Fluoro Equipment Review RHB Fluoro Syllabus

1
Fluoro Equipment ReviewRHB Fluoro Syllabus
Rad Prot

• Fluoroscopy Course
• Review QUESITONS
• June 2008 ccrt55 revised

2
History of fluoroscopy

• Thomas Edison invented the fluoroscope in 1896
• He was the first one to try to image the brain
• Fluoroscopy was performed in total darkness so
  the eyes had to be adjusted for 30 minutes by
  wearing red goggles

3
General Fluoroscopic Concepts

• 1. Primary factors associated with fluoroscopy
• 2. High-level fluoroscopic procedures
• 3. Pulsed fluoroscopic procedures
• 4. Scatter, magnitude, directionality leakage
  radiation
• 5. Dose trade offs versus quantum mottle
• 6. Potential image distortions

4
Basic Imaging Chain
5
Basic Componets of old Fluoroscopy Imaging
Chain
Primary Radiation
EXIT Radiation
Fluoro TUBE
PATIENT
105 Photospot
Image Intensifier
Image Recording Devices
ABC
Cassette
Fiber Optics OR
CINE
CONTROL UNIT
VIDICON Camera Tube
TV
6
Basic Componets of NEW DIGITAL FluoroImaging
Chain
Primary Radiation
EXIT Radiation
Fluoro TUBE
PATIENT
Analog to Digital Converter ADC
Image Intensifier
ABC
CCD
TV
7
Modern fluoroscopic system components
8
The image intensifier (I.I.)
I.I. Input Screen
Electrode E1
Electrode E2
Electrode E3
Electrons Path
I.I.Output Screen
Photocathode

9
IMAGE INTENSIFIERMEASURED IN ????IP VS OP
10
Image Intensifier

• VACUUM TUBE
• ENCASED IN A LEAD HOUSING
• 2MM PB
• (PRIMARY BARRIER)

11
Cesium Iodide (CsI) Phosphoron Input Phosphor

• CsI crystals grown linear and packed closely
  together
• The column shaped pipes helps to direct the
  Light with less blurring
• Converts x-ray photons to visible light

SIDE VIEW
12
Input phosphor

• X-rays hit this concave surface first.
• It is made of cesium iodide crystals shaped like
  tiny needles packed tightly together.
• The more crystals, the better the spatial
  resolution.
• The crystals convert the x-ray photons to light
  energy so the more crystals, the more energy
  converted to light the less radiation needed so
  patient dose goes down.

13
photocathode

• The photocathode is close to the input phosphor
  but cant touch it otherwise there would be a
  chemical reaction that would destroy the
  phosphor.
• The photocathode is made of antimony and cesium
  compounds. When these compounds come into
  contact with light they emit electrons
• The photocathode has the job of turning the light
  into photoelectrons.

14
Veiling glare

•   Scatter in the form of x-rays, light
  electrons can
• reduce contrast
• of an image intensifier tube.

15
Functioning of Image Intensifier
16
IMAGE INTENSIFIER

• FUNCTION
• CHANGE XRAY PHOTONS TO
• __________ PHOTONS (INPUT PHOSPHOR)
• TO __________(PHOTOCATHODE)

17
IMAGE INTENSIFIER

• FUNCTION
• CHANGE XRAY PHOTONS TO
• LIGHT PHOTONS (INPUT PHOSPHOR)
• TO ELECTONS (PHOTOCATHODE)
• ACCERATES ELECTRONS ACROSS TUBE AT 25,000 VOLT
  POTIENTAL
• CHANGED BACK TO LIGHT AT OUTPUT PHOSPHOR

18

• The ratio of the number of light photons striking
  the output screen to the ratio of the number of
  x-ray photons striking the input screen is called
  _____________

19

• The ratio of the number of light photons striking
  the output screen to the ratio of the number of
  x-ray photons striking the input screen is called
  fluxgain

20
Intensifier Flux Gain
21
IMAGE INTENSIFIER

• __________ Input Phosphor
• _______________ Output phosphor
• ELECTRON FOCUSING LENS
• CURRENT ATTRACTS e TO ANODE
• _________ KVP POTIENTIAL ACROSS TUBE

22
IMAGE INTENSIFIER

• CESIUM IODIDE Input Phosphor
• ZINC CADMIUM SULFIDE Output phosphor
• ELECTRON FOCUSING LENS
• CURRENT ATTRACTS e TO ANODE
• 25 35 KVP POTIENTIAL ACROSS TUBE
• Output phosphor contains a thin al plate to
  prevent light returning to the photocathode

23
measurement

• 1 Rem .01 Sievert
• 1 REM _____mSv
• 1 Rem _____mRem
• ?

