Hi
I don't think this is a good approximation. There are several models
in the literature now which try to make such measures available, but
they all require multiple b-shells and none of them has yet been
tested in in-vivo subjects on clinical machines.
I'm afraid the model used in bedpostx does not account for the many
different biophysical variables that you would need, to make such a
claim.
Sorry
T
On 29 May 2008, at 02:52, Scott Kolbe wrote:
> Hi Tim
> I am interested in removing the effect of oedema from my
> diffusivity calculations. Do you think it makes sense to divide the
> eigen values by the volume fraction output from BEDPOST? Do you
> think that the volume fraction itself could be used as a measure of
> axonal density?
> cheers
> Scott
>
> Tim Behrens wrote:
>> I don't think they have, but I don't see why you should not,
>> particularly if you are interested, for example, in the second
>> fibre fraction.
>>
>> Cheers
>>
>> T
>>
>> On 28 May 2008, at 02:11, Scott Kolbe wrote:
>>
>>> Just wondering if anyone has done any case/control comparisons on
>>> the local diffusion parameter estimates from BEDPOST/BEDPOSTX?
>>> cheers
>>> Scott
>>>
>>> --
>>> ========================
>>> Scott Kolbe
>>> Postgraduate Student
>>> Neuroimaging Group
>>> Howard Florey Institute &
>>> Centre for Neuroscience
>>> University of Melbourne
>>> VIC, Australia, 3010.
>>>
>>> ph: +61 3 8344 1887
>>> email: [log in to unmask]
>>> website: http://www.neuroimaging.org.au/index.php?id=383
>>>
>
>
> --
> ========================
> Scott Kolbe
> Postgraduate Student
> Neuroimaging Group
> Howard Florey Institute &
> Centre for Neuroscience
> University of Melbourne
> VIC, Australia, 3010.
>
> ph: +61 3 8344 1887
> email: [log in to unmask]
> website: http://www.neuroimaging.org.au/index.php?id=383
>
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