Radiologic scans (CT, MRI, ultrasound, PET) startle us with images of the internal and clinically unseen. The display of three-dimensional anatomic structures that can be enlarged, rotated, and enhanced by dyes and digitization, is fantastic and now commonplace. Imaging is the fastest rising service in health care; MRIs have increased tenfold in the last two decades. 

Visualization is courtesy of TheVisualMD.com

Radiologists can see anomalies the size of a pencil tip. If a patient has a symptomatic condition, scans are powerful and revelatory—there’s fluid around the heart, blood in the brain, and treatment begins. So why not scan the asymptomatic person as well? The hope of detecting some silent illness you may be harboring seems a simple, obvious strategy.

For-profit centers offer total body CTs and MRIs to walk-in visitors. When every organ, bone, and muscle is visualized, more than three-quarters of those without symptoms are discovered to have abnormalities, an average of 2.8 per person.

Without knee pain or a history of knee injury, for example, 40% of us have meniscal damage detected by MRI. Among people without back pain, over 50% have bulging lumbar discs, 80% if you include only those over fifty years old. Ten percent of asymptomatic adults have gallstones. Seven percent of those under fifty have had a stroke without knowing it. Fifteen percent of nonsmokers have small lung nodules on chest CT scans.

If you have a cold when you lie down in the scanner, you will almost certainly be diagnosed with sinusitis (sinus inflammation). And here you begin to realize the trouble with over-scanning.  Scanners often find a lot that’s wrong inside of us, perhaps too much.

Diagnosed with sinusitis, you might receive a prescription for antibiotics you didn’t need. You may stay home from work a little longer, rather than simply suffering the three days of sniffles. You might be asked to have a repeat scan to make sure your sinuses have “cleared,” putting you at greater risk of over-radiation (when you needed none) and over-diagnosis.

Having a scan abnormality when you feel perfectly well is even more problematic. Your doctor scans your ovary for a cyst, but finds an abnormality in your kidney that has produced no symptoms. These unexpected discoveries are extremely common, and while a few people end up being helped by the early identification of the hidden, the explosion in repeat testing (to make sure these irregularities aren’t changing quickly inside you), biopsies, and surgery, turn thousands into patients. Too often scans expose people who may never develop symptoms or meaningful illness to the harms of what turns out to be unnecessary treatment. These are the stories no one likes to share, even as they tell you the case of the incidentally found and successfully removed lung tumor. Too often scans lead to a cascade of difficult decisions for patient and doctor: do you pursue a radiologic shadow that might have remained hidden and clinically insignificant forever for the sake of reassurance you hadn’t thought you needed?

The visualizations modern scanners provide are amazing; it’s hard to resist stealing glances of our insides, which makes it all-too-easy to deny the over-diagnosis that results. But we need to be cautious in hunting indiscriminately in those who feel well. Too much knowledge can cause problems. Zeus hid fire from man. After Prometheus’ theft, Zeus sent man Pandora and her jar as retribution.

MD Stein

Follow us on Facebook!