24
measurement

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

25
PUBLIC EXPOSURE ?

• ______ OF OCCUPATIONAL
• NON MEDICAL EXPOSURE
• _____ RAD OR _____MRAD
• UNDER AGE 18 AND STUDENT
• .1 rem 1 mSv
• Pg 98 RTA BOOK

26
(No Transcript)
27
IMAGE INTENSIFIER

• BG MG X FG IS What?

28
Intensifier Format and Modes
Note focal point moves farther from output in mag
mode
29
MAG MODE VS PT DOSE

• MAG USED TO ENLARGE SMALL STRUCTURE OR TO
  PENETRATE THROUGH LARGER PARTS
• FORMULA????

• PATIENT DOSE IS INCREASED IN THE MAG MODE
• DEPENDANT ON SIZE OF INPUT PHOSPHOR

30
MAG MODE FORMULA

• IP OLD SIZE
• IP NEW SIZE MAG

31
MAG MODE VS PT DOSE

• MAG USED TO ENLARGE SMALL STRUCTURE OR TO
  PENETRATE THROUGH LARGER PARTS

• PATIENT DOSE IS INCREASED IN THE MAG MODE
• DEPENDANT ON SIZE OF INPUT PHOSPHOR
• FORMULA????

32
MORE FORMULASBG MG X FG

• BG MINIFICATION GAIN X FLUX GAIN
• MINIFICATION GAIN same e at input condensed
  to output phosphor ratio of surface area on
  input screen over surface area of output screen
• IP SIZE 2
• OP SIZE 2

33
BG MG X FG

• FLUX GAIN increase of light brightness due to
  the conversion efficiency of the output screen
• 1 electron 50 light photons is 50FG
• Can decrease as II ages
• Output phosphor almost always ____ inch
• Made of _____________phosphor
• Flux gain is almost always 50

34
BG MG X FG

• FLUX GAIN increase of light brightness due to
  the conversion efficiency of the output screen
• 1 electron 50 light photons is 50FG
• Can decrease as II ages
• Output phosphor almost always 1 inch
• Zinc cadnium phosphor
• Flux gain is almost always 50

35
Intensifier Format and Modes
Note focal point moves farther from output in mag
mode
36
Raster pattern scan lines
37
Video Field Interlacing
38
Horizontal resolution

• The number of dots on the horizontal scan line.
• How close together are they?
• It is the product of scan lines, frame rate and
  frequency rate

39
Vertical resolution

• How far apart are the horizontal scan lines?
  Since we cant have more than 525 scan lines, we
  can have more dots that are smaller
• The Kell factor is a component of vertical
  resolution. Memorize the number 0.7 and know
  that it is the Kell factor part of vertical
  resolution

40
KELL FACTOR

• VERTICAL RESOLUTION
• ABILITY TO RESOLVE OBJECTS SPACED APART IN A
  VERTICAL DIRECTION
• MORE DOTS(GLOBULES) MORE SCAN LINES
  MORE/BETTER RESOLUTION
• RATIO OF VERTICAL RESOLUITON
• OF SCAN LINES
• KELL FACTOR FOR 525 LINE SYSTEM
• IS ____________________

41
KELL FACTOR

• VERTICAL RESOLUTION
• ABILITY TO RESOLVE OBJECTS SPACED APART IN A
  VERTICAL DIRECTION
• MORE DOTS(GLOBULES) MORE SCAN LINES
  MORE/BETTER RESOLUTION
• RATIO OF VERTICAL RESOLUITON
• OF SCAN LINES
• KELL FACTOR FOR 525 LINE SYSTEM
• IS 0.7

42
Video Field Interlacing
43
VIDEO/CAMERA TUBE

• PLUMICON, VIDICON, ORTHOCON, CCDs
• TRANSFERS IMAGE FROM OUTPUT PHOSPHOR TO TV
  MONITOR
• CONNECTED BY FIBER OPTICS or Optical Lens
• VIDICON- MOST COMMOM
• PLUMICON BETTER RESOLUTION
• CCD Charged Coupling Devices
• ORTHOCON VERY

