White matter hyper intensities is a really fancy way to say that you have a few bright spots in your MRI that the radiologist would not expect to be there. Non-specific means that he doesn't have a cause or source for what they are, and non characteristic to demyelination means they are not in shapes or configurations typically seen in diseases that attack myelin such as MS. So as Sally said, the good news is that the radiologist reading the scan is saying that the MRI doesn't clearly show MS (or any other demyelinating disease).

However...be aware that radiologists are purely looking at the scan in front of them, and usually do not have the clinical file to review while reading your scan. So what would not otherwise be evidence of MS to the radiologist, MAY in fact be seen as evidence to your doctor, who has the knowledge of other symptoms and clinical evidence that may point that direction. I am not trying to scare you by saying that...just to convince you not to go into the doctor's office with an expected outcome.

I originally had 2 hyperintensities in my brain on an MRI, and 2 years later, had an MRI that the radiologist summarized with the equivalent of "no significant changes". I almost didn't go to my neurologist for my annual followup based on that report. But when I did, she looked at the scan herself and noted that by "no significant changes", the radiologist meant that I still had white matter hyperintensities...but what he neglected to point out was that instead of 2, I now had 7. Which was enough to allow the neurologist to give me an MS diagnosis and start on disease modifying medication.

So don't read too much into the radiologist's read of your MRI. Go to your doctor and let him or her tell you what they think it means to you.