Welcome to health care magic.
1.It looks like an age related changes seen in the brain, like volume loss,
atrophy, small vessel ischemic changes.
2.But it is seen generally symmetrically, in this case as mentioned in report it is asymmetric.
3.I suspect in this case - chronic vascular insufficiency.
4.MR angiogram will help to identify the vessel status, and cause of insufficiency.
5.its not of grater concern, but since it came in to light, get evaluate as some can be treated.
Good luck.
Hope i have answered your query,
any thing to ask ? do not hesitate to ask.
http://doctor.healthcaremagic.com/doctors/dr-ganesh/62888