:21, Sinead Kelly wrote: >>> >>>> Hi all, >>>> >>>> I'm running TBSS analysis on non-FA data: namely, AD, MD and RD values. As you know, the minimum and maximum intensity values need to be checked before running the 'tbss_preproc' script by entering the command 'fslstats ____.nii.gz -R'. >>>> >>>> However, I'm getting strange intensity values for some subjects... For example, one subject happens to have >>>> an RD intensity range of 0 - 4803.45. This doesn't seem normal - I would expect this (based on my Explore-DTI tractography results) to be more in the range of 0 - 0.0005. >>>> >>>> Just wondering if anyone could shed light on this: am I correct to assume that my range should be in decimals, not thousands? My FA data, however, is in the normal intensity range of 0:1. >>>> >>>> Many thanks, >>>> >>>> Sinéad >>>> >>> >>> -- >>> Saad Jbabdi >>> University of Oxford, FMRIB Centre >>> >>> JR Hospital, Headington, OX3 9DU, UK >>> (+44)1865-222466 (fax 717) >>> www.fmrib.ox.ac.uk/~saad >>> >> >> >> >> -- >> Sinead Kelly >> Neuropsychiatric Genetics Group >> Trinity Centre >> St. James's Hospital >> Dublin 8 >> > > -- > Saad Jbabdi > University of Oxford, FMRIB Centre > > JR Hospital, Headington, OX3 9DU, UK > (+44)1865-222466 (fax 717) > www.fmrib.ox.ac.uk/~saad > -- Sinead Kelly Neuropsychiatric Genetics Group Trinity Centre St. James's Hospital Dublin 8