Thanks so much. Since fdt_paths.nii.gz is an image file, how do you get the value M?
many thanks,
AJ
--- On Mon, 7/18/11, Stamatios Sotiropoulos <[log in to unmask]> wrote:
> From: Stamatios Sotiropoulos <[log in to unmask]>
> Subject: Re: [FSL] Probabilistic tractography
> To: [log in to unmask]
> Date: Monday, July 18, 2011, 3:04 AM
> Hi Aj,
>
> The "connectivity value" in probabilistic tractography from
> a seed A to a voxel B is defined as the ratio M/N, where M
> is the number of curves that start from A and go through B
> and N the total number of curves starting from A. This ratio
> gives an estimate of the probability of the path of least
> hindrance to diffusion.
>
> The waytotal file gives you N, the total number of *valid*
> curves that have started from A (after excluding curves that
> do not meet exclusion/inclusion criteria). M for each voxel
> in the image is described in the fdt_paths file. Dividing
> the two will give path probabilities.
>
> Hope this is clear,
> Stam
>
>
> On 18 Jul 2011, at 09:04, Adil Javed wrote:
>
> > Hi,
> > I have generated some data using tractography.
> The waytotal text file shows a number. Is it more
> accurate to report that number as connectivity value or an
> estimate of number of fibers per seed/mask on a plot?
> >
> > many thanks,
> >
> > aj
> >
>
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