Everage's FINAL chance to sit on our faces Flashcards
What color should dark room be painted?
white
3 eq. of things associated with ALARA:
Time, distance, shielding (cardinal principals)
Male that recived radiation who had AS experienced
Leukemia
State the relationship between grid ratio and exposure
Direct
Of radical induced cancers, Which has shortest latent period?
Leukemia only 7 years
Upper cervical practitioners, what grid do you need?
8:1
Give eq. of RAD reduced response that follows threshold response
Cataracts
This type of grid with strips that converge with angle of ray
Divergence
Which way do you angle Central Ray with linear grid
vertical
What grid permits least degree of error?
high ratio in terms of lateral angle
State 2 of 3 grid Motions
Reciprocate, Single Stroke, Oscalating
Can pregnant women take xrays?
yes
Define reproducibility?
Ability to produce same output (visible image) within 5%
Why should processor lid be open when turned off?
To prevent cross contamination due to evaporation
In this Processing agent, hydraconen is used as a ________ agent
developer
Black tree light found due to low humidity and _______.
static electricity
Random effect due to RAD like cancer is called
stocastic
Describe effect of using oxidized developer on Non-threshold Effect:
a) Density is Dec. b) Contrast is Dec. (Gets Whiter)
White areas on film due to:
photoelectric absorption
What type of tissue is most likely to undergo photoelectric absorption:
bone enamal
% of time that 1º beam aimed at one wall
use factor
This term defined between of lead strips/lead interspace
grid ratio
State Opt. KVP Spine
70-90
State Opt. KVP extremities
50-60 if non bucky
At what KV is it necessary to use bucky grid?
60
Why is problem to use bucky if don’t need one?
increase exposure
14x17 is largest film size, what grid ratio should you purchace?
10:1
purpose of floating lid
To catches oxidized developer from hurting film
Relationship SID and Distortion
indirect
This mutation is unique to RAD exposure
none
Can human cells recover from RAD damage?
yes
Latent Image?
invisible image of film before processing
latitude?
the ability to allow for error (forgiveness)
Hypo is another name for:
fixer
The current cumulative lifetime MPD formula
age * 1
Where do you wear a personal disimone
collar
State time, temp. method of manual processing
5 min. @ 68º
Developer temp. is 72º, how long do you develop
4 min
How do you install safe light filter?
Read words from left to right…b/c of gelatin must be away from the bulb
Film emulsion has these crystals suspended in gelatin
Silver halide crystals
Oxidized developer looks like
Coke or used motor oil
Proper name for film grainyness
quantom Mottel
How do you Dec. Q. Mottel
decrease system speed (dec. film screen speed)
What another way to decrease Q. Mottel
use higher mAs
Describe effect of crossover on blur
Inc. Blur (crossover = light striking through all parts of screen as it crosses through.
This type of contrast produced by High KVP, Low MAS techniques
long scale
What occurs if film screen contact occurs?
fog and blur
How far should safe light be from bench
4 feet
Relationship between film screen system speed and sharpness
inverse
Where is floating lid located?
