# Body composition measurements (sma, smd, sat, vat) at L3 level

**URL:** <https://discourse.slicer.org/t/body-composition-measurements-sma-smd-sat-vat-at-l3-level/45751>\
**Category:** Support\
**Tags:** segmentation\
**Created:** [January 12, 2026, 4:36pm UTC](https://discourse.slicer.org/t/body-composition-measurements-sma-smd-sat-vat-at-l3-level/45751 "2026-01-12T16:36:17Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![goz](https://avatars.discourse-cdn.com/v4/letter/g/4bbf92/32.png) [@goz](https://discourse.slicer.org/u/goz)\
**Post date:** [January 12, 2026, 4:36pm UTC](https://discourse.slicer.org/t/body-composition-measurements-sma-smd-sat-vat-at-l3-level/45751/1 "2026-01-12T16:36:17Z")

</div>

Hello everyone, I need your help 🙏

I want to measure the sma cm 2, smd hu, sat cm2 and vat cm2 values at L3 level CT dicom images.

But the software gives me the cm 3 volume , sat and vat values ,

how can i find the sma -sat-vat cm 2 ?

---

<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:** [January 12, 2026, 5:21pm UTC](https://discourse.slicer.org/t/body-composition-measurements-sma-smd-sat-vat-at-l3-level/45751/2 "2026-01-12T17:21:35Z")

</div>

Slicer calculates volumes in 3D. If you only segment a single slice, you need to divide by the slice spacing to get an area.

---

<div class="post-metadata">

**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:** [January 12, 2026, 5:34pm UTC](https://discourse.slicer.org/t/body-composition-measurements-sma-smd-sat-vat-at-l3-level/45751/3 "2026-01-12T17:34:00Z")

</div>

If you have a 3D segmentation, you can use “Segment Cross-Section Area” module in Sandbox extension to get cross-sectional area slice by slice.

---

<div class="post-metadata">

**Author:** ![goz](https://avatars.discourse-cdn.com/v4/letter/g/4bbf92/32.png) [@goz](https://discourse.slicer.org/u/goz)\
**Post date:** [January 13, 2026, 10:11pm UTC](https://discourse.slicer.org/t/body-composition-measurements-sma-smd-sat-vat-at-l3-level/45751/4 "2026-01-13T22:11:04Z")

</div>

Thanks a lot with heart 🙂

I use segment cross section area but i do everthing manually, when i choose the threshold it gives the whole segments.

When we enter threshold values, is it possible for the software to automatically segment fat and muscle in a single section ?