CT Scan Dye Containing Iodine May Affect Thyroid

I posted this as a blog the other day. Now, in response to Sherri's request, I'm also posting it on the Forum.

Hi Everyone,

I've been reading Sturdyville's recent comments and cautions about the use of contrast dyes in the tests we are given. So, the headline in my paper today warning about the "dangers" caught my attention. I Googled the topic and found several stories that have been published in the past few days. Here are two links, but you can Google the topic to find more. The first one is two days ago.

CT Scan Dye Containing Iodine May Affect Thyroid 1/24/12.

I've put here a few excerpts from the second link (a more scientific document), that highlight the findings

Iodine in Contrast Material Poses Thyroid Threat (published 1/25/2012)


"The risk of developing incident hypothyroidism was not statistically significant......."

"I wouldn't want patients who have urgent indications for catheter-based interventions to forgo those procedures for this concern," Brunelli said. "But it might be worthwhile to do follow-up testing in patients undergoing coronary imaging and who are at risk for arrhythmias or have limited capacity to deal with the consequences of iodine overload, such as those with heart failure or cardiomyopathy."

"Although there had been scattered previous reports of the occurrence of iodine-induced hyperthyroidism in individuals without known underlying thyroid pathology, the study by Rhee et al suggests that this may occur more commonly than was previously recognized," Pearce concluded.

While it would not be a scientific study, it might be interesting to know how many BAF members have had problems with hyperthyroidism after their treatments.

What's been your experience. I've been taking medication for hypothyrodism for 15 years.


Carole, thanks for posting this. I just finally had my thyroid checked (it was checked in the past yrs ago when I went through cancer treatment and was fine) and should have the results on Monday. Since my coiling and stent, I have been short of breath, my blood pressure is really high, weight gain, etc., etc. My regular md did order two tests immediately - my echocardiogram was excellent and I finally did the pulmonary function test today. I had a stent of severe hypoparathyroidism yrs ago, but they were able to reverse it and my blood work tests fine on that now.

Like Carole, I am wondering if anyone else has had problems with their thyroid - I also saw on Mayo Clinic's website that radiation may also cause hypothyroidism.

Does anyone know how much radiation we are exposed to - both during the angio and during a coiling? I know I was under the rads for 5 hrs for mine, as most people.


This is very intresting..

I have been taking meds for thyroid failure the last 10 years, sevearl years before this I did the radioactive iodine treatment which in the end killed off more of the thyroid then it was supposed too.. I normally have a thyroid check once every year. I have not thought about it latley and do believe I will ask if this has been done since my annie was discovered..

Thanks for posting this Carole!

I have found that the contrast material used by Radiology departments is the contrast recommended/made by the department's CT machine manufacturer, but if you were allergic to iodine, or shellfish (shellfish contain high levels of iodine) another contrast would be used. Please speak with the Radiology department prior to going in for a scan about alternatives to iodine based contrast. The alternative contrast is slightly more expensive for the department, but does not change the cost to you.

Also, ask for a MRI instead of a CT when available. CTs give off very high levels radiation, which is a cumulative/lifetime risk.

Thanks again, Carole.


Thanks, Julie.

Re: MRI vs CT - please be sure that your doctor is aware of any metal that may be in your body. This is particularly true for those of us who may have surgery before the advent of MRI's. (It's not that long ago :-)

As an example case, the clips that were used in my aneurysm surgery are metal so I cannot have MRI/MRA.

Take care.


Carole, thanks for providing this....

The contrast dye for the angiograms has been on my mind, a/w/a the radiation volume, for some time. Attempting to track down the rad volume, it is difficult to find much on angios for the cardio, and the brain is never referenced. I have asked for info on this beginning in 09/2010; have been advised that some research is being done, but not commitment, or suggestion, on when data may be available on the rad volume.

What surprised me is that thyroidism is being addressed, and renal is not being addressed. The contrast dye for both of these is a ris, particularly any patient with renal insufficiency.

Two avaialble products avaialble to review the labeling: Visipaque and Oxilan; likely others, which I do not know. For researching those, suggest strongly that the labeling of the Preccautions and Warnings.

My personal opinion is that this data should be available to patients who are making their decisions on coil vs clip. The contrast dye is used with each coil implant, after the usual four injections during the diagnostic angio; then, all of the follow-ups.

Carole, I absent mindedly deleted a message to Cari today; I will go back and attempt to reconsruct itha data.

Thank you for brining this data up; it jogged some thought/memory.


The "ris, " is supposed to be "risk" ... and meant to say to read the data on Precautions and Warnings.

Hi Pat,

I believe one of the articles that I saw on-line also referenced the impact on the kidney. You may want to Google this. There also has been a lot of news in the past few years about the overuse of CAT scans in general and the high exposure to radiation.

We do have to be careful of the potential side effects of new technologies. Our bodies are being bombarded with so much more radiation that previous generations.

Take care.



It was great you brought this info here from your b log. Culd you also put it in the Suggestion or On-line groups? You may have already...

thanks for so much info you have brought to us; I still smile for you when I think of your retirement and all you have planned...

Hugs and prayers,


Hi Pat,

The plans are coming to fruition. I can join the new neighborhood "coffee" group on my first day or retirement - never had time to do anything like this before. I already have a jury summons for my 3rd day of retirement - ugh! I've been checking out the line dancing and tai chi classes for retirees! It's going to be a hoot!

Lately a number of people have told me that I'm too young to retire! My response is that I'm retiring from work but not from life! :-))

My husband and I started dance classes again tonight. It was great!! We're learning the Cha-Cha - Detroit Style. We met some really nice people. I was a little concerned that I might get too dizzy with all the turns after the angio and not dancing for about a year. (It took me about a year to overcome the dizziness the first time we took lessons.) I voiced my concerns to the instructor, when he frowned at me because I wasn't doing all of them. It's funny how, after I told him that, I didn't seem to have a problem anymore! Maybe he took my concerns to heart and reduced the number of consecutive turns. :-)

Take care.