1. Introduction of Computed Tomography
James Chang

2. History of CT Radon-Nikodym theory of Johann.Radon
G.N.Huunsfeild invented CT in 1972
Nobel Prize in Physiology or Medicine 1979

3. 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 ( )
Stationary-Rotate
4st:fan beam X-ray and ring detector( )
5st electronbeam (50ms)

5. 4th Helical CT http://www.virtualmedicalcentre.com

6. CT from 1st to 4th generation
Original axial CT image from the dedicated Siretom CT scanner circa This image is a coarse 128 x 128 matrix

7. Data Acquisition

8. Sinogram
A visual representation of the raw data obtained in a computed axial tomography (CAT) scan.

9. Sinogram

10. Filtered Back Projection

11. Sinogram 1 2 15 3 15 1 2 15 3 15 1 2 15 1 13 3 15 1 2 15 3 15

12. Filtered Back Projection1 5 2 6 10 1 2 15 3 15 1 2 15 3 7 15 8 20 3 15 1 2 15 3 15 9 13 25 10 14 30 1 2 15 3 15

13. Filtered Back Projection11 15 35 16 40 1 2 15 3 15 1 2 15 3 15
Without filter Point object becomes widely spread out 1 2 15 3 15 1 2 15 3 15

14. Why do we Apply a Filter ?
Another diagram that illustrates this concept

15. From Sinogram to Image
Video:

16. Thank you