Why we doctors order far too many scans

July 23, 2010  |  General

There’s a provocative editorial in a recent New England Journal of Medicine about the explosive rise in high-tech medical imaging. Everyone knows doctors order a lot of CT scans, MRI scans, and ultrasound studies, and that the number of these has been steadily increasing. And the cost is enormous. From the article: ” . . . these costs were the fastest-growing physician-directed expenditures in the Medicare program, far outstripping general medical inflation.”

To be fair, rising use of new medical technology is expected because, well, it’s new. What is unclear is that how much of this increased use has led to improved health to justify the cost. Clearly much of it doesn’t, and unnecessary scans, particularly CT scans, lead to risk with no benefit.

The practice of “defensive medicine,” of doctors ordering tests out of a fear of being sued for missing rare conditions, is often given as a cause for overuse of scans. There is some truth to that: the article cites a Massachusetts study showing that 28% of scans are done for that reason. Lawsuits over failing to diagnose things are common; lawsuits about overuse of tests are vanishingly rare.

Physician conflict-of-interest also plays a part. Through a loophole in Medicare regulations, physicians are allowed to refer patients for scans from which the physician benefits financially. That is wrong and needs to be fixed.

But there are deeper reasons. The root cause may well be “the style and content of clinical education and their impact on medical practice.” In other words, how doctors are trained. We use scans unthinkingly, and, unthinkingly, can cause harm. Again from the editorial: “The greatest risk that patients face with unnecessary imaging is the needless exposure to downstream testing and inappropriate treatment related to misdiagnosis and the overdiagnosis of common but unimportant findings.” I’ve seen that happen more than a few times.

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6 Comments


  1. Thanks for the post. I agree. Again and again. I’m a general pediatrician and use imaging sparingly. I have the fortune to avoid it due to practicing in the community, not in the PICU like you.

    I don’t think you can talk about over-testing enough. Particularly when it comes to children.

    Effects of radiation exposure are far more dangerous for children, as you know.

    Please take a look at the Image Gently Campaign. A mission to improve appropriate use of radiation, dose-reduction, and education materials for MDs,families and technologists. The campaigns also works to employ families to be a part of the conversation.
    http://www.pedrad.org/associations/5364/ig/

    Here’s a post written by my husband, a pediatric radiologist. 5 Things You can do to image gently:
    http://seattlemamadoc.seattlechildrens.org/guest-blog-image-gently-5-things-you-can-do/

  2. Hi Wendy:

    Thanks for stopping by. Yes, the Image Gently initiative is an important one. It’s clear that, besides the issue of frankly unnecessary scans, CT scans on children are often done with more radiation than is needed to get good images. The Society for Pediatric Radiology has been in the forefront of trying to reduce this unneeded risk. I believe the AAP also has a policy statement about it. It’s not so much a problem at children’s hospitals, but it is at community hospitals.

  3. Funny I came across this… My 18 month old was in the hospital recently, for a week with severe sore throat and swelling of lymphnodes and tonsil on one side of neck. Her older sister had strep on and off for 30 days until Kephlex erradicated it. I asked them to do a strep test on the baby but they said babies don’t get strep and they wrote me off…they were focused on UTI although her neck was swollen as well. So, the strep swab wasn’t done. She ended up being Negative for UTI. Her culture was normal. Chest xray normal…kidney ultrasound normal.

    Anyway, It hurt her SO MUCH to swallow (she would wince) and she wouldn’t drink or turn her head in one direction. She had HORRIBLE breath and her nose was so congested she snored loudly. Her fever was high and at one point it reached 105 but quickly came down to 100 with fever meds in the hospital. She broke out in a terrible rash (heat I’m assuming) that went away with the fever. After 30 minutes she felt good enough to play just a little in the hospital. Blood tests were done… WBC was 20,000 then shot up to 46,000 the next day on Rocephin! Rest of blood counts were normal except for the sed rate which had skyrocketed to 100! Hospital pediatrician said she had severely swollen gums and she was getting 6 teeth including 3 molars! That contributed to the sed rate. Anyway, they treated her with another I.V. antibiotic and 24 hours later her WBC went down to normal. Her lymphnodes are back to normal or at least much better and she’s turning her head normally, one week later.

    2 days later the fever was gone- they mentioned CT scan to check for possible abscess in her lymph node, but I asked for ultrasound first and they agreed. Once she started responding so well to the medicine and literally running around the hospital, they decided the risk of CT outweighed the benefit. I was relieved…they checked her nodes via ultrasound and they were all reactive lymph nodes, the largest being 1.5cm.

    I had never been so scared in all my life- her regular pediatrican called in (never saw how well she was doing or that she had 6 teeth coming in) and told me to demand a CT scan immediately, that there was an abscess somewhere in her head b/c of the high sed rate. She said there is NO RISK WHATSOEVER from a CT scan. I spoke with the hospital pediatrician again and he said she was doing so well clinically (back to her normal self!) that the radiologist, an infectious disease specialist, AND two other pediatricians from Children’s Hospital didn’t recommend the head/neck CT.

    Here we are two weeks later and she’s fine. She is on rocephin for 7 days. We STILL don’t know what bacterial infection she had? Mono, adenovirus, was negative…although they said sometimes they take a few times to come back positive. What do you think? Is strep likely? Could she have had a terrible strep infection? Would you have ordered the CT scan? I was relieved when they didn’t recommend it…they said if there were any doubt, they would’ve absolutely recommended it and definitely not let us go home.

    I am asking for strep titers as well as whatever else they can give me. I need to know what happened to my healhty baby girl! I am so grateful she is well…but it’s tough not knowing. Could this have been a horrible virus along with the 6 teeth that brought her sed rate and WBC so high? Your opinion (I am not asking for your medical advice!) as a Pediatric Intensive Care Physician would be GREATLY appreciated! Thanks so much…

  4. A couple of thoughts.

    It is true that strep is rare in 18-month-olds, but it can happen. At this point, though, she’s already received treatment for it if it was strep. So I’d just be happy she’s better and not do any more tests at this point.

    The larger issue is that the scenario you describe is actually quite common, something doctors deal with every day, even (maybe especially) ICU doctors. The scenario is this: a child is admitted to the hospital, very, very sick; we do a bunch of stuff and the child gets better. We not infrequently have no idea why the child got better, or if our treatments really helped. But we’re happy that happened. People think medicine is a science. It’s not. It’s related to science and makes use of science, but it also contains a good measure of guesswork, intuition, and blind luck.

    As the doctors no doubt told you, both an elevated white count and an elevated sedimentation rate are quite nonspecific. This is especially true for the sed rate. It’s highly sensitive, meaning a whole host of things can elevate it because it’s really a test of inflammation happening anywhere in the body, but it’s one of the least specific tests we have.

    It sounds to me as if your child got good and appropriate care, and I’m glad to hear she’s better.

  5. Thanks so much for your quick reply :)

  6. I am going to try to stop worrying now and hope it never ever happens again!!!

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