Computerized Axial Tomography (CAT)

SCANS

By Abby Jeffers And

James Kloss

Before CAT Scans The problems with x-rays: X-ray radiographs offer only a two-

dimensional image In a radiograph, a 3-D mass becomes a

2-D image and it is hard to tell individual tissues apart

It is difficult to determine which bones and tissues are overlying and which are underlying

Development of CAT Scans • Godfrey Hounsfield and Allan

Cormack are credited as the inventors of the CAT scan

• Cormack developed the theoretical principals behind reconstructing 2-dimensional images into one 3-D image

• Hounsfield was the designer and builder of the first CAT scan machines

Evolution of the CAT scan • First-generation CAT

scanners had one x-ray source and one detector, which rotated around the patient

• Today, fifth-generation scanners have detectors and x-ray tubes that are switched on one at a time all around the patient.

What do they scan for in the body

• CAT scans internal organs, bones, soft tissue, and blood vessels.

• CAT scans provide better clarity than X-rays and reveals more important details than X-rays too.

How do they work

• In many ways CAT scans work very much like any other X-ray examination devices.

• In conventional X-rays small burst of radiation are aimed a the body and shot through the body.

• The result if a image that is recorded on photographic film or a special image recording plate.

How do they work 2

• Now CAT scans are very similar to X-rays because in a CAT scan there are numerous X-rays that rotate around A

• At the same time the X-rays are shooting beams of radiation that is being received by X-ray detectors on the opposite side of the patient.

• At the same time the examination table that you are laying on moves in and out of the machine.

• The movement of the table creates a spiral path for the X-ray beam to follow.

How do they work 3

• The CAT scan shoot X-ray beams at every angle for 360 ° around the body.

• A special computer process this large amount of data and produces a 2-D cross section of the human body.

• This technique is called Helical or Spiral CAT

Benefits of CAT scan

• It is painless, noninvasive, and very accurate.• CAT scans can provide information on bone,

soft tissue, and blood vessels all at the same time.

• Fast and simple • Provides real time imaging • No radiation remains in patients body after

CAT scan.

Risks of CAT scans

• Slight chance of cancer from excessive exposure to radiation.

• Pregnant women should not use CAT scans unless needed to because of the potential risk to the baby.

• Children should not have too many CAT scans because they are more sensitive to radiation.

What they look like

• CAT scans are typically a large box like machine with a hole or a short tunnel in the center.

• There is a examination table that slides into and out of the tunnel.

• The computer workstation the process information from the scan is located in a separate room.

Works Cited

• http://www.asnt.org/publications/materialseval/basics/may00basics/may00basics.htm

• http://www.aps.org/publications/apsnews/200411/history.cfm

• http://www.radiologyinfo.org/en/info.cfm?pg=bodyct#part_one

• http://www.mayfieldclinic.com/pe-ct.htm