Download Fluoroscopy - El Camino College

Fluoroscopy
Intro to EQUIPMENT
RT 244
FALL 2008
Week 1
Wed- CONTINUED
Basic Componets of “old” Fluoroscopy “Imaging Chain”
Conventional I I system
IMAGE INTENSIFIER
The anode of the II
Anode and Output Screen
Anode
Positively charged
25 kVp
Hole in center allows electrons to pass through to output screen
OUTPUT SCREEN
Usually 1 inch in diameter
Zinc cadnium sulfide coating
Changes electrons back to LIGHT
Image Intensifier
PROPERTIES
Image Quality
Contrast
Resolution
Distortion
Quantum mottle
Contrast
Controlled by amplitude of video signal
Affected by:
Scattered ionizing radiation
Penumbral light scatter
Veiling glare
Scatter in the form of x-rays, light & electrons can
reduce contrast of an image intensifier tube.
Resolution
Video viewing
Limited by 525 line raster pattern of monitor
Newer
digital monitors 1024 - better resolution
MORE
ON THIS LATER IN THE LECTURE
Image distortion
Shape Distortion
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Geometric problems in shape of input screen
Concave
shape helps reduce shape distortion, but does not remove it all
or pin cushion effect
Vignetting
FALL-OFF OF BRIGHTNESS AT PERIPHERY (EDGES) OF THE IMAGE
Vignetting
VIGNETTING…….
Darkness on edges (falloff of brightness)
Size Distortion
Affected by same parameters as static radiography
Primarily OID
Can be combated by bringing image intensifier as close to patient as possible
ABC
Basic Componets of “old” Fluoroscopy “Imaging Chain”
Brightness Control
Automatic brightness stabilization
Automatic adjustments made to exposure factors by equipment
Automatic gain control
Amplifies video signal rather than adjusting exposure factors
BRIGHTNESS CONTROL
ABC ABS AEC ADC
MAINTAINS THE BRIGHTNESS OF THE IMAGE – BY AUTOMATICALLY
ADJUSTING THE EXPSOURE FACTORS (KVP &/OR MAS) FOR THICKER
PARTS
SLOW RESPONSE TIME - IMAGE LAG
ABC
Automatic brightness control allows Radiologist to select brightness level on screen
by ↑ kVp or ↑ mAs
Automatic dose control
Located just beyond the Output Phosphor
Will adjust according to pt thickness
Automatic Brightness Control
Monitoring Image Brightness
Photocell viewing (portion of) output phosphor
TV signal (voltage proportional to brightness)
Brightness Control: Generator feedback loop
kVp variable
mA variable/kV override
kV+mA variable
Pulse width variable (cine and pulsed fluoro)
Quantum Mottle
Blotchy, grainy appearance
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Caused
by too little exposure
Most commonly remedied by increasing Ma
Controlled by the ABC
Affected by too little technique

size of patient

distance of II to patient

size of collimation
Fluoroscopic Noise
(Quantum Mottle)
Fluoroscopic image noise can only be reduced by using more x-ray photons to produce
image. Accomplished in 3 ways:
Increase radiation dose (bad for patient dose)
Frame-averaging:
creates image using a longer effective time
Can cause image lag (but modern methods good)
Improve Absorption Efficiency of the input phosphor
KEEP I.I. CLOSE TO PATIENT
reduces beam on time
Units of measurement
INPUT PHOSPHOR – IS MEASURED IN _________________________________
OUTPUT PHOSPHOR IS MEASURED IN
______________________________
Units of measurement
INPUT PHOSPHOR – IS MEASURED IN
Milliroentgens mR
OUTPUT PHOSPHOR IS MEASURED IN
CANDELAS (LIGHT)
VIEWBOXES ARE MEASURED IN: lamberts (light)
Fluoroscopic Imaging
Coupling I.I. to TV Monitor
2 Methods:
Fiber optics directly to T.V. camera.
