|
State the level of exposure where there is no genetic or
somatic damage. |
0 |
| Once a pregnancy becomes known,
radiation dose of the embryo-fetus shall be no greater
than___? |
0.05 rem (50 mrems) in any month or
knowing 0.5 rem at time of pregnancy, she shall not exceed
.05 rem during the remainder of the pregnancy. |
|
What
is the whole body non-occupational exposure allowed for the
general public in an unrestricted area? |
0.1 rem per year, 1.0mSv/year, 0.002 rem/hr
or 2mrem hr (continuous or frequent exposure) |
|
High radiation area for the public can not get ___? |
>0.1 rem/hr at 30 cm distance from the source. |
|
When under 18, the max permissible dose is___of the adult? |
1/10 |
|
For shielding purposes, the maximum permissible exposure for
controlled area is? |
0.1 R/week |
|
What is the average energy of an
X-ray beam produced at 80 kVp? |
(1/3)*80 = 26.67 kVp |
|
The maximum allowable yearly dose to the general population
is? |
0.5 rem/year (Technician 5 rem/year) for infrequent
exposure. |
|
Lead apron should be no less than___? |
0.25 mm lead equivalent |
|
Out
of total filtration required, how much is considered? |
0.5 mm (X-ray tube) add 1 mm
A and mirror=1 =2.5 mm total=Inherent + added |
|
Total
filtration is? |
0.5 mm inherent, 2 mm aluminum
equiv = 2.5mm equiv |
|
Gonad shield should be no less than___? |
0.5 mm lead equivalent |
|
State
the MPD for the general public per year |
0.5 REM |
|
State
the MPD for pregnant occupational workers exposure? |
0.5 REM per gestational
period |
|
In terms of REM, what is the quality factor of x-rays and gamma
rays? |
1 |
|
What two things must pregnant workers do in regards to
taking x-rays?
|
1. They do not take x-rays. 2. Get a new radiation badge -
fetal badge |
|
100
Rem = ______Sievert. |
1Sv |
|
100 Rad = _____Gray |
1Gy = 1 joule/kg. |
|
How much of the electric and kinetic energy of the projectile
electrons are converted to x-ray? |
1% |
|
___ mRem = 1 Rem |
1,000 |
|
In x-ray: ____R = _____Rad =
_____Rem |
1,1,1 |
|
X-rays are produced by two
methods. Please name them? |
1. Bremstrahlung
(braking) radiation - polychromatic
and 2.
Characteristic radiation which is monochromatic. (All X-rays
are a combination of the two). |
|
Percentage for repeat films associated with a foreign
object? |
2% |
|
Out
of total filtration required, how much added by manufacturer? |
2mm A1 equivalent |
|
The amount of aluminum filtration recommended for diagnostic
x-ray tube operating above 70 kVp should be at least? |
2.5 mm including the inherent filter |
|
What is the average exposure per year in the USA?
|
3.6mSv |
|
A
cervical spine radiograph requires 12 mAs at 72" SID. What mAs is required to achieve the same radiographic density if the SID is changed to 40"?
|
3.7 mAs |
|
How far should the safe light
be from the work station? |
4 feet |
|
Developer
temp. is 72º, how long do you develop? |
4 min. |
|
What is the old cumulative life
time exposure formula? |
(5n-18) where n = age |
|
Time
and Temperature of manual developer processing? |
5 minutes at 68°F |
|
For maximum speed and contrast, films in a 68 F developer
should be developed for? |
5 minutes (Manuel Processor) Developer. Fixer time is
10 minutes and Wash time is 20 minutes. 5, 10, 20. |
|
What
is the occupational (MPD) whole body exposure dose (Tech)?
|
5 REM/year (Technition) or 0.05
Sv
= 50mSv |
|
State MPD for pregnant
occupational exposure? |
5 Rem per gestation period
(9mo.) |
|
What is the dose limit for a fetus? |
5mSv |
|
What is the skin entrance radiation dose for the Chest 400
speed? |
5-15 mrad |
|
J\1PD
for pregnant employee? |
5 REM per gestation period |
|
State
annual MPD for your friendly neighborhood Radiology Tech? |
5 Rem/year |
|
Annual Whole body MPD for occup.
exposed people? |
5REM |
|
Percentage for repeat films associated with processing
errors? |
6% |
|
An upper GI exam is performed at 3 mA for 2 minutes.
