Volume subtraction CBCT

Operating system: Windows 10
Slicer version: 4.11

Hi everyone,

I am a new user of Slicer. I would like to calculate which differences exist in bone volume at two time points, pre-intervention and post-intervention. I have dicom files of CBCTs collected before and after the intervention and want to compare volume differences in specific regions of the maxilla. It is therefore important to be sure that I am always comparing the very same region to understand the effect of the intervention.

I am facing several problems and would ask your help.

  1. CBCT look extremely noisy after setting the threshold and displaying the 3D model. So I am wondering if also the volume calculation may be influenced by possible different CBCT image definition.

  2. In case the CBCTs have different coordinates, is there an automated and repeatable way to align the images?

  3. In the pre-intervention CBCT, I should measure the bone volume after simulating teeth extraction and subsequently compare this volume to the post-intervention CBCT (where the teeth is not present).

Could you please suggest any operative protocol that you think may apply to my purpose and the available data? Any help is higly appreciated.

Thanks in advance