Lens system which utilizes auxiliary imaging devices.
Directly to T.V.
Only cassettes can be used.
Beam splitting mirror
Basic Componets of “old” Fluoroscopy “Imaging Chain”
Beam splitting mirror
Often a beam splitting mirror is interposed between the two lenses.
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The
purpose of this mirror is to reflect part of the light produced by the image intensifier
onto a 100 mm camera or cine camera.
Typically, the mirror will reflect 90% of the incident light to other RECORDING
DEVICES
and transmit 10% onto the television camera*.
*TV MONITOR is the weakest link (low resolution)
Viewing Fluoroscopic Images
Lenses / Mirrors
Used to direct image to recording devices
Several mirrors in a series and angled - the last mirror is outside the II for the operator
to view
Image decreases as it is projected from 1 mirror to the next
Only 1 person can view image
RECORDING THE IMAGE
STATIC IMAGES
DYNAMIC IMAGES
Basic Componets of “old” Fluoroscopy “Imaging Chain”
Recording the Fluoroscopic Image
STATIC IMAGES
Cassettes
105 mm chip film = 12 frames per second
Digital fluoroscopy
DYNAMIC VIEWING:
Cine film
Videotape
Recording Fluoroscopic Images
IMAGE RECORDING
OLD II - ONLY FIBER OPTICS –NO LENS SPLITTER TO OTHER RECORDING
DEVICES
ONLY RECORED IMAGE ON SPOT CASSETTES (9X9 ONLY)
NEWER - TAKES CASSETTES or uses /105 PHOTOSPOT / VIDEO/ CINE
NEWEST = USES DIGITAL !!!!!!!!!
(but the tests* still have all of it!)
Basic Componets of “old” Fluoroscopy “Imaging Chain”
Fluoroscopy mA
Low, continuous exposures .05 – 5 ma
(usually ave 1 – 2 ma)
Radiographic Exposure
for cassette spot films
mA increased to 100 – 200 mA
RECORDING IMAGES
OLD (Smaller) II with fiber optic
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ONLY RECORDING WAS CASSETTE
CASSETTE “SPOT” IMAGES
TAKEN DURING FLUORO PROCEDURE
VERY OLD 9X9 inch cassettes
Later could take up to 14 x 14 inches
Cassettes
Standard size - 9” x 9” (old)
NOW CAN TAKE UP TO 14X14
Stored in lead-lined compartment until ready for exposure
When exposure is made, mA is raised to radiographic level
Multiple image formats
Image recording
Basic Componets of “old” Fluoroscopy “Imaging Chain”
70 & 105 PHOTOSPOT (CAMERA)
Photo spot camera will take the image right off the output phosphor
This requires less patient dose
70 & 105 mm roll film
CASSETTE SPOT FILMING
vs PHOTOSPOT FILMING
First type of recording used
9x9 cassettes then later up to 14x 14
9 on 1, 4 on 1, 2 on 1
Delay while filming (anatomy still moving)
Radiographic mA - must boost up to
100 – 200 mA for filming
And moving cassettes around inside tower
Higher patient dose
Replaced by Photospot (f/sec) filming
CASSETTE SPOT FILMING
vs PHOTOSPOT FILMING
Photospot (f/sec) filming –
Set at control panel from 1 f/sec – 12 f/sec
Used for rapid sequence:
Upper Esophogram
Voiding Cystourethrograms (Peds)
Lower patient dose
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Recording the Fluoroscopic Image
Dynamic systems
Cine film systems
Videotape recording
Static spot filming systems
TV camera and video signal
& Recording the image
Cine Film Systems
Movie camera intercepts image
16 mm and 35 mm formats
Record series of static exposures at high speed
30 – 60 frames per second
Offer increased resolution
At
the cost of increased patient dose
Cinefluorgraphy aka CINE
35 or 16 mm roll film (movie film)
35 mm ↑ patient dose / 16 mm –
higher quality images produced
30 f/sec in US – (60 frames / sec)
THIS MODALITY = HIGHEST PATIENT DOSE (10X greater than fluoro)
(VS SINGLE EX DOSE IS ↓)
Cine
Cinefluorography is used most often in cardiology and neuroradiology.
