Dr Oz: Thyroid Guard Compromise Mammogram Images?


Dr Oz: Thyroid Shields & Mammograms

Dr Oz followed-up his discussion on Thyroid Guards with a discussion of the harm of using a Thyroid Guard during Mammograms.  Clearly if there are no negatives of using Thyroid Guards, then all of us should use them – better to be safe than sorry, right?  But some of the doctors who disagree with Dr Oz said that Thyroid Shields actually can ruin Mammogram images, which means that the patient has to repeat it and will be exposed to twice the amount of radiation.

Dr Oz: Do Thyroid Guards Compromise Mammography?

Doctor Oz asked his panel of opposing doctors what price do we pay for using Thyroid Guards during mammography?  Dr Phil Evans said that during a Mammogram the radiation does not hit the Thyroid directly, but by wearing a Thyroid Shield you can compromise the Mammogram.  He showed a couple of Mammogram Images to show how the shield can cause part of the breast tissue to be cutoff.  When this happens, they said they have to re-do the Mammogram, which means taking two images instead of one so you get more radiation overall.


  1. Rad Doc says

    The conversation is not based on scientific fact and simply Dr. Oz’s opinion. Again, his understanding of the physics of mammography is simply not there. Ignorance leads to unwarranted concern of patients and frustrations of the trained technologists and radiologists forced to deal with this. I agree you want to avoid any unnecessary radiation to decrease your lifetime exposure. I actually am against airport scanners for that reason. But, the risk of increased radiation from repeat exams in mammography exceeds the benefit of wearing a thyroid shield during mammography. Nearly all of the minimal radiation that reaches the thyroid is due to Internal Scatter and the shield will not prevent that!
    I am speaking in reference to mammography only, not to other forms of x-rays where thyroid shields can be beneficial.

  2. says

    Even the panelist representing the radiology association admitted that he does not know why there’s been an increase in thyroid cancer in both women and men. Studies in Britain confirm a direct correlation of dental x-rays to thyroid cancer:


    Personally, if wearing a thyroaid guard may compromise imaging resulting in repeating x-rays, I would rather undergo additional x-rays wearing a guard versus a single x-ray without it.

  3. kim says

    If you are having a mammogram done by an xray TECHNICIAN you are already compromising your exam.

  4. says

    My job is a mammographer at a large breast care center. There is no problem with using a thyroid collar on patients. If the image is to be compromised, then the technologist would be able to see this before taking the exposure. An experienced technologist has no problems figuring this out. A patient that is short and stout might have a problem with the collar, but I never had a patient I could not use one on. We have thyroid collars in all our rooms.

  5. Matt says

    The comment that if you have your mammogram done by an xray technician ( Technologist is the appropriate term) it is already compromised, is completely idiotic and shows the ignorance that is surounding this iissue. You going to wear your thyroid shield when you fly. You get more radiation flying than you do from a mammogram. Why dont you wear some lead underwear while you are at it. Mammograms do not cause thyroid cancer. This is a TV show people.Real Drs that work in the field are telling you Dr Oz is incorrect!

  6. MsBest says

    I received the email the same day I had to get my mammogram. Well, I asked for the shield. Two days later I got a call that I had to come back in and take another “spot” test on the left breast. The spot test was extremely painful, because they use a smaller paddle. I received the results the same day that all was well. (I did not request shield for 2nd test). Now I hear on the “controversy” show that the shield can cause false results. I had never used the shield and never had a problem. Needless to say, I will never ask for it again. I will take my chances with the “very low” dose of radiation, rather than having to get a double dose. After listening to the doctors “IN THE FIELD” on the show, and hearing Dr Oz not wanting to admit he was incorrect in stating that, I would be very leery in taking heed to any more advise from his show. I will ask my personal physician.

  7. Mammotech says

    As an experienced mammographer who has studied radiation protection and spoken about this with a radiation physicist about this subject, I am tired of answering to patients about this subject. The amount of dose to the thyroid is minimal, you get the same amount just being a person on the planet for 30 minutes. People don’t realize how much background radiation they are exposed to every day. You get more radiation flying from NY to LA than you get having 4 mammogram studies. Think about how much dose pilots and flight attendants get every day, every year throughout their careers. Why are they singleing out mammography anyway?? Do they suggest thyroid shields for CT scans or Angiograms which are much more radiation dose? Oh and to answer to the person who said that having the mammography done by an xray technician has no idea what they are talking about. Mammography is the most regulated imaging field in the US. We have to have specific continuing education in breast imaging every year which is checked by the FDA every year. We have to show that we do a certian amount of studies every year. Our machines are checked more often by a physicist than other machines.
    Now about dental x-rays, the beam is directed towards the thyroid which is then recieving direct radiatiom not the minimal scatter that the thyroid is exposed to from mammography.

  8. Brigette says

    I do mammograms everyday. I will be glad to give anyone a thyroid shield. It will be a chance the patient takes in being overexposed if the images need repeated. Kim,you must not understand that you have to be an x-ray technologist before you can be a mammographer.Mammography is just one of the many fields a tech can choose to be in.It takes a special person to be in that room while a woman is facing the worst fear of her life.I am proud to be one of those people.And I will do whatever it takes to protect my patients from further problems,but if it causes unneccesary exposure,then I will leave that to the patients discretion.

