This document summarizes radiation safety procedures in the cathlab. It discusses x-ray physics, imaging modes, and measures of radiation used to monitor patient irradiation. It describes the biological effects of radiation, including both stochastic and deterministic mechanisms. It provides recommendations to reduce radiation exposure through principles of justification, optimization and dose limitation. Specific techniques discussed include minimizing fluoroscopy time, increasing distance from the patient, using protective shielding, and new technologies to monitor and reduce radiation dose in the cathlab.

1. RADIATION SAFETY
in the
Cathlab
Dr Hafeesh Fazulu
DM Resident
PIMS

4. X-Ray Physics

5. Cinefluorographic System

8. Imaging Modes

9. Measures of Radiation

14. Measurement of Patient Irradiation

15. Biological Effects of Radiation
Radiation injuries by two main mechanisms :
1. Stochastic mechanism – DNA damage
2. Deterministic mechanism – direct cell death (tissue reactions)

16. 1. Stochastic mechanism - Cancer
• Risk increases with accumulated dose
• Dose is cumulative. “No Washout phenomenon”
• Most radiosentive organs – Lung, Breast, Colon,
,bladder, thyroid
• Females – more risk
• <30years – greater risk

17. 90 minutes of fluoroscopic time
Left side

18. Management of Skin Injury
“Mechanical protection “
Early identification
No Skin Biopsy

19. Bone Injury

20. Eye Injury

22. Radiation Protection

23. • Objectives of radiation protection is to prevent deterministic effect
and reduce the probability of stochastic effects
• Principles
• Justification
• Optimisation
• Dose limitation

24. Justification of the procedure
• Whether the use of radiation gives more benefits than risks
• “right test is done on the right patient for 1the right reason“
• Appropriate selection of patients for cardiac imaging is the first step
toward enhancing radiation safety

25. Optimisation
• Protection should be optimized in relation to
the
• magnitude of doses
• number of people exposed
• To keep it ‘as low as reasonably acceptable’ (ALARA)

26. Types of radiation
• Primary radiation: before interacting
• Scattered radiation: after at least one interaction
• Leakage radiation: not absorbed by the X Ray tube
housing shielding
• Transmitted radiation: emerging after passage
through matter

27. • Three basic consideration for protection
• Time
• Distance
• Shielding
Using appropriate shielding, keeping a distance as safely as possible
and reducing radiation time are essential for radiation reduction

28. Time
• Take foot off fluoro pedal if not viewing the screen (“heavy foot”)
• Use last image hold (freeze frame)
• Use pulsed fluoro instead of continuous fluoro

29. Distance
• The exposure to the individual decreases inversely
as the square of the distance
• Known as the inverse square law
• Stand as far away from the source as feasible
Distance
from Beam 1 step 2 steps 3 steps 4 steps
Relative
Exposure Rate 100 25 11 6

30. X-ray tube position
• The largest amount of scatter radiation is produced
where the x-ray beam enters the patient
• Position the X-ray tube under the patient not above
the patient
• Decrease the amount of scatter radiation that
reaches your upper body

31. Diagram of radiation scatter in the catheterization laboratory. Most
radiation scatter occurs through the patient’s body and is increased
with increasing angulations.

33. • Increased magnification increases the dose
• Increases the image receptor’s dose requirements,
potentially increasing patient dose and scatter

34. • So the x-ray tube should be below and straighter, low magnification
and the image intensifier closer for the least radiation

36. Sheilding
• Use of materials that absorb radiation
• Lead is used as a radiation shielding material as it has a high atomic
number
• Minimum thickness of lead equivalent in the protective apparel
should be 0.5mm

37. • Four aspects of shielding in diagnostic radiology
1. X-ray tube shielding
2. Room shielding
3. Personnel shielding
4. Patient shielding (of organs not under investigation)

38. X-ray tube shielding(source sheiding)
• The x-ray tube housing is lined with thin sheets of lead because x-rays
produced in the tube are scattered in all directions
• This shielding is intended to protect both patients and personnel from
leakage radiation

39. Room shielding
• At least 35 cm thickness to wall which primary x ray beam falls
• Atleast 23 cm for walls on which scattered x ray falls
• 1.7 mm lead or equivalent for doors and windows
• Walls and windows of control room should have 1.5mm lead or
equivalent and radiation should be scattered twice before entering
the control room

40. Personal shielding
• Protective garments must be worn by all persons who are in the
procedure room
• These garments are designed to protect the gonads and 80% of the
active bone marrow
• The standard is a 0.5-mm lead apron, which stops ~95% of the scatter
radiation
• Further eye protection can be obtained by placing the TV monitor 60°
to the right of the operator

50. Patient sheilding
• Recommended that the thyroid and gonads be shielded, to protect
these organs especially in children and young adults
• Lower abdomen shielding for pregnant women

51. Dosimetry
• Refers to the monitoring of individuals who are
exposed to radiation during the course of their work
• Data from the dosimeter are reliable only when
the dosimeters are properly worn, receive proper
care, and are returned on time
• Radiation measurement is a time-integrated
dose i.e. for a fixed time like 6 months
• Institutional enforcement of the personnel dose
monitor policy establishes a safer environment

52. • Dosimeters are different types
• Pocket dosimeter
• Thermoluminescent dosimeter(TLD)

53. Thermoluminescent dosimeter (TLD)
• Thermo luminescence is the property of certain materials to emit
light when they are stimulated by heat
• Materials such as lithium fluoride (LiF), lithium borate (Li2B4O7),
calcium fluoride (CaF2), and calcium sulfate (CaSO4) have been used
to makeTLDs

54. • The measurement of radiation from a TLD is a two step procedure
• In step 1, the TLD is exposed to the radiation
• In step 2, the LiF crystal is placed in a TLD analyzer, where it is
exposed to heat producing light

55. Newer technologies to reduce radiation
exposure
1. Monitoring Dose in Real Time
• real-time display of radiation levels
• Can note when radiation spike is
happening
• Eg: RaySafe i2 system
• Teams can all see their personal
radiation exposure shown on an
overhead screen in the lab
• colored indications (red, yellow, green)
to give each individual user insight
2. Increased Shielding Without the
Weight

56. 3. Robotic Systems to
Remove Staff From the
Radiation Field
• Eg:Corindus Corpath
robotic PCI, Hansen Sensei
Robotic System, Stereotaxis
4. Angiography System
Advances - Reduce Dose
• improved X-ray tubes, more
sensitive detectors, and
software

57. 5. Lightweight Aprons and Anti-X-ray Hand Cream
• X-ray shielding aprons for the cath lab composed of bismuth
• half the weight of lead and provide 0.5 mm lead equivalent protection
• Can be folded and bent, machine washable
• FDA-cleared X-ray attenuating hand cream
• applied prior to donning gloves

58. THANK YOU