on top of developer
Floating lid is in the replenishment tank
true
What does developer roller look like:
rubbery and the other one is wood
State max safelight bulb
15 watt
Where is hardener found in automatic developing
fixer and developer
State annual MPD for extremities
50 REM
State annual MPD for general public:
.1 REM
State annual MPD for occupational
5 REM
MPD for pregnant
.5 REM/gestation period
Give the 3 factors that produce scatter
Collimation, KVP, and Patient Thickness
What would overdeveloped look like
Dark
What causes small white specks on film
dirty screen
Purpose of control badge
Monitors transport RAD
Name of XRAY reaction with matter, Fog
compton scatter
As FFD, TFD, & SID Inc. blur does what
Decrease
What is grid frequency:
of strips/ cm
Why is advantages to have high grid frequency
Don’t need moving grid and no lines on the film
Undesirable absorption of 1º beam XRAYs
grid cut-off
Describe appearance of grid cut off due to lateral exposure
light on one side
Describe grid cut off when CR is off center
underexposed on one side
Describe grid cut off SID is too Short
underexposed on both sides
Describe grid cut off SID is too Long
underexposed on both sides
Out of total filtration required, how much added by manufactor
2mm A1 equivilant
Out of total filtration required, how much is considered
0.5 mm
Name 5 RAD protection devices
Shelding, collimation, Inc. developed system speed, opt. KVP, filters, intensifying screens
This color safe light is used with other chromatic (green) film
GBX Red
Describe degree and direction with crosshatch grid
perpendicular and no angle
State level of fetal exposure under which no therapudic absorption is ecomended
below 10 RAD
Leakage Radiation
not from port
10 day rule (selective scheduling)
X-ray the first ten days following 1st day of period
Controlled area, Area where people work near XRAY or something like that:
- Can have 10x RAD that uncontrolled can have
Results in innershell radiation
photoelectric absorption
What cause processed radiosgraphs to Δ color with age
too much fixer
Proper range of humidity for film storage
40-60%
6 RAD induced malignancy
Leukemia, Skin Cancer, Thyroid, Bone, Lung, and Breast.
Example of radiation induced response relationship threshold dose relationship
Cataracts and sterility
3 factors that influence compton scatter interaction
Kv bt 60 and 125 , thickness, collimated field size
Male therapy for ankylosing spondolytis increases in
Increases in leukemia
2 devices to reduce scatter radiation
Bucky grid and collimator, compresision band
-mutation unique to radiation exposure
none
SID relationship to magnification
inversely related
5 radiation induced malignancies associated with radiation
Thyroid, and breast, skin, bone, lung
x-ray interaction that results in inner shell ionization
photoelectric absorption
1 disadvantage of using bucky grid
increase exposure
silver halide converted to black metallic silver
developer
where is a personal dissimeter worn
On collar or outside the apron
state the whole body MPD per year exposure
5 REM
causes sharp white very sharp specks on film
dust or litter on film or screen
safe light filter required for rare earth screen comb.
red
orthrochromatic refers to this type of film
Rare earth type, green sensitive
describe degree of central ray angulation used with a crossed hatch grid
None, must be perpendicular
this type of grid is designed so that the strip coincides with the beam
focused
what is leakage radiation
Radiation from tube housing other than 1 port
level of fetal exp. below which not therapeutic abortion recommended
10 RAD
cutoff of using improper SID
Underexposed on both sides
purpose of tissue compression
To decrease scatter and exposure
this process turns radiograph yellow with stain
Fixer/hypo retention, too long in the fixer
clean and intensifying screen
Gauze, manufacturers recommend wipe in 1 direction
what effect would excess developer temp rad
Radiograph would be too dark, overexposed
excess time in developer look like
Overexposed, black
use of oxidized developer would result in a radiograph that would be
Underexposure
open a cassette in daylight
purple
-open a cassette in daylight, and process
black
film out of film bin into processor
clear blue
why bluish tint to film base
Easier on eyes, cuts down glare
stage of processing latent is converted to manifested image
developer
purpose of fixer
clears off undeveloped crystals
PBL device?
Positive beam limitation, collimator is the device
interaction with matter results in fog
compton scatter
purpose of airgap technique
Decrease scatter, without grid to reduce exposure
HQ is used as a reducing agent in..
In developer
-thiosulfate used as a clearing agent in
fixer
relationship b/t system speed and exposure
inc system speed decrease rad exposure
-relationship b/t speed and sharpness
Sharper at a slower speed
-relationship b/t crossover exposure and sharpness
Increase crossover decrease sharpness
relationship b/t film contrast and film latitude
High contrast is opposite of long latitude=film responds to wide range of useful density
-MPD for extremities annual MPD
50 REM per year
-occurs of film screen contact is poor
Blurring b/c light is allowed to spread
What device is used to test for film screen contact?
a copper screen, wire mesh
Type of luminescence appropriate for intensifying screens?
