Apply deconvolution filter on the image to correct blurring

We worked on orbital bone reconstruction from CT images where segmentation of thin bones was very challenging. Deconvolution helped but simple unsharp masking worked about just as well in practice.

See these posts for some more details:

I would recommend not to worry about achieve optimal results by preprocessing. If you oversample the volume (so that you can represent thinner walls) and apply some edge enhancement filter then it should help. You can take care of the remaining issues in further segmentation steps (e.g., you can create a continuous bone surface from segmented contours by using WrapSolidify segment editor effect).