Possible Internal Decay

I recently inspected my pine tree and was generally pleased that visually it looks healthy. However, I was confused by a fungus at the roots. How can I determine the degree of rot inside the tree?

If you find fungus on the roots, it is very likely that internal rot has already begun. In this case, you should get a certified arborist report to see how serious the problem is, as my brother did. An arborist will take a CT scan of the trunk and large roots. If you want to read more about this, you can refer to the manual on Acoustic Tomography and Resistography Analysis.