Good Day Doc, We Just Got Result Of The Head

Good day Doc, we just got result of the Head CT scan of my 2 yrs old son. It says in his Ct scan that " There is parenchymal volume loss in both hemisphere, brain stem and cerebellum. The extraaxial CSF spaces and ventricles are prominent."
Can you enlighten me? What does that mean? We visited his pedia earlier but unfortunately she didn't attend her clinic today. Thank you!