1. FOR IMAGING PROFESSIONALS
Radiation Safety
&
Protection
FOR IMAGING PROFESSIONALS

2. RADIATION
PROTECTION

3. Objectives
Be able to discuss dose limits and typical doses during different radiological procedures
Be able to explain the relative risks of radiation
Have a knowledge of how to reduce radiation doses, especially to yourselves

15. Over one year

17. RADIOGRAPHIC UNITS
&
IMAGING TERMINOLOGY

18. Exposure measured in C/kg or Roentgen(R)
amount of charge (electrons) liberated per kilogram of Air (Ionization)
1R = 2.58x10-4 C/Kg

19. ABSORBED DOSE measured in Gray (Gy) or Rad
amount of energy deposited/ absorbed per kilogram of tissue
1Gy = 1 Joule/Kg
100 Rad = 1 Joule/Kg
1Rad = 1/100 Gy

20. EFFECTIVE DOSE - measured in Sieverts (Sv) or Rem
- amount of biological damage
- gives a measure dose as if received by the whole body
- used to equate dose to risk
1Sv = 1 Joule/Kg
100 Rem = 1 Joule/Kg
1Sv = 1/100 Rem

21. BONE MARROW DOSE (mRad)
Typical Doses During
Radiographic Exams
EXAM
BONE MARROW DOSE (mRad)
Gonadal Dose (mRad)
Male
Female
Skull 10
<1
C-Spine 20
Chest 2
Abdomen 30
100
200
L-Spine 60
175
400
Pelvis
300
150
Extremity

22. Typical Doses During Radiographic Exams
Technique
Dosage
Typical
mammography exam
30mRem
Chest
100mAs
360mRem
20mAs
70mRem
Abdomen
160mAs
1000mRem
During regular CT breast gets
700mRem
Low dose mammography
160mRem
Generally 1 CT exam is equivalent to 20 mammos

23. Summary of the National Council on Radiation Protection & Measurements
OCCUPATION EXPOSURE
1. Effective Dose Limits.
a. Annual
50mSv
5 rem
b. Cummulative
10mSv x age
1 rem x age
2. Equivalent Dose Annual Limits for Tissues and Organs
a. Lens of the eye
150mSv
15 rem
b. Localized area of the skin, hands and feet.
500mSv
50 rem

24. Summary of the National Council on Radiation Protection & Measurements
PUBLIC EXPOSURE (Annual)
1. Effective dose limits, continuos or frequent exposure.
1 mSv (0.1 rem)
2. Effective dose limits, infrequent exposure
5 mSv (0.5 rem)
3. Equivalent Dose Annual Limits for Tissues and Organs
a. Lens of the eye
15mSv (1.5 rem)
b. Localized area of the skin, hands and feet.
50mSv (5.0 rem)
4. Negligible individual dose (annual)
0.5 mSv (0.05 rem)

25. Radiographic Examinations
Typical Doses during
Radiographic Examinations

26. SOURCES OF RADIATION

27. SOURCES OF RADIATION

28. SCATTER RADIATION

29. PEDIATRICS
More radiosensitive than adults due to sensitive cells and developing organs
Gonad shielding important
Radiographic examinations difficult:
Patient movement
Exposure technique more critical

30. Typical Fluoroscopy
Equipment setup

36. Biological Effects of
Ionizing Radiation

37. Effects of Ionizing Radiation

38. HUMAN RESPONSES TO IONIZATION RADIATION
Acute Radiation Syndrome
Hematologic Syndrome
Gastrointestinal syndrome
Central nervous system
Local Tissue damage
Skin
Gonads
Extremities
Hematologic depression
Cytogenic damage
EARLY EFFECTS

39. HUMAN RESPONSES TO IONIZATION RADIATION
Acute Radiation Syndrome
Hematologic Syndrome
Gastrointestinal syndrome
Central nervous system
Other malignant disease
Bone cancer
Lung cancer
Breast cancer
Leukemia
Genetically significant dose
Lifespan shortening
LATE EFFECTS

40. Effects of Ionizing Radiation
Photograph of the patient’s
back 6-8 weeks after multiple coronary
angiography and angioplasty procedures.
Photograph of the injury weeks after
the procedures. A small ulcerated area is
present.

41. Effects of Ionizing Radiation
Photograph of the patient’s back months
after the procedures. Tissue necrosis is evident
Close-up of the lesion shown in C

42. Effects of Ionizing Radiation
Photograph of the patient’s
back after Grafting.

43. Effects of Ionizing Radiation

44. The probability of occurrance, but not the severity of
Stochastic Effects of
Ionizing Radiation
The probability of occurrance,
but not the severity of
the effect depends upon dose

45. cancer birth defects genetic effects Stochastic Effects of
Ionizing Radiation
cancer
birth defects
genetic effects

46. Effects of Ionizing Radiation
Based upon studies of Hiroshima atomic bomb survivors, statisticians predict that an effective dose of 10 mSv (1 rem) given to a population of one million would
result in 400 additional cancer deaths!

47. Effects of Ionizing Radiation
Radiogenic cancers have a year latency period
Radiologists during the first half of the twentieth century discovered this the hard way

48. As Low As Reasonably Achievable.
A.L.A.R.A. policy
Radiation exposure of personnel
and the general public should be kept
As Low As Reasonably Achievable.