44
VIDEO/CAMERA TUBE

• VIDICON MOST COMMOM
• good resolution with moderate lag ok for
  organs
• Uses ANTIMONY TRISULFATE
• PLUMICON (a modification of Vidicon)
• BETTER RESOLUTION / (? dose)
• Better for moving part like the heart faster
  response time
• High performance, lag may improve, but ?quantum
  mottle
• Uses LEAD OZIDE
• ORTHOCON VERY - Larger (Not used) BEST
  RESOLUTION WITH NO LAG
• Functions as both II and pick up tube
• CCD smaller longer life, very little image
  lag

45
Type of TV camera

• VIDICON TV camera
• improvement of contrast
• improvement of signal to noise ratio
• high image lag
• PLUMBICON TV camera (suitable for cardiology)
• lower image lag (follow up of organ motions)
• higher quantum noise level
• CCD TV camera (digital fluoroscopy)
• digital fluoroscopy spot films are limited in
  resolution, since they depend on the TV camera
  (no better than about 2 lp/mm) for a 1000 line TV
  system

46
Viewing Fluoroscopic Images
47
Image Quality

• Contrast
• Resolution
• Distortion
• Quantum mottle

48
Contrast

• Controlled by amplitude of video signal
• Affected by
• Scattered ionizing radiation
• Penumbral light scatter

49
Resolution

• Video viewing
• Limited by 525 line raster pattern of monitor
• Newer digital monitors 1024 - better resolution

50
Size Distortion

• Affected by same parameters as static radiography
• Primarily OID
• Can be combated by bringing image intensifier as
  close to patient as possible

51
Shape Distortion

• Geometric problems in shape of input screen
• Concave shape helps reduce shape distortion, but
  does not remove it all
• Vignetting or pin cushion effect

52
Image distortion
PINCUSHION EFFECT
PINCUSHION ?? WHAT IS VIGNETTING??
53
Image Quality

• Terms that are necessary to know
• Vignetting is the loss of brightness at the
  periphery of the II due to the concave surface
• Pincushion effect is the drop off at the edges of
  the II due to the curved surface
• Quantum mottle is the grainy appearance on the
  image due to statistical fluctuations
• The center of the II will always have the best
  resolution.
• Lag is the blurry image from moving the II too
  fast

54
Degree of scatter??
55
Degree of scatter??

• 135 under 45 over

56
Regulations about the operation

• Fluoroscopic tubes operate at currents that range
  from0.5 to 5 mA with 3 - 4 the most common
• AEC rate controls equipment built after 1974
  with AEC shall not expose in excess of 10 R/min
  equipment after 1974 without AEC shall not expose
  in excess of 5 R/min

57
Other regulations

• Must have a dead man switch
• Must have audible 5 min. exposure timer
• Must have an interlock to prevent exposure
  without II in place
• Tube potential must be tested weekly
• Brightness/contrast must be tested annually
• Beam alignment and resolution must be tested
  monthly
• Leakage cannot exceed 100mR/hr/meter

58
more regulations

• Must have a device to prevent operation at a SOD
  of less than 12
• A bucky slot cover must be provided
• Aprons must be at least 0.25 mm Pb equivalent
• 2.5 mm Al equivalent filtration is required
• Must provide at least 12 and preferably 15
  between source and table top

59
Fluoroscopy exposure rate

• For radiation protection purposes the fluroscopic
  table top exposure rate must not exceed 10
  mR/min.
• The table top intensity should not exceed 2.2
  R/min for each mA of current at 80 kVp

60
Patient Protection

• A 2 minute UGI results in an exposure of
  approximately 5 R!!
• After 5 minutes of fluoro time the exposure is
  10-30 R
• Use of pulsed fluoro is best (means no matter how
  long you are on pedal there is only a short burst
  of radiation)
• ESE must not be more than 5 rads/min
• W/0 AEC 10 WITH 20 BOOST

61

• Always keep the II as close to the patient as
  possible to decrease dose
• Highest patient exposure happens from the
  photoelectric effect (absorption)
• Boost control increases tube current and tube
  potential above normal limits
• Must have continuous audible warning
• Must have continuous manual activation

