MRI

[Lisa88]

Hi Dr. Nagler,
A few months ago, I had two MRI's. First I had a brain/ear MRI without contrast only. Then two weeks later, a brain/ear MRI with contrast. The first without contrast showed hyperintensities in the white matter of the left frontal lobe. The second with contrast two weeks later showed all clear.
I know there could have been a fault with the machinery here.
But as a surgeon who has dealt with MR before, I ask you this:
First question: What shows up on non contrast MRI that does not show up on with contrast MRI?
I had thought the with contrast was the master of all MRIs.
Second question: Should those with non pulsatile t get an MRA?
Thanks, Dr. Nagler.
Lisa

 

[Dr. Nagler]

First question: What shows up on non contrast MRI that does not show up on with contrast MRI?
I had thought the with contrast was the master of all MRIs.

I am not a neuroradiologist, but here's how I have come to understand it specifically in regards to the work-up for tinnitus. When an MRI of the brain and internal auditory canals is indicated (for example to rule out acoustic neuroma in a patient with unexplained asymmetrical tinnitus), large tumors will generally be readily seen on a non-contrast study, but smaller tumors might only be seen on a contrast study because the contrast enhances the tumor. However, unless you have a non-contrast study to use in comparison, it is possible even a contrast-enhanced small tumor might be missed.

Second question: Should those with non pulsatile t get an MRA?

Generally not except possibly in the case of an unexplained constant non-pulsatile somatosound originating in the head or neck, but even that's a stretch.

Hope this helps more than confuses.

Dr. Stephen Nagler