1. RT 123 INTRODUCTION & Review of Radiation Protection (Merrills Ch. 2)
WK #3

8. MARIE & PIERRE CURIE 1898 “NAMED RADIOACTIVITY”
DEVELOPED A RADIATION DETECTOR
1914 (WW1) DEVELOPED A MOBILE RADIOGRAPHY X-RAY “CAR” TO TAKE XRAY IN THE BATTLE FRONTS
TRAINED 150 “TECHNICIANS” TO OPERATED CARS

11. Early measurement of Radiation
Skin dryness & erythema
AKA radiodermatitis
Ulcers formed
Cataracts
Cancers

14. DIAGNOSTIC RADIOLOGY STATIC – STILL SHOTS DYNAMIC XRAYS IN MOTION
FLUOROSCOPY

18. STANDARD VS SI UNITS
R C/kg
Rem - Sievert
Rad - Gray

22. 100 R = 1 C/kg 1Rad = 1/100 Gray 1 Rem = .01 Sievert (Rad + QF = REM)
measurement
100 R = C/kg
1Rad = 1/100 Gray
1 Rem = .01 Sievert
(Rad + QF = REM)
1 REM = 10 mSv
1 Rem = 1000mRem

23. How dangerous the type of radiation is
Quality Factor
How dangerous the type of radiation is
Alpha + fast neutrons = 20
X-ray, Beta, Gamma . = 1

24. REM
IS A PRODUCT OF THE
QF x RAD

25. Why did the bunny die?? BUNNY A Received 200 rads BUNNY B

26. Why did the bunny die?? BUNNY A 200 rads of X-RAY = 200 RADS BUNNY B
200 rads of alpha =
4000 rads

28. Permissible Occupational Dose
Annual dose:
5 Rem / year 50 mSv / year
Cumulative Dose
1rem x age mSv X age

29. Occupational Dose ANNUAL LIMITS
WHOLE BODY = 5 REMS / 5000mRem
LENS OF THE EYE = 15 REMS
EXTREMITIES = 50 REMS

30. OCCUPATIONAL EXPOSURES
5 REMS / YEAR
BUT NOT TO EXCEED 1.25 REM/QUARTER
AVERAGE ACTUAL EXPOUSRE IS APPROXIMATELY 50 mrem/year
OLD “MPD 5(Age – 18)”

31. PUBLIC EXPOSURE 10 % OF OCCUPATIONAL NON MEDICAL EXPOSURE
.5 RAD OR 500 MRAD
UNDER AGE 18 AND STUDENT
.1 rem mSv
Pg 98 RTA BOOK

33. CARDINAL RULES OF RADIATION PROTECTION
TIME
DISTANCE
SHIELDING

36. ROOM SHIELDING PRIMARY SHIELD – PRIMARY BEAM DIRECTED AT WALL
1/16 LEAD FEET HIGH

37. ROOM SHIELDING SECONDARY – NO PRIMARY BEAM 1/32 LEAD
CONTROL BOOTH (SECONDARY)
BEAM SCATTERS 2X BEFORE HITTING
LEAD WINDOW – 1.5MM LEAD EQ

38. MONITORING
CONTROLLED AREA – Used by occupationally exposed personnel (monitored)
100mrem / WEEK
UNCONTROLLED AREA – PUBLIC
2 mrem per week*

39. SHEILDING TECHNOLOGIST . 25 mm LEAD LEAD APRON, GLOVES
THYROID SHIELD, GLASSES
PATIENT –
GONAD SHEILDING
. 5 mm LEAD

40. GONAD SHIELDING MUST BE . 5 MM OF LEAD
MUST BE USED WHEN GONADS WILL LIE WITHING 5 CM OF THE COLLIMATED AREA (RHB)
KUB. Lumbar Spine Pelvis
male vs female shielding

41. TYPES OF SHEILDING
FLAT /CONTACT
SHAPED
SHADOW

56. Personnel Monitoring Devices
Film Badges
TLD / POSL
Pocket Dosimeter
Ring Badge

60. MEASUREMENT FILM BADGE TLD POSL POCKET DOSIMETER ABOVE 10 MREM
NOT ACCURATE

61. REM
IS A PRODUCT OF THE
QF x RAD

63. Pregnancy & Embryo
Mother –
occupational worker (5 rem)
Baby – (500 mRem)
.5 rem/ year rem/month
5 mSv mSv / month

64. Declared Pregnant Worker
Must declare pregnancy – 2 badges provided
1 worn at collar (Mother’s exposure)
1 worn inside apron at waist level
Under 5 rad – negligible risk
Risk increases above 15 rad
Recommend abortion (spontaneous) 25 rad
(“Baby exposure” approx 1/1000 of ESE)

65. Pregnant patient ALWAYS ASK LMP before exposure made
“10-day Rule” No longer used
“Grace period” of implantation
STATE – Beam 5 cm within gonads

66. PREGNANT PATIENTS ASCERTAIN LMP - IF FETUS IS EXPOSED
PHYSICSTS WILL NEED INFORMATION:
WHICH XRAY MACHINE USED (MR/MAS)
# OF PROJECTIONS (INC REPEATS)
TECHNIQUE FOR EACH EXPOSURE
SID
PATIENT MEASUREMENT AT C/R
FLUORO TIME & TECHNIQUE USED
PHYSICIST WILL CALCULATE FETAL DOSE

69. RADIATION DOSE TO PATIENTS
ESE - ENTRACE SKIN EXPOSURE (MEASURED BY A TLD)
SKIN DOSE
GONADAL DOSE
BONE MARROW DOSE
(MEAN GLADULAR DOSE- MAMMO)

70. AP VS PA EXPOSURE/ESE

74. SOMATIC & GENETIC STOCHASTIC VS NON STOCHASTIC
A = STOCHASTIC
“CHANCE” EFFECTS
GENETIC, LEUKEMIA, CANCER
DIAGNOSTIC RADIOLOGY
B= NON-STOCHASTIC
THRESHOLD EFFECTS
DETERMINISTIC
SOMATIC EFFECTS
SKIN ERYTHEMA, CATARACTS, STERILITY
RAD -MALIGNANCIES

75. GSD 0. 20 mSv or 20 millirem GENETICALY SIGNIFICANT DOSE
Takes all of the population into account
Annual AVERAGE gonadal dose to population of childbearing age
0. 20 mSv or 20 millirem
rem or rad???

76. REDUCING REPEATS TECHNIQUE CHARTS CAREFUL REVIEW OF TECHNICAL FACTORS
REFER TO TECHNIQUE BOOK AND
ASK WHEN YOU ARE NOT SURE!

83. Carlton Ch 13 - p. 208 & 210 & 214 “AVE” CHEST EXPOSURE - 2 IMAGES
(Ave – Pt meas 23cm pa 40cm lat)
PA KVP 5 MAS 16:1 GRID 400RS 72”
LAT 110 KVP 20 MAS 16:1 GRID 400 RS 72”
WHAT IS THE PATIENT’S DOSE??

84. PEDIATRIC EXPOSURE MORE SENSITIVE TO RADIATION THAN ADULTS
LIMIT BEAM TIME
MAY REMOVE GRID (REDUCE EXPOSURE)
AP VS PA
COLLIMATION & SHIELDING !!!!!!!!!!!!!!!
GENDER DIFFERENCES
IMMOBILATION