The phrase “a picture is worth a thousand words” is distinctly American. According to The Phrase Finder, it was used widely and exclusively in the US media starting in 1911.
So it would make sense that Americans apply the same logic to medical imaging. Unfortunately, we are in a much grayer (read: charcoal) area when it comes to the diagnostic value of all those studies. Most medical imaging comes at a price: ionizing radiation, a known carcinogen. (Though for some reason, the US Department of Health and Human Services did not officially recognize radiation as carcinogenic until 2005 — go figure.)
We used to take a fairly casual approach to those nifty little waves of energy that pass right through you. My mom tells amazing stories of the Buster Brown “shoe fitter” — an actual fluoroscope that was deployed in stores to ensure a proper fit. Kids were so entertained by the devices they used to stand on them repeatedly, fascinated by the moving images of their tiny irradiated toes.
The amount of radiation exposure from, say, a chest CT scan (equivalent to about 70 conventional chest X-rays) really only becomes significant if patients are receiving lots of studies. But this happens more often than you might imagine. Yes, trauma patients get scanned a lot, but so do patients with less life-threatening problems like chronic abdominal pain.
How much radiation are we talking about? The National Council on Radiation Protection and Measurements, a federally chartered agency, has been pondering issues surrounding radiation exposure since 1964. Granted, this is the same federal government that was also doing above-ground nuclear testing with reckless abandon until 1963. Their motto then: “Strontium-90 — we’ve added it to your milk!” But I digress.
The NCRP publishes riveting titles like Report #154: Cesium-137 in the Environment: Radioecology and Approaches to Assessment and Management. But occasionally they hit the jackpot and get the kind of recognition all physicists long for. Report #160 was just such a document. Quite simply, it was the first time anyone had taken a systematic look at radiation exposure in the US in more than 25 years. Some highlights:
- Medical imaging now accounts for nearly half (48%) of total US resident radiation exposure, up from 15% in the 1980s.
- CT scans represent 50% of total medical radiation exposure, up from 3% in the 1980s.
- In 2006, US doctors performed CT scans at four times the rate in the UK.
And sadly, much of this testing has little or no medical justification. Explanations for increased imaging rates include:
- Financial (doctors who own their own imaging equipment order tests at rates up to 7 times that of doctors who are not owners)
- Laziness (doctors who order imaging may avoid conflict with patients and/or shorten appointment duration/complexity)
- Fear of malpractice
- Patient preference and direct-to-patient marketing (“whole body” CT scans and heart scans)
So the next time one of your providers suggests a quick trip through the scanner, ask him or her if it’s really necessary. Not only will you impress your doctor with your thoughtfulness, you might just save your body a little damage.