CT scans and x-rays draw patients into risk and overutilization

Many patients erroneously believe that x-rays and CAT scans have no risk.

In their minds, they are non-invasive studies that can cause no harm. Since there are no incisions or anesthesia, they regard the experience as having the same risk as taking a family photograph. How wrong they are.  In my mind the danger from non-invasive radiology studies may surpass the risk of hard core medical treatment. True, radiology tests won’t puncture an organ or a blood vessel, as a surgeon or a gastroenterologist can. Imaging studies do not cause direct damage, but they may lead patients onto the medical battlefield.

These diagnostic tests are an insidious force that draws patients into a spiral of direct risk and medical overutilization.


Is this post a shot at radiologists? No, it’s a shot at all of us. Remember, radiologists never order CAT scans; the rest of us physicians do. I certainly am distressed with the obsessive manner that my radiology colleagues interpret studies today, identifying innocent, tiny ‘abnormalities’ that will then light a fuse for further studies. In many of these cases, the CAT scans were ordered for defensive purposes, and the radiologists’ interpretations often keep the defensive medicine train lumbering forward.

On July 1, 2010, the New England Journal of Medicine, the most prestigious medical journal in the world, published 2 commentaries on CAT scans and medical imaging. While readers are free to review the first and second essays in the journal, I will summarize the major points here:

• Nearly 400 patients in the U.S. who underwent brain-perfusion scans are known to have received an overdose of radiation. How many folks have received a ‘brain sizzle’ that we do not know about?
• Radiation doses from CAT scans are hundreds of times higher than standard x-rays.
• There is persuasive medical evidence that radiation is carcinogenic.
• Physicians like me who order scans have limited knowledge of radiation doses and toxicity.
• Technology exists and can be further developed to reduce radiation exposure to patients.
• There are no evidence-based standards on the proper role for medical imaging tests. It’s a free for all.
• CAT scans are overutilized. Amazingly, about 10% of the U.S. population undergoes a CAT scan each year.  So far, I’ve never undergone one.  How much longer can I hold out?
• Individual patients should have their radiation exposure history tracked.
• Physicians often order CAT scans and other imaging studies believing this will lower their risk of being sued for medical malpractice.  I can vouch for this in my own experience.
• Radiologists, also seeking to lower their legal risk, routinely identify insignificant abnormalities and advise that these ‘lesions’ be evaluated and scanned in the future to verify that they have not changed.
• Effective tort reform is one mechanism to reduce the number of unnecessary imaging tests.
• Scans are routinely ordered when the probability that the disease exists is low. I have addressed the consequences of this approach in a prior post.
• Radiologists serve as technicians, rather than serve as medical consultants to assist clinicians.
• Medical students are not trained to rely upon medical evidence with regard to imaging tests. Bad habits learned in medical school tend to be sustained throughout a career.

CT scanning, and related medical technologies, are towering milestones that have revolutionized the medical profession.  They have eliminated millions of exploratory surgeries and have allowed physicians to make and exclude various critical diagnoses.  We couldn’t function without them.  Nevertheless, CT scan overuse is rampant, and there are no forces that are curtailing or guiding its use.  We are spending billions of dollars on scans that are not medically necessary.  I have ordered some of these scans personally, so I acknowledge that my own practice needs remediation.

We describe medical imaging tests as non-invasive, but this is deceptive.  First, there is direct risk of harm from accumulated radiation exposure.  Secondly, and more importantly, there are the indirect consequences.  For many patients, the radiology suite is a danger zone, a trap door that can drop patients into a medical cascade with no way out.

Michael Kirsch is a gastroenterologist who blogs at MD Whistleblower.

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  • Marc Gorayeb, MD

    1) Although xray machines and routine lab analyzers should be available to any physician’s practice, devices requiring substantial capital investment should not be owned by a physician whose practice is involved in ordering such tests.
    2) For those physicians who have no financial interest in ordering these tests, tort reform is the only way to get us to moderate our behaviors. At least that is the case for me, and, I strongly suspect, most everyone. Guidelines, pre-approvals, and other bureaucratic roadblocks will fail without liability protection.
    3) A reminder that credibility is our currency; do not oversell the medical risks involved in doing a CT scan. Propaganda that attempts to create a rule out of an exception, or that uses shady statistics, will get you nowhere.

