# Obtain outside contour

**URL:** <https://discourse.slicer.org/t/obtain-outside-contour/8143>\
**Category:** Support\
**Created:** [August 23, 2019, 7:27am UTC](https://discourse.slicer.org/t/obtain-outside-contour/8143 "2019-08-23T07:27:09Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![mikecsu](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@mikecsu](https://discourse.slicer.org/u/mikecsu)\
**Post date:** [August 23, 2019, 7:27am UTC](https://discourse.slicer.org/t/obtain-outside-contour/8143/1 "2019-08-23T07:27:09Z")

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Operating system: win10  
Slicer version: slicer 4.10.0 /4.10.1  
Expected behavior:  
Actual behavior:

Hi,there . I would like know if i can segment the skin of a head CT images with the help of “Segmenteditor module”, i want the outside contour of the head, and there are many tools i  
can use, but i don’t know which one can perfectly do this work ?( i know i can simply use  
pure manual segmentation method,s like draw、paint… but it is time-consuming)

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/a/1/a1f25cddf5983c0ab50bba57206d5ce61d0eb4dc.jpeg)

Any help would be appreciated.

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**Author:** ![JanWitowski](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/janwitowski/32/4512_2.png) [@JanWitowski](https://discourse.slicer.org/u/JanWitowski)\
**Post date:** [August 23, 2019, 1:20pm UTC](https://discourse.slicer.org/t/obtain-outside-contour/8143/2 "2019-08-23T13:20:52Z")

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I think a good starting point would be to threshold whole head:

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/7/6/76bb3b7c2ea86e70408d871d340710cfa1d102a3.png)

And then use Hollow to get the outer layer:

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/d/a/da7c33debb90c86f46873d57dc4c65ea9fd1369b.jpeg)

This requires minor manual processing but should get you a satisfying result within a few minutes:

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/0/1/012463558b34e15c578ded44191df1db9f00f9ab.jpeg)

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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:** [August 23, 2019, 4:39pm UTC](https://discourse.slicer.org/t/obtain-outside-contour/8143/3 "2019-08-23T16:39:01Z")

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This segmentation recipe may also help: [https://lassoan.github.io/SlicerSegmentationRecipes/SkinSurface/](https://lassoan.github.io/SlicerSegmentationRecipes/SkinSurface/)

Also, a new “surface solidify” extension will be added to Slicer very soon, which may further automate the process (see status [here](https://github.com/Slicer/ExtensionsIndex/pull/1655)).

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**Author:** ![mikecsu](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@mikecsu](https://discourse.slicer.org/u/mikecsu)\
**Post date:** [August 26, 2019, 3:18am UTC](https://discourse.slicer.org/t/obtain-outside-contour/8143/4 "2019-08-26T03:18:41Z")

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It did work. Thank you .