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- $Unique_ID{BRK00281}
- $Pretitle{}
- $Title{Can Magnetic Imaging Help Diagnose Knee Injuries?}
- $Subject{magnetic resonance knee diagnosis Special Procedures procedure
- Laboratory Tests lab test MRI x-ray imaging computed tomography CT CAT scan scanning
- strong magnetic field hydrogen atoms radio waves energy density tissues damage
- muscles ligaments tendons tumors cysts joint fluid muscle ligament tendon}
- $Volume{P-17}
- $Log{
- Muscles and Tendons of the Knee*0006201.scf
- Anatomy of the Knee*0006601.scf
- Anatomy of the Knee Ligaments*0015501.scf}
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- Copyright (c) 1991-92,1993 Tribune Media Services, Inc.
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- Can Magnetic Imaging Help Diagnose Knee Injuries?
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- QUESTION: Can magic imaging help diagnose knee injuries?
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- ANSWER: That's "magnetic resonance" imaging or MRI, and while it is not
- magic, it is very helpful in diagnosing many different conditions. MRI works
- on a completely different principle from that of x-ray imaging or computed
- tomography (CT or CAT scanning), which both used x-rays.
- In MRI, x-rays are not used at all. The patient is placed in a machine
- that creates a strong magnetic field, which causes the hydrogen atoms in that
- body (and there are a lot, hydrogen is extremely common) to line up and point
- in the direction of the field. A short pulse of radio waves then causes these
- atoms to wobble a bit and then go back to spinning in alignment. This wobble
- releases some of the radio energy back and depending on the density of
- hydrogen in the tissues, different tissues send back different signals. These
- signals are processed into computerized pictures of the tissues.
- Unlike X-rays, the MRI process does not "see" bone tissue, because it
- lacks hydrogen atoms, but it is excellent for soft tissues, which may be seen
- even more clearly without being hidden by the dense bone. MRI imaging offers
- great accuracy for diagnosis especially in structures like the knee, which are
- made up of many types of tissue. Physicians can examine the knee for damage
- to the muscles, ligaments and tendons, as well as for tumors, cysts, and
- changes in the joint fluid.
- There are no known adverse affects to MRI, although some people feel
- claustrophobic while in the machine. Another plus is that there is no need to
- inject any contrast materials into the joint to make certain features stand
- out. However, MRI is expensive, but the cost is coming down as it is becoming
- more widely used.
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- The material contained here is "FOR INFORMATION ONLY" and should not replace
- the counsel and advice of your personal physician. Promptly consulting your
- doctor is the best path to a quick and successful resolution of any medical
- problem.
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