CT / CAT Scan

CT scan and CAT scan are abbreviations for computed axial tomography. CT scans are painless, and like a traditional X-ray, they do not require any invasive techniques. (1) Just like in traditional X-rays, CT scans use small doses of radiation to produce images. When the radiation passes through your body, some is blocked, which changes the amount exiting on the other side. Detectors measure this, and computers assign different shades of black and gray to the different levels of radiation. These shaded pictures are the images the doctor sees. (2)

The CT scan is a type of X-ray that allows doctors to get a view of internal organs that is more detailed and more accurate than the flat scan of a traditional X-ray. Images produced by a traditional X-ray are two-dimensional flat images. CT scans produce three-dimensional images that provide much more detail and information to the doctors. With more information, doctors can do a better job diagnosing problems and determining appropriate treatment.
The three dimensional images are produced because of the different way a CT scan looks at eh body. Traditional X-rays are stationary, so the image produced is a flat picture taken from only one angle. A CT scan, on the other hand, rotates around the body taking pictures from many different angles. Each image shows a "slice" of the body. When the "slices" are combined, the resulting picture is three-dimensional.

CT scan machines look like body sized tubes. The person getting scanned lies still on a platform inside the tube. The scanner then rotates around the body X-raying it from many different angles. The images are sent to a computer where the doctor sees them as a three dimensional image on the computer monitor. The images can be sent from there to a printer if the doctor so desires.

'CT / CAT Scan' Sources:
  1. Radiological Society of North America, Inc. (RSNA), http://www.radiologyinfo.org/en/info.cfm?pg=bodyct
  2. CT Scan-Mayo Clinic Staff, Jan.12, 2006, http://www.mayoclinic.com/health/ct-scan/FL00065

 

 

 

 

 
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