CAT scans were developed to address limitations of x-rays in providing only 2D images that made differentiating tissues difficult. Godfrey Hounsfield and Allan Cormack invented the CAT scan, with Cormack developing the theoretical principles and Hounsfield building the first machines. Modern CAT scans have detectors and x-ray tubes that rotate around the patient to provide 3D images of internal organs, bones, soft tissue, and blood vessels with greater clarity than x-rays. CAT scans work by emitting x-rays from multiple angles that are detected and processed by a computer to construct 2D cross sections.

1. Computerized Axial Tomography (CAT) SCANS By Abby Jeffers And James Kloss

2. 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

3. 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

4. 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.

5. 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.

6. 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.

7. 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.

8. 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

9. 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.

10. 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.

11. 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.

12. 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