For your short relaxation times.
The unit of magnetic field is the Tesla, named after Nikola Tesla (visionary / genius / crazy / misunderstood et cetera). A company named after Tesla is Tesla Motors, who make the Tesla Roadster. Check this out:
Magnetic media (e.g. your credit card) may be affected at field strengths of 3 millitesla (mT). For comparison, this magnetic field strength is about 100 to 200 times stronger than the normal magnetic field on the surface of the Earth (depending where you are on the planet). The 3 mT field line around a typical shielded 1.5 T MRI magnet is about 2 metres from the side of the magnet, and less than 3 metres from the ends of the magnet.
Notice that the magnetic field around an MRI magnet is 500 times smaller than the strength at the isocentre at just 2 to 3 metres distance!
I wonder how the magnetic field affects the newer chip-and-pin microchip which is embedded in credit cards. Anyone care to comment?
Have you always wanted to express your passion for MRI physics but never knew how? (Come on, admit it.) If only there was an easy way of breaking into a conversation about the intrinsic nature of spin!
Well fear not, dear reader, now there is a way. Continue Reading »
Of course, the answer to any headline which asks a question is “No”. Try this with newspaper headlines. If the answer was “Yes!” the headline would read: “MRI attracts the iron in your blood!” But I digress.
Isn’t iron, well, iron? Why isn’t it attracted by the MRI magnet?
Edward M. Purcell
Nobel Prize in Physics lecture, 11th December 1952.
“I have not yet lost a feeling of wonder, and of delight, that this delicate motion should reside in all the ordinary things around us, revealing itself only to him who looks for it.”