# Risks of CT scans **URL:** \ **Category:** In My Humble Opinion\ **Created:** [March 4, 2013, 2:29pm UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994 "2013-03-04T14:29:08Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![newcrasher](https://avatars.discourse-cdn.com/v4/letter/n/b3f665/32.png) [@newcrasher](https://boards.straightdope.com/u/newcrasher)\ **Post date:** [March 4, 2013, 2:29pm UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/1 "2013-03-04T14:29:08Z")
My employer has arranged for us to have access to $99 cardiac CT scans. It’s basically a CT of your heart that measures calcium buildup in your arteries and is supposed to help gauge your chances of a heart attack. I’m 40 with diabetes (under control w diet and exercise only - a1c 5.4), am 20lbs over weight (but losing steadily!), and have periods in my life where I have taken pretty poor care of my body so I was interested. A little research shows there is no clear correlation between cardiac CTs and better outcomes and that there is concern about the levels of radiation CTs expose you to and the potential for cancer. I had a thoracic CT. About 5 years ago. I had a health issue pop up last year that could have required a CT but the doc said he didn’t like to just sling CTs around because of the radiation concerns, and the problem was resolved without one. So what do you think? Is the cardiac CT worth the radiation risk? - You are not my doctor. I am not seeking medical advice, simply your opinion on the risk/reward of the cardiac CT. In all likelihood you live in your parents’ basement and live on a steady diet of Internet porn, Pringles, and Mountain Dew. I would never take health advice from such a person\* 😛 THANKS! ---
**Author:** ![yoyodyne](https://avatars.discourse-cdn.com/v4/letter/y/a9a28c/32.png) [@yoyodyne](https://boards.straightdope.com/u/yoyodyne)\ **Post date:** [March 5, 2013, 5:44pm UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/2 "2013-03-05T17:44:29Z")
I think, even given the odds of a random CT helping diagnose something you didn’t know you had, the benefits outweigh the radiation risk. ---
**Author:** ![howye](https://avatars.discourse-cdn.com/v4/letter/h/a9adbd/32.png) [@howye](https://boards.straightdope.com/u/howye)\ **Post date:** [March 5, 2013, 5:57pm UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/3 "2013-03-05T17:57:41Z")
You might want to check this site out: [http://www.radiologyinfo.org/en/safety/index.cfm?pg=sfty\_xray](http://www.radiologyinfo.org/en/safety/index.cfm?pg=sfty_xray). I am guessing that depending on the scan, you could be increasing your risk in what they classify as a low to moderate fashion. Then again, it is only a risk and maybe they find something. ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [March 5, 2013, 6:20pm UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/4 "2013-03-05T18:20:35Z")
> [@yoyodyne](#): > > I think, even given the odds of a random CT helping diagnose something you didn’t know you had, the benefits outweigh the radiation risk. Agreed, although I do hesitate to put myself into machines that they have to leave the room to turn on. ---
**Author:** ![Ferret\_Herder](https://avatars.discourse-cdn.com/v4/letter/f/e47774/32.png) [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)\ **Post date:** [March 5, 2013, 6:45pm UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/5 "2013-03-05T18:45:56Z")
> [@DCnDC](#): > > Agreed, although I do hesitate to put myself into machines that they have to leave the room to turn on. Well, your average person might have one CT scan in their lifetime. A CT technician probably runs these scans at least several times a day or more, depending on how busy that location is. ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [March 5, 2013, 6:54pm UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/6 "2013-03-05T18:54:47Z")
> [@Ferret\_Herder](#): > > Well, your average person might have one CT scan in their lifetime. A CT technician probably runs these scans at least several times a day or more, depending on how busy that location is. I know. It’s just humorous to me. And it makes you think about TSA employees standing next to an x-ray machine all day, everyday, and nobody seems to give a shit. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [March 5, 2013, 7:00pm UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/7 "2013-03-05T19:00:32Z")
