# After I got the cross-sectional area of a ROI, How can I measure its HU values?

**URL:** <https://discourse.slicer.org/t/after-i-got-the-cross-sectional-area-of-a-roi-how-can-i-measure-its-hu-values/23162>\
**Category:** Support\
**Tags:** segmentation, extensions-manager\
**Created:** [April 28, 2022, 7:46am UTC](https://discourse.slicer.org/t/after-i-got-the-cross-sectional-area-of-a-roi-how-can-i-measure-its-hu-values/23162 "2022-04-28T07:46:11Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![lyk-snail](https://avatars.discourse-cdn.com/v4/letter/l/e480ec/32.png) [@lyk-snail](https://discourse.slicer.org/u/lyk-snail)\
**Post date:** [April 28, 2022, 7:46am UTC](https://discourse.slicer.org/t/after-i-got-the-cross-sectional-area-of-a-roi-how-can-i-measure-its-hu-values/23162/1 "2022-04-28T07:46:11Z")

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Hello!  
I’ve been using 3D slicer for a while. I have got the cross-sectional area of a muscle after I used the “segment editor” module AND the " Segment Cross-Section Area" module. But I don’t know how to measure the HU values of the ROI. How can I get the average, median, max，min HU value of it. I used CT image datas.  
Thank you!

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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:** [April 28, 2022, 5:06pm UTC](https://discourse.slicer.org/t/after-i-got-the-cross-sectional-area-of-a-roi-how-can-i-measure-its-hu-values/23162/2 "2022-04-28T17:06:11Z")

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You can use Segment Statistics module to get these statistics for each segment.

If you need the values separately for each slice then you may use @jmhuie’s [SegmentGeometry](https://github.com/jmhuie/Slicer-SegmentGeometry) extension. Currently it provides only average, but would not be hard to add other statistics as well if there is a good reason. Note that min/max are extremely fragile metrics (a single voxel could throw off your results), probably you would want to use percentiles (1st and 99th or 5th and 95th) instead.

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**Author:** ![jmhuie](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jmhuie/32/7086_2.png) [@jmhuie](https://discourse.slicer.org/u/jmhuie)\
**Post date:** [May 1, 2022, 8:17pm UTC](https://discourse.slicer.org/t/after-i-got-the-cross-sectional-area-of-a-roi-how-can-i-measure-its-hu-values/23162/3 "2022-05-01T20:17:51Z")

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> [@lassoan](#):
>
> Currently it provides only average, but would not be hard to add other statistics as well if there is a good reason.

Yep, wouldn’t be difficult at all to add extra calculations if you decide there are certain ones you’d like