11. RADIATION HEALTH EFFECTS: FILTRATION ON THE X-RAY BEAM

Question 1

1. What is mass proportional to?

Answer 1

• the number of photons in the X-Ray beam

Question 2

2. What does the X-Ray beam pass through in the process of leaving the X-ray Tube?

Answer 2

• it passes through certain components of the tube
• these are collectively called the Inherent Filtration

Question 3

3. What is the Inherent Filtration made up of?

Answer 3

1. The glass or ceramic envelope which maintains the
   vacuum
2. The cooling oil
3. The window of the X-Ray Tube
   • this is usually make of Beryllium

Question 4

4. What is the Inherent Filtration measured in?

Answer 4

• it is measured in Aluminium Equivalents (mm Al)
• the thickness of the Aluminium would produce the same
  degree of attenuation as the thickness of the material in
  question

Question 5

5. What kind of added filtration does every X-Ray tube have?

Answer 5

• every X-Ray tube has external or added filtration
• this helps to remove lower energy
• this removes the softer X-Rays from the beam

Question 6

6. Why do we want to remove the low energy photons?

Answer 6

DUE TO THE PHOTOELECTRIC EFFECT:
- low energy photons will be absorbed by the human body
- this will decrease the patients radiation protection

Question 7

7. What are the added/external filters made of?

Answer 7

• Aluminium
• this will be used with the diagnostic range of the X-Ray
  energies

Question 8

8. Why do we use Aluminium?

Answer 8

• it has a low atomic number
• it will be more likely to absorb or scatter the low energy
  photons

Question 9

9. What can be said about low energy X-Rays?

Answer 9

• they have sufficient energy to increase patient radiation
  doses
• they do not have enough energy to contribute to the
  radiographic image formation

Question 10

10. Which material is a better filter for high energy radiation?

Answer 10

• Copper

Question 11

11. What does the amount of filtration added depend on?

Answer 11

• it depends on the maximum generating voltage of the
  tube
• it is usual to have between 1.5mm - 2 mm of filtration

Question 12

12. What are three important effects of Filtration?

Answer 12

1 . The process of filtration does not affect the E-Max

2. The intensity of the beam will be decreased
   (less photons)
3. The average energy of the beam will increase

Question 13

13. What can be said about Beam quality?

Answer 13

• it is proportional to the filtration
• beam intensity is inversely proportional to the filtration

Question 14

14. Which organisation determines Quality Assurance for Radiation exposure?

Answer 14

• the Council Directive 2013/59/EURATOM

Question 15

15. What does Quality Assurance revolve around?

Answer 15

• it revolves around all the planned and symmetric actions
• that are necessary to provide adequate assurance
• that a structure, component or procedure will perform
  satisfactorily in compliance with the agreed standards

Question 16

16. What else is a part of Quality Assurance?

Answer 16

• Quality Control

Question 17

17. What is Quality control?

Answer 17

• it is the set of operations intended to maintain or to
  improve quality

THESE OPERATIONS INCLUDE:
- programming
- coordinating
- implementing

WE CAN MAINTAIN OR IMPROVE QUALITY BY:
- monitoring
- evaluation
- maintenance
- at required levels of all the characteristics of the
equipment performance

THESE LEVELS OF EQUIPMENT PERFORMANCE CAN BE:
- defined
- measured
- controlled

Question 18

18. What does Article 61, Paragraph 1 of the Council Directive state?

Answer 18

Question 19

19. What is Quality Control used for?

Answer 19

• it is the process of managing the quality
• it is the inspection of the implemented techniques and
  activities
• it ensures that they are fulfilling the requirements for
  quality

Question 20

20. What is Quality Assurance used for?

Answer 20

• it is used to verify the quality of the output
• it looks after all the planned activities that can be
  demonstrated to provide confidence that a product of
  service will fulfil requirements for quality

Question 21

21. What is the Quality Management System used for?

Answer 21

• all the organisational processes that ensure quality

Question 22

22. What kind of Quality Assurance protocols for equipment using ionising radiation are available?

Answer 22

1. THE IPEM REPORT 91:
   - this recommends the standards for the routine
   performance testing of diagnostic X-Ray imaging
   systems
   - it is one of the most comprehensive QA Protocols
   - it specifies a lot of tests that need to be done in order
   to comply with European and International Legislation

Question 23

23. List the components of the X-Ray mechanisms that are tested by the IPEM Report 91 tests?

Answer 23

1. X-Ray Tubes
2. Generators
3. Film/screen Radiography processors
4. AEC Devices
5. Computed Radiography (CR)
6. Direct Digital Radiography (DDR)
7. Image Display and hardcopy devices
8. Mammography
9. Dental Radiography
10. Fluoroscopy
11. Fluorography
12. Computed Tomography
13. Patient Dose Management

Question 24

24. List the times at which the IPEM Report 91 tests can be done?

Answer 24

1. At the time of equipment delivery
   (this is when the acceptance testing is done by a medical physicist)
2. Weekly
   (done by the Radiographer)
3. Monthly
   (done by the Radiographer)
4. Every three months
   (Medical Physicist)
5. Every Six Months
   (Medical Physicist)
6. Once a year
   (Medical Physicist)
7. After any service
   (Medical Physicist)

Question 25

25. List the specialised equipment needed to perform the IPEM Report 91 Tests?

Answer 25

1. X-Ray Multimeters
2. Precision Dosimeters
3. mAs meters
4. Survey Meters
5. X-Ray rulers
6. Test Phantoms
7. Filters