# How can I segment cartilage from paranasal sinus tac

**URL:** https://discourse.slicer.org/t/how-can-i-segment-cartilage-from-paranasal-sinus-tac/27728
**Category:** Support
**Created:** [February 9, 2023, 7:14pm UTC](https://discourse.slicer.org/t/how-can-i-segment-cartilage-from-paranasal-sinus-tac/27728 "2023-02-09T19:14:03Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![mburibe\_18](https://avatars.discourse-cdn.com/v4/letter/m/a88e4f/32.png) [@mburibe\_18](https://discourse.slicer.org/u/mburibe_18)
#### Post date: [February 9, 2023, 7:14pm UTC](https://discourse.slicer.org/t/how-can-i-segment-cartilage-from-paranasal-sinus-tac/27728/1 "2023-02-09T19:14:04Z")

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I am trying to segment nasal cartilage from a CT scan of the paranasal sinuses, but I have not been able to accurately locate the threshold so that this area to be segmented can be marked.  
Could you please help me ??

thank you !

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/2/3/236535b0f60c1ac6e9d7ef05bc5c1614ea8cfdac.png)

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### Author: ![philippepellerin](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/philippepellerin/32/16062_2.png) [@philippepellerin](https://discourse.slicer.org/u/philippepellerin)
#### Post date: [February 12, 2023, 9:24am UTC](https://discourse.slicer.org/t/how-can-i-segment-cartilage-from-paranasal-sinus-tac/27728/2 "2023-02-12T09:24:25Z")

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There is not enough contrast to easily segment the nasal cartilage, you will have to do that manually and can do that only if the CT is of high quality… I have tried the same for many years…

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### Author: ![mohammed\_alshakhas](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/mohammed_alshakhas/32/10025_2.png) [@mohammed\_alshakhas](https://discourse.slicer.org/u/mohammed_alshakhas)
#### Post date: [February 13, 2023, 12:01pm UTC](https://discourse.slicer.org/t/how-can-i-segment-cartilage-from-paranasal-sinus-tac/27728/3 "2023-02-13T12:01:00Z")

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Playing with contrast helps a lot when you need to segment a structure like that .  
You can use an option in contrast tool to enhance the area you work in . It helped me many time .  
you will most likely end up manually painting it .  
but remember there are a lot of tool to make it easier like smudge paint and fill holes

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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: [February 15, 2023, 5:49am UTC](https://discourse.slicer.org/t/how-can-i-segment-cartilage-from-paranasal-sinus-tac/27728/4 "2023-02-15T05:49:12Z")

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Note that once you segmented a few dozens cases, you can start to train an AI segmentation model using MONAILabel extension. Since this is a difficult segmentation task (thin structures and low contrast), so you might need a few hundred images for robust and accurate segmentation.