Forums » Open clinical » Radiology » Expose yourself to the facts...
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Expose yourself to the facts...
posted at 26/1/2012 9:45 AM GMT
on bmj.com
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Posts: 81
First: 27/10/2011 Last: 16/2/2012 |
Radiology journal have been running some good editorial debates recently. If you haven't caught them, I thought they'd make for some interesting discussion on doc2doc. The latest has been on informed consent for radiation exposure... (http://radiology.rsna.org/content/262/1.toc) |
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Re: Expose yourself to the facts...
posted at 26/1/2012 11:54 AM GMT
on bmj.com
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Posts: 516
First: 19/4/2010 Last: 23/2/2012 |
The other day a woman in clinic essentially *demanded* a HRCT to reassess her static bronciectasis. There was essentially no clinical indication for the test. I got her to sign a consent formed with the radiation dose stated explicitly (8 mSv, for a helical CT in our unit) and in terms of background radiation (about 4 years, ish, or 2 years in Aberdeen). Once she'd signed it, I put in the form for a non-urgent scan. There was no change from the previous scan. |
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Re: Expose yourself to the facts...
posted at 26/1/2012 12:38 PM GMT
on bmj.com
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Posts: 241
First: 15/7/2011 Last: 22/2/2012 |
hipradiologist - I read in a British Journal quoting American sources that 1.5-2% of all US cancers are attributable to CT scans. Do you think this can be true?. Knowing nothing about ionising radiation myself I was somewhat taken aback by this figure. |
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Re: Expose yourself to the facts...
posted at 26/1/2012 4:40 PM GMT
on bmj.com
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Posts: 611
First: 12/3/2010 Last: 21/2/2012 |
Kirked, |
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Re: Expose yourself to the facts...
posted at 26/1/2012 5:56 PM GMT
on bmj.com
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Posts: 290
First: 9/12/2011 Last: 21/2/2012 |
In Response to Re: Expose yourself to the facts...: hipradiologist - I read in a British Journal quoting American sources that 1.5-2% of all US cancers are attributable to CT scans. Do you think this can be true?. Knowing nothing about ionising radiation myself I was somewhat taken aback by this figure. Posted by kirked Xrays and CT scans do originate from Ionizing radiation sources, but limit their exposure to Gamma radiation, no beta or alpha, so this is a different source dose, and has a different Biometric. Airline pilots are often warned not to fly too often since cosmic rays give them similiar doses to x-rays, but there again Gamma only. Holding a rod of uranium will give you residual Beta and alpha radiation, and possibly neutron exposure. DuaneF |
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Re: Expose yourself to the facts...
posted at 27/1/2012 10:23 PM GMT
on bmj.com
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Posts: 81
First: 27/10/2011 Last: 16/2/2012 |
Here is some scary stuff: I have read sources that talk about 1 lethal cancer for every 100s to 1000 CTs (http://www.aafp.org/afp/2010/0115/p111.html). Also, 1-2% of all cancers are likely to be from CT scanning and clinicians continue to want more and more of them. DON"T reqest so many, people! However, cancer induction is so difficult to estimate because the damage that x-rays cause to DNA and other cellular machinery is a stochastic effect (i.e. non-dose dependent) as opposed to a deterministic effect such as that which lead to skin changes, hair loss and other features of 'radiation sickness'.
Interestingly, the concept of hormesis says that in small doses, radiation and other such bad things could be good for you! (http://en.wikipedia.org/wiki/Hormesis) N.B. Gamma rays are only iatrogenically encountered in the RADIOLOGY department from the decay of radio-isotopes such as metastable technetium-99 (99m-Tc) or PET imaging from the annihilation of a positron (emitted by the radio-isotope) and a nearby electron. Also - the cosmic radiation exposure (which could be electrons, protons, small nuclei antimatter...) from cross-atlantic flight is lest than half of that of a chest radiograph. Consent for air travel, living up mountains, farting, tying shoes... ? |
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Re: Expose yourself to the facts...
posted at 28/1/2012 11:36 AM GMT
on bmj.com
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Posts: 241
First: 15/7/2011 Last: 22/2/2012 |
HIPRADIOLOGIST yOU WROTE THE EXTRACT BELOW: hipradiologist - I read in a British Journal quoting American sources that 1.5-2% of all US cancers are attributable to CT scans. Do you think this can be true?. Knowing nothing about ionising radiation myself I was somewhat taken aback by this figure. |
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Re: Expose yourself to the facts...
posted at 28/1/2012 6:54 PM GMT
on bmj.com
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Posts: 290
First: 9/12/2011 Last: 21/2/2012 |
Good points Hip Radiologist, as a side note, stochastic effects are being studied for military troops encountering various Space or near space missions, high altitude, and other things like submariners, and stuff, I suspect Nanotechnology will cause some serious problems with micro-particle matter, and interfering with cellular biology, and a sort of interdependent type of pharmocokinetics of the nano particle, and nano-medicines. This is a big frontier. Duanef |
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Re: Expose yourself to the facts...
posted at 28/1/2012 10:05 PM GMT
on bmj.com
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Posts: 1213
First: 7/3/2009 Last: 17/2/2012 |
Reccurrent exposure to CT can increase cancer risk. Nothing new in it. The mentioned 1-2% figure is familiar to me.Does that reflect a true risk from a single CT or a few CT's? Hard to tell,especially since some subpopulations are more sensitive to radiation damage, such as carriers of ATM, Fanconi and Bloom mutation. Yes,I know, don't jump at me all at once, these conditions are rare, however carrier states of one damaged allele are estimated to be as high as 2-3% in certain populations. These carriers' cells were shown to be sensitive to DNA breakage and instability and for them CT can cause more damage than to others.
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Forums » Open clinical » Radiology » Expose yourself to the facts...
