MRI question

[purplelady]

My doctor wants me to do an MRI with
contrast. I told her that I am sensitive
to medication and that I don’t feel safe
doing the contrast. I looked it up and it said
that in rare cases there can be an allergic
reaction. Has anyone done MRI with
contrast? I don’t think doctors understand
about medication sensitivities.

 

[wabi-sabi]

Perhaps you could do some allergy testing beforehand to make sure the contrast will be OK.

 

[hapl808]

I believe NAC is sometimes used before CT contrast to protect people with kidney issues.

For me, the marginal increase in CT or MRI resolution is not worth the damage or risk of contrast. But I have pretty bad sensitivities and I agree that doctors are completely unaware and not very understanding. I've had bad outcomes almost every time I have gone against my judgment and risked a medical test or procedure that worried me, but that may just be luck of the draw.

 

[YippeeKi YOW !!]

Has anyone done MRI with
contrast?

I've had somewhere in the range of 25 or so CT scans, and 4 or 5 MRI's .... memory blurs, but I think that the MRI uses a lot less gadolinium, while the CT scan sometimes uses gastrografin and gadolinium ....

If you're allergic to shellfish, a CT scan with contrast could precipitate a bad allergic reaction due to the contrast solution....

I'm not sure what your Dr(s) would be looking for, but you might ask them if they could get the result they need without contrast solutions .... they'll probably say no because the contrast-less MRI would require tighter inspection by a really good radiologist, but you can insist. It's your body.

Have they explained to you what the contrast solutions they use are composed of and how they work? That would probably be helpful.

EDIT .... for typos and clarity ...

 

[Judee]

My boss at my former job became badly allergic to shrimp after having a scan with the dye. It created a cross reaction in her. Eventually she was able to eat shrimp again but it took a long time.

 

[YippeeKi YOW !!]

My boss at my former job became badly allergic to shrimp after having a scan with the dye. It created a cross reaction in her. Eventually she was able to eat shrimp again but it took a long time.

Yeah, the CT scan contrast, and probably (tho not sure) the MRI contrast is composed of iodine and shellfish among othr things, so the cross-reaction is understandable .... and a bummer if you're fond of shrimp ....

 

[Nat kea]

I did an allergy test immediately before the MRI, in their office. But before that I took an antihistamine pill. The doctor said that it was impossible. So, after three days I had blisters on my palms, itched for a week, then healed and looked like calluses. All palms in karostah. Strange reaction. The contrast was without iodine, something else.

 

[Zebra]

Hi @purplelady

I would suggest discussing the pros & cons of using contrast with your doctor.

Contrast *IS* necessary for certain MRI image protocols.

If your doctor is looking for something specific, chances are he or she selected "with contrast" for a reason. So again, I would suggest asking your doctor.

BTW: In the past 6 years I've had roughly 16 MRIs, most with contrast. Never had a problem. About 2 years ago, my neuro told me that the gadolinium contrast typically used in MRIs was found to linger in the brain, but that's a side effect I am willing to accept in exchange for critical images, like brain, spinal cord, and heart.

 

[valentinelynx]

If you're allergic to shellfish, a CT scan with contrast could precipitate a bad allergic reaction due to the cntrast solution....

Actually, the connection between seafood allergies and IV contrast allergy (as well as allergies other types of iodinated medical products, such as surgical preps) is a myth. It was based on a 1975 article (Shehadi, 1975) that found a correlation between patients with atopic reactions to foods (not just seafood) and the tendency to have allergic-type reactions to IV contrast dyes. IV contrast dyes cause reactions because they are potent stimulators of the release of histamine and mast cells. Patients with a tendency to atopy are likely to have more reactive mast cells.

Frequently people believe that a seafood or IV contrast dye reaction is an "allergy to iodine". An allergy to iodine would be fatal, as iodine is ubiquitous in the body. Unfortunately, the myth is also pervasive in medical practice, as pre-op nurses and even radiology personnel frequently have a protocol of asking patients if they are allergic to seafood, and if so, avoid iodinated contrast dyes. It might make sense if they asked about a allergies to any food, or a history of frequent atopic reactions in general, but not specifically seafood.

