Ask the Experts

Question:

I read somewhere that when you have scans done with gadolinium, the brain and spine should be done on separate occasions. Is that true?

I have a memory from one of the lectures we had at the meeting that timing was essential when you use contrast!

A year ago they scanned my spine and brain at the same session, and they found two tumors in the spine, but nothing in the brain. From what I´ve read and from the lectures I understand that you "invariably" get brain tumors if you have spinal tumors. I´m worried that maybe they missed something!

Shall I ask for a new brain scan, do you think?

Answer:

We often do the spine and brain at the same time. Because of the normal blood brain barrier the contrast "sticks around" longer in the brain and spine than in the rest of the body. As a result there is a longer window of opportunity to scan. That is not to say that a huge amount of time can elapse between the spine and the brain after contrast. We try to scan both within 15 minutes of injection.

Regarding the spine/brain lesion question. It is quite possible to have just spine and no brain lesions. It’s not the most common but it does occur. If there was a big delay between the spine and the brain scans after contrast very tiny (2-3mm) lesions might be harder to see. But they should not be symptomatic.

For abdominal imaging, speed is much more important because the contrast is not contained by the blood brain barrier and leaks out much faster. That's why rapid scanning is much more important in the abdomen.

-- Peter L. Choyke, M.D., Diagnostic Radiology Department, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland

As printed in the VHL Family Forum 8:4, December 2000.  For permission to reprint, please contact VHL Family Alliance, editor@vhl.org. Further information is available from the VHL Family Alliance, info@vhl.org.