Scannell: The radiation risk posed when you undergo CT scans
It’s often said, “What you don’t know won’t hurt you.” But I’ve never understood the rationale behind that. In fact, as a doctor, I’d argue otherwise — that what you don’t know can harm you a great deal.
I’m thinking of this in light of recent studies concerning radiation exposure from medical imaging tests like computerized tomography (CT) scans. Many of us don’t know that we’re exposed to ionizing radiation when we undergo a CT scan, that ionizing radiation is a carcinogen or that data links an increased risk of cancer to low-level doses that are commonly used in CT imaging.
And while that increased risk may be small, it’s also cumulative over time — a concern for patients who receive multiple scans.
The benefits of CT scans in diagnosing disease and saving lives are indisputable. But, like any medical test or treatment, CT scans entail potential risks that should be balanced against expected benefits. Unfortunately, we’ve paid little attention to the radiation risks.
Putting the risk in perspective is difficult, considering the various yardsticks by which meaningful radiation exposure and cancer risks are measured. But, in broad terms, we can consider the constant background radiation from natural sources that we’re exposed to every day. While a chest X-ray exposes us to a 10-day dose of background radiation, a chest CT scan delivers about 2 years’ worth. And the average 3-year dose we get from a CT of the abdomen and pelvis more than doubles when the scan is repeated with and without contrast.
It’s important to remember that the increased cancer risk from a single CT scan remains low for most individuals. Still, the risk accumulates with additional scanning, and it constitutes an unnecessary risk if the scan isn’t medically necessary.
That latter point deserves underscoring because about 30 percent of CT scans performed in …read more
Source:: The Mercury News – Health
