MAGNETIC RESONANCE IMAGING
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What is the MRI?
Magnetic Imaging Resonance (MRI) is a medical imaging technique to create pictures of the anatomy of the body. MRI utilities the science of nuclear magnetic resonance. Hydrogen atoms are used to generate the images; they exist in large amount in the body as water and fats. Thus MRI scan are more accurate in generating images in soft-tissue organs. The MRI creates a magnetic field which causes the hydrogen atoms to align in one direction. These atoms releases energy when they recover their alignment.
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What is inside the machine?
Primary Magnetic CoilSuperconducting magnets generate an uniform magnetic field that aligns the protons within the body to the Larmour frequency.
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Gradient CoilProduces a gradient/ variations in the field strength within the magnetic field. Pinpoints an exact point in the body to resonate at Larmour frequency.
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Radio Frequency CoilExcitement of the protons at specific regions. Radio frequency will alter the alignment of the protons - differing from the main magnetic field.
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How does it produce the image?Radio frequency from the RF coil will excite and realign the protons. Protons will be spinning at a different direction from the main magnetic field. The radio frequency is pulsed to allow time for the protons to recover to their initial state and align to the main magnetic field. During the recovery, the protons will release energy which will be picked up by the receiver. From this release of energy, the computer will be able to form an image of the internal of the body.
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