# Structures segmented in either Arterial/Venous phases are slightly misaligned when switching view to the other phase

**URL:** <https://discourse.slicer.org/t/structures-segmented-in-either-arterial-venous-phases-are-slightly-misaligned-when-switching-view-to-the-other-phase/23748>\
**Category:** Support\
**Tags:** segmentation\
**Created:** [June 7, 2022, 7:53am UTC](https://discourse.slicer.org/t/structures-segmented-in-either-arterial-venous-phases-are-slightly-misaligned-when-switching-view-to-the-other-phase/23748 "2022-06-07T07:53:36Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![rjk](https://avatars.discourse-cdn.com/v4/letter/r/ed655f/32.png) [@rjk](https://discourse.slicer.org/u/rjk)\
**Post date:** [June 7, 2022, 7:53am UTC](https://discourse.slicer.org/t/structures-segmented-in-either-arterial-venous-phases-are-slightly-misaligned-when-switching-view-to-the-other-phase/23748/1 "2022-06-07T07:53:36Z")

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Operating system: macOS 12.3.1  
Slicer version: 5.0.2  
Expected behavior: arterial+ venous phases align perfectly  
Actual behavior: slight offset between structures between A and V phases, e.g., a structure segmented in phase A will be in a slightly different position when switching view to phase V.

Is there a way in settings to account for this minor discrepancy?

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**Author:** ![mau\_igna\_06](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/mau_igna_06/32/9056_2.png) [@mau\_igna\_06](https://discourse.slicer.org/u/mau_igna_06)\
**Post date:** [June 7, 2022, 8:57am UTC](https://discourse.slicer.org/t/structures-segmented-in-either-arterial-venous-phases-are-slightly-misaligned-when-switching-view-to-the-other-phase/23748/2 "2022-06-07T08:57:43Z")

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Maybe this is the error i s smoothing @lassoan pointed out asometime ago in vtk forum

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<div class="post-metadata">

**Author:** ![rjk](https://avatars.discourse-cdn.com/v4/letter/r/ed655f/32.png) [@rjk](https://discourse.slicer.org/u/rjk)\
**Post date:** [June 7, 2022, 8:59am UTC](https://discourse.slicer.org/t/structures-segmented-in-either-arterial-venous-phases-are-slightly-misaligned-when-switching-view-to-the-other-phase/23748/3 "2022-06-07T08:59:50Z")

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This occurs in segmentations that have not gone through any smoothing yet, if I’m understanding your comment correctly (novice user).

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**Author:** ![mau\_igna\_06](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/mau_igna_06/32/9056_2.png) [@mau\_igna\_06](https://discourse.slicer.org/u/mau_igna_06)\
**Post date:** [June 7, 2022, 9:02am UTC](https://discourse.slicer.org/t/structures-segmented-in-either-arterial-venous-phases-are-slightly-misaligned-when-switching-view-to-the-other-phase/23748/4 "2022-06-07T09:02:13Z")

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If the phases you mean are different timestamps then it is not that, you should register them to match