The procedure uses a movie camera to record the image from the image intensifier.
These units cause the greatest patient doses of all diagnostic radiographic
procedures, although they provide very high image quality.
The high patient dose results from the length of the procedure and relatively high
inherent dose rate.
For this reason special care must be taken to ensure that patients are exposed at
minimum acceptable levels.
Patient exposure can be minimized in a number of ways. The most obvious means of
limiting exposure is to limit the time the beam is on.
 CINE - 2mR per frame (60f/sec)
400 mr per “look”
More on Cine
Synchronization
Framing frequency
F-number of the optical system
Framing and patient dose
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Synchronization
Camera shutters and x-ray pulsed fluoro happen at the same time
Only exposes pt when shutter is open to record image
Patient radiation dose ↑ as #/f/sec ↑
(filming a TV show – pattern seen)
F-number of the optical system
Speed of any given camera system
The amount of light made available to the lens
Framing and patient dose
syll = Pg 31
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
OVERFRAMING vs Exact Framing
Framing frequency
Number of frames per second
Cine – division of 60 (7.5, 15,30,90,120)
Organ if interest determines f/s rate
Patient exposu
More on Safety later….
RECORDING DEVICES
RESOLUTION P 542 (3rd ed)
OPTICAL MIRROR – BEST BUT NOT
MEDIUM
SPOT FILM CASSETTES 6LP/MM
PHOTO SPOT 105 / 70
CINE 35 MM / 16 MM
DIGITAL (?) (VS FILM)
VIDEO – VIEWING REALTIME
VIDEO TAPE - PLAYBACK
PERMANENT RECORDING
Line pair gauges
Line pair gauges
Video disc
This technique is referred to as electronic radiography.
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Fluoroscopic
radiation continues only long enough to build up a useful image on the
display monitor.
The image is stored as a single television frame on the video disc recorder.
There is about a 95% reduction in patient dose.
Video tape
Utilizes VHS or high-resolution tapes.
Patient’s exposure to radiation is not increased.
Used for barium swallows.
Image Quality - Review
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
OVERFRAMING vs Exact Framing
Monitoring
VIDEO/CAMERA TUBE
PLUMICON, VIDICON, ORTHOCON
VIDICON MOST COMMOM
ORTHOCON – VERY $$$$
PLUMICON – BETTER RESOLUTION
TRANSFERS IMAGE FROM OUTPUT PHOSPHOR TO TV MONITOR
CONNECTED BY FIBER OPTICS
VIDEO/CAMERA TUBE
PLUMICON, VIDICON, ORTHOCON, CCD’s
TRANSFERS IMAGE FROM OUTPUT PHOSPHOR TO TV MONITOR
CONNECTED BY FIBER OPTICS or Optical Lens
VIDICON-
MOST COMMOM
– BETTER RESOLUTION
CCD – Charged Coupling Devices
ORTHOCON – VERY $$$$
PLUMICON
VIDEO/CAMERA TUBE
VIDICON MOST COMMOM
– good resolution with moderate lag – ok for organs
Uses ANTIMONY TRISULFATE
PLUMICON (a modification of Vidicon)
– BETTER RESOLUTION / (↓ dose)
Better for moving part like the heart –faster response time
High performance, lag may improve, but ↑quantum mottle
Uses LEAD OZIDE
ORTHOCON – VERY $$$$ - Larger (Not used) BEST RESOLUTION WITH NO
LAG
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Functions
as both II and pick up tube
CCD – smaller & longer life, very little image lag
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
TV camera and video signal (II)
Vidicon (tube) TV Camera
camera tube have a diameter of approximately
1 inch and a length of 6 inches.
