[Insight-users] Image Series Order - itk::ImageSeriesReader, SetReverseOrder

[Luis Ibanez]

Hi Michael,


                 Welcome to ITK !


Thanks for the detailed description of your problem.

With that, you are starting with a good precedent  :-)


If you are finding necessary to play with the order of
reading the DICOM slices in order to get the anatomical
orientation of the images to match, then chances are that
the image have been acquired with different orientations.

The good news for you is that ITK provides classes for
correctly taking image orientation into account.


What you want to do first is to replace the use of
"itk::Image" in your code, with "itk::OrientedImage".


The OrientedImage will make sure that the image orientation
that is encoded in the direction cosines stored in the
DICOM header, is propagated and taking into consideration
at every step of the image registration process.


Once you introduce the itk::OrientedImage in replacement
for the itk::Image, you shouldn't need to manipulate the
slice order in the ImageSeriesReader class.


Note that for this,
You should use ITK 3.6 or a later CVS version.


Please give it a try and let us know if you find any
problems.



    Thanks


       Luis



-------------------
M. Wirtzfeld wrote:
> 
> Good afternoon,
> 
> We are currently writing registration code to handle mono-modality and 
> multi-modality image registration using CT and MR data-sets.
> 
> At the present time, the code is able to perform registration using both 
> of these data-sets.  The fixed-image is two-dimensional (treated as 
> three-dimensional image-type by the code) and the moving-image is a 
> volume created from a sequence of two-dimensional DICOM slices.
> 
> Using the itk::ImageSeriesReader class, mono-modality CT registration 
> requires the SetReverseOrder method of this class to be called with a 
> "true" boolean value and MR registration requires a "false" boolean 
> value when the respective volumes are created.
> 
> I have ensured that the maximum-step used by the optimizer is properly 
> set in both cases.
> 
> I believe the root of this requirement lies in the meta-data of the 
> DICOM images that comprise the CT and MR data-sets, but I do not know 
> why or what to look for in order to help find an answer.
> 
> I have not used ITK extensively and this is my first experience with 
> image-processing.
> 
> 
> 
> Any help is greatly appreciated,
> 
> 
> Michael.
> 
> Michael Wirtzfeld
> Robarts Research
> 
> "Prefer the standard to the offbeat." - Strunk & White
> 
> 
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