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North Bergen, NJ
A 26-year-old female asked:

I've gotten a few scans this year. 3 ct scans and 3 mri, one with contrast. can i have cancer because of it?

2 doctor answers5 doctors weighed in
Dr. Randy Baker
Holistic Medicine 41 years experience
Not yet but...: First, MRI's have no radiation & don't increase cancer risk. CT scans expose you to 150-1100 times the amount of radiation of a regular X-ray but even with 3 in a year the odds you will get cancer from that exposure is extremely small. probably no more than 1-2%, and it would take many years for it to develop. See http://www.scientificamerican.com/article/how-much-ct-scans-increase-risk-cancer/
Created for people with ongoing healthcare needs but benefits everyone.
Dr. Cynthia Archer
Internal Medicine 20 years experience
The jury is still out on the impact of Electromagnetic fields, but I agree that this risk is negligible compared to the data these scans yielded. It's unlikely you had normal studies, or you would not have had so many repeat imaging studies done. The risks associated with contrast are probably a more salient thing to consider.
Nov 17, 2014
Dr. Cynthia Archer
Internal Medicine 20 years experience
Extremely unlikely: So unlikely that the likelihood approaches zero. You have more radiation exposure on a cross country flight, or hiking at altitude. That said, WHY did you have all those scans? If you have had unintentional weight loss, night sweats, or other unexplained pain, the scans may be looking for cancer. But the risk of cancer due to the scans is nearly zero. Why did you have them?
Created for people with ongoing healthcare needs but benefits everyone.
Dr. Randy Baker
Dr. Randy Baker commented
Holistic Medicine 41 years experience
The radiation dose of a cross-country flight is .02-.05 mSv. The average dose of a CT scan is 2-20 mSv, which is equivalent to 100-1000 cross-country flights- see http://www.radiologyinfo.org/en/safety/?pg=sfty_xray I agree the risk is still small , but the National Cancer Institute estimates each year there are about 30,000 cancers caused by CT scans, much more than zero risk!
Nov 16, 2014
Dr. Cynthia Archer
Internal Medicine 20 years experience
Provided original answer
But that risk is small when compared with the total number of scans done each year, data which was not provided in context of the percentage of scans done yearly. In addition, the risk of the scan may be far outweighed by the data it yields, whether the findings abnormal or normal, they are useful to the diagnostician requesting the scan. Everything we do in medicine is weighing risk v benefit.
Nov 17, 2014
Dr. Cynthia Archer
Internal Medicine 20 years experience
Provided original answer
Scans should not be performed unless they are clearly necessary. But in that case, the benefit of the scan is worth the risk (which is still low). It's not good medical practice to cause patients to worry or have them choose to avoid a potentially life saving radiologic study due to the small risk of cancer due to scans based on estimates of cases. Correlation is not causality.
Nov 17, 2014
Last updated Nov 24, 2014

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