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ESE FOR FLUORO

• TLD PLACED AT SKIN ENTRACE
• POINT for fluoro
• 1 5 R/MINUTE AVE IS ________R/MIN

63
ESE FOR FLUORO

• TLD PLACED AT SKIN ENTRACE POINT
• 1 5 R/MINUTE AVE IS 4 R/MIN
• (now closer to 1 3 R/min)
• When not known assume 4 R

64
The law requires the Bucky slot cover to be lined
with ____________ of lead equivalent to protect
or gonads from unnecessary radiation
65
List one RECORDING method that HAS LOWERPATIENT
DOSE ______________________
66
When recording dynamic images using cine, the
higher the frames per second, the ___________ the
patient dose
67
The law requires that total filtration during
fluoroscopy should be __________________
68
Between spot film cassettes and photospot
films, the_____will increase patient dose.
However, between the two the ______will produce
better image quality.
69
Between spot film cassettes andphotospot films,
the _cassette__ will increase patient dose.
However, between the two the _cassette__ will
produce better image quality.
70
The x-ray tube current automatically increases to
________level of mA when a spot film is taken.
71
The x-ray tube current automatically increases to
_100- 200__ level of mA when a spot film is
taken.
72
The cumulative timer should not exceed _____ min.
73
The cumulative timer should not exceed _5__ min.
74

• INTERGRAL DOSE
• 100 ERGS OF TISSUE 1 RAD EXPOSURE
• OR ___ RAD ___ERGS

75

• INTERGRAL DOSE
• 100 ERGS OF TISSUE 1 RAD EXPOSURE
• OR 1 GM RAD 100 ERGS

76
SSD TUBE TO SKIN DISTANCE

• FIXED UNITS
• 18 PREFERRED
• 15 MINIMUM
• MOBILE UNITS ( C-ARMS)
• 12 MINIMUM

77
SSD TUBE TO SKIN DISTANCE

• FIXED UNITS
• 18 PREFERRED
• 15 MINIMUM
• MOBILE UNITS ( C-ARMS)
• 12 MINIMUM

78
PATIENT PROTECTION

• NAME 4 WAYS TO LIMIT DOSE TO THE PATIENT DURING
  FLUORO EXAM

79
PATIENT PROTECTION

• LIMIT SIZE OF BEAM
• BEAM ON TIME
• DISTANCE OF SOURCE TO SKIN
• PBL
• FILTRATION (2.5 mm Al eq) _at_ 70
• SHEILDING
• SCREEN/FILM COMBO -OVERHEADS

80
According to your California syllabus, list more
6 things that will reduce patient exposure
81
According to your California syllabus, list more
6 things that will reduce patient exposure

• Collimating to the area of interest
• Using last frame hold
• Keeping the pt. / detector distance to a minimum
• Using high kv low mA
• Pulsed Fluoro with low frame rates
• Using the largest II mode

82
(No Transcript)
83
GONAD SHIELDING

• MUST BE . ______ OF LEAD
• MUST BE USED WHEN GONADS WILL LIE WITHING _____
  OF THE COLLIMATED AREA (RHB)
• KUB. Lumbar Spine Pelvis
• male vs female shielding

84
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

85
Gonad shielding dose

• ? receive 3x more dose than
• ? for pelvic x-rays
• 1 mm lead will reduce exposure (primary) by about
  _______?
• by about 90 95 ?

86
Gonad shielding dose

• ? receive 3x more dose than
• ? for pelvic x-rays
• 1 mm lead will reduce exposure (primary) by about
  50 ?
• by about 90 95 ?

87
KEEP I.I. CLOSE TO PATIENT
88
Over vs under the table fluoro tubes
89
Framing and patient dosesyll Pg 31 which is
BEST

• The use of the available film area to control the
  image as seen from the output phosphor.
• Underframing
• Exact Framing, (58 lost film surface)
• Overframing,(part of image is lost)
• Total overframing

90
Framing and patient dosesyll Pg 31 which is
BEST

• The use of the available film area to control the
  image as seen from the output phosphor.
• Underframing
• Exact Framing, (58 lost film surface)
• Overframing,(part of image is lost)
• Total overframing

91
EXPOSURE RATES FLUORO

• MA IS 0.5 MA TO 5 MA PER MIN
• AVE DOSE IS 4 R / MIN
• IF MACHINE OUTPUT IS 2 R/MA/MIN WHAT IS PT
  DOSE AT 1.5 MA FOR 5 MIN STUDY?

