I Had An MRI Once To Rule Out I Was

I had an MRI once to rule out I was only having migraines. The radiologist found what he called a black spot. He initially said I might have had a stroke before I was born. I was about 57 at the time. This seemed unlikely to me and my neurologist. My doctor never determined what it could be. Any ideas? It still bothers me? I'm a healthy 64 year old woman, migraines under control with Topomax, no real problems.