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Author Topic: Are diagnostic x-rays harmful?  (Read 3652 times)

Mike

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Are diagnostic x-rays harmful?
« on: 02/10/2010 05:30:03 »
Mike asked the Naked Scientists:
   
Chris,

I needed 6 x-rays of my chest and lower back/hips for a pre-employment health screen. The place they sent me to took 10 before I said no more. They said they couldn't seem to get what they wanted on them ("you have long lungs"-hmm, that's a new one) and that one was not dark enough.

My question to you is as follows: should I feel as outraged as I do about this?

That seems to me to be way over the line considering that at least 4 of them were screw-ups and if I hadn't told them to stop, I'm not sure how many more they would have given me. I know she wanted more because she said so. "Hey, this is for a pre-screen for a job, so, you're only hurting yourself." Both of the quotes are just that, quotes.

Was this safe, reckless, or something in-between?

Thank you,
Mike          

What do you think?
« Last Edit: 02/10/2010 05:30:03 by _system »


 

Offline chris

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Are diagnostic x-rays harmful?
« Reply #1 on: 03/10/2010 23:32:11 »
Hi Mike

X-rays are ionising radiation and, as such, have the potential to damage DNA, introducing mutations and therefore causing cancers.

However, the doses delivered during the majority of therapeutic interventions are very low. A chest x-ray, for instance, delivers a dose equivalent to 4 days of incidental cosmic radiation exposure; that is, in one chest xray you get about the same ionising radiation dose as 4 days of normal life. So, out of a lifetime, the effect is trivial.

However, where the risk / benefit calculation becomes trickier is with things like whole body CT, often used in screening programmes in the US. Here the dosages can be very high - equivalent to years of cosmic radiation in a single scan - meaning that the risks are therefore proportionally higher. Stratifying the assessments so that those in whom a problem is likely to be detected receive the highest-risk investigations is therefore appropriate.

Chris
 

Offline Geezer

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Are diagnostic x-rays harmful?
« Reply #2 on: 04/10/2010 05:07:30 »
....which is a lot more than can be said for these things. I remember seeing my toe bones when I was a kid!

http://www.orau.org/ptp/collection/shoefittingfluor/shoe.htm
 

Offline tommya300

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Are diagnostic x-rays harmful?
« Reply #3 on: 04/10/2010 06:34:24 »
Mike asked the Naked Scientists:
   
Chris,

I needed 6 x-rays of my chest and lower back/hips for a pre-employment health screen. The place they sent me to took 10 before I said no more. They said they couldn't seem to get what they wanted on them ("you have long lungs"-hmm, that's a new one) and that one was not dark enough.

My question to you is as follows: should I feel as outraged as I do about this?

That seems to me to be way over the line considering that at least 4 of them were screw-ups and if I hadn't told them to stop, I'm not sure how many more they would have given me. I know she wanted more because she said so. "Hey, this is for a pre-screen for a job, so, you're only hurting yourself." Both of the quotes are just that, quotes.

Was this safe, reckless, or something in-between?

Thank you,
Mike         

What do you think?

Can they do an MRI to get the best resolution?
 

Offline peterson121

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Are diagnostic x-rays harmful?
« Reply #4 on: 13/12/2011 07:18:55 »
Well, as far as i know, x-ray results are valid for a certain time.
 

Offline CliffordK

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Are diagnostic x-rays harmful?
« Reply #5 on: 13/12/2011 07:50:04 »
I'm not sure about your job requirements.

Chest X-Rays are normally not recommended for routine screening of Lung Cancer in asymptomatic non-smokers.

http://www.chestx-ray.com/smoke/LungCaScreening.html

So, only about 15% of the most treatable early stage 1 cancers are detected with chest X-Rays, an apparently it doesn't lead to an overall decrease in Lung Cancer related deaths.

CT screening apparently has a greater detection rate, but it is costly, and I believe they are still studying long-term morbidity/mortality.  And, of course, it has a higher ionizing radiation dose.

Here are some notes about X-Rays:
Diagnostic X-rays are our second largest source of whole body exposure. A dental X-ray gives us about 1 mrem, and a chest X-ray gives us about 6 mrem, but nearly all other X-rays give far higher exposures: pelvis, 90 mrem; abdomen, 150 mrem; spine, 400 mrem; barium enema, 800 mrem. Often a series of X-rays is taken, giving total exposures of several thousand millirems. The average American gets about 80 mrem per year from this source,
[...]
for each millirem of radiation we receive, our risk of dying from cancer is increased by about 1 chance in 4 million.

Anyway, you can calculate a positive risk from X-Rays, as well as potentially calculating a benefit (if borne out by randomized studies).

The risk from an x-ray or a few x-rays is low, but one should consider the diagnostic benefits of the study.

As mentioned above, an MRI is much more expensive, but doesn't have associated ionizing radiation.  However, it may also have different diagnostic benefits when compared to the standard X-Ray.  An X-Ray is good at detecting abnormalities in BONE.  Less so with soft tissue, although it may help pick out abnormal tissue densities.
 

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Are diagnostic x-rays harmful?
« Reply #5 on: 13/12/2011 07:50:04 »

 

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