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<div>Hello Sara,</div>
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<div>As you did not give the specifics of the problem you want to address the suggested approaches are rather generic. Assuming here that the anatomical structure of interest in the scans did not deform (not MRs of the heart in different phases of the cardiac
cycle): </div>
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<div>1. Prospective approach -</div>
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<div>If you can accurately identify three or more corresponding points in each of the datasets you can use the LandmarkBasedTransformInitializer (https://itk.org/SimpleITKDoxygen/html/classitk_1_1simple_1_1LandmarkBasedTransformInitializerFilter.html) to estimate
the transformation. Ideally these points can be localized with sub-voxel accuracy - possibly derived from markers which occupy a large number of voxels so that undersegmentation/oversegmentation has minimal impact on the point localization.</div>
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<div>2. Retrospective approach -</div>
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<div>Run a rigid registration between the images and see if the results have a visibly better alignment. After registration you can use a linked cursor to see if corresponding points appear closer to their expected locations.</div>
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<div>An example of using a linked cursor with SimpleITK Python notebooks can be found here: </div>
<div>https://github.com/InsightSoftwareConsortium/SimpleITK-Notebooks/blob/master/67_Registration_Semiautomatic_Homework.ipynb</div>
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<div>Another option is to resample the moving image and view the images using ITK-SNAP's linked cursor.</div>
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<div> Ziv</div>
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<span style="font-weight:bold">From: </span>Sara Gh <<a href="mailto:sg.ele.eng@gmail.com">sg.ele.eng@gmail.com</a>><br>
<span style="font-weight:bold">Date: </span>Monday, October 24, 2016 at 12:49 PM<br>
<span style="font-weight:bold">To: </span>"<a href="mailto:insight-users@itk.org">insight-users@itk.org</a>" <<a href="mailto:insight-users@itk.org">insight-users@itk.org</a>><br>
<span style="font-weight:bold">Subject: </span>[ITK-users] SimpleITK - Subpixel shift detection in MRI<br>
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<div>Hello, </div>
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I have three orthogonal intrasubject MRI volumes. Is there any way in SimpleITK to check if the volumes have subpixel (subvoxel) shifts or not?
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<div>Thanks,</div>
<div>Sara Gh<br>
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