Consumer Reports, January 2015

A few months ago, I went to the dentist for a regular cleaning. A friendly assistant greeted me, led me to the dental chair, and wrapped a heavy plastic apron around my neck. She told me I was due for x-rays. My teeth and gums felt just fine. I thought to myself, didn’t I just get one last time? Rather than talk with a stranger about my mouth, I said, “OK” and bit down on a bitewing x-ray. As expected, the results were normal.

What I didn’t know at the time is that most people only need a teeth x-ray every 24 to 36 months, according to a new Consumer Reports article on medical radiation. Medical imaging tests that emit radiation, like CT scans and X-rays, can save lives when used properly, but research by the New England Journal of Medicine suggests that one third of CT scans are unnecessary, and too much radiation can increase your cancer risk. Doctors are ordering over 80 million radiation-based imaging tests each year, yet many people aren’t told about the risks. Read on to learn more about how you can protect yourself from over-radiation.

Watch: What You Need to Know About Medical Radiation

I was shocked to learn that 15,000 people are estimated to die each year because of cancers caused by the radiation in CT scans. Less than 10 percent of people surveyed by Consumer Reports said their doctors had warned them about radiation risks. Only 4 percent ever told their doctor they did not want a CT scan.

“No one says that you should avoid a CT scan or other imaging test if you really need it, and the risk posed by any single scan is very small,” says Marvin M. Lipman, M.D., Consumer Reports’ chief medical adviser. “But the effect of radiation is cumulative, and the more you’re exposed, the greater your cancer risk. So it’s essential that you always ask your doctors why they are ordering an imaging test and whether your problem could be managed without it.”

What drives this problem? The main reasons for excessive scanning are financial incentives (doctors get paid by volume), fear of lawsuits, or because patients are demanding them thinking it will help their situation, unaware of the risks.

If you suffer a car crash or other serious accident, you can expect a CT scan. But if you are suffering back pain, you probably don’t need an image scan unless your doctor suspects nerve damage, and in that case an MRI, not a CT or X-ray, is appropriate.

Doctors need to do a better job educating their patients about the risks and benefits of any medical imaging test, and should welcome questions from their patients. Patients need a reliable, independent source of information such as Consumer Reports.  Patients should come prepared with a set of questions to ask their doctor each time they are recommended an imaging test.

Consumer Reports, January 2015

Consumer Reports, January 2015

6 questions to ask before you get any imaging test    

  1. Why is the test necessary? You should never refuse a test if it’s needed. But they’re often not. Ask why the test is being done, how the results will affect your treatment, and what will happen if you skip it.
  2. Is there a safer alternative? Ultrasounds or magnetic resonance imaging (MRI), which don’t expose you to radiation, can sometimes be used instead.
  3. Is your doctor credentialed? Ask whether the radiology facility is accredited by the American College of Radiology, (the ACR’s accreditation process addresses dose and image quality, unlike some other accreditors), whether the CT technologists are credentialed by the American Registry of Radiologic Technologists, and whether the person interpreting the studies is a board-certified radiologist or pediatric radiologist. Also check to see whether the radiology professional, imaging facility, or referring physician has joined efforts to reduce the overuse of medical imaging, such as Image Gently, which focuses on children, and Image Wisely for adults.
  4. Has your doctor invested in a CT scanner or radiology clinic? An in-office CT scanner may seem convenient, but it carries an inherent financial conflict of interest. And studies show that physicians who own scanners use imaging much more than those who refer their patients to out-of-office radiology centers. So ask your doctors whether they are referring you to a machine or an imaging center that they have a financial interest in.
  5. What’s the right dose for me? The smaller or thinner you are, the lower the radiation dose you need. The circumference of your chest, hip, thigh, or waist can also change the dose.
  6. Do you have a prior scan? If you recently had an X-ray or a CT scan of the same area, ask whether your doctor can use that instead. And ask for CDs of your scans, for future visits.

Have you asked your doctor any of these questions? If you have done so, tell us about your experience in the comments, or tweet at us @CUsafepatient.