Volume/Depth Analysis of a 3D Image

[DanF]

I was wondering if it is possible to determine the volume of pores/lesions in
a specific region in a 3D image of a bone. I am really new to using ImageJ
and unfamiliar with its capabilities and would appreciate all the help. I
have linked a picture of the bone and have outlined the region where I want
to find the volume/depth of.

http://i62.tinypic.com/jjnujp.png

Thanks!