Hi,
Bedpostx does not fit a model with multiple unrestricted tensors, which
would give this kind of information. Instead, the fitted model comprises of
perfectly anisotropic (sticks) and isotropic (ball) compartments. The reason
is that geometrical constraints are needed for the multi-tensor model to be
identifiable.
Therefore, each fibre compartment has only axial diffusivity, as it is
assumed to be perfectly anisotropic. Furthermore, the same diffusivity is
shared across all compartments.
Cheers,
Stam
----- Original Message -----
From: "Rajendra Morey" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, May 04, 2010 6:19 PM
Subject: Re: [FSL] Diffusion Tensor for Multiple Fibers
>
> To Clarify Liz's query and respond to your question, given the information
> that describes the portion of the diffusion signal explaned by each fiber
> (from Bedpostx), we want to further subdivide that signal for the primary
> fiber into an axial diffusion component and a radial diffusion componenet.
> Similarly we want an axial and radial diffusion component for the
> secondary
> fiber. Any thoughts on how to get this information ?
>
>
> Raj
>
>
> -----Original Message-----
> From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On Behalf
> Of Matt Glasser
> Sent: Tuesday, May 04, 2010 1:00 PM
> To: [log in to unmask]
> Subject: Re: [FSL] Diffusion Tensor for Multiple Fibers
>
> Why do you want to do that? Bedpostx outputs estimates of the fiber
> orientation and the proportion of the diffusion signal explained by the
> fiber.
>
> Peace,
>
> Matt.
>
> -----Original Message-----
> From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On Behalf
> Of Liz Selgrade
> Sent: Tuesday, May 04, 2010 11:49 AM
> To: [log in to unmask]
> Subject: [FSL] Diffusion Tensor for Multiple Fibers
>
> Hello,
>
> I have run BEDPOSTX on a lot of my data. Is it possible to now calculate
> diffusion tensors for my primary and secondary fiber directions?
>
> Thank you!
> Liz Selgrade
>
>
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