[Insight-users] EPI Ground Truth

[kavec at messi.uku.fi]

Hi,

you should consider first talking to an MRI physicist in order to confront what
you would like to do. It is possible that there are people on this list who
could provide you some insight, but I am afraid, it is quite off topic for
majority.

Martin

Citát Arash Jahangir <arash at vije.ca>:

> Hi all,
> I'd like to generate ground truths for the purpose of evaluating brain EPI
> registration algorithms.  I'd like your feedback and advice about this as
> well as any resources on the net you may think are useful to the task.
>
> 1. One approach is to consider a T2 image as a good proxy for EPI.  The
> challenge then is to create a realistic distortion that can serve as a
> synthetic EPI.  Obviously the intensity values will not be quite the same.
> So the question here is then:
>    1a) Are the intensity variations between T2 and EPI close enough to make a
> warped T2 a good synthetic EPI?
>    1b) What is a good approach to create a realistic warp to transform T2 to
> EPI?
>
>
> 2)  The second approach is to collect a set of registered EPI-T2 (or EPI to
> any other undistorted MRI image) set that human experts believe are excellent
> registrations.  Then generate a statistical model for the typical warps that
> undistort the EPI images.  Finally use one or more corrected (i.e.
> undistorted/registered) EPI images as ground truth and apply the synthetic
> warp to it to get a distorted EPI.  The issues here are:
>    2a) Is this a sound approach?  What normalization issues should I consider
> before applying a generic warp field based on statistics on an undistorted
> image to produce a synthetic distorted EPI?
>    2b) Is there a database of registered EPI images?
>    2c) Are the correction warp fields for those EPI images available and if
> not, how can I recover it
>
> 3.  I guess I should have asked this first :)  what work has already been
> done in this area?  Are there programs or databases the provide warped and
> undistorted EPI ground truths?
>
>
> Any and all feedback is highly appreciated.
>
> Arash