Help deciphering MRI results?

My 18 month old son had an MRI last week, and I got the report today. I need help deciphering some of this if anyone is willing to help!! His pediatrician only told me he had thinning of the white matter, and kind of explained it to a small extent, but I am still clueless. He did not tell me about the other findings. I have no idea what a foci is! :-D

   Here is what it says:


    Findings: There are few periventricular T2 prolongation foci represent nonspecific gliosis. White matter thinning is noted. Stable small fluid signal space in left basal ganglia represents developmental cyst. No hydrocephalus. No evidence of midline shift or mass-effect. No evidence of restricted diffusion is seen to suggest acute infarction. Fluid is seen in the left mastoid air cells.

   IMPRESSION:

1. White matter thinning is noted.
2.There are few periventricular T2 prolongation foci represent nonspecific gliosis.
3. No acute intracranial abnormality.

  Any help would be appreciated!!