Magnetic Resonance Imaging

Claimed by Noah Schaich

Magnetic Resonance Imaging (MRI) is a medical device that uses radio waves and strong magnets connected to a computer to create a cross-sectional view of organs and tissue within the human body.

The Main Idea

The concept behind the MRI is nuclear magnetic resonance, which basically says that when atomic nuclei are exposed to a strong magnetic field, they will emit or absorb radio waves. In the applications of an MRI machine, the hydrogen atoms are examined, and because different organs and tissue in the body are composed of varying amounts of hydrogen atoms, they will emit or absorb different radio waves. These waves can be collected and analyzed by a computer, and when they are displayed, the different organs and tissue in the body will be distinct.

The development of the MRI machine was a huge innovation in the medical world because it allowed doctors to analyze the body in a non-invasive manner. MRI machines are often used to look at the soft tissue in the body, since that is what they can detect. An MRI might be used for the following purposed:

1. Brain and Spinal Cord injuries and abnormalities
2. Tumors
3. Heart Problems
4. Liver and other abdominal organs

How it Works

There are 4 main steps to how an MRI machine collects images of the body.

1. The MRI machine emits a steady magnetic field. Protons in the hydrogen cells in the body react to this steady electric magnetic field by becoming magnetized.
2. The MRI machine emits radio waves that alters the steady state orientation of the protons.
3. The MRI machine stops emitting radiation and collects the body's electromagnetic transmission. Different tissues in the body will emit different kinds of radio waves, and for varying amounts of time.
4. The signals are collected and analyzed by a computer. They are used to construct images of the body.

Images

MRI Machine:

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Cross-Sectional view of brain:

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History

The concept for an MRI machine comes from nuclear magnetic resonance(NMR), which is when atomic nuclei absorb or emit radio waves in the presence of a strong magnetic field. This concept was expanded on by Raymond Damadian, who discovered that if using this technique to look at cells in the human body, cancerous cells would appear different because they contain more water, and thus more hydrogen atoms. The first NMR image was produced in 1973 by Paul Lauterbur, and 4 years later, in 1977, the first body scan using an MRI prototype machine was produced.

See Also

Further reading

Clinical Cardiac MRI [1]

MRI: Basic Principles and Applications [2]

External links

Medical News Today [3]

Mayo Clinic [4]

Tesla Society [5]

FDA [6]

References

1. http://www.medicalnewstoday.com/articles/146309.php
2. http://www.teslasociety.com/mri.htm
3. http://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/MedicalImaging/ucm200086.htm
4. http://www.mayoclinic.org/tests-procedures/mri/basics/definition/prc-20012903