Parts of the camera tube
Glass envelope
Electron gun (Cathode)
Control grid
Electrostatic grids
Target
Camera Tube steps
Light is received by the camera tube.
The light from the II is received at the face plate of the target assembly.
Electrons are formed into an electron beam (by the control grid) at the electron gun.
Electrons are burned off by thermionic emission then focused and accelerated to the
target. (made of antimony trisulfide)
Target of the Camera Tube
The electrons scan the signal plate similar to reading a page.
Starting in the upper left across to the right, then back to the left to right.
This is called an active trace.
The movement of the electron beam produces a RASTER pattern.
The same pattern occurs in the TV monitor.
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The signal plate sends the electrical video signal to the control unit which amplifies the
signal and synchronizes the pulses between the camera tube and the TV monitor.
This synchronization
Vidicon Target Assembly
Viewing Systems
Video camera charge-coupled device (CCD)
Video monitor
Digital
Video Viewing System
Closed circuit television
Video camera coupled to output screen and monitor
Video cameras
Vidicon or Plumbicon tube
CCD
Synchronization (Sync Signals)
TV camera and video signal (V)
TV Monitor
TV MONITOR
CRT – Cathode Ray Tube
Much larger than camera tube – but similar function
The electrons are synchronized by the control unit – so they are of the same intensity
and location as the electrons generated by the pick up (camera) tube.
TV Monitor
The TV monitor contains the picture tube called cathode ray tube (CRT).
It works like the camera tube.
With an electron gun and control grids the electron beam is fired toward the anode.
The TV screen contains small fluorescent crystals
Video Field Interlacing
Different types of scanning
Line pair gauges
Two fields = a frame (525 lines)
It take 1/30 of a second.
To prevent flicker, two fields are interlaced to form on television frame.
There are 60 fields and 30 frames per second.
The eye cannot detect flickering above 20 frames/sec.
RASTER Pattern
The electron beam moves in the same raster pattern as in the camera tube.
The signal consists of many individual pulses corresponding to the individual location
on the camera tube target.
The varying voltage pulses are later reassembled into a visible in by the TV monitor.
TV RESOLUTION-Vertical
Conventional TV: 525 TV lines to represent entire image. Example: 9” intensifier (9”
FOV)
10
–9”
= 229 mm
–525 TV lines/229 mm = 2.3 lines/mm
–Need 2 TV lines per test pattern line-pair
–(2.3 lines/mm) /2 lines/line-pair = 1.15 lp/mm
Actual resolution less because test pattern bars don’t line up with TV lines. Effective
resolution obtained by applying a Kell Factor of 0.7.
Example: 1.15 x 0.7 Kell Factor = 0.8 lp/mm
Kell Factor
The ability to resolve objects spaced apart in a vertical direction.
More dots = more scan lines = more/better resolution
Kell factor for 525 line system is 0.7
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
TV RESOLUTION-Horizontal
Along a TV line, resolution is limited by how fast the camera electronic signal and
monitor’s electron beam intensity can change from minimum to maximum.
This is bandwidth. For similar horiz and vertical resolution, need 525 changes (262 full
cycles) per line. Example (at 30 frames/second):
262 cycles/line x 525 lines/frame x 30 frames/second
= 4.2 million cycles/second or 4.2 Megahertz (MHz)
Bandpass/Horizantal Resolution
Horizontal resolution is determined by the bandpass.
Bandpass is expressed in frequency (Hz) and describes the number of times per second
the electron beam can be modulated.
The higher the bandpass, the better the resolution
TV SYSTEMS
Images are displayed on the monitor as individual frames – which tricks the eye into
thinking the image is in motion (motion integration)
15 f/sec – eye can still see previous image
Weakest Link - 2 lp /mm resolution
Real Time
Final Image
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The
result of hundreds of thousands of tiny dots of varying degrees of brightness.