Here a couple of links to read about the mythology of the seafood allergy/IV contract connection:
MYTH OR REALITY: ARE SHELLFISH ALLERGIES RELATED TO CONTRAST REACTIONS?
Intravenous Radiocontrast Media: A Review of Allergic Reactions

In any case, MRI contrast is not the same as CT contrast. It's a substance called gadolinium that works by temporarily changing the magnetic properties of tissues to enhance imaging under MRI (to put it very simplistically). There are reports of rare adverse reactions in patients with pre-existing kidney failure, which can cause retention of gadolinium in the body, possibly resulting in a syndrome called nephrogenic systemic fibrosis. True allergic (anaphylactic) reactions to gadolinium are very rare, according to this article, occurring in 1/10,000 patients who receive gadolinium.

 

[YippeeKi YOW !!]

Actually, the connection between seafood allergies and IV contrast allergy (as well as allergies other types of iodinated medical products, such as surgical preps) is a myth.

I'll have to let my oncologist, his two nurse practitioners and the rest of his considerable staff, along with the 6 colleagues in his practice, and their entire staffs know ....

Also the surgical team at the hospital who removed some lymphatic tumors on my neck and who used Povidone-iodine (PVP-I), also known as iodopovidone, both on me, and to thoroughly disinfect their own hands.

For a CT scan, the first contrast agent, Gastrografin, which you have to drink a couple of hours prior, is, as the name implies, a gastric radiopacity solution which, according to JAMA, the NIH, and numerous other sources readily available in a quick google, is, and I'm quoting the NIH here, " ....a water-soluble iodinated radiopaque contrast medium ...".

This is followed just before the scan by the intravenous application of yet another iodine based contrast agent, Isovue, which sends a flood of warmth thru your body that is more surprizing and discomforting than unpleasant.

Unfortunately, the myth is also pervasive in medical practice

As are so many, many more ....

In any case, MRI contrast is not the same as CT contrast. It's a substance called gadolinium

As I noted above ....

True allergic (anaphylactic) reactions to gadolinium are very rare,

I'll have to have a chat with my body then.

It;s going to be a busy week, apparently ...

according to this article,

I cant seem to open your article, probably because I'm on my creaky old IE 11 browser instead of my loathsome Chrome. Will read it later, and thanks for the link.

I had very mild reactions, all things considered, to the gadolinium: moderate swelling of my face and lips, some nausea and dizziness, blurry vision, unsteady gait, stinging skin, hives, and a real biatch of a headache. Most of that didn't last more than 20 hours or so, resolving gradually in about 1 1/2 to 2 days....my oncologist told me I was having a mild allergic reaction to contrast used for the MRI.

There are reports of rare adverse reactions in patients with pre-existing kidney failure, which can cause retention of gadolinium in the body,

Severe anaphylactic shock-type reactions may be rare, but gadolinium accumulates and is retained in tissues, especially the brain, forever, regardless of kidney function, tho it would be much worse in that case. Which is probably why I only had 4 or 5 MRI's vs the almost too numerous to count CT scans.

t's a substance called gadolinium that works by temporarily changing the magnetic properties of tissues to enhance imaging under MRI (to put it very simplistically).

They improve the " .... sensitivity and specificity of diagnostic images by altering the intrinsic properties of tissues, which influence the fundamental mechanisms of contrast....". I have to wonder if something that has the power to change intrinsic properties of tissues is going to be so easily ushered out of the body, as well as the soft tissues that comprise the brain.

An allergy to iodine would be fatal, as iodine is ubiquitous in the body.

True, but there's a difference between the minute endogenous amounts in the human body, measured in micro- and nanograms, and a whole whacking load delivered suddenly both thru the gut (Gastrografin), and intravenously (Isovue). And sensitization, which can also be extremely uncomfortable, is somewhat different from a severe, lethal, full-blown allergic reaction.

It's possible that all that iodine used both in the IV given just before the CT scan starts, which IS an iodine-based product called Isovue, and the Gastrografin may have contributed to some of the thyroid issues I had to deal with post treatment. In fairness, I already had mild thyroid issues going into all that, but it was soooooo much worse after all that exposure....

@purplelady
The bottom line, if you've slogged thru all this so far, is that gadolinium is only used about 1/4 to 1/3rd of the time in MRI's, so if you're still uncomfortable with it after asking your Dr to explain why the contrast is essential to the value of the MRI, tell your Dr "No. Fun ride, and thank you, but no ...". It may not be absolutely essential, it may be more of an ease of results interpretation issue.

Whatever you decide, sending positive vibes and empathy. It isnt easy to stand up to medical insistence. And could you update us and let is now how you're doing when you're able?