A hospital's imaging magnetic resonance imaging (MRI) room has no space for credit cards. MRI magnets used to paint accurate pictures of your insides are strong enough to pull a screwdriver out of your hands from a meter away. , Portable devices can be cheaper more in store, however. The researchers report in the next week Physical Review Letters that high-quality images of at least some parts of the body like the lungs, can be made using a magnet to 10 times lower than that native art pin refrigerators.
With traditional MRI, someone slipped into the hole of a giant superconducting magnet that generates a field some 20,000 times stronger than the Earth. The field aligns the nuclei of hydrogen atoms within the body, leaving the spinning atoms as tiny synch bar magnets. Then a brief advice electromagnetic pulse nuclei so they flicker like quirky tops. The whirling atoms emit an electromagnetic wave of its own which can be detected. By adding a second weak magnetic field to change the frequency of the atoms in different places, researchers can map the density of water molecules and build a clear picture of the tissues and internal organs.
Ron Walsworth of Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and his colleagues took a slightly different approach. They used a pioneering technology several years ago by physicist from Princeton University William Happer: First align atomic nuclei in gas rubidium with a laser, and then allow them to mix with a helium gas -3 (helium least one neutron). When the atoms collide, a portion of the alignment is gradually transferred to the helium atoms. toxic rubidium atoms can then be removed. Because the helium atoms are an inert gas, they can stay lined up for a few minutes at a time, even without a magnetic field.
In one test, researchers have inflated the lungs of a rat with polarized helium gas and makes high quality photos cavities with a resolution of one millimeter. The magnetic field used to adjust the rotation rate them was only 40 times stronger than the Earth. "It is embarrassing simple," Walsworth said. "You and your brother can liquidate your own magnet and get an MRI as well as what you get in a hospital," he said, although Science NOW is not recommended.
Researchers had known that such a low field imaging with tissue could be done, but no one had bothered to put all the pieces together, says Walsworth. Still, others are impressed: "It's a beautiful piece of work," says Alex Pines, a Lawrence Berkeley National Laboratory physicist in California. "They are very sharp images."
traditional MRI magnets can cost a million dollars, says Pines. The technique could lead to MRI at low price Laptop for imaging the lungs, they say it. Happer added that the lungs are only the beginning. Replacing helium with xenon gas, which is absorbed like oxygen in the blood, also allow researchers to take small budget MRI arteries and brain he predicted.
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