inside a computer tomograph (CT / CAT scan / x-ray computed tomography)

[mike240se]

ive seen this for myself many times. is this lead over the eyes something new?

[tangotwowithme]

If you are having your head or face scanned you will not have lead placed over your eyes. Lead interferes with the passage of x-rays and will create image distortion on CT images.

[marcvie9]

2:35 is that a paprica?

[alin0steglinski0]

nope. no eye tumors here... i have been scanned well over 10 times in the last 5 years. eyes open watching the gantry spin :) 32 slice ftw

[pmscompany]

In my life I've had like 3 or 4 tests of these blows to the head and when I was with a blood cancer. And in a couple of opportunities left my eyes open. And listened as revolved around me. It is a magnificent machine! I never imagined I could be at risk to have my eyes open.

[danielrichardbond]

Err, I've just seen in Wikipedia (not always reliable) that in the US 0.4% of cancers can be attributed to past CT scans - kinda worrying... How do they know whether a CT scan is the cause of a cancer though??

[bionerd23]

@danielrichardbond

i think they can only do this via statistics... 1.2% of people between 40 and 60 with certain variables (e.g. body weight, smoker yes/no, etc.) have cancer. amongst those with the same variables but who ALSO had a CT scan in the past, 1.4% have cancer. thus, 0.2% of cancers in that age group are caused by CT scans.

...something like that, these arent accurate numbers or anything. :P

by the way, the risk for the eye is more a fogging of the lens (cataract).

[danielrichardbond]

I also had a CT scan, two years ago and wasn't told to close my eyes. I remember watching the thing spinning round, wondering how it worked. No eye tumours yet...

[mellerz252]

my exposure, what potential complications could I develop?

Should I be worried?

Could the scan have done any damage to my health, regardless of how significant or insignificant it may be?

I ask you bionerd because you seem pretty sincere and you certainly appear to know your stuff! I haven't been able to get anything worthwhile from anyone, it's always "you're alive" etc.

So I'd appreciate a little honesty, just be straight with me please!LOL

Thank you bionerd, and anyone else who may reply

[bionerd23]

@mellerz252

i dont think a one-time exposure does all that much damage; it's just an unnecessary exposure of a radiation-sensitive organ. with lots of exposure, the lens of the eye can turn "foggy" (so-called cataract). but, as i said, a single exposure isnt all that dangerous. should you be put into a CT repeatedly for some reason (as it is e.g. done with cancer patients to check for metastasis every few months), i think protecting the eyes as good as possible would be a good idea.

[gyroscannt]

@bionerd23 Please! Closing your eyes during a scan will protect nothing, the only reason the radiographer will ask you to close your eyes is to protect them from the laser localising lights used to position your head prior to a scan, if you are having multiple follow-up CT scans to the head then you may be asked to wear Bismuth eye protectors to minimise x-ray exposure to the lens. If your doctor recomends a headscan then the clinical need far outways any possible long term effects.

[mellerz252]

I had a CT scan on my head last year, when I was 19. It was due to being struck round the head, and having recurring headaches.

They found nothing, and I was given the all clear.

I was completely oblivious to what I was being exposed to, and from what I've learnt since, I'm really concerned I had it done.

I wasn't given any of the lead protection you mention, I wasn't told to close my eyes, and I spent most of the time looking directly at the gantry.

Considering my age at the time, and....

[wawa1196]

i always had my eyes open when i have had cat scans

[EA78751]

this is so cool

[spotlightman1234]

i had to have my eyes open during my scan because they were looking for something in my eye and it wasn't so special

[bionerd23]

@spotlightman1234

yeah, you cannot see the radiation emitted from a CT scanner with your eyes, sadly.

[nik282000]

O.O I was put into a CT scanner for my shoulder and I was not asked to close my eyes and they did not give me a lead shield. I was heavily medicated at the time so I never thought of it but that's a little alarming.

[bionerd23]

@nik282000

if your eyes were far away from the main area of interest - e.g. just the area up to your neck was scanned - it's not really harmful. it's only advisable to use lead if the head passes the gantry and gets scanned, too. the stray radiation is minor.

[gnazkull]

about time you made another video :P i know that was a little selfish to say but i love your videos :)

[bionerd23]

@gnazkull

yeah, you're right. :(

i'm reeeeeally lacking time lately, that's the problem. i'm busy for approx. 60 hours a week, and that leaves little time for experiments.

[LordPlextor]

Interesting to see, what happen, when the x-rays hit the CCD.

[101blender]

I like the bellpepper next to the other fruit. I also like your camera type. Reminds me of older cameras.

