# How to calculate BMD

**URL:** <https://discourse.slicer.org/t/how-to-calculate-bmd/15333>\
**Category:** Support\
**Created:** [January 4, 2021, 2:10pm UTC](https://discourse.slicer.org/t/how-to-calculate-bmd/15333 "2021-01-04T14:10:05Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Farhan](https://avatars.discourse-cdn.com/v4/letter/f/b2d939/32.png) [@Farhan](https://discourse.slicer.org/u/Farhan)\
**Post date:** [January 4, 2021, 2:10pm UTC](https://discourse.slicer.org/t/how-to-calculate-bmd/15333/1 "2021-01-04T14:10:05Z")

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Sir, how to calculate BMD of bone in 3d slicer.  
Sir, I am working on upper cervical spine and I have to find Young’s modules of elasticity(E) and Poisson’s ratio(u) of different parts of c1, c2 spine.  
What is the relationship between BMD and E and u.  
Kindly reply the questions.

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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:** [January 4, 2021, 2:31pm UTC](https://discourse.slicer.org/t/how-to-calculate-bmd/15333/2 "2021-01-04T14:31:48Z")

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There is no universal formula to convert between radiologic density (voxel value on CT, in Hounsfield units) and BMD; or BMD to mechanical properties. There are lots of papers that use various assumptions and approximations to set mechanical properties directly from CT voxel values. I would recommend to use the method described in one of the recent, highly cited papers.

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**Author:** ![manjula](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/manjula/32/80981_2.png) [@manjula](https://discourse.slicer.org/u/manjula)\
**Post date:** [January 4, 2021, 3:30pm UTC](https://discourse.slicer.org/t/how-to-calculate-bmd/15333/3 "2021-01-04T15:30:18Z")

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Hi,

We have calculated BMD with MircoCT using the method described [here](https://www.bruker.com/fileadmin/user_upload/8-PDF-Docs/PreclinicalImaging/MolecularImaging/Albira_App_Notes/AP0123_-_PMOD_Software_Protocol_for_Obtaining_Bone_Mineral_Density_Units.pdf).

We are yet to publish our papers based on this yet.

Basically, the main prerequisite is to have a **Calibrated** machine.  
Then we measured the HU means in 3 phantoms with know density. And as Prof Lasso suggested in the final version we took 5 samples to get the

> [@Bone Mineral Density (BMD) measurement method](https://discourse.slicer.org/t/bone-mineral-density-bmd-measurement-method/11010/2):
>
> 3 measurement points are very few. At least for initial exploration, I would add at least 5-10 points, just to have an idea about shape and amount of noise in the curve.

You can pretty much replicate this process in 3D Slicer provided you have a calibrated machine and phantoms with know density.

[![]( " - YouTube") ](https://www.youtube.com/watch?v=eYEzVD6W0YU)

The resources we used are,  
Fortunately, we did not have to (research team) do the calibration by ourself but it was done by the professionals.  
[https://drive.google.com/file/d/1-NBlVGr5gSFJzyYT9wlulZBkykQnhYLr/view?usp=sharing](https://drive.google.com/file/d/1-NBlVGr5gSFJzyYT9wlulZBkykQnhYLr/view?usp=sharing)

[![](https://img.youtube.com/vi/l0D4gjwsDI0/maxresdefault.jpg "Bruker microCT tutorial: Calibration and measurement of bone mineral density (BMD and TMD) in bone.") ](https://www.youtube.com/watch?v=l0D4gjwsDI0)

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**Author:** ![Farhan](https://avatars.discourse-cdn.com/v4/letter/f/b2d939/32.png) [@Farhan](https://discourse.slicer.org/u/Farhan)\
**Post date:** [January 14, 2021, 1:51pm UTC](https://discourse.slicer.org/t/how-to-calculate-bmd/15333/4 "2021-01-14T13:51:09Z")

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Sir, please share paper which set mechanical properties directly from CT voxel value as you described earlier. I am finding difficulties to find such paper.  
Kindly share.

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**Author:** ![Joseph\_L](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/joseph_l/32/66811_2.png) [@Joseph\_L](https://discourse.slicer.org/u/Joseph_L)\
**Post date:** [December 5, 2023, 12:13am UTC](https://discourse.slicer.org/t/how-to-calculate-bmd/15333/5 "2023-12-05T00:13:03Z")

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Is it possible for you to update these links? Most of them are broken

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**Author:** ![NIE\_XIUPING](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/nie_xiuping/32/69995_2.png) [@NIE\_XIUPING](https://discourse.slicer.org/u/NIE_XIUPING)\
**Post date:** [November 13, 2024, 10:05am UTC](https://discourse.slicer.org/t/how-to-calculate-bmd/15333/6 "2024-11-13T10:05:45Z")

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Could you please update these broken links?