What is the total exposure if the patient's exposure rate is
1.2 R/mA/minute? |
7.2 |
|
With
upper cervical tech, what is recommended grid ratio |
8:1 |
|
What is the skin entrance radiation dose for the extremity
(elbow, shoulder...)? |
8-30 mrad |
|
Upper cervical practitioner
should purchase what grid ratio? |
8:1 |
|
The exposure rate 3 feet from a
source of radiation is 40mR per hour. What is the exposure rate at 6 feet? |
10 |
|
|
>10cm patient parts |
|
If a technique is based on 200
speed imaging system and requires 30 mAs, 80 kVp, 40" SID, what must be done to compensate if a new 600-speed system is
used?
|
10 mAs |
|
Level of fetal exposure below
which no abortion is recommended? |
10 RAD |
|
Regular full spine (14 x 17), what is
grid ratio? |
10:1 |
|
What size grid is appropriate for 14x17 films? |
10:1 |
|
When is it necessary to use a
grid? |
> 10 cm Thickness
and
> 60kVp |
|
Percentage for repeat films associated with patient
motion? |
11% |
|
Full spine x-rays are taken with what grid ratio
of? |
12:1 |
|
What size grid is appropriate for 14 x 36 films? |
12:1 or 16:1 |
|
What is the maximum Watts for a safe light? |
15 Watts |
|
What is the annual permissible dose for the Eye? |
15 rem |
|
State the maximum safe light voltage? |
15 Watts |
|
How much must the kv change to double radiographic density? |
15% |
|
If you decrease your exposure time by 1/2 you can increase
your kVP by_______ and still obtain the same overall film
density? |
15% |
|
For RAO projection of the neck the central ray has? |
15 degrees caudal tilt. (RPO-15 up) |
|
What procedure is used to perform a AP view of the sacrum? |
15 degree cephalad tube tilt |
|
Maximum allowable dose for the lens of the eye? |
<15 rem/year or 0.15 Sv/y |
|
20 mRad of x-ray exposure = ____mRem . |
20 |
|
If 5 MAS is required at 40 SID what MAS do you need at 80 SID? |
20 MAS |
|
Percentage for repeat films associated with poor
positioning? |
25% |
|
This
amount of change in this factor is required to see change in radiographic density? |
30% |
|
X-rays produced during diagnostic radiography have
energies of approximately what?
|
40KeV to 120KeV |
|
Proper range of humidity for film storage? |
40 - 60% |
|
Embryological effect for absorbed abortion? |
50 rad asorbed=>abortion |
|
What is the annual permissible
dose for the skin & extremities? |
50 REM/year
or 0.5 Sv/year |
|
J\1PD for any extremity? |
50 REM/year |
|
What is the optimum KVP for extremities under 10cm of thickness? |
50 to 60
if non bucky |
|
What percentage of X-rays taken are of the chest? |
50%-25% lumbar/abdomen, 17% extremities, 9% neck with 2.2
films/exam. |
|
Percentage of repeat films ass with exposure calculation
error ? |
50% |
|
Operating portable x-ray equipment requires ___between
technologist and patient, x-ray tube and useful beam? |
6 ft. |
|
Range of temperature manual processing limited to? |
60 - 75 degrees (Automatic
processing 92-95 degrees). |
|
The maximum lifetime accumulated exposure for a technician
30 years old is? |
60 rems (30-18=12, 5 (5 rem/year) x 12=60 rems) |
|
What percentage of all X-rays are taken in a Hospital
setting? |
64% - 7% in med group, 19% in private practice and 10%
other. |
|
What % Attenuation is expected of 75kVp primary beam by a
lead apron of 0.25 mm lead, .5 mm gonadal shield and 1.0
lead block? |
66.0%, 88% and 99.99% |
At
least _____ kVp is required to produce useful energy K-
characteristic X-rays of tungsten? |
69 |
|
What is the optimum KVP for spine
imaging? |
70 to 90 |
|
Which FFD should the Chest, AP full spine and Neutral
lateral cervical be taken at? |
72 FFD |
|
X-ray taken at 100mAs at 90kVp can be changed to
200mAs___and still maintain the same radiographic density? |
72 kVP (90 x .2=180, 90-18=72) |
|
How much of radiographic image is produced by intensifying screen? |
95% |
|
About___% of recorded density (blackening) on the film
exposed with intensifying screen is photographic in origin? |
98% |
|
How much of the electric and kinetic energy of the projectile
electrons are converted to heat? |
99% |
|
In an x-ray tube, fast moving electrons collide with
matter to produce x-rays. When the electrons interact
with the atoms of the target what are two ways that the
energy is given off?
