Exploding Tattoos Carissa Ferraro Sarah Fiorelli Anne Adams
The Myth Tattoos are reported to "explode" when put inside an MRI scanner, because of the strength of the magnetic field within the MRI machine. The claim is that trace metal filaments in tattoo ink are attracted to the magnets within the machine (which are 20 times stronger than the Earth's magnetic field), making them explode off the patient's skin.
Part of an MRI machine Magnetic Resonance Imaging: • Primary Magnet- this is the main part of the MRI machine. This magnet creates the magnetic field. • Gradient Magnets- these are the fine tuning part of the machine. This allows the machine to focus on specific parts of the body. • The Coil- emits a radio frequency waves into the patient's body. There are different coils for different parts of the body. It detects the energy given off by the magnetic induction from the processing of atoms.
How it Works? • Moving a magnet near a wire will create a current flowing in the wire. • The MRI machine is made up of one big coil/loop with a magnet. • Changing a magnetic field (induction) inside the loop creates a current that can produce the magnetic resonance imaging • The current makes an electromagnetic field • Before a patient enters the MRI machine the hydrogen atoms in their body all pointing in all different directions • When the patient enters the MRI machine the atoms line up in the direction of the magnetic field.
How it Works? (continued) • The magnetic field runs straight down the center of the machine. • This then makes the hydrogen protons line up in the direction of this magnetic field, pointing towards the patient's head or feet. • Half the protons point towards the patient's feet and the other half point towards to the head. This makes many of the protons cancel each other out because for every proton pointing in one direction there is an atom pointing in that same direction. • Only a couple protons out of every million aren't cancelled out, the protons that are not cancelled out give us a detailed MRI.
How it Works?(continued) • Now the MRI machine emits a radio frequency pulse that is specific to the hydrogen • The MRI machine emits this pulse towards the area of the body that needs examination • Unmatched protons absorb this energy, and then gradient magnets turn on and off altering the magnetic field. • When the RF pulse is turned off the hydrogen protons slowly return to their natural state, and release the previously absorbed energy that is detected by the coils, and sent to the computer system • Once they are sent to the computer, the image is created for a doctor to further examine.
Components of Tattoo Ink Many people are under the impression that tattoos are composed of different colored ink, when actually they consist of two main components: pigments and carriers.
Composition of Pigments The pigment of tattoos is composed of different elements to form the different colored "inks". • Blue: Calcium Copper Silicate • Red: Iron Oxide • Green: Chromium Oxide • Yellow: Curcuma • Black: Carbon • White: Zinc Oxide
Carriers Carriers are an essential component to tattoo "ink". They are the liquids that deliver the pigments beneath the skin. Commonly Used Liquid Carriers: • Listerine • Witch Hazel • Purified Water • Propylene Glycol • Vodka • Glycerine
Validity The only ink that has the potential to react with the magnetic field is red ink (made from iron oxide). Even so, the amounts of iron in the skin are too small to make a tattoo "explode" when under the MRI scanner. There have been some reports of redness or irritation at the tattoo site, but no explosions.
Prison Tattoos? An objection to the debunking of the myth is that it doesn't account for tattoos administered in prison. These tattoos aren't administered with sterile needles, but often with whatever is available -- mechanical pencils, paper clips, staples, or guitar strings. The ink can be comprised of whatever the artist can get, mostly melted plastics and pen ink. Still, the amount of iron found in the prison tattoos are most likely not enough to make the tattoo explode.
Historical Validity Patients who received tattoos years ago have reported slight to severe pain when undergoing a scan. This may be because tattooing has only recently been strictly regulated for health concerns, and pigments used to contain metal fragments in larger proportions than they do today. While pain is still a serious side effect, tattoos can't "explode" in an MRI scanner.
What We've Learned While the magnetic field in an MRI machine is quite strong, the metal found in tattoos isn't enough to make it explode (although the field is strong enough to injure patients who wear metal jewelry, etc.). Also, none of us will ever get a tattoo.
Bibliography http://orthopedics.about.com/cs/sportsmedicine/a/mri.htm http://www.bellaonline.com/articles/art57596.asp http://tattoo.about.com/cs/tatfaq/a/mri_scan.htm http://tattoos.lovetoknow.com/Tattoo_Ink http://science.howstuffworks.com/mri.htm http://www.convictedartist.com/prison_tattoos.html