92
EXPOSURE RATES FLUORO

• MA IS 0.5 MA TO 5 MA PER MIN
• AVE DOSE IS 4 R / MIN
• IF MACHINE OUTPUT IS 2 R/MA/MIN WHAT IS PT
  DOSE AT 1.5 MA FOR 5 MIN STUDY?
• 15R

93
EXPOSURE RATES FOR FLUORO

• CURRENT STANDARD
• _______ R/MIN (INTENSIFIED UNITS)
• HLC BOOST MODE _______ R/MIN
• OLD (1974) NO ABC NON IMAGE
• INTESFIED 5 R/MIN

94
EXPOSURE RATES FOR FLUORO

• CURRENT STANDARD
• 10 R/MIN (INTENSIFIED UNITS)
• HLC BOOST MODE 20 R/MIN
• OLD (1974) NO ABC NON IMAGE INTES
• 5 R/MIN

95
DOSE REGULATIONS

• BEFORE 1974 - AT TABLETOP
• 5R/MIN (WITHOUT AEC)
• 5R/MIN (WITHOUT AEC) BOOST MODE
• After 1974 with AEC
• 10 R/MIN 20R/MIN BOOST

96
RADIATION PROTECTIONThe Patient is the largest
scattering object

• Lower at a _____ DEGREE ANGLE from the patient
  PRIMARY BEAM
• AT 1 METER DISTANCE -
• _______ OF INTENSITY PRIMARY XRAY or 0.1

97
RADIATION PROTECTIONThe Patient is the largest
scattering object

• Lower at a 90 DEGREE ANGLE from the patient
  PRIMARY BEAM
• AT 1 METER DISTANCE -
• 1/1000 OF INTENSITY PRIMARY XRAY or 0.1

98
BUCKY SLOT COVER

• _________ MM LEAD

99
BUCKY SLOT COVER

• .25 MM LEAD

100
ISOEXPOSURE CURVES
101
TOWER CURTAIN

• ________MM LEAD EQ

102
TOWER CURTAIN

• .25 MM LEAD EQ

103
PERSONNEL PROTECTION

• SCATTER FROM THE PATIENT
• TABLE TOP, COLLIMATOR, TUBE HOUSING, BUCKY
• STRAY RADIATION LEAKAGE OR SCATTER RADIATION
• IS LIMITED TO? _____________

104
PERSONNEL PROTECTION

• STRAY RADIATION LEAKAGE OR SCATTER RADIATION
• IS LIMITED TO? _____________
• 100 MR/HR _at_ 1 METER

105
PERSONNEL PROTECTION

• STANDING BEHIND A PROTECTIVE PRIMARY (1/16TH pb)
  BARRIER
• PRIMARY RADIATION EXPOSURE 99.87 REDUCED
• PORTABLE BARRIER 99 REDUCTION

106
PERSONNEL PROTECTION

• PROTECTIVE APRONS
• 0.25 PB 97 ? TO SCATTER
• 0.5 PB 99.9 ? TO SCATTER
• THYROID SHEILDS (0.25 0.5)
• GLOVES (0.25 0.5)

107
PERSONNEL PROTECTIONMONITORING

• FILM BADGE
• TLD
• POSL
• POCKET DOSIMETER
• RING BADGE

• Which is most sensitive to radiation?
• Which one has a permanent record?

108
PERSONNEL PROTECTIONMONITORING

• FILM BADGE
• TLD
• POSL
• POCKET DOSIMETER
• RING BADGE

• Which is most sensitive to radiation?
• Which one has a permanent record?

109
PERSONNEL PROTECTIONMONITORING

• DOSE LIMITS
• WHOLE BODY __________
• EYES _________________
• EXTREMITIES (BELOW ELBOW/KNEES)
• ___________________ ??????

110
Occupational DoseANNUAL LIMITS

• WHOLE BODY 5 REMS / 5000mRem
• LENS OF THE EYE 15 REMS
• EXTREMITIES 50 REMS

111
(No Transcript)
112
Where should a dosimeter badge be worn?
113
(No Transcript)
114
Who should wear 2 badgesname 2
115

• Pregnant technologist
• Interventional
• ??Portable/ Surgery ???

