Thank you for using Justanswer for your concern.
Of course, in your specific case, the best answer will come from your doctor in conjuction with the doctor that read your MRI. But from the information you have given us this indicates a small area of damage. This is not uncommon. This could come from anything from a prior bump on the head, to high cholesterol, and other causes. It would be worrisome if there were larger and additional areas, or if similar findings were found to be increasing rapidly.
I went to review the exact meaning of microangiopathic gliosis, and found a complete answer to your question. Normally, we explain this ourselves, but since it explains so well your situation, I am sending you the link:
I will also sent you a link so that you can see the structures of the brain, speciffically the ventricles. I am not sure what "tigone" is. I do not find it in any medical dictionary.
Here are pictures of the ventricles: http://www.octc.kctcs.edu/gcaplan/anat/Notes/API%20Notes%20L%20Central%20Nervous%20System-Brain.htm
I hope this helps.
If you need to discuss or have questions, please reply.