MRI Question — What Can an MRI Without Contrast Show That an MRI With Contrast Cannot?

Hi Dr. Ancill,

Thanks for joining us.
Your work with the brain is intriguing.
Wonder if you may be able to answer the following question:

What can an MRI without contrast show that an MRI with contrast cannot? I always thought the one with contrast was the most specific. Thanks.

Background to this question:
I have no symptoms of MS or other except for tinnitus. Tinnitus was induced Nov 2013 through intransal topical lidocaine solution during a menstrual migraine.

Spring 2014, I had an MRI without contrast done. Then two weeks later an MRI with contrast with the same company/radiologist.

The first one without contrast read:
There is a nonspecific 8 mm T2/FLAIR hyperintense focus within the centrum semiovale of the left frontal lobe with 2 adjacent 2 mm T2/FLAIR foci immediately posteriorly. Cerebral hemispheres are otherwise unremarkable.

The second MRI with contrast read:
The previously identified T2/FLAIR ... are not seen on post contrast sequence.

The advice for both read:
Clinical correlation is advised to exclude chronic small vessel ischemic disease, vasculitis, postinfectious or postinflammatory demyelinating processes or lesions.

One doctor noted this could have been a machine malfunction with the non contrast. Really don't want to have to have another MRI done with tinnitus.
Do I have to worry about this, if the MRI with contrast came up clear?

Thanks.
Lisa

 

Ultimately, MRIs are cameras and can only 'see' to the limit of their resolution which is a few millimetres. I have no idea how intranasal lidocaine could (1) cause tinnitus or (2) be related to nonspecific lesions in the left frontal lobe. Now, I am a Canadian, so the US medical system is a mystery to me - I would advise that you get a recognized neuroradiologist to look at the data and get an independent 2nd opinion. I cannot comment on possible diagnoses and it would be improper to speculate. I can say that the older you are, the more likely it is to find these nonspecific signals in the brain and it likely means nothing at all. I would also advise that you discuss your concerns with your own doctors - on any forum, you never know what someone will tell you.