Ct Scans And Mri's

CT Scans and MRI
Shelly Jones
August 10, 2011

CT Scans

CT or Computed imaging scans are radiographic (roentgenogram) images complied with the use of a ready reckoner. Images are taken in three to five millimeter slices, which when complied represent a three dimensional image of the interior structures of the body. Physicians use these images to essay the intimates of a diligent without having to cut them open.
The process by which an X-ray photon is produced is simple. A super heated watt filament inside a senselessness releases electrons. This is called thermionic emission. The released electrons flow across the vacuum in an electron cloud or space mail to jolt with a rotating tungsten wheel.
The free electrons interact with the tungsten components in two ways. The electrons might approach the nucleus of the atom and slow down, losing might in the form of a photon. This reaction is called Bremsstrahlung radiation. It happens 85% of the time. The other interaction is called Characteristic radiation. Free electrons collide with an electron in an inner shell of an atom, causing both(prenominal) electrons to spin off in other directions. An electron from a higher shell drops down to fill the empty space, losing energy in the process, which is emitted in the form of a photon. These photons are what make up the x-ray beam.




The CT scanner looks like a short tube or closed chain with a pitiful table in the middle. Inside the doughnut are a rotating X-ray tube, and an image receptor system, that connect to a computer that reconstructs and assembles the radiographic data into the CT image. During the scan, the table moves through the doughnut with the patient on it, and the X-ray tube and detectors circle the patient in a spiral pattern.
The X-rays tick different types of tissue to different degrees. This is called attenuation. The CT scanner is programmed to exchange the intensity of the X-rays in format to image the different types of tissue. sometimes a dye, called contrast, will...If you want to get a full essay, order it on our website: Orderessay



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