The largest and most important component of a magnetic resonance imaging system is a magnet.The unit that marks the grade of the magnet is called a Tesla.Another commonly used unit of measurement for magnets is the gaussian (1 tesla =10,000 gauss).Current magnetic resonance imaging magnets range from 0.5 to 2.0 teslas, or 5,000 to 20,000 gauss.[kyodo news, July 1] the institute of materials and materials research in tsukuba, ibaraki prefecture, Japan, announced the development of the nuclear magnetic resonance imaging system, the magnetic field intensity reached the highest level of 24 tesla in the world.According to small series engaged in the magnet industry experience, the basic judgment of the magnet is the strong magnetic ndfeb.A neodymium iron about the size of a thumb, with a relatively poor performance of the brand (material), about 5000Gs, adsorption on the metal surface, is almost not off.What's more, magnetic resonance magnets are slightly larger in size, and there is more than one magnet in the device.When two magnets are attached together, the magnetic forces are superimposed.The following picture is a small disc magnet. The circle ndfeb strong magnet strong magnet large suction magnet.Because the magnets are so powerful, metal objects can become dangerous projectiles if taken into the scanning room without strict precautions.For example, paper clips, pens, keys, scissors, hemostatic forceps, stethoscopes, and any other small object can suddenly be pulled out of your pocket.The metal then disengages from the body, accelerates rapidly and flies instantaneously towards the opening of the magnetic field (where the patient is), posing a threat to the safety of everyone in the room.The magnetic force acting on an object increases exponentially as it approaches the magnet.Suppose you stand 4.6 meters away from the magnet with a pipe wrench in your hand.You may feel a slight pull (depending on the magnet size and material).The pull increases a lot when you take a few steps.When you get within a meter of the magnet, the wrench is likely to slip out of your hands.In addition, the heavier the metal, the more dangerous it may be -- because it is much more attracted by magnets.Mop buckets, vacuum cleaners, drip racks, oxygen bottles, stretchers to carry patients, heart monitors and countless other objects have all been sucked into magnetic fields of mris.Small objects can usually be pulled from magnets by hand.Large objects may have to be towed away with a winch, or even the magnetic field may have to be turned off.