How harmful is the radiation from a CT scan?

How harmful is the radiation from a CT scan?

Not very, just like smoking

Are you the sinus guy from a few days ago?

acute doses of x-ray/gamma radiation below like 10 mSv are not harmful at all. It was shown from the atomic bomb blasts(acute dose of x-ray radiation you'd get just like a CT scan or x-ray) to not be harmful. all doses under 5 mSv had zero excess cancers compared to regular populations not exposed.

it was shown last year that in old people, CT scans of the chest below 7.5 mSv had no detectable DNA damage

it was shown in another study that the LOWEST average dose for a solid cancer was like 35 mSv, much higher than any CT scan. most CT scans are of the head(angled away from the eyes), one of the least radio-sensitive parts of the body, at like 2 mSv or less, not high enough to do jack shit even in an acute dose. we used to give adult doses to children in the 80s and 90s.

there is no way the doses you receive in a CT scan cause cancer. it has never ever been shown in decades it has been researched. it's harmful maybe if you're a small child and you're receiving a dozen scans in the same spot, but otherwise, there's no way

here is a second table. they don't even include the 5 mSv and under group because there was no excess, and the vast majority of the 5+ mSv group excess is at the high end, nearing 100 mSv.

Depends on how high the dose is. At low dose levels (< 100 mSv), the distinction between acute vs non-acute exposures doesn't matter. The cancer risk from an effective dose of 2 mSv is the same whether it was received from a CT scan or from natural background radiation.

The comparison of low level exposures to background radiation is just a simplification for the general public who would either quickly lose interest or go into panic mode if we were to try to explain all the nuances involved in radiation biology. I've had patients express relief as well as go into panic mode on me when I tried to explain the how low the risks were from their diagnostic scan. True, it's not completely accurate, but the primary purpose for the comparison is to provide some perspective.

t. Imaging Physicist

If you went through ten times in a row, you'd look like pic related...

No single scan is dangerous at all, otherwise they would not exist. People greatly overestimate the dangers of radiation and think a silly dental bitewing or airport backscatter scanner is going to kill them. Only medical physicists can really explain why it is or isn't dangerous and it would absolutely never ever be used if it was thought to be dangerous in the doses that these procedures are administered in.

Fucking lethal, OP. I knew a guy that got a chest CT then a few hours later he chocked to death. Doctors insist that the two are unrelated, but seriously whats the probability of two unrelated events happening together?

>he chocked to death

chocking to death sounds really awful.

X-rays are deadly

>but seriously whats the probability of two unrelated events happening together?

50%

He either chocks to death or he doesn't. 50/50

>tfw my friends dad chocked to death

little bill was such a cutie ^.^

It's not harmful at all and that's pretty laughable. A whole body dose of 20 mSv per year is the annual limit for certain nuclear bodies after loads of research. You will never get whole body 20 mSv dose from any CT scan or any kind of medical imaging. Using tissue weighting factors, this is very easily understood and clears up a whole lot...

For example, a head CT will have an effective dose of 2 mSv. That's the dose that your WHOLE BODY would receive. Your head in reality only received 0.02 mSv. This is why it's really, really silly to be scared of plain film x-rays, CT scanners, airport scanners, or whatever else people are afraid of. Even a big bad CT scanner outputs peanuts in comparison to anything anyone has ever observed to cause any problems, like 20/50/100/200+ mSv whole body, not fucking .015/.02/1/2 mSv whole body.

If people just understood that the Sievert is a WHOLE BODY dose and that you need to account for the tissue weighting factor to get the real dose to the part scanned, there would be no histeria over a CT scan and whether or not it gives you cancer, because the dose is really, really low. Get a dozen scans and be like 2 years old, then you might have a problem.

and no, it doesn't matter if it's acute or chronic at these low doses. It's just too low of a dose to overwhelm your bodies natural repair mechanisms if it even needs to use them. These people in the atomic bomb blasts like were getting HUGE whole body doses. A 5 mSv dose to just the colon translates to ~60+ mSv WHOLE BODY, which is fucking ridiculous and you would never get a dose anywhere near shit like that from a CT scan.

So what about the LNT hypothesis? Obviously a CT scan will not cause immediate or short-term effects - but in the long run? Isn't every bit of ionizing radiation you receive (regardless of the source) adding to the chances to develop some sort of cancer one day?

LNT model is really awful for any one case, but it is a very convenient and conservative political tool and this is the reason it's used. What do you mean by in the long run? These doses are too low to cause any damage at all. Your head will receive 0.02 mSv in a head CT scan. That's insignificant in comparison to the excess cases from Hiroshima and Nagasaki. They were receiving very high whole body doses that were on average 200 mSv. That's your brain receiving 2 mSv by itself. Do you now see why x-rays, CT scanners, airport backscatter scanners, and other such things are absolutely not something to worry about? It's laughable.

What if I'm an albino?

>Isn't every bit of ionizing radiation you receive (regardless of the source) adding to the chances to develop some sort of cancer one day?

I have some more to add after . of course it will increase risk, but it's a really small increase that is insignificant throughout your life. Seeing is a really simple way to show why this doesn't matter.

Anyone that received a colon dose of 5 mSv or less had absolutely zero problems for their entire lifetime from that acute blast. The colon has a tissue weighting factor of .12, so these 36,459 people received whole body doses of up to ~41 mSv with NO PROBLEMS. In comparison, your head CT scan was a ~2 mSv whole body dose.

Do you NOW understand? What could possibly make you think that this would affect you AT ALL? These tens of thousands of people were receiving up to TWENTY TIMES that dose and had no problems for their entire life.

THIS is why it's laughable.

and this is why there is nothing statistically significant under 100 mSv. They're talking about a 100 mSv whole body dose. There is nothing statistically significant between 40-100 mSv, and there is ZERO under ~40 mSv. There is no CT scan where the organ is receiving fucking 5+ mSv. That's insane. They're receiving like 0.02 mSv, totally manageable dose in any adult human, acute or chronic.

I wish medical physicists would just explain it to people so the bullshit fear-mongering, asinine articles would go away.

this is the best way you'll ever see this described desu