These dots are arranged in a specific patterns along horizontal scan lines.
Usually 525 scan lines.
The electron gun within the picture tube scans from top to bottom in 1/60 of a second,
(262 1/2 lines) called a field.
TABLE MOVEMENT
horizonatal to upright ~ 30 sec
End of Week 1 Day 2
Digital Fluoro
DIGITAL FLUORO
DIGITAL Fluoro System
ADC –
ANALOG TO DIGITAL CONVERTER
TAKE THE ANALOG ELECTRIC SIGNAL CHANGES IT TO A DIGITAL SIGNAL
TO MONITOR –
BETTER RESOLUTION WITH DIGITAL UNITS
Digital Fluoroscopy
Use CCD to generate electronic signal
Signal is sent to ADC
Allows for post processing and electronic storage and distribution
Video Camera Charged Coupled Devices (CCD)
Operate at lower voltages than video tubes
More durable than video tubes
Semiconducting device
Emits electrons in proportion to amount of light striking photoelectric cathode
Fast discharge eliminates lag
CCD’s
Modern Digital Fluoro System
under table tubes
Remote – over the table tube
Newer Digital Fluoroscopy
Image intensifier output screen coupled to TFTs
TFT photodiodes are connected to each pixel element
Resolution limited in favor of radiation exposure concerns
Digital – CCD
using cesium iodide
Exit x-rays interact with CsI scintillation phosphor to produce light
The light interact with the a-Si to produce a signal
The TFT stores the signal until readout, one pixel at a time
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CsI phosphor light detected by the AMA of silicon photodiodes
Digital Uses Progressive Scan
1024 x 1024
Higher spatial resolution
As compared to 525
8 images/sec
(compared to 30 in 525 system)
DSA & POSTPROCESSING
DSA
Mobile C-arm Fluoroscopy
Fluoro & Rad
Protection INTRO
RHB
Regulatory Requirements
1. Regarding the operation of fluoroscopy units
2. Regarding personnel protection
3. Regarding patient protection
Fluoroscopic Positioning Previewing
Radiographers are trained in positioning
Unnecessary radiation exposure to patient is unethical
Fluoroscopic equipment should not be used to preview patient’s position
Patient Protection
Tabletop exposure rate
Maximum 10 R/min
Typically 1 – 3 R/min
Some
books ave is 4 R/min **
Patient Protection
Minimum source-to-skin distance
12” for mobile equipment
15” for stationary systems
Audible alarm at 5 mins.
