Hi,
Thank you for posting your query.
The CT brain findings are not something to be concerned about. 
Atrophy (shrinkage of brain) is normal with advancing age, and is a natural process, which can not be reversed.
Regarding ischemic changes (lack of blood supply to brain), you should get your risk factors screened for (including BP, sugar, 
cholesterol, etc). After consulting a doctor, you may need to take 
aspirin to prevent further 
brain ischemia.
Please get back if you require any additional information.
Best wishes,
Dr Sudhir Kumar MD (Internal Medicine), DM (Neurology)
Senior Consultant Neurologist
Apollo Hospitals, Hyderabad,
My personal URL on this website:  http://bit.ly/Dr-Sudhir-kumar 
My email: drsudhirkumar@yahoo.com
My blog: http://bestneurodoctor.blogspot.com/