  • http://thedocsquawk.com thedocsquawk

    MR for everyone.

  • http://drpauldorio.com Paul Dorio

    I agree with your comment that patients and doctors must be vigilant regarding the number and frequency of scans they undergo/order so that radiation risks are decreased when possible. And I thank Dr Gorayeb for his exhortation that people not propagandize imaging radiation risk, but instead understand the risks and keep appropriate perspectives when a test is deemed to be necessary.

    But a criticism, if you will:
    “There are no evidence-based standards on the proper role for medical imaging tests. It’s a free for all.” – patently false, Michael. You should know that the ACR publishes extensive Appropriateness Criteria, detailing which imaging modalities may be appropriate for a given clinical indication. The fact that no one follows these criteria does not mean they do not exist.

    In addition, might I correct two other comments made by you as you lambast the role of Radiologists while not taking “potshots” at us:

    1- Radiologists “serve as technicians.” We could certainly and conceivably assume the gatekeeper role and truly be consultants if non-radiologists had any interest in using the Radiologist in that fashion. And if medical liability safeguards were put in place that would allow the radiologist to have some confidence that their suggestions would not result in subsequent litigation.
    2- Radiologists do not “identify insignificant lesions.” It may be semantics, but what we do is correctly identify and note abnormalities which may, through experience, observation or statistical probabilities, turn out to be “insignificant.” Please feel free to keep your perspective but it is inaccurate.

  • http://www.lowradiationdosect.com William Shuman

    While this blogger states that the value of CT is unproven, here are a couple of other concepts which are also unproven:

    – Medical radiation under 100 mSv causes cancer.
    – Overutilization of CT is rampant (many make statements and attach percentages, but if you trace references back, there’s no data).

    Nonetheless, we still accept an obligation to minimize radiation and to maximize appropriateness. But how? Best hope: use your radiologist as a consultant, with that radiologist armed with the ACR Appropriateness Guidelines. While those Guidelines are not perfect nor are they backed by rock-solid evidence, they are the best thinking available in this imperfect world today.

    William Shuman, M.D.
    Professor
    Medical Director of Radiology
    Vice Chair of the Department of Radiology
    University of Washington Medical Center

  • http://blog.radiology.ucsf.edu Fergus Coakley

    Inappropriate use of CT is a real issue, but we would make a few comments from the perspective of radiologists (i.e., the doctors who actually oversee and interpret these studies):

    CT is probably overused and data does show CT radiation doses are higher and more variable than they should be (and of course, variability characterizes all medical practice, not just the use of imaging tests). However, we must remember that the benefits of CT are real while the radiation risk from the low doses associated with CT scans is extrapolated from higher doses (mainly from atomic bomb survivors). This extrapolation (the linear non-threshold theory) is a safe and cautious approach, but may overestimate the risk at low doses which have never been directly proven (an analogy is to assume that driving at 10 mph is 10 percent as dangerous as driving at 100 mph). The assumption that the dose risk is cumulative is also a prudent approach, but similarly unproven.

    The solution to the CT “problem” (insofar as it exists) will likely require greater input from radiologists on appropriate use of imaging. Some of this consultancy/gatekeeping function (no, we are not just technicians!) can be done by decision software at the time of order entry. Prevention of physician referral to imaging equipment they own and profit from is also required; portraying such arrangements as “patient centered” or “integrated” care are fig leaves for non-radiologists who see owning and overusing such scanners as revenue sources with little or no regard for appropriate or optimized use.

    The frequently quoted tort reform as an important component of containing healthcare costs is a canard – data does not support the notion that states with tort reform have substantially lower costs and even when the indirect costs of defensive medicine are included, malpractice concerns are estimated to only account for about 4-7 percent of total healthcare costs.

    Fergus Coakley, M.D.
    Chief, Abdominal Imaging
    Department of Radiology & Biomedical Imaging
    UCSF Medical Center

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