# Does anyone know how to visualize points in IJK coordinates in RAS coordinates?

**URL:** <https://discourse.slicer.org/t/does-anyone-know-how-to-visualize-points-in-ijk-coordinates-in-ras-coordinates/22229>\
**Category:** Support\
**Tags:** segmentation, dicom, python, 3d-model\
**Created:** [March 1, 2022, 8:39am UTC](https://discourse.slicer.org/t/does-anyone-know-how-to-visualize-points-in-ijk-coordinates-in-ras-coordinates/22229 "2022-03-01T08:39:47Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![zhuyingxinxs](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/zhuyingxinxs/32/13663_2.png) [@zhuyingxinxs](https://discourse.slicer.org/u/zhuyingxinxs)\
**Post date:** [March 1, 2022, 8:39am UTC](https://discourse.slicer.org/t/does-anyone-know-how-to-visualize-points-in-ijk-coordinates-in-ras-coordinates/22229/1 "2022-03-01T08:39:47Z")

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Once you’ve determined the coordinates of a point in IJK coordinates, how do you visualize it in RAS coordinates? Do we have to do a coordinate transformation first?

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**Author:** ![Alex\_Vergara](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/alex_vergara/32/15205_2.png) [@Alex\_Vergara](https://discourse.slicer.org/u/Alex_Vergara)\
**Post date:** [March 1, 2022, 8:44am UTC](https://discourse.slicer.org/t/does-anyone-know-how-to-visualize-points-in-ijk-coordinates-in-ras-coordinates/22229/2 "2022-03-01T08:44:01Z")

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RAS are not coordinates but rather orientation.

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**Author:** ![ebrahim](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ebrahim/32/13403_2.png) [@ebrahim](https://discourse.slicer.org/u/ebrahim)\
**Post date:** [March 1, 2022, 11:06am UTC](https://discourse.slicer.org/t/does-anyone-know-how-to-visualize-points-in-ijk-coordinates-in-ras-coordinates/22229/3 "2022-03-01T11:06:08Z")

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They can be thought of as a coordinate system in Slicer.

e.g. volume nodes have an IJK-RAS coordinate transformation  
and perhaps other things

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<div class="post-metadata">

**Author:** ![ebrahim](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ebrahim/32/13403_2.png) [@ebrahim](https://discourse.slicer.org/u/ebrahim)\
**Post date:** [March 1, 2022, 11:12am UTC](https://discourse.slicer.org/t/does-anyone-know-how-to-visualize-points-in-ijk-coordinates-in-ras-coordinates/22229/4 "2022-03-01T11:12:46Z")

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I’m not sure what “visualize” means here, but if it’s a volume node you can use `GetIJKToRASMatrix` to go between the two coordinate systems.

Maybe this can help: [Script repository — 3D Slicer documentation](https://slicer.readthedocs.io/en/latest/developer_guide/script_repository.html#get-markup-control-point-ras-coordinates-from-volume-voxel-coordinates)