# Where is HU at Segment Statistics module?

**URL:** <https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861>\
**Category:** Support\
**Created:** [April 12, 2023, 11:32am UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861 "2023-04-12T11:32:37Z")\
**Posts on this page:** 20\
**Page:** 1

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**Author:** ![Igor1023](https://avatars.discourse-cdn.com/v4/letter/i/ec9cab/32.png) [@Igor1023](https://discourse.slicer.org/u/Igor1023)\
**Post date:** [April 12, 2023, 11:32am UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/1 "2023-04-12T11:32:37Z")

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Hy everyone. Im a student of Sechenov Medical University. Now im trying to manage with 3D Slicer and i want to know, where can i find Haunsfield Units here. Thank you.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/e/e/eeba81f765440ea20900d9052cc3de4e3dce1698.jpeg)

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**Author:** ![rbumm](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/rbumm/32/9404_2.png) [@rbumm](https://discourse.slicer.org/u/rbumm)\
**Post date:** [April 12, 2023, 1:23pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/2 "2023-04-12T13:23:42Z")

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Please select a volume in the Segment Statistics extension to get the HU.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/7/a/7aa2fb982ca581d896fb2998712db8703320bc48.jpeg)

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**Author:** ![Igor1023](https://avatars.discourse-cdn.com/v4/letter/i/ec9cab/32.png) [@Igor1023](https://discourse.slicer.org/u/Igor1023)\
**Post date:** [April 13, 2023, 12:32pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/3 "2023-04-13T12:32:28Z")

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excuse me, are those 3 columns HU?

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/5/6/562b8cf9c6b75554d4cbea63026d8f00c0924f9d.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:** [April 13, 2023, 12:53pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/4 "2023-04-13T12:53:03Z")

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Yes, in clinical CT images voxel values are specified in HU, therefore the intensity statistics (minimum, maximum. mean, median, standard deviation values) are all computed in HU.

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**Author:** ![Igor1023](https://avatars.discourse-cdn.com/v4/letter/i/ec9cab/32.png) [@Igor1023](https://discourse.slicer.org/u/Igor1023)\
**Post date:** [April 19, 2023, 2:07pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/5 "2023-04-19T14:07:42Z")

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im sorry again. but what if i need to measure density in two or more specific areas of tumor or implant etc

P.S sorry for my english

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/1/8/18fcaba4c49b6387c52aca5da4670dbf3168e895.png)

Arrows are showing areas of interest

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**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:** [April 19, 2023, 2:10pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/6 "2023-04-19T14:10:51Z")

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You can use the Segment Editor to define the regions over which you want to measure the HU values.

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<div class="post-metadata">

**Author:** ![Igor1023](https://avatars.discourse-cdn.com/v4/letter/i/ec9cab/32.png) [@Igor1023](https://discourse.slicer.org/u/Igor1023)\
**Post date:** [April 19, 2023, 2:27pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/7 "2023-04-19T14:27:01Z")

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Thank you. in the right corner there is a result of segmentation. H I J K columns shows density of all CT images or only of my region?

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<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:** [April 19, 2023, 2:31pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/8 "2023-04-19T14:31:01Z")

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From the screenshot the values in the H I J columns of the segment statistics are for the segment named ‘bone’, not the full volume. Make additional segments in the segment editor and you will get additional rows with the per-segment HU values.

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<div class="post-metadata">

**Author:** ![Igor1023](https://avatars.discourse-cdn.com/v4/letter/i/ec9cab/32.png) [@Igor1023](https://discourse.slicer.org/u/Igor1023)\
**Post date:** [April 19, 2023, 2:49pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/9 "2023-04-19T14:49:28Z")

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ok thank you. so if i want to measure specific points i need to define smaller region including those points, right?

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<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:** [April 19, 2023, 2:52pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/10 "2023-04-19T14:52:10Z")

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Correct. Use segments if you want to calculate statistics over multiple voxels, or use the DataProbe to look at the values at specific points.

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<div class="post-metadata">

**Author:** ![Igor1023](https://avatars.discourse-cdn.com/v4/letter/i/ec9cab/32.png) [@Igor1023](https://discourse.slicer.org/u/Igor1023)\
**Post date:** [April 19, 2023, 3:00pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/11 "2023-04-19T15:00:04Z")

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thank you. is 3982 dencity on HU?

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/c/d/cdba9049b95bdb29613499b9ce99567c1b3fc78b.png)

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<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:** [April 19, 2023, 3:03pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/12 "2023-04-19T15:03:13Z")

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That depends on the calibration of your scan. Clinical CTs are generally good, but cone-beam CTs are often not calibrated. You can search for information on this. Slicer just reports what’s in the images.

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<div class="post-metadata">

**Author:** ![Igor1023](https://avatars.discourse-cdn.com/v4/letter/i/ec9cab/32.png) [@Igor1023](https://discourse.slicer.org/u/Igor1023)\
**Post date:** [April 19, 2023, 3:09pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/13 "2023-04-19T15:09:47Z")

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no i mean in what units of measurement is this number?

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<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:** [April 19, 2023, 3:23pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/14 "2023-04-19T15:23:14Z")

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The units are whatever is in your file.

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<div class="post-metadata">

**Author:** ![Igor1023](https://avatars.discourse-cdn.com/v4/letter/i/ec9cab/32.png) [@Igor1023](https://discourse.slicer.org/u/Igor1023)\
**Post date:** [April 19, 2023, 4:09pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/15 "2023-04-19T16:09:35Z")

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can you please say where i can find average value of density at my segmet?

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<div class="post-metadata">

**Author:** ![Igor1023](https://avatars.discourse-cdn.com/v4/letter/i/ec9cab/32.png) [@Igor1023](https://discourse.slicer.org/u/Igor1023)\
**Post date:** [April 19, 2023, 4:30pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/16 "2023-04-19T16:30:09Z")

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hi, can you please tell how to measure average density of my segmentation?

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<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:** [April 19, 2023, 4:34pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/17 "2023-04-19T16:34:01Z")

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Sorry if it’s not coming through but I believe we have already told you exactly what you are asking. Were you able to create multiple structures and get the statistics for each segment?

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<div class="post-metadata">

**Author:** ![Igor1023](https://avatars.discourse-cdn.com/v4/letter/i/ec9cab/32.png) [@Igor1023](https://discourse.slicer.org/u/Igor1023)\
**Post date:** [April 19, 2023, 4:37pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/18 "2023-04-19T16:37:47Z")

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im sorry. im asking not about it. i have my segmentation and i wnat to know average density of it, not for another segemts. just of segment that i already have. i suugest that it is mean column. but i cant say exactly, so im asking you about it

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<div class="post-metadata">

**Author:** ![Igor1023](https://avatars.discourse-cdn.com/v4/letter/i/ec9cab/32.png) [@Igor1023](https://discourse.slicer.org/u/Igor1023)\
**Post date:** [April 19, 2023, 4:39pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/19 "2023-04-19T16:39:12Z")

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![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/8/e/8e50a32ebc183586bbb00a621a7b3e174fd11ff5.png)  
average density of this one, who named as bone

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<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:** [April 19, 2023, 4:53pm UTC](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861/20 "2023-04-19T16:53:02Z")

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Yes, in this case average density (x-ray absorption) is the mean column of the segment statistics when the CT is selected as the scalar volume.

[Next page](https://discourse.slicer.org/t/where-is-hu-at-segment-statistics-module/28861.md?page=2)