49. A.L.A.R.A. policy correct exposure factors
correct radiographic technique
appropriate radiation protection
appropriate development/viewing techniques
appropriate radiographic positions for examination
minimize repeat examinations
continuing education

50. performing fluoroscopy
Qualifications for
performing fluoroscopy
Only a physician or a registered
x-ray technologist under the direct
supervision of a physician may
perform fluoroscopy.

51. Radiation Protection Staff
3 Basic Categories
Time
Distance
Shielding

52. General Radiation Safety
Reduce of your exposure
Increase from the source
Make use of available
TIME
DISTANCE
SHIELDING

53. Time minimize time in radiography or fluoroscopy rooms
minimize time spent with patients who are undergoing therapy treatment eg. nuclear medicine procedures, radioactive implants
Know Your Protocol
Read the procedure through carefully
Understand the steps clearly or
Have the protocol displayed where you can see it
Practice the technique beforehand

54. This is the Inverse Square Law.
Distance
The distance between you and the isotope is of paramount importance for high energy emitters and penetrating radiations.
The intensity of radiation at different distances is represented by the formula:
This is the Inverse Square Law.

55. The Inverse Square Law.

56. The Inverse Square Law.

57. Distance
Inverse Square Law - double the distance from the source of radiation - reduce dose by a factor of 4
General rule - 3 meters (approximately 10 ft) from the source of radiation - dose is insignificant

59. to patients and personnel
Methods to reduce dose
to patients and personnel
Fluoro only when viewing monitor
Use pulsed fluoroscopy when possible
Use last image hold

60. Shielding Personal shielding
lead aprons - at least 3 - 5mm Pb equivalent provide up to 90% shielding.
thyroid / eye shielding during fluoroscopy
lead glove (5mm + Pb eq.) if hands are likely to be in the beam
Lead drape on fluoro tower provides an additional 90% protection of the remaining 10% from lead aprons above.

61. Shielding
Protective barriers
lead glass / acrylic for windows, lead sheets in doors or plaster board walls, brick walls
minimize directing primary beam at widows / doors
best position to be located during x-ray exposure

62. RADIATION MONITORING BADGES
State law requires that, during fluoroscopy, one badge must be worn outside the apron at the collar level.
Some institutions provide additional badges, usually upon request during pregnancy

64. RADIATION MONITORING BADGES
Badge readings are reviewed regularly by the RSO
Institutional investigation levels are set below regulatory limits
Personnel are notified regularly and badge readings are posted

65. HEMATO-LYMPHOPOIETIC
HIROSHIMA AND NAGASAKI
CASE STUDY ON EFFECT OF IONIZATION RADIATION
Incidence
Mortality
ALL TUMORS
 Total (%)
9.014 (100%)
5859 (100%)
SOLID TUMOR TOTAL
95.5
8612
5529
Digestive system
53.2
4796
3534
Respitory system
11.4
1027
828
Female Breast
5.9
529
141
Female Genitals
9.9
891
402
Male Genital
1.8
160 68
Other solid cancers
13.3
1209
556
HEMATO-LYMPHOPOIETIC
4.5
330

66. Common sources of radiation for the general population
1,300 Radiation dose, in millirems (mrem), from a single full-body computed tomography (CT) scan
1.5 Miles Distance you’d need to have been from the Hiroshima atomic explosion to receive an equivalent dose
29 Radiation dose, in mrem, from smoking a pack of cigarettes
300 Average annual radiation dose from natural sources, in mrem, per person in the U.S.
1 Average annual radiation dose, in mrem, from eating one or two bananas a week
0.08% Increase in risk of death from cancer after a full-body CT scan
3.75% Increase in risk of death from cancer if you receive a full-body CT scan annually starting at age 25
57 MILLION Number of full-body CT scans performed in 2003
$16 BILLION Estimated annual cost of unnecessary diagnostic imaging
7 Percentage of patients informed of the risks of their CT scans
Sources: American College of Radiology, David J. Brenner/Columbia University Medical Center,
U.S. Food and Drug Administration, David C. Levin/Thomas Jefferson University Hospital, National
Institutes of Health, Nuclear Energy Institute, Yale University School of Medicine

67. REMEMBER
Protect YOURSELVES
and
the PATIENTS

69. REFERENCES
1990 Recommendations of the International Commission on Radiological Protection, ICRP Publication 60, Permagon Press, Oxford
Brennen S.E. and Putney R.G., eds (1983) Dose reduction in diagnostic radiology, The Hospital Physicist’s Associtaion Plaut S., (1993) Radiation protection in the x-ray department, Butterworth-Heinemann, Oxford
Bushong S.C., (2004) Radiological science for technologists: Physics, Biology and Protection, 8th Ed. Mosby, St Louis
Faulkner K. and Wall B.F., eds (1988) Are x-rays safe enough? Patient dose and risks in diagnostic radiology, The Institute of Physical Science in Medicine, Report No. 55
Norris, Teresa G., Radiation Safety in Fluoroscopy. Radiologic Technology. Vol 73 No 6, August 2002, 511
Seeram E., (1997) Radiation protection, Lippincott, Philadelphia
Sherer, Mary Alice., Visconti, Paul J., Ritenour, Russell.,(2002) Radiation Protection in Medical Radiography, 8th Ed. Mosby, St Louis.
Web D.V., Solomon S.B. and Thomson J.E.M., (1999) Background radiation levels and medical exposure in Australia, Radiation Protection in Australia, Vol 16 No 2 pp.25-32