[Insight-users] Fast Marching Filter produces blank output

[Charlotte Curtis]

I've put up my speed image and original at
http://www.uoguelph.ca/~curtisc/<http://www.uoguelph.ca/%7Ecurtisc/>in
dicom format (seemed to be the only one I could get to work properly).
However, I didn't have much luck getting a list of my seed points - I could
only get them in "world" coordinates, which isn't much help.  Basically, I
just seeded several locations on the inside of one of the bones, and I
experimented with several different bones, seed points, and number of seed
points.

What should I be looking for to make sure the speed function is in the
correct range?  Once again, thank you very much for your help,

Charlotte

On 9/27/07, Charlotte Curtis <curtisc at uoguelph.ca> wrote:
>
> Thanks Dan, I'll see if I can save those images and put them up tomorrow
> when I get back to school.  I really do hope it's something I'm doing wrong
> and not a problem with the program.
>
> On 9/27/07, Dan Mueller <dan.muel at gmail.com> wrote:
> >
> > On 28/09/2007, Charlotte Curtis <curtisc at uoguelph.ca> wrote:
> > > I'm using ITK filters through MeVisLab, it comes with nearly all of
> > them
> > > implemented as modules.
> >
> > Okay.
> >
> > > It was my understanding that the stopping value should be somewhere
> > around
> > > the values of the voxels at the edge of the region, which for me is
> > > somewhere between 200 and 1000 HU.  I've tried using very large
> > numbers, but
> > > I still get nothing output.
> >
> > The stopping value has nothing to do with the intensity range of the
> > input image -- it tells the algorithm at what *arrival value* the
> > processing should stop. If you are not sure, make the value large or
> > use the default (which will force the algorithm to take longer to
> > execute, but guarantee you a result).
> >
> > > I posted a screenshot from the program showing (left to right): the
> > input
> > > image, the FastMarching dialogue box, and the speed image.  It can be
> > found
> > > at http://www.uoguelph.ca/~curtisc/MeVisScreenshot.png<http://www.uoguelph.ca/%7Ecurtisc/MeVisScreenshot.png>
> > .
> >
> > Unfortunately a screenshot doesn't help very much. It is best to
> > inspect the raw data (especially the speed function to ensure it is in
> > the correct range). Can you temporarily save the speed function you
> > are using and post this? Also, the initial trial seed/region would be
> > helpful.
> >
> > Cheers, Dan
> >
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://public.kitware.com/pipermail/insight-users/attachments/20070928/999eebb2/attachment.html