[coilgunman]

i was wondering about what happens if you put your camera in the beam of the clinac at full power emiting x rays. can you make it? yeah i know is a very expensive machine and can be used for treat a patient instead a camera and probably you camera are going to damage but (if you have the possibility to make it)the experiment is gona be sweeeeet!

[bionerd23]

@coilgunman

i already had it NEAR the beam of a linac (if you saw that video). just, i cannot put my camera INTO the beam, simply as i cannot afford buying a new camera right now, sorry...

[CodeWarriorx0539]

I just had one done on my sinus(no lead to cover the eyes)... its sucks knowing you're getting a huge dose of radiation to your head ....

[Pada007gangster]

wait waa.... i went through it without lead sheet or closing my eyes (they never told me to close em)....and I saw it all...I wonder if it has anything to do with my eye sieght getting worse...

[bionerd23]

@Pada007gangster

radiation exposure is linked to eye cataract (fogging of the lens). i'm not sure if it can be held responsible for e.g. being increasingly nearsighted.

[michalchik]

OK, I am declaring that you have a radiation fetish.

[bionerd23]

@michalchik

it's called "being radiophile" to be precise.

[michalchik]

@bionerd23 Weird, but kind of fun. How do you feel about non-ionizing radiation?

[bionerd23]

@michalchik

it's pretty handy. :P

i like seeing stuff, i like feeling warm, i like cooking things with radiation and i also like listening to radio traffic. cant say i despise any radiation!

[jeriellsworth]

Thanks for taking this much effort for us in youtube land.

[SuperFinGuy]

That is pretty cool, can you actually see the beam of x-rays with your eyes, or only the camera can pick that up?

[10mintwo]

@SuperFinGuy Rontgen and Brandes reported being able to see x-rays with the unaided eye around the time of their discovery a hundred years ago, but I am unaware of any other reports replicating the observation. Obviously it isn't something you can do on a whim. A nice experiment might be to get a person needing a cranial CT scan to dark-adapt their eyes and report if they see anything. But people in a position to need such a scan would prob be in too much pain to fuck around with such things.

[bionerd23]

@SuperFinGuy

well, 10mintwo already posted a very good reply, but anyway... i dont think it's possible. a camera ccd just works very different to the retina; in our retina, only a certain wavelength (so-called "visible light") can be processed, while cameras naturally see infrared and UV, which has to be filtered / minimized (that is done within the lens). at the same time, ionizing radiation produces those "flashes", too; it's just a really different architecture compared to our eyes. ;)

[SuperFinGuy]

@bionerd23 I guess the beam would have to be stronger so as to ionize the air and make visible flashes.

[bionerd23]

@SuperFinGuy

yeah, that'd work. however, as that doesnt even happen with a linear accelerator for radiation therapy that emits 6 Gy a MINUTE (!), i dont think i want to be anywhere near that if it happens - not without shielding, anyway. :P

[SuperFinGuy]

@bionerd23 "not without shielding, anyway :P"

lol it would be like burning radiation but I am sure you wouldn't resist being around :D

[10mintwo]

@SuperFinGuy By the by, you CAN see the air ionization effect for incredibly intense X-ray sources such as those produced by synchrotrons. If you go to the wikipedia page for "synchrotron light source" the image at the top of the page (that lil' ole me uploaded :o) shows this phenomenon. The very same effect has also been noted as the infamous "blue flash" by victims of criticality accidents. Basically, if you are in the observable vicinity of radiation-induced air ionization; you're fucked.

[SuperFinGuy]

@10mintwo That picture illustrates pretty well what I had in mind. Didn't think you'd have to use synchrotron radiation to do the trick! Synchrotron energy is pretty nasty, it is the stuff that pulsars expel with their collimated jets.

[bionerd23]

@10mintwo

wow, i didnt see that article yet. thanks for an amazing photo, too!

[Cheejyg]

YOU'RE EYES WILL BE COVERED WITH LEAD??? HOLY SHIT!!

[L0wnyus]

I will always open my eyes in a ct scan from now on it looks so cool :D

[Geomanb]

toll!

[DidntKnowWhatToPut1]

I envy you Bionerd...I'll never have a chance to piss about with an CT scanner!

[bionerd23]

@DidntKnowWhatToPut1

why? dont you ever have open house days at hospitals in the UK?

[DidntKnowWhatToPut1]

@bionerd23 o_O nope. I'm glad Germany dose though; its a nice idea \o/

[ChemHandbook]

@bionerd23 I have a feeling we do only we don't have any cool doctors that'll let us put cameras in CAT scans D:

[gnanmorder]

Cool!