Green/yellow, rare earth type
What type of luminescence do our screen exhibit?
flurescence
What do you call the percentage of time a primary beam is aimed at a particular wall?
use factor
Which is most consistent with quantum mottel?
higher speed
Old formula for determining the maximum cumulative exposure for a occupationally exposed in person?
5(n-18)
Developer converts silver halide to?
black metallic silver
What is reproducibility?
It is the ability to produce same image with same mA, time and KVP
What happens if the thickness of the object and size when comptom scatter increases and KVP?
increases
Describe classical scatter in terms of energy loss and change of direction
The photon strikes the atom, it interacts with the outer shell and gives up no energy but does change direction
What two probabilities that an electron will undergo photoelectric absorption interaction?
a) low energy b) high atomic number
Archival quality of film is established in this stage of processing?
fixer
How often are firm badges monitored?
monthly
TLD badges?
every three months
At this level of exposure no genetic or somatic damage occurs
none
Film badge reports express occupationally exposed persons dosage in these units?
Millirem/seivert
Improper grid radius results in this pattern of grid cutoff? Unilateral or bilateral?
Bilateral
Describe SID and sharpness relationship?
SID increases, sharpness increases
Define what is PBL?
Positive Beam Limitation, it is a collimator
Two purposes of fixing?
a) to clear off undeveloped silver halide b) harden film
Remnant radiation is?
Rays that interact and make the image, transmitted and scattered rays.
What is the relationship between the reflective layer and screen speed?
The reflective layer and redirect isotropic rays going away from the film, more light make it to the film so the speed of the system is greater
what is the effect of reflective layer on sharpness?
decrease
This color safe light filter is required for rare earth film screen combinations?
Red, GBX
Central ray may be angled in this direction when using a linear grid?
In the direction of the strips, in our case, cephalad and caudal
Three advantages of tissue compression?
Reduced scatter, less exposure, improves contrast, improves detail, can decrease ovarian disease
Total filtration is?
.5 mm inherent, 2mm aluminum equiv.= 2.5 mm equiv.
Why is a cross hatch grid not recommended?
Less margin of error and you have to aim the beam perfectly, no angling in any direction, much more sensitive to short or long SID’s
Ground the film loading bench, why?
to avoid static
Where is the hardener found manual processing?
in the fixer
What is TVL.?
Tenth value layer, thickness of a material that will reduce the intensity of the beam to one tenth it’s value
Effect of using oxidized developer on density and contrast
Density decreases and contrast decrease
Effect of using a higher than appropriate developing temperature on both density and contrast
Density increases, contrast decreases
Dark room should not be painted this color?
Black, need color to reflect safe light
Silver is reclaimed from?
the fixer
Full spine x-rays are taken with what grid?
12:1
This type of effect is a random effect from chronic low dose exposure?
stochastic
What different types of exposure are allowed in a controlled area vs uncontrolled?
Primarily occupied by radiation workers, people who also may have a benefit rather than a risk. The controlled area can received up to 10 times the exposure of uncontrolled area
Relationship between grid ration and radiation exposure?
Higher the ratio, the more exposure, higher grid ration, less consistent with ALARA
According to Gurney-Mott theory, this is the latent image formation center?
sensitivity spec
With upper cervical technique, what is the recommended grid ratio?
8:1
Regular full spine (14 x 17), what is ratio
10:1
In order from most sensitivity to least
WBC and RBC, Epithelial cells, muscle and nerve cells
Two benefits to using compensating filtration?
Less exposure to the patient and a more uniform density on the film
Linearity?
The ability to change mA and time and get the same amount of mAs
your appropriate effective radiation dose is: (spine)
1.5 mSV (15 REM)
your appropriate effective radiation dose is: (extremity)
0.001 mSv (.0001 REM)
Comparable to natural background radiation for: (spine)
3 hours
Comparable to natural background radiation for: (extremities)
7 weeks
additional lifetime risk of fatal cancer from examination: (spine)
very low
additional lifetime risk or fatal cancer from exam: (extremities)
negligible