116
Who wears a ring dosimeter?
117
Nuc Med Tech
118
TLDSensitive to ___mrem?
119
(No Transcript)
120
Report at least every quarterPreserved for a
minimum of 3 years
121
RHB NOTIFICATION (

• IMMEDIATE REPORT WITHIN
• _________________________
• TOTAL DOSE OF 25 rems
• Eye dose 75 rem
• Extremity 250 RADS

122
RHB NOTIFICATION (EXP IN 24 HOURS)

• IMMEDIATE WITHIN 24 HOURS
• TOTAL DOSE OF 25 rems
• Eye dose 75 rem
• Extremity 250 RADS

123
RHB NOTIFICATION (EXP IN 24 HOURS)

• OVEREXPOSURE
• Report within ________________
• TOTAL DOSE OF 5 rems
• Eye dose 15 rem
• Extremity - 50 REMS

124
RHB NOTIFICATION (EXP IN 24 HOURS)

• OVEREXPOSURE
• Report within 30 DAYS
• TOTAL DOSE OF 5 rems
• Eye dose 15 rem
• Extremity - 50 REMS

125
LICENSE RENEWAL

• WITHIN ________OF EXPRIATION
• NOTIFICATION OF CHANGE OF ADDRESS

126
LICENSE RENEWAL

• WITHIN 30 DAYS OF EXPRIATION
• NOTIFICATION OF CHANGE OF ADDRESS

127

• HIGH RADIAITON AREA
• ___________mRem ( 0.1 rem / (1 msV)
• _at_ 30 cm from the source of radiation

128

• HIGH RADIAITON AREA
• 100 mRem ( 0.1 rem / (1 msV)
• _at_ 30 cm from the source of radiation

129

• RADIATION AREA
• RHB
• __________ ( 0.005 rem / (.05 msV)
• _at_ 30 cm from the source of radiation
• PUBLIC _______ per week (STAT)

130

• RADIATION AREA
• RHB 5 mRem ( 0.005 rem / (.05 msV)
• _at_ 30 cm from the source of radiation
• PUBLIC 2 mrem per week (STAT)

131

• A controlled area is defined as one
• that is occupied by people trained in radiologic
  safety
• that is occupied by people who wear radiation
  monitors
• whose occupancy factor is 1
• ALL OF THE ABOVE

132

• A controlled area is defined as one
• that is occupied by people trained in radiologic
  safety
• that is occupied by people who wear radiation
  monitors
• whose occupancy factor is 1
• ALL OF THE ABOVE

133
RHB RULES RHB RP PG61

• LICENTIATES OF THE HEALING ARTS
• (MD, DO, DC, DPM)
• MUST HAVE A
• RADIOLOGY SUPERVISOR OPERATORS PERMIT
  CERTIFICATE
• TO OPERATE OR SUPERVISE THE USE OF X-RAYS ON
  HUMANS
• SUPEVISORS MUST POST THEIR LICENSES

134
RHB RULES RHB RP PG62

• ALL XRAYS MUST BE ORDERED BY A PHYSICIAN
• VERBAL OR WRITTEN PRESCRIPTION
• See Section C Technologist Restrictions

135
Declared Pregnant Worker

• Must declare pregnancy 2 badges provided
• 1 worn at collar (Mothers exposure)
• 1 worn inside apron at waist level
• Under 5 rad negligible risk
• Risk increases above __________rad
• Recommend abortion (spontaneous) 25 rad
• (Baby exposure approx 1/1000 of ESE
• 1/50 th dose of mother)
• www.ntc.gov/NRC/RG/08/08-013.html

136
Declared Pregnant Worker

• Must declare pregnancy 2 badges provided
• 1 worn at collar (Mothers 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
• 1/50 th dose of mother)
• www.ntc.gov/NRC/RG/08/08-013.html

137
CARDINAL RULES

• TIME
• DISTANCE
• SHEILDING

138
CARDINAL RULES

• ______________________
• _______________________
• ____________________

139
(No Transcript)
140
HVL TVL

• The amount of material required to reduce the
  energy of the beam by..
• HVL _______________________
• TVL _____________________
• Examples 100 50 - 25 12.5 6.25 - 3.12
• ?How many to reduce to 1/2 ? 1/10th ?

