Apr 14, 2013 - 9:29 pm
I am posting the following information from an article that appeared in the April 2013 issue of "Consumer Reports on Health."
"CT scans: Know your radiation risk"
Doctors today are using CT scans and other tests more than ever before. And if used at the right time and for the right patient, they can be lifesaving. But the doctors ordering those radiation-emitting tests are doing a poor job of explaining their risks to patients, according to new research.
In a recent study in the Archives of Internal Medicine, researchers from the University of Washington School of Medicine surveyed 235 patients who had undergone a non-urgent computed tomography (CT) scan and found that one-third of them didn't know they had been exposed to radiation. Of those who were aware of the danger, only 45 percent said their health care provider had informed them about it. Most of the patients substantially under-estimated the level of exposure, and most said they were not worried about any risk of cancer.
Radiation from CT scans--each of which is equivalent to 100 to 500 chest x-rays--might contribute to an estimated 29,000 future cancers a year, a 2009 study suggests. Yet some hospital systems and some doctors continue to order them more often than they should, exposing patinets to needless risk and expense.
"Many health care providers have little knowledge about radiation and thus are poorly equipped educators," wrote the authors of the study in the Archives of Internal Medicine. In fact, about one in five physicians fails to receive formal instruction about radiation exposure, according to a small study at the University of Colorado School of Medicine. The researchers also found that even doctors who do get a few hours of training aren't more likely to discuss radiation risks with patients.
It's a doctor's job to ensure that patients are aware of the benefits and risks of their recommendations. If you feel uninformed, talk with your doctor. Here are some tips for doing just that:
1) Find out if you really need a CT scan. If your doctor orders one, ask whether magnetic resonance imaging (an MRI) or an ultrasound can be done instead.
2) Be wary of double scans. A double CT scan, one with a contrast agent and another without, can offer useful information, but it's not usually needed.
3) Ask another doctor. Get a second opinion if you think a CT scan is being pushed too strongly. Studies have found that physicians who own scanners use imaging substantially more than those who refer patinets to radiology centers.
4) Break the routine. Currently, a CT scan is only recommended for screening for lung cancer in people with the highest risk for the disease.
Twenty to 40 percent of computed tomography (CT) scans could be avoided if the physicians ordering them followed clinical guidelines governing their use, according to a study in the July 14, 2010 Journal of the American Medical Association. If your doctor orders a CT scan or any of the other tests listed below, ask if it's really necessary, and make sure that you understand the benefits and risks.
EXAMINATION RADIATION DOSE (in milisieverts) TIME*
Computed tomography (CT)
Sinuses .06 2 months
Head 2.0 8 months
Chest 7.0 2 years
Abdomen & Pelvis 10 3 years
Fluoroscopy (Continuous X-ray)
Barium swallow 1.5 6 months
Coronary angiography 5 to 15 20 months to 5 years
Lung 2.0 8 months
Bone scan 4.2 1 year, 4 months
Cardiac 12.5 4 years
Arm or leg 0.001 Less than 1 day
Chest (one view) 0.1 10 days
Lumbar spine 0.7 3 months
Abdomen 1.2 5 months
Mammography 0.7 3 months
Bone density 0.001 Less than 1 day
*TIME--This refers to the time needed to accumulate comparable exposure from typical environmental radiation (I could not get this to fit in the column)
I thought this was quite interesting information. I am just reporting this as stated in the article and cannot verify or explain these numbers, so please don't put me on the spot!