How Do Cat Scans Work?
The Beginning
The computerized axial tomography, or CAT, scan machine was invented in 1972 by a British engineer named Godfrey Hounsfield from EMI Labs in England and physicist Allan Cormack from Tufts University in Massachussetts. The CAT scan machine has come a long way since the beginning. Initially it was used for images of the head but now can be used to secure an image from any part of the body. Advances have also come in the speed of reading an image. An image that once took days to construct is now available in 5 to 10 seconds. In 1979 Hounsfield and Cormack won the Nobel Prize for Medicine for their contribution to medical science.
The Technology
During a CAT scan, the patient is placed on a platform bed. This bed moves slowly through a ring which can be built into a wall or in the CAT machine itself. Attached to this ring is a moveable X-ray detector and X-ray tube. As the patient moves through the ring on the bed, a motor turns the ring while the detector and tube scan the body and send the images back to a computer. The body is scanned one "slice" at a time so that the machine can pick up a more accurate photo. Scanning the body in a circular motion gives more accurate information from the shadows and lights that are created by the machine, such as size and thickness of an internal object or mass.
These X-ray beams are much more powerfu than a simple X-ray machine. They not only pass through soft objects such as human body tissue, but they also can pass through dense objects such as bone and rock.
The shadow and light images that are picked up are sent back to a computer which takes all the data and creates an accurate picture of the inside of the body and bone structure.
The Benefits
CAT scan machines take X-ray technology a few steps further. While X-rays can reveal a mass inside the human body, a 3-dimensional reading from a CAT scan can reveal the size, depth and exact location of the same mass. CAT scans take the guesswork and assumption out of medical diagnosis.
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