I had an MRI of my neck recently. No radiation from that, but the radiologist who read the images recommended a CT scan to follow up on an abnormality he noted. My doctor said he'd order the scan. Because I was given excessive radiation as a child (my adenoids destroyed with radiation because at the time it was thought to be safer than surgery), I'm careful about radiation exposure. I told my doctor I'd have the CT scan if he thought it was really necessary, but asked if it really was. In response, he referred me to a specialist for evaluation.
The specialist examined me, found nothing wrong, and said I absolutely didn't need a CT scan. Pointing out that CT scans carry a high dose of radiation and yet are ordered almost casually these days, he declared, "Save your radiation."
A Harvard Medical School website says, “Over 80 million CT scans are performed in the United States each year, compared with just 3 million in 1980.” The article talks about radiation exposure, and concludes:
“So until we know more, you will want to keep your exposure to medical radiation as low as possible. You can do that in several ways, including these:
Discuss any high-dose diagnostic imaging with your clinician. If you need a CT or nuclear scan to treat or diagnose a medical condition, the benefits usually outweigh the risks. Still, if your clinician has ordered a CT, it's reasonable to ask what difference the result will make in how your condition is managed; for example, will it save you an invasive procedure?
Keep track of your x-ray history. It won't be completely accurate because different machines deliver different amounts of radiation, and because the dose you absorb depends on your size, your weight, and the part of the body targeted by the x-ray. But you and your clinician will get a ballpark estimate of your exposure.
Consider a lower-dose radiation test. If your clinician recommends a CT or nuclear medicine scan, ask if another technique would work, such as a lower-dose x-ray or a test that uses no radiation, such as ultrasound (which uses high-frequency sound waves) or MRI (which relies on magnetic energy). Neither ultrasound nor MRI appears to harm DNA or increase cancer risk.
Consider less-frequent testing. If you're getting regular CT scans for a chronic condition, ask your clinician if it's possible to increase the time between scans. And if you feel the CT scans aren't helping, discuss whether you might take a different approach, such as lower-dose imaging or observation without imaging.
Don't seek out scans. Don't ask for a CT scan just because you want to feel assured that you've had a "thorough checkup." CT scans rarely produce important findings in people without relevant symptoms. And there's a chance the scan will find something incidental, spurring additional CT scans or x-rays that add to your radiation exposure.”