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Introduction of Computed Tomography. James Chang. History of CT. Radon-Nikodym theory of Johann.Radon G.N.Huunsfeild invented CT in 1972 Nobel Prize in Physiology or Medicine 1979. The generation of CT. Translate-Rotate 1 st : pencil beam X-ray and single detector
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Introduction of Computed Tomography James Chang
History of CT • Radon-Nikodym theory of Johann.Radon • G.N.Huunsfeild invented CT in 1972 • Nobel Prize in Physiology or Medicine 1979
The generation of CT Translate-Rotate • 1st : pencil beam X-ray and single detector • 2st:pencil beam X-ray and mutidector (30) Rotate-Rotate • 3st:fan beam X-ray and mutidector (300-800) Stationary-Rotate • 4st:fan beam X-ray and ring detector(1000-2400) • 5st electronbeam (50ms)
4th Helical CT http://www.virtualmedicalcentre.com http://www.imaginis.com/ct-scan/how-does-ct-work
CT from 1st to 4th generation • Original axial CT image from the dedicated Siretom CT scanner circa 1975. This image is a coarse 128 x 128 matrix
Sinogram A visual representation of the raw data obtained in a computed axial tomography (CAT) scan. http://www.physics.ubc.ca/~mirg/home/tutorial/fbp_recon.html
Filtered Back Projection Without filterPoint object becomes widely spread out
Why do we Apply a Filter ? • Another diagram that illustrates this concept
From Sinogram to Image Video: http://www.youtube.com/watch?v=kMMyvQF-CYQ&NR=1