This is just saying that on your MRI - they can see the space around the blood vessels with course through the brain.
This is simply the space around the blood vessel which is traveling through the brain.
This is normal, everyone has these spaces, and some people just have them larger than others, hence the "prominent spaces".
This does not mean anything to you. It is simply a description of your brain on the scan.
A friend, who is a cardiologist, advised me to:
1) Call my internist.
2) See a neurologist.
3) Have and additional CAT Scan or MRI done.
Do you think those additional steps are necessary?
I would not think any of those steps are necessary.
Of course, I don't know your full medical history, nor can I actually see your MRI pictures, so it may be safest to have your internist review this as well.