# CT grey/white matter segmenation

**URL:** <https://discourse.slicer.org/t/ct-grey-white-matter-segmenation/773>\
**Category:** Support\
**Created:** [July 27, 2017, 4:01am UTC](https://discourse.slicer.org/t/ct-grey-white-matter-segmenation/773 "2017-07-27T04:01:01Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![hph10128](https://avatars.discourse-cdn.com/v4/letter/h/6de8d8/32.png) [@hph10128](https://discourse.slicer.org/u/hph10128)\
**Post date:** [July 27, 2017, 4:01am UTC](https://discourse.slicer.org/t/ct-grey-white-matter-segmenation/773/1 "2017-07-27T04:01:01Z")

</div>

Hi all,

I have perfusion CT maps that I registered to 24 hour post-op CTs. My end goal is to segment grey and white matter in both the perfusion and post-op CTs. I attempted to use the EM segmentation module for MRI segmentation but am unable to register the post-op non-perfusion CT to the atlas. Does anyone have any suggestions on how to perform this segmentation? Should I be using the EM segmentation module? Any advice/suggestions are greatly appreciated.

Thanks,

Hailey

---

<div class="post-metadata">

**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [July 27, 2017, 1:46pm UTC](https://discourse.slicer.org/t/ct-grey-white-matter-segmenation/773/2 "2017-07-27T13:46:03Z")

</div>

Hi Hailey -

Using CT for gray/white matter segmentation is be pretty hard. Here’s a recent paper that shows good results and it should give some ideas. The described method is not currently implemented in Slicer, but the building blocks should mostly be available.

-Steve

[https://www.nature.com/articles/s41598-017-00239-z](https://www.nature.com/articles/s41598-017-00239-z)