X-ray chest result : ill defined soft opacities seen in both middle and rt. lower zones. impression: infective process both lungs. note: marked regression in the lesion noted as compared to previous x-ray chest. can you please explain what it means?

Getting better: The lung is usually full of air which is not dense. A density implies something other than air fills the space. This description suggests the thing filling that space is not very dense as would be fluid accumulated during infection. (bone or thick tissue is denser) It is in more than one place. The regression means it is getting less dense or better.