# Opening segmentation without mastervolume

**URL:** <https://discourse.slicer.org/t/opening-segmentation-without-mastervolume/22373>\
**Category:** Support\
**Created:** [March 8, 2022, 3:03pm UTC](https://discourse.slicer.org/t/opening-segmentation-without-mastervolume/22373 "2022-03-08T15:03:59Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![laura.h](https://avatars.discourse-cdn.com/v4/letter/l/0ea827/32.png) [@laura.h](https://discourse.slicer.org/u/laura.h)\
**Post date:** [March 8, 2022, 3:03pm UTC](https://discourse.slicer.org/t/opening-segmentation-without-mastervolume/22373/1 "2022-03-08T15:03:59Z")

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Operating system: Windows 10  
Slicer version: 4.11.20210226

Hello, I am new to slicer and have a problem with opening my finished segmentation without a mastervolume.

I use a dummyFile (.nhdr), generated with my original binary data (CT), as the mastervolume for the segmentation.  
When I open the finished segmenation and the dummyFile, I am able to view all slices.

But when I try to open the finished segmentation (.seg.nrrd) without the mastervolume, only three of the 512 slices (that I can usually choose with the scroll bar) are shown. The scrollbar directly jumps from one end to the middle to the other end.

Is there a specific way to save/export the segmentation (should still be .seg.nrrd or .nrrd), so that I can open it without the mastervolume and still be able to view all slices?

Thank you in advance!  
Laura

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<div class="post-metadata">

**Author:** ![laura.h](https://avatars.discourse-cdn.com/v4/letter/l/0ea827/32.png) [@laura.h](https://discourse.slicer.org/u/laura.h)\
**Post date:** [March 11, 2022, 12:13pm UTC](https://discourse.slicer.org/t/opening-segmentation-without-mastervolume/22373/2 "2022-03-11T12:13:54Z")

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[https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/c/b/cb832617a16928f1ae31fe57e1431989f7875c26.mp4](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/c/b/cb832617a16928f1ae31fe57e1431989f7875c26.mp4)

Additional video:

First you can see the segmentation with the master volume (dummyFile) and then without the mastervolume.

Without the mastervolume the red scrollbar jumps from -1.0000 to 0.0000 to 1.0000, whereas with the mastervolume it ranges from 0.0000 to 255.0000.