[Insight-users] conversion of scan transofmration matrix between different modality

[kevin cavin]

Hello, Bill: 
 
        At this moment I retrieve the dicom voume from the MR and CT machines and the images are in AVS field format due to internal reasons. Then I use ITK to register the MR and CT volume. I display both of voulme and find the orientation is different. I manually adjust the orientation and get good registration. 
 
        If I understand what you said correctly, if both volume are read in dicom format, the registration should take care the difference of orientation automatically. If so, It will be necessary to retrieve the voume in dicom format. 
 
        But I still do not understand how ITK can deal with issue automatically. Does it mean only the volume in DICOM will work in this way. If the volumes are saved in other format, such as VTK, AVS etc, the application should deal with the orientation transformation. 
 
        More explanation will be appreciated. Thanks ! Since  I am using python instead of C++ to programm, I do not know whether  print command will work in the same way. 
 
Calvin 
 
 
 
 
       
 
       
  


--- On Thu, 10/1/09, Bill Lorensen <bill.lorensen at gmail.com> wrote:


From: Bill Lorensen <bill.lorensen at gmail.com>
Subject: Re: [Insight-users] conversion of scan transofmration matrix between different modality
To: "kevin cavin" <beibeiwen2003 at yahoo.com>
Cc: insight-users at itk.org
Date: Thursday, October 1, 2009, 9:11 PM


Calvin,

As I said, the orientation difference should be taken care of during the registration process. Is the data being read as DICOM? If not, how are you reading it?

Please ->Print(std::cout) the fixed and moving images after you read them and post the results of the Print.

Bill


On Thu, Oct 1, 2009 at 8:31 AM, kevin cavin <beibeiwen2003 at yahoo.com> wrote:






Hello, Bill : 
 
     Thanks for  your reply.  What I hve found with the orginal volume is the orientation for CT and MRI scan is different. If I directly register these  two volume, I will get wrong registration result.  I assume the transformtion of orientation for one scan is necessary. but how can I do that with available ITK ? 
     I am using ITK version 3.12. 
 
Kind regards 
 
Calvin 


--- On Wed, 9/30/09, Bill Lorensen <bill.lorensen at gmail.com> wrote:


From: Bill Lorensen <bill.lorensen at gmail.com>
Subject: Re: [Insight-users] conversion of scan transofmration matrix between different modality
To: "kevin cavin" <beibeiwen2003 at yahoo.com>
Cc: insight-users at itk.org
Date: Wednesday, September 30, 2009, 11:36 PM





ITK should handle this. ITK uses the information stored in DICOM to compute an origin, spacing and direction. You should not have to convert the volume, assuming the patient scans are landmarked (in the scanner) at a similar location.

What version of ITK are you using? 


On Wed, Sep 30, 2009 at 11:04 AM, kevin cavin <beibeiwen2003 at yahoo.com> wrote:







Hi, Folks: 
 
      When I use ITK to register two dicom volume  from different modalities.  I have found that MR and CT scan often have different scan transformation matrixes. For example for CT scan the z direction is the y direction of MR scan. This will pose problem to register the two volumes with ITK. I am wondering whether in ITK the probelm can be solved soneway by using some function embedded. Do I need to write individual program to manula convert one of the volume.  Thanks in advance ! 
 
Kind regards 
 
Calvin 
 
 

 

 

_____________________________________
Powered by www.kitware.com

Visit other Kitware open-source projects at
http://www.kitware.com/opensource/opensource.html

Please keep messages on-topic and check the ITK FAQ at: http://www.itk.org/Wiki/ITK_FAQ

Follow this link to subscribe/unsubscribe:
http://www.itk.org/mailman/listinfo/insight-users







      
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.itk.org/pipermail/insight-users/attachments/20091001/da882e78/attachment-0001.htm>