[Mrtrix-discussion] RE: Mrtrix tractography questions

[Marc Seal]

Hello Donald et al,

We have a couple of questions regarding the tractography mechanics involved
in MRtrix

1. How does Mrtrix start sampling tracts from ROI’s? That is, if you provide
an ROI how does MRtric decide where to start the tract from? From the
boundary of the ROI or from the centre? Do you take into account if the ROI
overlaps grey and white matter?

2. We are also interested in your thoughts on putting a “weighting” on tract
length.  
A number of studies suggest that if were using a simple deterministic
tracking algorithm to measure connections between multiple ROI’s we should
weigh long tracts since there is bias towards longer tracts. Does the same
apply for your algorithms? We were even suspecting that using the
probabilistic tracking option there would be bias against longer tracts?



cheers

Marc



> Marc Seal
> Group Leader, Developmental Imaging, Murdoch Childrens Research Institute
> Senior Research Fellow, Department of Paediatrics, The University of Melbourne
> 
> The Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052,
> Australia
> M  0423 606 185  |  T +61 3 9345 4310   |  F   +61 3 9345 4325
> E   marc.seal at mcri.edu.au
> www.mcri.edu.au
> 
>  Please consider the environment before printing this email




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