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Thread: Magnetic resonance imaging

  1. #1 Magnetic resonance imaging 
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    Not sure why you posted this originally in philosophy...

    I am not aware of there being any scientific evidence of it being so, since it operates at a sub-atomic level aligning the atomic spin of atoms. Should be harmless, if not then holding strong magnets would also be dangerous.

    The only problem I see is that you should tell them if you are sword swollower and lost some of your props.... :wink:
    Welcome to the forum by the way...


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    Everything away from normal is potentialy dangerous, even strong magnetic field. Several, non life-threating events have been reported. From increased heart rate, slightly increased temperature, possible photophobia . . . It was proven, that in stron magnetic field (of 3 Tesla and even more) cells are proliferating more rapidly (but just a little 2-8%). Our professor told us to be so 2 years ago . . . Study has been done in vitro with fibroblasts. There is also (like Brain said) danger with prothesis, home-made tatoos with higher amount of iron, and cardiostimulators . . . Considering these facts, it is possibly the most harmless diagnostic procedure in medicine, but not the cheapest

    There is just one disadvantage to think of . . . it takes a long time to shut it down after the imaging is over . . .
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    Increased heart rate & temperature can just be symptoms of anxiety, have you ever been in an MRI: they're scary! & photophobia could be just because its quite dark in there! I doubt those are a direct effect of the magnetic field.

    All the tatoo & cardiostimulator stuff are checked out usually before you have the scan.
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    You might be confusing it with "Nuclear Magnetic Resonance Imaging" or NMRI - but it's the same thing, they changed it cos people were a bit frightened of the word 'nuclear'....
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    How do you make the connection? - I cannot see any similarity, a nuclear weapon only produces an intense pulse of light at very high temperature. The blast is caused soley by the gas in the atmosphere being instantly superheated, resulting in expansion, after cooling the air gets 'sucked back in'.
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    The increase of temperature is not related to the magnetic field, but to the microwaves (like the one in our oven) sent by the MRI.

    Normally at the normal state, all the spins of the atoms are randomly setted. Within the magnetic field, all the spins are aligned.
    When they are aligned, a microwave stimulate the atoms and made them oscillate. It's the oscillation under two kind of stimulations wich is studied and create the pictures.
    So the increase of heat is related to the microwaves, and not the magnetic field itself
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    Quote Originally Posted by Searcher
    Then that should be harmful if it's related to the microwave which 'is' radiation directed to the individual in an MRI.
    I think you will find the 'RF' energy is less than that of a mobile phone, which is 10,000 times less than an average microwave, so there won't be a problem, at these levels any extra heating of tissue can be easily regulated by your metabolism. A sauna will put far more electromagnetic radiation into your body than any NMRI scanner ever could.
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    Quote Originally Posted by Searcher
    It's said that the MRI doesn't use any radiation so that's untrue. I never thought the Sauna had radiation either. Does that mean the stove has radiation?! Which one has more radiation, the sauna, microwave, x-ray, television, computer, cell-phone or mobile phone? (if you know the answer in order)
    Some radiations are totally harmfull, and others not. The light is a kind of radiation, and is not harmfull.
    X ray, gamma, UV, and alpha radiations are harmful.

    For the stove there isn't radiation outside, because it's built around a faraday cage.
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    Quote Originally Posted by Searcher
    Quote Originally Posted by Megabrain
    I think you will find the 'RF' energy is less than that of a mobile phone, which is 10,000 times less than an average microwave, so there won't be a problem, at these levels any extra heating of tissue can be easily regulated by your metabolism.
    You said that the high frequency of heating results in radiation directed into your body and that a less amount can be regulated by your metabolism but I thought that if you're exposed to radiation, it causes some damage already and can't be undone and only can be not ruined further if you avoid it.
    Well you guys need to understand the difference between being bombarded with EM waves (Heat light radio IR & even ultraviolet, xray) and Nuclear radiation, ie being bombarded with sub-atomic particles, ----Get the idea?
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    It really depends upon the dose, which would be measured in watts/cm Squared for EM radiation and in the case of ionizing radiation the roentgen
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    Quote Originally Posted by Searcher
    Not sure what gamma and alpha radiation is but of the ones I listed, which ones are the harmful type of radiation?

    The order from most to least harmful probably is:

    microwave
    x-ray
    UV from the sun
    tv
    computer
    cell phone
    mobile phone
    sauna

    Is that right?
    hmm, I we thing this way, soon we can make a list of thousand lists what is harmful. Im adding PDA (not patent ductus arteriosus, but palm computer). Btw. not all types of UV light is dangerous (There is UV-A, B and C).
    But we have uncoupled the respiration from oxidative phosphorylation Rather stay close to MRI
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    Em radiation can be harmful, looking at the sun for exapmle, some UV light, Microwaves, it's a question of dosage, Ionizing radiation (all mass radiates to some extent, background radiation, radiation from space. Heat is a form of radiation - to much heat...
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    No known harmful effects of listening to the radio unless it's Des O'connor or some item that annoys you. That is in 100 years of radio reception no harmfull effects have been recorded or noticed.

    Radios (and all electronic equipment including you PC) emit radio waves, just turn on an old AM radio and move it towards your PC - for a cocophony of sounds!

    UV sun blockers? I think they act simply like a mirror to certain UV wavelengths, (like you can see through black bin liners using Infrared).
    But that is a guess - so you might need to look it up!.
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    There is two kinds of radiations : the ones who create ionisations, and the others.
    Ionisations are dangerous for the DNA : there is long term effects and the existence of a cumulative dose.
    There isn't such things for microwaves. Two much microwaves and you will be cooked, but if not, the heat will go away, and at the light of today science, there isn't any real proofs of others backside effects of microwaves.
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