# World coordinate do not give me the correct dicom coordinate

**URL:** https://discourse.vtk.org/t/world-coordinate-do-not-give-me-the-correct-dicom-coordinate/440
**Category:** Support
**Created:** [March 11, 2019, 2:41am UTC](https://discourse.vtk.org/t/world-coordinate-do-not-give-me-the-correct-dicom-coordinate/440 "2019-03-11T02:41:08Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![zandarina](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/z/4af34b/32.png) [@zandarina](https://discourse.vtk.org/u/zandarina)
#### Post date: [March 11, 2019, 2:41am UTC](https://discourse.vtk.org/t/world-coordinate-do-not-give-me-the-correct-dicom-coordinate/440/1 "2019-03-11T02:41:08Z")

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Dear all,

I use itk to perform 2d segmentation of a 3d volume given by a dicom series  
and i need to add some seeds with the mouse for some 2d slices. So i am  
forced to show a 2d slice in vtk obtained with itk (using extractfilter) in  
a vtk windows flipping the slide as it is upside down. Then i pick a point  
with the mouse to choose the seeds. But i found that it does not give the  
exact coordinate. At least it is different frm the one given in slicer 3d.  
As i need it for itk segmentation and accuracy is very important. Is there  
any way to get the same coordinates fro itk and vtk?

Thanks