1. Examples of Good & Bad Practice: Effect of the wedge filter and field size in the skin dose distribution
L 9.1

2. Educational Objectives
How wedge filter & field size affect the skin dose
When and how to use wedge filter
Lecture 9.1: Examples of good and bad practice

3. Lecture 9.1: Examples of good and bad practice
Philips systems
Lecture 9.1: Examples of good and bad practice

4. Lecture 9.1: Examples of good and bad practice
Series 14:
KVP: 88
Distance source to detector: 1048
Exposure time 8
X-ray tube current 467
Intensifier size mm
Positioner primary angle 5.2 (LAO)
Positioner secondary angle 28.3
13 Sep 04; 40414
Example of lack of wedge filter use in a left projection. Image quality is not good (too bright in the upper left corner of the image) and in addition, more dose per frame than necessary. Bad practice!.
Lecture 9.1: Examples of good and bad practice

5. Lecture 9.1: Examples of good and bad practice
Series 21:
KVP 87
Distance source to detector 995
Exposure time 8
X-ray tube current 472
Positioner primary angle
(RAO)
Positioner secondary angle 28.8
13 Sep 04; 40414
Example of lack of wedge filter use in a right projection. Image quality is not good (too bright in the upper right corner of the image) and in addition, more dose per frame than necessary. . Bad practice!.
Lecture 9.1: Examples of good and bad practice

6. Lecture 9.1: Examples of good and bad practice
Series : 6
(0008,0020) : Study Date : 21/09/2004
(0008,0080) : Institution Name : HOSPITAL SEVERO OCHOA
(0008,1090) : Manufacturer's Model Name : INTEGRIS Allura Flat Detector
(0018,0060) : KVP : 78.0
(0018,1110) : Distance Source to Detector : 1.08
(0018,1111) : Distance Source to Patient : (?)
(0018,1150) : Exposure Time : 6
(0018,1151) : X-ray Tube Current : 812
(0018,1510) : Positioner Primary Angle : -31.2
(0018,1511) : Positioner Secondary Angle : 32.2
Example of appropriate use of the wedge filter. (flat panel). Good practice!.
Lecture 9.1: Examples of good and bad practice

7. Lecture 9.1: Examples of good and bad practice
No wedge filter used. Image partially saturated.
Bad practice!.
Lecture 9.1: Examples of good and bad practice

8. Lecture 9.1: Examples of good and bad practice
0.5 mGy/fr
0.8 mGy/fr (60% more)
Lecture 9.1: Examples of good and bad practice

9. Use of wedge filter in right projections

10. Lecture 9.1: Examples of good and bad practice
Effect of the wedge filter in skin dose distribution (right projections). Saving skin dose and improving image quality. Good practice!.
Lecture 9.1: Examples of good and bad practice

11. Lecture 9.1: Examples of good and bad practice

12. Lecture 9.1: Examples of good and bad practice
Areas in red are saturated in the slow film. Skin dose more than 1.2 Gy.
Lecture 9.1: Examples of good and bad practice

13. Philips Integris: Use of wedge filter in left projections

14. Lecture 9.1: Examples of good and bad practice
Effect of the wedge filter in skin dose distribution (left projections). Saving skin dose and improving image quality. Good practice!.
Lecture 9.1: Examples of good and bad practice

15. Lecture 9.1: Examples of good and bad practice

16. Lecture 9.1: Examples of good and bad practice
Areas in red are saturated in the slow film. Skin dose more than 1.2 Gy.
Lecture 9.1: Examples of good and bad practice

17. Use of wedge filter in right and left projections

18. Lecture 9.1: Examples of good and bad practice

19. Lecture 9.1: Examples of good and bad practice

20. Lecture 9.1: Examples of good and bad practice
Areas in red are saturated in the slow film. Skin dose more than 1.2 Gy.
Lecture 9.1: Examples of good and bad practice

21. Geometry with small field size

22. Lecture 9.1: Examples of good and bad practice

23. Lecture 9.1: Examples of good and bad practice
68 cm2
28 cm2
26 cm2
Lecture 9.1: Examples of good and bad practice

24. Lecture 9.1: Examples of good and bad practice
Areas in red are saturated in the slow film. Skin dose more than 1.2 Gy.
Lecture 9.1: Examples of good and bad practice

25. Geometry with big field size

26. Lecture 9.1: Examples of good and bad practice

27. Lecture 9.1: Examples of good and bad practice
1.2 Gy
113 cm2
0.6 Gy
41 cm2
Lecture 9.1: Examples of good and bad practice

28. Lecture 9.1: Examples of good and bad practice
Areas in red are saturated in the slow film. Skin dose more than 1.2 Gy.
Lecture 9.1: Examples of good and bad practice

29. No wedge filter used. Geometry with big radiation field size
No wedge filter used. Geometry with big radiation field size. Overlapping of radiation fields could occur.

30. Lecture 9.1: Examples of good and bad practice

31. Lecture 9.1: Examples of good and bad practice
319 cm2
234 cm2
91 cm2
Lecture 9.1: Examples of good and bad practice

32. Lecture 9.1: Examples of good and bad practice
Areas in red are saturated in the slow film. Skin dose more than 1.2 Gy.
Lecture 9.1: Examples of good and bad practice

33. Lecture 9.1: Examples of good and bad practice
Patients who had multiple coronary angiographies and who underwent more than four PTCAs PTCAs performed during 14 years was analysed.
14 patients were included in the study. Each patient had undergone between 4 and 14 coronary angiographies and between 5 and 10 PTCAs, performed over a period of 2-10 years.
Lecture 9.1: Examples of good and bad practice

34. Lecture 9.1: Examples of good and bad practice
Mean values of maximum skin dose per procedure were 217 mGy for the diagnostic studies and 391 mGy for the PTCAs.
Only a slight radiation skin injury was clinically demonstrated in one patient with a history of 10 coronary angiographies and 10 PTCAs (estimated maximum skin dose 9.5 Gy).
Lecture 9.1: Examples of good and bad practice

35. Lecture 9.1: Examples of good and bad practice
CONCLUSION:
IC procedures performed on modern X-ray systems under QA programmes and by cardiologists trained in RP, repetition of procedures is not the main cause of possible skin radiation injuries.
Lecture 9.1: Examples of good and bad practice