brain cyst/white matter

I just got results from a cat scan, small hypo density syst near left choroidal fissure.  And was told the MRI came back showing a small amount of white matter?  I know I did not ask enough about the MRI, I panicked.  I was told to see a neurologist.  My symptoms are swooshing sounds, throbing, and pressure.  I also get headaches.  Last few weeks it has been mostly pressure.  Does anyone know what this sounds like.  I was sure it was just a cyst but now hearing there is white matter that scares me.