Same rules for collimation
Patient Protection
Typical exposure rates
Cinefluorography
7.2 R/min
Cassettes
30 mR/exposure
105 mm film
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10
mR/exposure
Protection of Radiographer and Radiologist
Single step away from the table decreases exposure exponentially
Bucky slot cover
Lead rubber drape
Radiologist as shielding
Protection of Others
Radiographer’s responsibility to inform others in the room to wear lead apron
Do not initiate fluoroscopy until all persons have complied
PUBLIC EXPOSURE
10 % OF OCCUPATIONAL
NON MEDICAL EXPOSURE
.5 RAD OR 500 MRAD
UNDER AGE 18 AND STUDENT
.1 rem 1 mSv
COLLIMATION
The PATIENT’S SKIN SURFACE
SHOULD NOT BE CLOSER THAN
___________ CM BELOW THE COLLIMATOR?
____________ INCHES?
Protection
Regulations about the operation
Fluoroscopic tubes operate at currents that range from0.5 to 5 mA with 3 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
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 (monitored)weekly
Brightness/contrast must be tested annually
Beam alignment and resolution must be tested monthly
Leakage cannot exceed 100mR/hr/meter
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
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
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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
Rad Protection
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
ESE FOR FLUORO
TLD PLACED AT SKIN ENTRACE POINT
 1 – 5 R/MINUTE AVE IS 4 R/MIN
INTERGRAL DOSE –
100
ERGS OF TISSUE = 1 RAD EXPOSURE
OR 1 GM RAD = 100 ERGS
SSD – TUBE TO SKIN DISTANCE
FIXED UNITS
18” PREFERRED
15 “ MINIMUM
MOBILE UNITS ( C-ARMS)
12’ MINIMUM
PATIENT PROTECTION
LIMIT SIZE OF BEAM
BEAM ON TIME
DISTANCE OF SOURCE TO SKIN
PBL
FILTRATION (2.5 mm Al eq) @ 70
SHEILDING
SCREEN/FILM COMBO
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
Gonad shielding & dose
♀ receive 3x more dose than
♂ for pelvic x-rays
1 mm lead will reduce exposure (primary) by about 50% ♀
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
by about 90 – 95 % ♂
KEEP I.I. CLOSE TO PATIENT
Over vs under the table
fluoro tubes
Framing and patient dose
syll = Pg 31
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
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
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
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
RADIATION PROTECTION
The 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%
BUCKY SLOT COVER
.25 MM LEAD
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Bucky Slot Cover
ISOEXPOSURE CURVES
PERSONNEL PROTECTION
SCATTER FROM THE PATIENT
TABLE TOP, COLLIMATOR, TUBE HOUSING, BUCKY
STRAY RADIATION – LEAKAGE OR SCATTER RADIATION
TOWER CURTAIN
.25 MM LEAD EQ
Lead curtain & dose reduction
Pulsed Fluoro
Some fluoroscopic equipment is designed for pulsed-mode operation. With the pulsed
mode, it can be set to produce less than the conventional 25 or 30 images per second.
This reduces the exposure rate.
Collimation of the X ray beam to the smallest practical size and keeping the distance
between the patient and image receptor as short as possible contribute to good exposure
management.
PERSONNEL PROTECTION
STANDING BEHIND A PROTECTIVE PRIMARY (1/16TH pb) BARRIER:
PRIMARY RADIATION EXPOSURE – 99.87% REDUCED
PORTABLE BARRIER = 99 % REDUCTION
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)
PERSONNEL PROTECTION
MONITORING
FILM BADGE
TLD
POSL
POCKET
RING
DOSIMETER
BADGE
PERSONNEL PROTECTION
MONITORING
DOSE LIMITS
WHOLE BODY
17
EYES
EXTREMITIES (BELOW ELBOW/KNEES)
Report at least every quarter
Preserved for a minimum of 3 years
RHB NOTIFICATION (EXP IN 24 HOURS)
(RP Syllabus – pg 68)
IMMEDIATE reporting – WITHIN 24 HOURS
TOTAL DOSE OF 25 rems
Eye dose – 75 rem
Extremity – 250 RADS
OVEREXPOSURE – received w/in 24 hrs
Must be ReportedWITHIN 30 DAYS
TOTAL DOSE OF 5 rems
Eye dose – 15 rem
Extremity - 50 REMS
LICENSE RENEWAL
WITHIN 30 DAYS OF EXPRIATION
NOTIFICATION OF CHANGE OF ADDRESS
HIGH RADIAITON AREA –
100 mRem ( 0.1 rem / (1 msV)
@ 30 cm from the source of radiaton
RADIAITON AREA –
RHB: 5 mRem ( 0.005 rem / (.05 msV)
@ 30 cm from the source of radiation
PUBLIC 2 mrem per week* (STAT)
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
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
RHB “RULES” RHB RP PG62
ALL XRAYS MUST BE ORDERED BY A PHYSICIAN
VERBAL OR WRITTEN PRESCRIPTION
See Section C – “Technologist Restrictions”
DOSE
18
CINE - 2mR per frame (60f/sec)
400 mr per “look”
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)
www.ntc.gov/NRC/RG/08/08-013.html
FLUOROSCOPY
End of wk 1
RT 244 2008

19