# Not able to select masks for registration in elastix

**URL:** <https://discourse.slicer.org/t/not-able-to-select-masks-for-registration-in-elastix/35871>\
**Category:** Support\
**Tags:** registration, elastix\
**Created:** [May 2, 2024, 12:49pm UTC](https://discourse.slicer.org/t/not-able-to-select-masks-for-registration-in-elastix/35871 "2024-05-02T12:49:33Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Chih-Ying-Huang](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/chih-ying-huang/32/70266_2.png) [@Chih-Ying-Huang](https://discourse.slicer.org/u/Chih-Ying-Huang)\
**Post date:** [May 2, 2024, 12:49pm UTC](https://discourse.slicer.org/t/not-able-to-select-masks-for-registration-in-elastix/35871/1 "2024-05-02T12:49:33Z")

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Operating system: Windows10  
Slicer version: 5.6.2  
Expected behavior: Registration between 2 abdominal CT image with masks  
Actual behavior:  
After import my binary mask as segmentations in slicer, I was not able to find a mask to select, as the following image shows:

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/e/a/eaa0f2609d48981c05e12416aacb3e3b1f46b50f.png)

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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:** [May 2, 2024, 12:52pm UTC](https://discourse.slicer.org/t/not-able-to-select-masks-for-registration-in-elastix/35871/2 "2024-05-02T12:52:42Z")

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Mask must be a label volume or segmentation. You can either convert the scalar volume to labelmap volume in Volumes module; or when you select the data for loading in the “Add data” window, choose “Segmentation” in Description column, or keep the description “Volume” and check the “LabelMap” option.

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<div class="post-metadata">

**Author:** ![Chih-Ying-Huang](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/chih-ying-huang/32/70266_2.png) [@Chih-Ying-Huang](https://discourse.slicer.org/u/Chih-Ying-Huang)\
**Post date:** [May 2, 2024, 1:10pm UTC](https://discourse.slicer.org/t/not-able-to-select-masks-for-registration-in-elastix/35871/3 "2024-05-02T13:10:26Z")

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Thank you for your prompt reply, but I think I have imported my binary mask as segmentation:

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/a/9/a9218fc03f1797cdda5fe9e42a27ace5b17d0922.jpeg)  
 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/c/3/c316987650240457fee60e7b32c2865b94cd2960.png)

But still, I am unable to select it from the masks in the elastix module.