Reciprocity law in radiography definition

MPHY 502 Diagnostic Imaging Physics Part I

Lecture 5

Radiography Part 1

1. What is the magnification factor (mathematical Equation) of the diagram below?

2. What causes the partial volume artifact when taking plane x-rays?

3. How can one reduce the partial volume artifact?

4. When magnifying an object, it would seem like we should get better spatial resolution. What aspect of geometric magnification works against better resolution?

5. What is an intensifying screen (you will need to research this question)

6. What are the advantages and disadvantages of a thick intensifying screen?

7. Describe the process of reduction chemistry in film-based radiography.

8. How has x-ray quality improved since the inception. Give a brief history from 1895 to today. What do you think will happen in the next 125 years (1/8th of a millennium)?

9. How has dose to the patient and dose to the radiographer changed in the last 125 years?

10. What is Reciprocity Law Failure (Schwarzschild effect)?

11. What are the limits on the Reciprocity Law?

12. What are the 4 parts of film processing?

13. What is the function of “Fixer”?

14. What is the mathematical definition of “transmittance of light”?

15. Show how optical density of 3 = 0.1%

16. According to the Bureau of Standards what is the mathematical definition of overexposed?

17. According to the Bureau of Standards what is the mathematical definition of underexposed?

18. How does the H&D curve help us understand in Radiology?

19. In plain film radiography what are the tradeoffs of latitude. Be specific in terms of speed and dynamic range and dose. This question requires a thoughtful response.

20. What is computed radiography?

21. Name 4 steps in computed radiography excitation and emission.

22. How is the red laser light filtered out in a CR readout?

23. How are CCDs & CMOS devices different from CR devices?

24. What is a Quantum Limited Detector?

25. What is a Quantum Sink?

26. What is an x-ray Quantum Limited Detector and how might it be different than question 24?

27. Name 3 detector technologies.

28. What is TDI

29. What are the advantages of TDI?

30. What are the disadvantages of TDI?

31. What is the best thing about the CMOS detector?

32. Why would anyone want to use a TFT detector.

33. Name two important ways a TFT detector better than a CMOS detector?

34. Name two different types of TFT arrays

35. What are the pros and cons to the two different types of TFT arrays?

36. What is required (and should be on your spreadsheet check list) of every x-ray instrument?

37. What is a standard configuration for table top radiography? Make sure to discuss SID, etc..

38. What is AEC

39. Why are there typically more than one AEC detector in a chest Bucky?

40. What is a bucky?