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
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