I have been diagnoses with gliosis involving the basal ganglia what does this mean exactly

My MRI report says that there is some mild gliosis predominantly on the right side side involving the basal ganglia and adjacent to the body of the right lateral ventricle.  There is also some relative tight stenosis  of right M1 branch of the MCA no evidence of acute infarct on image. More mild abnormality on the right cause for vascular findings not determined but suggestions of artheromatous disease, vasculitis, radiation and a number of  uncommon underlying conditions

Please explain