[Insight-users] Volume registration using position vectors -- newbie question

[Luis Ibanez]

Hi Frank,

 From your description it seems that you only need to resample
image B using the grid of image A.

That is, you are relying on the fact that both images have been
acquired from the same scanner, and that the image origing and
direction cosines are correct.

That should work fine.

Just remember to use the itk::OrientedImage<> instead of the
itk::Image.

The itk::OrientedImage will take the Direction cosines into
account when it is used by the interpolator of the Resample
ImageFilter.


Please read the ITK Software Guide,

      http://www.itk.org/ItkSoftwareGuide.pdf

in particular Section 6.9.4 "Resample Image Filter" in
pdf-pages 254-448.

This section describes in detail how to use the ResampleImageFilter.


    Regards,


       Luis



-----------------------
Frank Ezekiel wrote:
> Luis:
> 
>         Thank you for the initial response.     At this point, my goal 
> has changed slightly.   I'm looking to use ITK to write a function that 
> will align MovingImage to FixedImage WITHOUT any intensity based 
> registration.
> 
>         That is, I want to use ONLY the DCM (direction cosine matrix) 
> and coordinate offset data included in a dicom header.
> 
>         (The reason is that my FixedImage space is from single voxel 
> spectroscopy, so there is inadequate intensity information to use a cost 
> function + resampling for alignment.)
> 
>         Can ITK do this?     It basically just requires computing and 
> applying the "difference transformation" between two images acquired in 
> the same session.
> 
> 
> Thanks again for the help,
> 
> Frank
> 
> 
> 
> 
> 
> At 07:34 AM 8/5/2007, Luis Ibanez wrote:
> 
>> Hi Frank,
>>
>>
>> You may want to start with the example:
>>
>>
>>       ImageRegistration8.cxx
>>
>>
>> in the directory:
>>
>>
>>       Insight/Examples/Registration
>>
>>
>> This example is described in detail in the
>> ITK Software Guide
>>
>>    http://www.itk.org/ItkSoftwareGuide.pdf
>>
>> in the "Image Registration" chapter.
>>
>>
>> We *STRONGLY* recommend you to read the entire chapter
>> before you start playing with the registration. You
>> should also read the Section on image resampling since
>> they are very closely related.
>>
>> Since your images seems to be from the same modality
>> and same patient, you can probably solve this by using
>> the following components:
>>
>>   1) Mean Squares Metric
>>   2) VersorRigid3D Transform
>>   3) Linear Interpolator
>>   4) VersorRigid3DTransformOptimizer
>>
>> Note that, since you are reading this from DICOM,
>> you want to replace the "itk::Image" type in the
>> code with "itk::OrientedImage" type, in order to
>> make sure that the direction cosines of your images
>> are taken into account.
>>
>> ---
>>
>> Examples on how to read DICOM series are available
>> in the directory:
>>
>>
>>            Insight/Examples/IO
>>
>> and are described as well in the ITK Software Guide
>> in the Chapter "Reading and Writing Images".
>>
>>
>> Please let us know if you find any problems
>> while setting up your registration code.
>>
>>
>>
>> Regards,
>>
>>
>>    Luis
>>
>>
>> --------------------
>> Frank Ezekiel wrote:
>>
>>> Hi:
>>>     I have multiple MRI acquisitions acquired on Siemens Medspec 4T 
>>> and stored in Dicom.   I'm looking for the quickest and easiest way 
>>> to compute the rotations and translations needed to align one dataset 
>>> with the other (assuming no movement).
>>>     Could someone please enumerate my options within ITK for doing 
>>> this?    I really just want a robust readout of angles and mm 
>>> translations given Dicom 3.0 files with tags (0020,0032) and 
>>> (0020,0037) filled in.
>>>     Suggestions?
>>> Thanks mucho,
>>> Frank
>>> _______________________________________________
>>> Insight-users mailing list
>>> Insight-users at itk.org
>>> http://www.itk.org/mailman/listinfo/insight-users
> 
>