Rescale voxel values of CBCT to MDCT HU

[ahmad_abbas]

I have a CBCT and MDCT of the same specimen and I want to “convert” the grey values in CBCT accordingly the ones in MDCT and consequently be able to measure “HU” values in the CBCT volume?

[ahmad_abbas]

I have a CBCT and MDCT of the same specimen and I want to “convert” the grey values in CBCT accordingly the ones in MDCT and consequently be able to measure “HU” values in the CBCT volume?

[lassoan (Andras Lasso)]

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?

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

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, [Screenshot from 2020-04-06 10-…

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?

[ahmad_abbas]

i need the HU units for the treatment planning system and monte carlo simulation

[lassoan (Andras Lasso)]

For radiation therapy treatment planning you indeed need voxels in HU, so you need to calibrate the intensity as described in the topics linked above.