porosity measurement in specimen

[kavanaa1]

Hi,

I have hundreds of CT scan slices that were taken from metal specimens to determine the amount of contained porosity. I want to try extract a total volume porosity measurement from each specimen, but the pores are very small relative to the cross section of the slices (50-100 micron pore diameters in a 6mm diameter section).
Is it possible within Image J to take the sequence of these slices and determine the shape of the pore and the volume porosity value. Attached is an example of the raw image slice.

thank you