What Does Chronic Microvascular Ischemia Mean?

I just received the results of an MRI of my brain - done because I was having pains on the left side over my eye, I was trying toget a definition of Chronic microvascular ischemia. I was assuming microvascular was small veins in the brain. Also need to know what "No foci of restricted diffusion to suggest acute infarction. and #3 Stable mild to moderate ventriculomegaly.