Imaging Methods

Imaging Methods - Imaging Methods: How do they work? STATIC...

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Imaging Methods: How do they work? STATIC METHODS: CT: Computed Tomography is based on the x-ray principal: as x-rays pass through the body, they are absorbed or attenuated (weakened) at differing levels creating a matrix or profile of x-ray beams of different strength. This x-ray profile is registered on film, thus creating an image. In the case of CT, the film is replaced by a banana shaped detector which measures the x-ray profile. MRI: Like X ray, MRI is based on a discovery in the physic lab: when the nuclei of hydrogen atoms--single protons, all spinning randomly--are caught suddenly in a strong magnetic field, they tend to line up like so many compass needles. If the protons are then hit with a short, precisely tuned burst of radio waves, they will momentarily flip around. Then, in the process of returning to their original orientation, they resound with a brief radio signal of their own. The intensity of this emission reflects the number of protons in a particular
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This note was uploaded on 11/12/2009 for the course PSY 3321 taught by Professor Ceballos during the Spring '09 term at Texas State.

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