Why do they inject dye for a CT scan?

Related questions

1. What does a CT scanner cost?
2. What is a 32 slice CT scanner?
3. What is slice thickness in CT scanning?
4. Can I drink water before CT scan with contrast?
5. What is the fastest CT scanner?
6. What does a CT scan of abdomen with contrast show?
7. How much does a 64 slice CT scan cost?
8. Why is CT called CAT scan?
9. Can you drive after a CT scan?
10. What is a CT scan used for?

Tags

1. #contrast
2. #parts
3. #fluid
4. #vessels
5. #scans
6. #intravenous
7. #helps
8. #always
9. #blood
10. #called
11. #special
12. #clearly
13. #before
14. #immediately
15. #usually
16. #liver
17. #injected
18. #clear
19. #kidneys
20. #injection