# Edit existing segmentation in 3D

**URL:** <https://discourse.slicer.org/t/edit-existing-segmentation-in-3d/9010>\
**Category:** Support\
**Tags:** segmentation\
**Created:** [November 4, 2019, 11:58am UTC](https://discourse.slicer.org/t/edit-existing-segmentation-in-3d/9010 "2019-11-04T11:58:09Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![JordinaAviles](https://avatars.discourse-cdn.com/v4/letter/j/b19c9b/32.png) [@JordinaAviles](https://discourse.slicer.org/u/JordinaAviles)\
**Post date:** [November 4, 2019, 11:58am UTC](https://discourse.slicer.org/t/edit-existing-segmentation-in-3d/9010/1 "2019-11-04T11:58:10Z")

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Hi everyone,

I have a doubt regarding the segmentation in 3D Slicer.

I am opening a CT (mha) and it’s segmentation for the heart (.nrrd) and I want to edit the segmentation but the only way I can do it is painting slice for slice.

Is there any way to edit an existing segmentation in a similar way as the region growing does (you paint only a slice and the program makes corrections in whole 3D volume)?

If I need to fix every slice in the image it seems very tedious to me.

Thanks,

Jordina

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [November 4, 2019, 12:12pm UTC](https://discourse.slicer.org/t/edit-existing-segmentation-in-3d/9010/2 "2019-11-04T12:12:41Z")

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You have many options for 3D editing, such as:

- paint effect with sphere brush option enabled, smudge option enabled for automatic segment selection)
- Scissors effect
- Smoothing effect with joint smoothing method
- Shrink segments to small seeds using Margin effect then grow them using Grow from seeds

However, as you have already noticed, “fixing” a segmentation usually takes much longer time than creating a new segmentation from scratch and paying more attention or using better tools.