Geometry: New Tools for New Technologies: Hour 1: Unit 4: X-Ray Vision the CAT Scan

How is geometry used to program a robot's movement? How do zoo planners use geometry to make habitats that are enjoyable and safe? Why do people who plan garbage pickups and snowplow routes need geometry? Geometry: New Tools for New Technologies I and II explores the exciting world of Geometry in the 20th century.

Unit 4: X-Ray Vision the CAT Scan (14:23)

Summary of the Video

X-ray Vision: The CAT Scan, hosted by mathematician Larry Shepp (AT&T Bell Laboratories), shows the way mathematics has been involved with developing soft tissue x-rays for medical diagnosis. Against the backdrop of a story of helping a boy who has been hurt in a bicycle accident, the development of CAT scanners is explored. Key individuals involved were Roentgen, the physicist who accidentally discovered x-rays, and the mathematician Johann Radon, who solved a problem about recovering information about geometric objects by computing line sums. Radon was not thinking about medical imaging, but solving a mathematical puzzle. Only after the development of high-speed digital computers could physics, mathematics, and engineering concepts be put together to create a practical soft-tissue x-ray machine. A simple analogy to Radon’s work demonstrates using simple geometry and algebra, the intuitive ideas used for image reconstruction.

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