X-ray, CT scans, and voxels are medical imaging techniques. X-rays use radiation to pass through objects, revealing internal structures. CT scans take multiple X-ray images from different angles and use computer processing to reconstruct voxels, or 3D pixels, creating a cross-sectional view inside the body. Voxels are volume elements that make up a 3D image. CT scans allow doctors to non-invasively see inside tissues and organs to diagnose and monitor medical conditions.

1. REMOTE SENSING: X-ray ,CT-Scan, Voxels Group 2 Rishab, Wattsuwach

2. X-ray Tube

3. Modern X-ray tube

5. The size of the aperture, produced by overlapping metal plates, through which the X-ray beam passes after leaving the tube

6. The use of a lead grid in front of the photographic film to absorb scattered X-ray photons

7. The variation with thickness x of an absorber of the percentage transmission of a parallel beam of X-ray radiation is illustrated

8. “Voxel”

9. Principles One area must have a difference in density. Computers can collect the information(density) to create a 3-D picture Pixel is a unit that tell you how much its dots per inch Target material

10. Reconstruction of Voxels 1 4 7 2

11. 5 +  9 +  1 4 7 2 5 5 5 9 9 9

12. 1 4 45°  + 1 7 2   11 2

13. 1 11 2 + 5 5  9 9 6 16 11 20

14. 6 8 6 16 1 4 11 20 + +  7 2   14 22 8 6 17 28

15. 4 3 7 + 4 1 4 14 22 3 17 28 7 7 2  17 26 20 35

16. Divide by 3 17 3 Deduct 14 26 12 1 4   20 35 6 21 2 7 Reconstruction of each pixel require millions of computations 7 4 = 14 + + 3 The 3-D image can be constructed through storing all the reconstructed pixel on the memory. Background Radiation

17. Comparison Old technologies X-ray film transparency Ultrasound Its application CT scan Used in medical work Used in the airport (destructive objects)

19. 2-D and it’s not consistentProcesses

20. Examples

21. Reference A Level Science Applications Support Booklet: Physics (University of Cambridge) http://www.nlm.nih.gov/medlineplus/ency/article/003330.htm http://www.radiologyinfo.org/en/info.cfm?PG=bodyct http://www.emedicinehealth.com/ct_scan/article_em.htm

22. Task Rishab Reconstruction of Voxel Slide preparation Watsuwach Principles of X-ray Applications and comparisons Ultrasound