Patients need to know about CT scan and X-ray radiation

Americans get the most radiation in the world.

That fact is hardly surprising, when you consider the number of medical tests patients endure.

According to a story from the Associated Press, “the U.S. accounts for half of the most advanced procedures that use radiation, and the average American’s dose has grown sixfold over the last couple of decades.”

Doctors often don’t keep track of the number of scans and radiation exposure patients accumulate. So it’s not surprising that some patients with chronic symptoms have 10 or more CT scans. A more formal way to keep track of radiation exposure, perhaps with electronic medical records, would be helpful for doctors.

A recent study suggested that up to 2% of cancers is due to radiation from diagnostic tests. That fact should be better publicized to patients, along with the amount of radiation each test emits.

This X-ray risk calculator, for instance, is a handy tool for patients prior to undergoing a scan.

Also, diminishing the incentives to ordering the scans in the first place needs to be addressed. This includes malpractice fear, managing patients’ expectation to “do something,” and coordinating care between multiple physicians.

I applaud the AP for this piece, which continues their excellent series illustrating the risks of overtesting and overtreatment.

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  • Dr Synonymous

    A key to decreasing excess use of CT scans is informed consent. Look for a consent form to inform a patient about the risks and benefits of the CT scan you are ordering or they are getting. You won’t find one in the two hospitals I use for admissions, nor the local children’s hospital. I’ve spoken with ED physicians, hospital admin people, radiologists, nurses and patients about this. Who will take responsibility for being more neighborly (honest) with our patients?

    The marketing team from Children’s Hospital came to my office to market expanded CT scanning potential and I asked if they had the consent forms yet for parents to sign before CT scans on their children. “No”, was their answer- two years in a row. “Please tell your radiologists, starting with the chief of radiology that I will not order any CT scans until I see a copy of the consent form that my patients parents will see and sign before their child receives radiation of that magnitude.”

    Fellow physicians, wouldn’t it help if the public knew ahead of time about radiation, so gradually they would have a better understanding of benefits and harms of diagnostic imaging?

  • Paul Dorio

    Dr Synonymous: I agree with your sentiment that appropriate consent and discussion should be done by the radiology department and its personnel to educate patients as to the risks of radiation exposure from imaging studies.

    But wouldn’t you think the buck should stop slightly sooner than that?

    A reasonable perspective is that he/she who orders a CT scan or X-ray should be equally able and responsible to inform his/her patients as to the risks, benefits and alternatives of the desired study. It is an error, in my opinion, for non-radiology personnel to continue to shift the blame for imaging radiation exposure to radiologists/radiology. If radiologists were responsible for ordering the studies that are performed throughout the world, it would be a different story. But, since the vast number of radiology studies are intiated by non-radiologists desiring to care for their patients by obtaining useful information through imaging, perhaps the first discussion should come from the patient’s primary doctor.

  • JPB

    I agree that we are getting too much radiation but just try saying “No” to your doctor when s/he orders a test! Trust me, it’s not pleasant saying “No” to a doctor….

  • Paul Dorio

    I feel for your perspective, JPB, and it dawns on me that informed consent is fine, but how many people then refuse a study because they’ve been informed as to possible adverse events? As a physician who obtains informed consent on patients daily, I know for a fact that 99.9% of patients listen and absorb the risks, benefits and alternatives, and then go ahead and sign the consent anyway. Of course, that’s the goal of informed consent.

    Dr S’s comments imply that, through informed consent, people would refuse imaging studies, thereby decreasing radiation exposure. Is that realistic or reasonable?

    • apurvab


      IMy experience has been that for tests that have an equivocal benefit/low pre-test probability, advising patients of the risk of radiation exposure is quite successful in either disuading them, or choosing a safer alternative (ultrasound, watchful waiting). Most patients understand that if a test is likely to be unhelpful, and has a risk of injury, its porbably best avoid.

      • Paul Dorio

        I completely agree, apurvab. But your comment begs the question: Why are those studies ordered in the first place, assuming we are not including reasons such as defensive medicine?

        In addition, once upon a time radiologists were looked at more as gatekeepers. If the medical profession were geared that way again it might actually ameliorate the issue of overutilization to some degree. It would at least ensure, hopefully, that the proper study gets done. There is currently a very pervasive mentality that any attempt by radiologists to perform the “gatekeeper” function is looked at as arguing, fighting, refusing, etc. So most radiologists reasonably choose to side with job-security and not anger referring clinicians. Not ideal, but practical.