141
SHEILDING PG 72 RHB

• HVL expressed 2 ways
• HOW MUCH IT REDUCES THE ORGINAL BEAM INTENSITY
• HOW MUCH IS REQUIRED FOR BARRIER THICKNESS
  (amount needed to attenuated the beam

142
We recall that as an occupationally exposed
individual, federal law limits annual
occupational whole body radiation dose to
5 rem (5000 mrem or 50 mSv)
However ..
143
We recall that as an occupationally exposed
individual, federal law limits annual
occupational whole body radiation dose to
____________ rem (5000 mrem or 50 mSv)
However ..
144
For female workers of child bearing age who are
or may be pregnant, this occupational dose limit
is reduced (with respect to the fetus) to
0.5 rem (500 mrem or 5 mSv)
Preferably distributed evenly over the entire
gestation period
145
Pregnancy Embryo

• Mother
• occupational worker (5 rem)
• Baby (______ mRem)
• __________ rem/ year __________rem/month

146
Pregnancy Embryo

• Mother
• occupational worker (5 rem)
• Baby (500 mRem)
• .5 rem/ year 5 mSv
• .05 rem/month .5 mSv / month

147
PREGNANCY DOSE

• 10 day rule (no longer used)
• No threshold for exposure
• Leukemia , congential abnormailies cander
  induction, resportion or death of the embryo and
  genetic effects
• Therapetuic Abortion not justified
• 15 rads (risk is increased)
• 25 rads or less no injury seen
• ABSORBED DOSES 50 RADS could result in a
  spontaneous abortion

148

• The NCRP states that the risk (to the
  embryo/fetus) is considered to be negligible at 5
  rads or less when compared to the other risks of
  pregnancy
• and the risk of malformation is significantly
  increased above control levels only at doses
  above ___________rads

149

• is significantly increased above control levels
  only at doses above 15 rads

150
RHB Rad Prot CH. IX p 51

• ALARA (no minimum threshold)
• STOCHASTIC EFFECTS
• NON TRESHOLD (CA GENETIC)
• NON STHOCAHSTIC (DETERMINISTIC)
• SEVERITY OF EFFECTS VARIES WITH RADIATION DOSE
  (THRESHOLD)
• (CATARACTS, SKIN, BONE MARROW,
• STERILITY

151
7 Dose Response Relationships

• LINEAR NON THRESHOLD
• ASSUMES ANY AMOUNT OF RADIATION IS CAPABLE OF
  CAUSING A BIOLOGIC RESPONSE
• THE RELATIONSHIP BETWEEN THE RADIATION DOSE AND
  BIOLOGIC RESPONSE IS CONSIDERED TO BE DIRECTLY
  PROPORTIONAL

152
SOMATIC GENETICSTOCHASTIC 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

153

• Name of 1?
• 2?
• 3?
• ? is the type of biological dose response effect
  that is considered in for radiation safety
  purposes

154
(No Transcript)
155
DOSE

• CINE - 2mR per frame (30 OR 60f/sec)
• 400 mr per look
• WHAT WOULD BE THE PATIENTS DOSE FOR A 2 MIN
  PROCEDURE
• AT 30 F/SEC?

156
FLUORORAD PROTECTIONREVIEW QUESTIONS
157

• If at ½ foot from the radiation source the
  intensity of exposure is 240 mR per hour and you
  remain at this location for 10 minutes, you then
  moved 2 feet away from the radiation source and
  remained there for 20 minutes? What is your
  total exposure?

158

• The greatest contribution of unnecessary
  radiation exposure to the patient comes
• from the x-ray operators failure to

159

• The greatest contribution of unnecessary
  radiation exposure to the patient comes
• from the x-ray operators failure to
• collimate the x-ray beam to the area of clinical
  interest only
• use proper gonadal shielding
• use past screens and films
• use proper exposure (technical factors

160

• The greatest contribution of unnecessary
  radiation exposure to the patient comes
• from the x-ray operators failure to
• COMMUNICATE
• COLLIMATE
• SHIELD

161

• . All of the following must be posted in areas
  where x-ray production machines
• are utilized except
• each x-ray supervisor and operator permit
• each certified radiologic technologist
  certificate and technologist fluoroscopy permit
• Radiologic Health Department Form RH-2364,
  Notice to Employee
• each physicians license for the healing arts

162

• During a 2 minute (fluoroscopy exposure time)
  routine upper GI series
• examination a typical x-ray exposure
  to the patient is

163

• For a fluoroscopic system equipped with and
  automatic brightness control
• (automatic exposure control) mechanism and where
  the x-ray tube is fixed
• below the table, moving the image intensifier way
  from the patient will

164

• If at one foot from the radiation source the
  intensity of exposure is 240
• milliroentgens (mR) per hour and you remain at
  this location for 10 minutes
• you will receive and exposure of 40
  milliroentgens (mR). What source and remained
  there for 20 minutes?