  9. Kayla says

    I just hate it when people comment and give advice on areas they are not trained in. I am a mammographer and x-ray technologist and this controversy has only scared patients. Alot of the “repeat” x-rays are not “repeats” at all. Those “spot” mammograms with the smaller paddles is because the radiologist saw something on your mammogram of concern. They are localizing the compression to just that small area so they can get a better view. The technologist did NOTHING wrong the first time. The area must have changed from last time and the radiologist just wants to make sure that it is nothing to worry about. We have patients come in for these “spot” views all the time, alot of the time it turns out to be nothing. Without these “spot” views alot of breast cancers would not be found. Dr. Oz needs to stick to his area of cardiology and get off television. If he wants to continue preaching about radiation maybe he should continue his schooling and become a radiologist.

  10. Greg Hodges, Ph.D. says

    I am a professional health physicist who does, among other things, consultations and surveys of radiation generating equipment. Some comments I’d like to add:

    1) It is good that these topics are discussed and public awareness is raised about potential problems, but I don’t sense that the topic was well addressed by Dr. Oz. I believe he meant well, but where is he basing his connection that a lack of thyroid shields in dental clinics and mammography suites has been a SOURCE of increased thyroid cancers? Using this logic, we should wear a thyroid shield every day to shield ourselves from all the external sources of radiation that we constantly absorb. Has he considered other potential causes of thyroid cancer (e.g. diet, pollution, etc.) and their weights upon their contributions to the risk for thyroid cancer? What evidence (outside of raw speculation) gives him the suspicion that radiation exposure to the thyroid from these studies is indeed a genuine concern?

    2) Doesn’t Dr. Oz know that a lot of the scatter generated is INTERNAL? This is because the energies used in dental x-rays and mammograms produce Compton Scattering: scatter radiation that bounces all throughout the insides of the body. A thyroid shield simply cannot help when the scatter travels up/down the neck, UNDER THE SKIN.

    3) It is true that more prevention is better, but there is a point of diminishing return. We use what is called the ALARA principle for all radiation safety (As Low As Reasonably Achievable) and shielding that offers no palpable benefit is basically dead weight, or a “security blanket” (read: placebo) to ease the anxiety of the wearer. If the shield gets in the way of the image, then it is more harmful than simply being an inconvenience. There are times and places where extra shielding is not warranted nor beneficial, so they are not worn.

    4) Very important to note: the amount of radiation he is talking about is very small. The scatter radiation that hits the thyroid is typically a small fraction of the primary radiation from an x-ray tube (assuming the thyroid isn’t in the field of view), and dental x-rays/mammograms are low-yield sources of x-rays to begin with. You get more radiation exposure to your thyroid from a chest x-ray, and even then when you consider the amount of radiation it takes to induce thyroid cancer (no simple number here for comparison), you find that you are focusing too much on a trifle. There is a vast wealth of empirical data that show that cancer risks are small with the exposures acquired by these studies. A good example is this: a chest x-ray imposes about as much risk for death (by cancer, including thyroid cancer) as smoking 9 cigarettes or driving about 30 miles of driving on the highway. And, like I said, you get more radiation from the chest x-ray than a dental x-ray or a mammogram.

    I hope people realise that Dr. Oz is allowed to have his opinions and speculations – but when he puts forth his suspicions as facts to the general public, he does more harm than good to genuine efforts to ensure radiation safety in hospitals. He should have at least prefaced his show with what he knows versus what he merely speculates or offers as conjecture. Better still, to have invited an actual health physicist to his show instead of more doctors who may or may not have any better of an idea than he does.

  11. janice dulemba says

    As a mammography technologist for over 20 years, i am always open to new ways to practice A.L.A.R.A. (as low as reasonably allowable), which is our mantra in this field. I have been following this subject for a while, and there are more and more patient’s asking for thyroid shields to be used during mammography. Many officials in the health care field have declared it is not necessary, as the x-ray beam does not go directly through the thyroid during an exam. The physics of mammography are a little different for each person, depending on body habitus, positioning, angles used, etc. I have found that shilding the thyroid does not interfere much for some mamm exams and interferes a lot in some others.
    I have had to repeat or take an additional image or two on several cases, because of the shield getting in the way. Also, no woman is going to accept being told that her particular body habitus (ie short neck, obesity, among many other factors) does not lend itself to being able to use a shield. I don’t know what the solution is at this point, but one of the problems arising from this hysteria is that now women are even asking for thyroid shields during CHEST x-ray exams and even NECK x-ray exams, which absolutely does, in 100% of cases, compromise the exam. Ces’ la vie’

  12. monica says

    if it doesn’t interfere with the exam give it to people. I recentely had a mammogram and I had no idea about this topic. Radiation produces cancer, also toxins we get from the food we eat (pesticides residues in the food), and other pollutants in the air we breathe. Also not everybody has the same faculty to eliminate toxins to avoid getting cells to turn into cancer cells. So any radiation saving is just a plus.

    “you get more radiation from being outdoors for 30 minutes than you get in a mammogram” is this really true? why then, doctors don’t advise people not to be outdoors too long?

  13. Natasha says

    I’d just like to point out that a 20% repeat rate is huge. My repeat rate for a mammogram (and yes I am audited every 6 months) is just under 1%. I also perform about 3000 mammograms a year on average. National accreditation for Radiographers (or technologist, sorry I’m from Australia) is a repeat rate of 3%. Quite a difference there. I would not hire a Radiographer with a repeat rate of 20%! Even if turns out to not be quite that high, anything over 5% is unacceptable.

    We do not use shields in our mammography at my work, with the blessing of the cancer insitute in Australia (the governing body on cancer treatment and provides funding for the national breast screening program). To simply say “It can’t hurt” is to ignore the scientific literature that states thyroid dose is almost zero. This is nothing but hysteria about radiation. If you want to be concerned about radiation, worry about the over-requesting of CT scans.

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