Difficulty Registering Pre- and Post-Surgery CBCT Datasets without Fiducials

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1

Hi all,

I’m currently working on a project involving two DICOM datasets acquired via CBCT (cone-beam CT). The first dataset was taken before a surgical procedure, and the second one after a tooth extraction. Unfortunately, I don’t have any external fiducial markers in the images, so I’m using IGT Wizard Registration based on anatomical landmarks.

Despite using a relatively high number of fiducial points (10), it seems very difficult to achieve a good overlap between the two scans. The registration always appears slightly off.

Could the issue be related to the inherent limitations of CBCT, such as reduced accuracy or image quality in the peripheral regions? Or is there something else I might be missing?

Any suggestions or shared experiences would be greatly appreciated!

Thanks in advance,
Anna

2

Did you try just the regular registration flow with General Registration? There is pre-post CBCT in the SampleData you can test with. You may need to mask out the moving parts (neck/jaw).