# Question About Threshold Tool in Segmentation

**URL:** <https://discourse.slicer.org/t/question-about-threshold-tool-in-segmentation/43284>\
**Category:** Support\
**Created:** [June 10, 2025, 1:50pm UTC](https://discourse.slicer.org/t/question-about-threshold-tool-in-segmentation/43284 "2025-06-10T13:50:35Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Aya\_Gamal](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/aya_gamal/32/79442_2.png) [@Aya\_Gamal](https://discourse.slicer.org/u/Aya_Gamal)\
**Post date:** [June 10, 2025, 1:50pm UTC](https://discourse.slicer.org/t/question-about-threshold-tool-in-segmentation/43284/1 "2025-06-10T13:50:35Z")

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I have a question regarding the threshold tool in segmentation. When I set the threshold value, several segments appear merged together in one segment. I would like to separate each of them into individual segments. Could you please advise me on how to do that?

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**Author:** ![Deep\_Learning](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/deep_learning/32/15345_2.png) [@Deep\_Learning](https://discourse.slicer.org/u/Deep_Learning)\
**Post date:** [June 10, 2025, 3:50pm UTC](https://discourse.slicer.org/t/question-about-threshold-tool-in-segmentation/43284/2 "2025-06-10T15:50:03Z")

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Many options. 1. lower the threshold if they are really not connected. 2. Use the scissors tool 3. etc etc

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**Author:** ![jamesobutler](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jamesobutler/32/7511_2.png) [@jamesobutler](https://discourse.slicer.org/u/jamesobutler)\
**Post date:** [June 10, 2025, 4:24pm UTC](https://discourse.slicer.org/t/question-about-threshold-tool-in-segmentation/43284/3 "2025-06-10T16:24:20Z")

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You may be interested in the “Islands” effect where you can “Split islands to segments”.

> **[Segment editor — 3D Slicer documentation](https://slicer.readthedocs.io/en/latest/user_guide/modules/segmenteditor.html#islands)**