> [@newcrasher](#): > > So what do you think? Is the cardiac CT worth the radiation risk? X-rays and other ionizing radiation is bad for you. The less you expose yourself, the better off you are, at least in terms of cancer risk. I generally avoid X-rays unless there’s a real problem that I’m trying to diagnose (as opposed to just prophylaxis). My teeth are good, so I only get them X-rayed every two years. I can’t see myself opting for a CT scan unless there’s something seriously wrong, or I’ve got a problematic family medical history. Medical doctors are the ones who read peer-reviewed publications that study things like this, i.e. the merits of prophylactic X-rays/CT scans as weighed against the increase in lifetime cancer risk due to radiation exposure. Barring input from a doc in this thread, you might want to browse JAMA or other medical journals to look for studies on this subject that back their conclusions with real data. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [March 5, 2013, 7:05pm UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/8 "2013-03-05T19:05:22Z")
> [@DCnDC](#): > > I know. It’s just humorous to me. > > And it makes you think about TSA employees standing next to an x-ray machine all day, everyday, and nobody seems to give a shit. THe machines for X-raying carry-on luggage are pretty well sealed against leakage by the entrance/exit curtains and by shielding on the other surfaces. the X-ray backscatter body scanners were something of a concern: they don’t give much radiation to the passengers who pass through them, but for TSA employees standing nearby for an entire shift, it could add up. It seems those machines are being phased out in favor of millimeter-wave scanners, although I didn’t see any mention of concern for TSA employees; it was officially all about passenger exposure and passenger privacy. ---
**Author:** ![OtakuLoki](https://avatars.discourse-cdn.com/v4/letter/o/ac8455/32.png) [@OtakuLoki](https://boards.straightdope.com/u/OtakuLoki)\ **Post date:** [March 5, 2013, 10:25pm UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/9 "2013-03-05T22:25:49Z")
Speaking as a former rad health professional, I wouldn’t get the CT scan, unless you have some specific reason your doctor thinks you should be concerned for the build-up of calcium in your heart. I get that you’re not in perfect health, now, and that you have had several risk factors in your history - but without a symptom, or concern, this sounds like you’re being asked to subsidize the imaging center on the odds that one tenth of one percent of the people\* who get screened will be found to be at risk for the condition being screened for. IOW, there is a known drawback to the testing - i.e. increased whole body lifetime radiation exposure. There is, unless I’ve missed something in your OP, no reason at this time for you to believe you have the condition being screened for. And it’s going to be money out of your pocket, even at subsidized cost. As an aside: over-testing, or generating false demand for testing, are factors that, in general, are driving up health care costs in this country. I would take the chance, in your shoes, to do what you could to stop that here. In short, the proposed benefit is minimal, the risk is small, but real, and the cost to you (plus whatever your employer is going to be paying) seems to be pure profit for the imaging center - without any clear medical need. Snake oil by another name. Granted, snake oil that can be lifesaving under other conditions, but for you, with your current health history? Snake oil. Don’t do it. Obligatory disclaimers: IANAD; IANYD; If you have specific medical concerns talk to your GP. If you have a cardiologist, ask them. ---
**Author:** ![OtakuLoki](https://avatars.discourse-cdn.com/v4/letter/o/ac8455/32.png) [@OtakuLoki](https://boards.straightdope.com/u/OtakuLoki)\ **Post date:** [March 5, 2013, 10:32pm UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/10 "2013-03-05T22:32:51Z")
Whoops. Dangling asterisk, sorry. That incidence of finding the condition is purely fictional, a number pulled out of my arse for sake of argument. ---