        • apurvab

          Paul – Because they help eliminate certain diagnoses and help favor others – the same reason anything, even an examination itself, should be undertaken. Sometimes watchful waiting is a good surrogate, but if there are risks to waiting, like delaying an important diagnoses, then the patient needs to be involved in the decision making process as to whether that risk is worth it to them.

  • Dr Synonymous

    In my first two sentences I lament not having an informed consent form for ME (the ordering family physician) and the other physicians who order CT scans. A form helps with focus. Meeting to prepare the form may generate a level of consensus. Approval of the form may require legal input. A safer direction would accidentally be generated by these behaviors.
    Currently physicians seem unaware that we’re making America glow in the dark. We’re insensitive to the overuse of CT scans, so others (non-physicians) are now calling our attention to it. We need to wake up as a profession about this issue.

    • Paul Dorio

      I agree, which is why all radiology departments should hopefully be adhering to the ACR-sanctioned ALARA (As Low As Reasonably Achievable) principle of judicious radiation exposure. As this topic becomes more publicized and general public awareness increases, it is my opinion that anyone who uses imaging to assist in achieving diagnoses will be held to the appropriate high standards. Migration of imaging requests towards those radiology practices/hospitals that achieve the lowest radiation exposures may even happen.

  • rezmed09

    Radiation exposure from CT and tragic mis-haps from MRI Magnets need to be part of the consent.

    It may cut down on unnecessary testing

  • Kim

    Radiologists make a lot of money from these scans. Why would they want to talk a patient out of a CT exam. I have had 3 CT’s, not once were the risks explained to me. One of them was defensive, done in an urgent situation. I was scared, didn’t know what was going on, and agreed out of fear. Next time I do not trust the doctor and take my chances.

  • Paul Dorio

    Kim, It is most important to me that patients/people become as informed as possible before simply refusing to accept the help offered by their doctor.

    Here is a radiation risk calculator, that kevinmd has had on his site previously:

    The calculator can help give us some idea of what kind/amount of exposure we may get from various exams. Keep in mind though, that there are so many factors that go into each exam, that these “calculations” are VERY rough estimates. With each passing month/year, we decrease radiation exposure by improving the scanning protocols and scanners used. It is possible, for example, to perform a CT scan of the chest on someone with slightly different parameters and have very different radiation doses as a result. I could get more technical, but the main point is that doctors are not out to just make lots of money. They are trying to help you answer a question about an issue you may be having. (And CT scans make far less than you’d think)

    For instance, if you have a car accident, the emergency doctor may reasonably want to get a CT scan of parts of your body to see if anything has been injured. These are life-saving maneuvers. If someone has chest pain and shortness of breath, a CT scan could find the clots in the lungs that could be life-threatening. There are so many other examples that I could write for years trying to list them all.

    As long as patients are informed about their choices and the risks, benefits and alternatives to tests that doctors feel may be helpful, then fair decisions can be made about whether to undergo those tests.

  • Kim

    “As long as patients are informed about their choices and the risks, benefits and alternatives to tests that doctors feel may be helpful, then fair decisions can be made about whether to undergo those tests.”

    It’s hard to use a risk calculator in an urgent situation and you don’t have an iphone. If I had time to do my own research and reflect, I would have refused the CT. The doctor’s notes clearly indicated she didn’t have a handle on a chronic condition-and ordered it defensively. I was too scared to see it clearly-and I didn’t think about radiation. I doubt the doctor cared at all about my future.

  • Caroline Andrews

    I’ve found that it’s not always easy for patients to refuse a CAT scan. I went to the ER in severe pain with a problem I was very familiar with, a partial twist in my small intestine, and asked that I wait to have a CAT scan unless it didn’t clear up on it’s own because I had had one on each of 3 previous visits (to the same ER) that all showed the same thing. I said I was very familiar with my symptoms from multiple bouts with the problem, the previous scans from that ER were in my records, and the problem had always cleared on its own. The nurse seeing me started yelling at me and told me I should just go home since I wouldn’t follow their orders. He grudgingly looked at the records of my previous visits but continued to be very unpleasant and bullying until the pain subsided and I was able to leave.

  • drrjv

    I think the real issue is the increasing use of the emergency room. I had one patient who went to the local ER for headaches 10 times in a 12 month period and got – drum roll please – 10 CT scans of the head (all normal, by the way). Today, I saw a patient that ran over a concrete wheel stop at the local Walmart – no injuries – taken to the local ER and got head and cervical spine CT scans.


      Aha. So the solution would be more preventive medicine. Less ER use. Perhaps that would result in fewer unnecessary radiology imaging studies. I agree.

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