Definition
Magnetic resonance imaging (MRI) is a non-invasive way to take pictures of the body.
Unlike x-rays and computed tomographic (CT) scans, which use radiation, MRI uses powerful magnets and radio waves. The MRI scanner contains the magnet. The magnetic field produced by an MRI is about 10 thousand times greater than the earth's.
The magnetic field forces hydrogen atoms in the body to line up in a certain way (similar to how the needle on a compass moves when you hold it near a magnet). When radio waves are sent toward the lined-up hydrogen atoms, they bounce back, and a computer records the signal. Different types of tissues send back different signals. For example, healthy tissue sends back a slightly different signal than cancerous tissue.
Single MRI images are called slices. The images can be stored on a computer or printed on film.
MRI can easily be performed through clothing. However, because the magnet is very, very strong, certain types of metal can cause significant errors, called artifacts, in the images.
How the test is performed
You may be asked to war a hospital gown or clothing without metal fasteners (such as sweatpants and a t-shirt).
You will be asked to lie on a narrow table, which slides into the middle of the MRI machine. If you have a fear of confined spaces (claustrophobia), tell your doctor before the exam. You may be prescribed a mild sedative, or your doctor may recommend an "open" MRI, in which the machine is not as close to the body.
Small devices, called coils, may be placed around the head, arm, or leg, or other areas to be studied. These devices help send and receive the radio waves, and improve the quality of the images.
Certain exams require that a special dye (contrast) be given before the test. The dye is usually given through an intravenous line (IV) in your hand or forearm. The contrast helps the radiologist see certain areas more clearly.
During the MRI, the person who operates the machine will watch you from a room next door. Several sets of images are usually need, each taking from 2 to 15 minutes. Depending on the areas being studied and type of equipment, the exam may take 1 hour or longer.
2007-06-11 11:41:38
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answer #1
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answered by jennifer g 7
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Yeah, Technically they Are Cool, See I. I. Rabi, Lamour Frequency, but I Think your Question Has to Do With the Process, Depending How Good your Neurologist is, he/she May Accept the Eval. of the Radiologist, A Gross Defect Will Be Immediately Obvious to Both of the Above. I Have had MRI Brain Scans Many Times. BTW, Be Still During the MRI.
2007-06-11 10:51:30
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answer #2
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answered by Anonymous
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The technology behind MRI's is pretty cool.
It stands for Magnetic Resonance Imaging
After they have you lie down & strap you in so your head won't move....
1st - they inject you with a metallic type substance that reacts to the huge magnet. It feels really cold going in - it's weird, but neat.
2nd - they run a really loud magnet over the area - like the head - that aligns all the particles in the injected substance.
3rd - they take a picture of the "bounced back" image projected from the particles.
The results will come afterwards - the doctors have to review the images first.
2007-06-11 10:38:29
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answer #3
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answered by CoronaGirl 3
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In short it is NMR or Nuclear Magnetic Resonance a technique used in chemistry. It was changed to MRI because the people that developed it thought having Nuclear in the name would be bad since people would get scared off. All thats true by the way!
2007-06-11 12:40:41
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answer #4
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answered by Anonymous
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Result is posted to your GP
Jewellery off, lie down, you go into a tunnel very noisy, come out.... lasts up to 45mins
You can listen to music to mask the noise
2007-06-11 10:39:39
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answer #5
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answered by ALLEN B 5
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