**Author:** ![newcrasher](https://avatars.discourse-cdn.com/v4/letter/n/b3f665/32.png) [@newcrasher](https://boards.straightdope.com/u/newcrasher)\ **Post date:** [March 5, 2013, 11:30pm UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/11 "2013-03-05T23:30:49Z")
> [@OtakuLoki](#): > > Speaking as a former rad health professional, I wouldn’t get the CT scan, unless you have some specific reason your doctor thinks you should be concerned for the build-up of calcium in your heart. I get that you’re not in perfect health, now, and that you have had several risk factors in your history - but without a symptom, or concern, this sounds like you’re being asked to subsidize the imaging center on the odds that one tenth of one percent of the people\* who get screened will be found to be at risk for the condition being screened for. > > IOW, there is a known drawback to the testing - i.e. increased whole body lifetime radiation exposure. There is, unless I’ve missed something in your OP, no reason at this time for you to believe you have the condition being screened for. And it’s going to be money out of your pocket, even at subsidized cost. > > As an aside: over-testing, or generating false demand for testing, are factors that, in general, are driving up health care costs in this country. I would take the chance, in your shoes, to do what you could to stop that here. > > In short, the proposed benefit is minimal, the risk is small, but real, and the cost to you (plus whatever your employer is going to be paying) seems to be pure profit for the imaging center - without any clear medical need. > > Snake oil by another name. Granted, snake oil that can be lifesaving under other conditions, but for you, with your current health history? Snake oil. Don’t do it. > > Obligatory disclaimers: IANAD; IANYD; If you have specific medical concerns talk to your GP. If you have a cardiologist, ask them. I tend to agree. I cancelled the CT. I excercise regularly, am a vegetarian, and am losing weight at a slow, steady, sustainable rate. Unless I have some other cardiac concerns, I will skip the extra radiation. ---
**Author:** ![USCDiver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/uscdiver/32/354_2.png) [@USCDiver](https://boards.straightdope.com/u/USCDiver)\ **Post date:** [March 6, 2013, 12:23am UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/12 "2013-03-06T00:23:59Z")
There are also less risky means of assessing your cardiac health such as stress tests. ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [March 6, 2013, 12:34am UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/13 "2013-03-06T00:34:34Z")
Take the scan. You will only glow for a day or two afterward. ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [March 6, 2013, 2:51am UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/14 "2013-03-06T02:51:08Z")
Speaking as a diabetic, doing something that increases your risk of cancer in order to determine your risk of heart disease seems to be a six-of-one, half-dozen-of-the-other kind of deal. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [March 6, 2013, 5:28am UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/15 "2013-03-06T05:28:55Z")
> [@Machine\_Elf](#): > > X-rays and other ionizing radiation is bad for you. The less you expose yourself, the better off you are, at least in terms of cancer risk. This is essentially the Linear No-Threshold model that most regulatory agencies have adopted, but a lot of research that suggests that low doses of ionizing radiation can actually improve health and even reduce cancer risk. ---
**Author:** ![OtakuLoki](https://avatars.discourse-cdn.com/v4/letter/o/ac8455/32.png) [@OtakuLoki](https://boards.straightdope.com/u/OtakuLoki)\ **Post date:** [March 6, 2013, 5:49am UTC](https://boards.straightdope.com/t/risks-of-ct-scans/651994/16 "2013-03-06T05:49:44Z")
**Surreal** , I’m actually one of those people who believes that the Linear No-Threshold model is unlikely to be 100% accurate. Having said that, I also believe that it’s the sensible choice of models for regulatory purposes. Furthermore, per wikipedia the rough estimate for a modern thoracic chest CT is about 1 mSv, or 100 mREM. (Older models have higher dose estimates, however - I’ve seen them as high as 12 mSv, or 1.2 REM for some of those.) This, as an acute dose, is going to be far above anything I’d have considered a “low dose of ionizing radiation,” for any threshold model of radiation exposure that I’d ever seen. I grant I’m not _au fait_ with all current research, so I may be wrong about what dose levels the current arguments are ranging around, this is not the place where I’d be cavalier about accepting radiation dose because of the arguments in favor of some threshold model for cumulative radiation exposure risk. 100 mREM isn’t _that_ much, I’ll agree, easily. It’s also equivalent to anywhere for one to three years of radiation exposure from background sources for most people. (blah, blah, average, based on reasonable suntanning, no air travel, etc. etc. etc.) Again, if there’s any kind of _specific_ reason for getting a chest CT done, I wouldn’t let the radiation exposure stop me. Not for a moment. That’s not the case here, and this isn’t the where I’d go to look at increasing one’s radiation dose levels.