165

• When the target to panel (tube to patient)
  distance is increased from 12 to 18 inches the
  ESE to patient is approximately
• a. Increased by 45
• c. Decreased by 100
• b. Increased by 25
• d. Decreased by 45

166

• At 1 foot from a source the output intensity is
  300 mR/hr and you were there for 20 minutes.
• What is the intensity total if you moved 2 feet
  away and remained for an additional 40 minutes?

167

• Fluoro equipment made after 1974 with AEC shall
  not produce an exposure rate to the patient in
  excess of
• a. 1 R/ min c. 5 R/min
• b. 10 R/min d. 20 R/min

168
You are fluoroscoping a patient using 80 kilivolt
peak (kvp) technique. At this

• Kilovolt peak (kvp) the intensity of the x-ray
  beam at table top should not exceed how many
  roentgens per minute for each milliampere (ma) of
  current?
• 0.2 roentgens per minute
• 1.0 roentgens per minute
• 2.2 roentgens per minute
• 5.0 roentgens per minute

169

• The NCRP states that the risk (to the
  embryo/fetus) is considered to be negligible at 5
  rads or less when compared to the other risks of
  pregnancy ,
• and the risk of malformation is significantly
  increased above control levels only at doses
  above how many rads
• a. 7 b.10 c.15 d. 25

170

• A high radiation area is any area , accessible
  to individuals, in which there exists radiation
  at such levels that an individual could receive
  in any one hour a dose to the whole body in
  excess of how many millirems ?
• a.5 b. 10 c. 50 d. 100

171

• Which of the following technical factors will
  create the highest skin entrance dose to the
  patient?
• A. 80 kvp 300 ma .5s no filter
  B. 80 kvp 300ma 1/10s
  no filter
• C. 80 kvp 1000ma 1/20s 2.5mm al eq. filter
  
• D. 80 kvp 800ma 1/60 sec .05mm al eq filter

172

• The exposure rate to a tech at 4 feet from the
  source is 240 m R/hr. What distance would be
  necessary to reduced the rate below 60 mR/hr?
• A. 1 foot
• B. 6 feet
• C. 2 feet
• D. 9 feet

173

• If 85 kvp, 400ma 0.12s 150mR - what is the
  mr/mas?
• A. 0.32
• B. 3.1
• C. 33.1
• D. 17.6

174

• Each time an x-ray beam scatters, its intensity
  at 1 meter from the scattering object is what
  fraction of its original intensity?
• A. 1/10
• B. 1/100
• C. 1/500
• D. 1/1000

175

• The California Radiation ControlRegulations
  define dose to mean radiation absorbed per unit
  mass. Whole-Body dose means exposure to which of
  the following
• I Major portions of the whole body
• II Head and trunk
• III Gonads
• IV Lens of the eye
• V Active blood-forming organs
• VI Whole body excluding extremities
• I only b. I, III, IV VI
  only
• c. I IV only d. all of the above

176

• Which of the following gives the least patient
  exposure?
• a. mirror optical system
• b. vidicon TV camera
• c plumicon TV camera
• d. image orthicon

177

• Which of the following gives the best resolution?
• a. mirror optical system
• b. vidicon TV camera
• c plumicon TV camera
• d. image orthicon

178

• During a CINE exam in which 35 mm film and a
  frame rate of 30 frames per second are utilized,
  what is the approximate skin exposure in
  roentgens/minutes?
• a. 1 (given 2mr/frame)
• b. 2 5
• c. 5 10
• d. over 10

179

• It may be advisable to wear a second personal
  monitoring device if a worker is
• 1. performing routine radiological procedures
• 2. pregnant
• 3. a student
• 4. performing special procedure
• examinations

180

• All of the following must be posted in areas
  where x-ray producing machines are utilized
  EXCEPT
• a each x-ray supervisor and operator permit
  
• b. each certified radiologic and operator permit
• c RHB form Notice to Employees
• d. each physicians license for the healing arts