# Rescale voxel values of CBCT to MDCT HU **URL:** https://discourse.slicer.org/t/rescale-voxel-values-of-cbct-to-mdct-hu/12876 **Category:** Support **Created:** [August 6, 2020, 2:48pm UTC](https://discourse.slicer.org/t/rescale-voxel-values-of-cbct-to-mdct-hu/12876 "2020-08-06T14:48:03Z") **Posts on this page:** 1 **Showing post:** 3

### 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: [August 6, 2020, 4:07pm UTC](https://discourse.slicer.org/t/rescale-voxel-values-of-cbct-to-mdct-hu/12876/3 "2020-08-06T16:07:02Z")

If you know the correspondence between original values and HU then applying that transformation to voxel intensities should be trivial. If you need don’t know it then you need to do a few measurements. These topics should help: > [@From CT to qCT?](https://discourse.slicer.org/t/from-ct-to-qct/11782): > > Dear all Is there an extension that allows to extract segment statistics for known CT calibration parameters? I would like to extract bone density values instead of HU. Thanks > [@Bone Mineral Density (BMD) measurement method](https://discourse.slicer.org/t/bone-mineral-density-bmd-measurement-method/11010): > > I have been told a method of calculating BMD from micro CT data using a proprietary software and i am wondering about the accuracy of the method and replicating it with the 3D Slicer. The way it was done in the software was, we use 3 phantoms of know density, water and 0.25 and 0.75 and the mean hounsfield values was water 0 = -575.936 0.25 = 1142.4 0.75 = 3267.8 so the equation was X =(y+11.708)/4381.1 so i try to do this the same with the 3D Slicer, Note that for many operations, such as visualization, registration, segmentation, a calibrated CT is useful, but not essential. What is your application? What would you like to achieve overall? --- _[View the full topic](https://discourse.slicer.org/t/rescale-voxel-values-of-cbct-to-mdct-hu/12876)._