[Insight-users] register of MRI and a partial fMRI

[Yu Qi]

Hi Karthik,
 
I did use the initializer to set centre. But I wonder if it matters that I set region before set centre. Does one influence the other?
 
The tranform parameters used in my application are copied from example ImageRegistration8.cxx as follows
 
  VersorType     rotation;
  VectorType     axis;
  
  axis[0] = 0.0;
  axis[1] = 0.0;
  axis[2] = 1.0;
  const double angle = 0;
  rotation.Set(  axis, angle  );
  transform->SetRotation( rotation );

and the translationScale = 1.0 / 1000.0;

  optimizer->SetMaximumStepLength( 0.2000  ); 
  optimizer->SetMinimumStepLength( 0.0001 );

my data sets are MRI 256X256X256

                   and fMRi 64X64X28

is there any problems with these settings?

Thank you!

Best regards,

Yu Qi


Karthik Krishnan <Karthik.Krishnan at kitware.com> wrote:
Hi Yu,

Print out the parameters of the transform. There just isn't enough
overlap between the fixed and the moving image to start with (or the
transform is driving you too far away too soon). See
itkMattesMutualInformationImageToImageMetric.txx


Line: 702
if( nSamples < m_NumberOfSpatialSamples / 4 )
{
itkExceptionMacro( "Too many samples map outside moving image buffer: "
<< nSamples << " / " << m_NumberOfSpatialSamples << std::endl );
}


Remember that if you are using the centered transform, set the center
(for example with the CenteredTransformInitializer helper class).

See Examples/Registration/ImageRegistration9.cxx

Thanks
kk

Yu Qi wrote:

> Hi Luis,
> Thanks for your instruction.
> I tried to set region to the fixed image by setting
> start[2]=size[2]/2 and size[2]/=2 immediately after reading the image.
> I use the Mattes MI metric and Centered Rigid 3D image transformation.
> But every time I tried to run the .exe, it always told me there are
> too many samples outside the moving image. And I choose a smaller
> number for number of samples. I still got the same exception.
> Why should this happen?
> It works well before I set the region.
> Best Regards,
> Yu Qi
>
> */Luis Ibanez /* wrote:
>
>
> Hi Yu,
>
> Yes, you can use ITK for registering a fMRI to an MRI
> even if they dont fully cover the same anatomical
> regions.
>
> You may want to use the MRI image as the Fixed image and
> set the FixedImageRegion to the rectangular box that covers
> the brain plus a border of about 10 millimeters. Take the
> fMRI image as the Moving image.
>
> You may want to use any of the MutualInformation Metrics
> available in ITK.
>
> For a full list of the Image Metrics please look at the
> Groups in Doxygen:
>
> http://www.itk.org/Insight/Doxygen/html/group__RegistrationMetrics.html
>
>
>
> Regards,
>
>
> Luis
>
>
> ------------------
> Yu Qi wrote:
>
> > Hi,
> >
> > I have a MRI volume of the whole head and
> > a fMRI volume of the brain.
> >
> > Can I register these two directly with ITK?
> >
> > Do I! need to use the SetRegion() to MRI volume?
> >
> > Thanks!
> >
> >
> >
> >
> > *Best Regards!*
> > **
> > *Yu Qi*
> >
> >
> >
> >
> >
> ------------------------------------------------------------------------
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> >
> >
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---------------------------------
Do You Yahoo!?
150万曲MP3疯狂搜，带您闯入音乐殿堂
美女明星应有尽有，搜遍美图、艳图和酷图
1G就是1000兆，雅虎电邮自助扩容！
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