Re: [Freesurfer] --inittp 0 in mri_robust_template

[Martin Reuter]

Hi Marisa, 

usually a random time point is selected as an initial registration target. From 
there we map all images (including the initial target) to a common mid space 
and create the first template there, then we register to that template and 
iterate. This speeds things up, but is theoretically not totally unbiased (due 
to the special role of the initial target). Now since all get resampled, this 
potential bias is very small (i.e. could not be measured) , so I selected this 
to be the default in the interest of having a fast registration. Further the 
randomness across subjects will remove any potential remaining bias in a group 
analysis.

Now if you specify no init, we will first create a really bad looking template, 
register to that and iterate (so it is completely unbiased), but will take much 
longer to converge. I don’t recommend doing this. 

Best, Martin

> On 17. Sep 2020, at 15:12, Marisa Johanna Nordt  wrote:
> 
> 
> Hi, 
>  
> I have a question regarding the flag  -- inittp 0 (no init ) in 
> mri_robust_template. What does ‘no init’ mean in this context and which 
> consequences arise from using this flag? 
>  
> Thank you! 
> Best, 
> Marisa 
> 
> ___
> Freesurfer mailing list
> Freesurfer@nmr.mgh.harvard.edu 
> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer 
> 
___
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer

[Freesurfer] --inittp 0 in mri_robust_template

[Marisa Johanna Nordt]

External Email - Use Caution

Hi,

I have a question regarding the flag  -- inittp 0 (no init ) in 
mri_robust_template. What does ‘no init’ mean in this context and which 
consequences arise from using this flag?

Thank you!
Best,
Marisa

___
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer