# When I attempt local threshold extension, I cannot click with left mouse button.

**URL:** <https://discourse.slicer.org/t/when-i-attempt-local-threshold-extension-i-cannot-click-with-left-mouse-button/12850>\
**Category:** Support\
**Created:** [August 4, 2020, 12:07pm UTC](https://discourse.slicer.org/t/when-i-attempt-local-threshold-extension-i-cannot-click-with-left-mouse-button/12850 "2020-08-04T12:07:46Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![hsnam](https://avatars.discourse-cdn.com/v4/letter/h/f475e1/32.png) [@hsnam](https://discourse.slicer.org/u/hsnam)\
**Post date:** [August 4, 2020, 12:07pm UTC](https://discourse.slicer.org/t/when-i-attempt-local-threshold-extension-i-cannot-click-with-left-mouse-button/12850/1 "2020-08-04T12:07:46Z")

</div>

Operating system: Mac OS Mojave  
Slicer version: 4.10.2  
Expected behavior:  
I want to get ROI using a local threshold extension.

Actual behavior:

When I attempt the local threshold, I cannot click with the left mouse button (I cannot make an ROI).  
Just I can do change width and level.

Could you kindly help me?

Hyo Suk Nam

---

<div class="post-metadata">

**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 4, 2020, 12:53pm UTC](https://discourse.slicer.org/t/when-i-attempt-local-threshold-extension-i-cannot-click-with-left-mouse-button/12850/2 "2020-08-04T12:53:19Z")

</div>

Local threshold effect only works in recent Slicer Preview Releases.

---

<div class="post-metadata">

**Author:** ![Sunderlandkyl](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/sunderlandkyl/32/79987_2.png) [@Sunderlandkyl](https://discourse.slicer.org/u/Sunderlandkyl)\
**Post date:** [August 4, 2020, 1:38pm UTC](https://discourse.slicer.org/t/when-i-attempt-local-threshold-extension-i-cannot-click-with-left-mouse-button/12850/3 "2020-08-04T13:38:30Z")

</div>

The local threshold effect should work in Slicer 4.10.2. You need to use cmd+click to add the selected region to the segment.

---

<div class="post-metadata">

**Author:** ![hsnam](https://avatars.discourse-cdn.com/v4/letter/h/f475e1/32.png) [@hsnam](https://discourse.slicer.org/u/hsnam)\
**Post date:** [August 4, 2020, 1:45pm UTC](https://discourse.slicer.org/t/when-i-attempt-local-threshold-extension-i-cannot-click-with-left-mouse-button/12850/4 "2020-08-04T13:45:26Z")

</div>

Thanks Andras !!

Sincerely  
Hyo Suk

2020-08-04 오후 10:03, Andras Lasso via 3D Slicer Community \<[slicer@discoursemail.com](mailto:slicer@discoursemail.com)\> 작성:

Local threshold effect only works in recent Slicer Preview Releases.

–  
_Previous Replies_  
Operating system: Mac OS Mojave  
Slicer version: 4.10.2  
Expected behavior:  
I want to get ROI using a local threshold extension.

Actual behavior:

When I attempt the local threshold, I cannot click with the left mouse button (I cannot make an ROI).  
Just I can do change width and level.

Could you kindly help me?

Hyo Suk Nam

---

<div class="post-metadata">

**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 4, 2020, 1:59pm UTC](https://discourse.slicer.org/t/when-i-attempt-local-threshold-extension-i-cannot-click-with-left-mouse-button/12850/5 "2020-08-04T13:59:27Z")

</div>

@Sunderlandkyl is right, Local threshold effect does work in Slicer-4.10.2. If you still have issues then describe in more details what you mean by “change width and level” (or send a few screenshots or screen capture video).