|
99% given off as heat, 1% able to give up their energy in
one step that produces a photon |
|
1 rad = 0.01 Gy = ? |
100 ergs/gm (100 rad = 1Gray=1 joule/kg) |
|
State the average annual exposure
that medical personnel receive. |
< 100 mREM |
|
Diagnostic X-ray tube housing must be sufficiently shielded
to limit exposure one meter from housing to____? |
100 mR/hr or .1 R/hr |
|
How many REM = 1 Sievert? |
100 |
|
Difference of exposure between controlled/uncontrolled area |
100 mr/ 10 mr per week allowable exposure |
|
Which imaging system would result
in the most radiation exposure to the patient? |
100 speed |
|
Which imaging system would you choose if you were imaging extremities? |
100 speed |
|
Cataractogenic effect occurs at? |
Several hundred rads |
|
A lumbar spine radiograph
requires 30 mAs at 40" SID. What mAs will be required to
achieve the same radiographic density if the SID is changed
to 80"? |
120 mAs |
|
What is the skin entrance radiation dose for an AP and
Lateral Cervical spine? |
AP=95 mrad with the lateral 125 mrad. |
|
What is the skin entrance radiation dose for the thoracic
spine? |
200 mrad |
|
What is the skin entrance radiation dose for the abdomen? |
300 mrad |
|
What is the acute dose for female and male infertility? |
>300 rad=>infertility in female and >30 rad=>temporary
infertility in male. |
|
Define isotropic? |
360 degree emission of light
or
360 degrees divergence of x-rays
and other types of light |
|
What is the lowest film-screen
system speed that you should consider using for routine
spinal radiographs? |
400 speed |
|
The lowest dose given in a single exposure to permanently
sterilize a male is: |
500 rads |
|
The lowest dose given in a single exposure to permanently
sterilize a female is? |
1000 rads |
|
Which imaging system would result in a radiograph with the most quantum mottle? |
1200 speed |
|
Which imaging system would result
in the least radiation exposure to the patient? |
1200 speed |
|
Which imaging system is the most
consistent with the ALARA concept? |
1200 speed |
|
State the annual whole body MPD
for occupationally exposed persons in mRem. |
5,000
mRem |
|
What device is used to test for film screen contact? |
A copper screen, wire mesh |
|
To maintain the same radiographic density, increase of 10
kVp for an exam operating in the 70kVp range can be
compensated by? |
A reduction of exposure time by 50% (Cut time in 1/2). |
|
How does a grid work? |
A thin sheet of metal (lead) has a high atomic number and it
absorbs protons and electrons. |
|
Explain effects of using oxidized
developer on Non-Threshold Effect? |
a) Density is
↓ b) Contrast
is ↓. (Gets Whiter) |
|
What are the three things that can happen to an x-ray
photon? |
Absorbed, scattered, no interaction (pass through) |
|
Why is the back of the room lined with
lead? |
Absorb back scatter |
|
Why is the back of the cassette lined with lead? |
Absorb backscatter |
|
Sodium carbonate to soften and swell the emulsion so that
the reducers can reach exposed grains is the function of? |
Activator during the Developing stage. |
|
Name a practice that is not advisable? |
Advertise free x-ray exams during health fairs. |
|
Compare the cost of Full Wave
Rectification to High Frequency Rectification. |
Add $3000 |
|
If a lumbar spine x-ray was accidentally taken during
her first term of pregnancy, what should the doctor do? |
Advise the patient not to take unnecessary x-rays anymore. |
|
What is the current cumulative life time exposure formula? |
Age times 1 |
|
Yellowish and brownish discoloration suggests? |
Aged fixer. |
|
What are the 5 radiographic opacities from most
radiolucent to the most radiopaque?
|
Air, fat, soft tissue (fluid), mineral (bone), and metal |
|
This radiation can be stopped by
a piece of paper, what kind is it? |
Alpha |
|
What has the highest specific x-ray ionization? |
Alpha particle |
|
How is film manufactured to increase its' speed? |
Amount of crystals, size and
shape |
|
Coherant Scattering photon interacts with? |
All
electrons of the atom - found in diagnostic x-ray |
|
What is the measure of current flow?
|
Ampere - since current flow is small milliampere mA |
|
The ____ side of the x-ray tube
emits x-rays that are relatively perpendicular to the film. |
Anode |
|
What is the Anode heel effect? |
An x-ray beam is not uniform as it exits anode. There is
decreased intensity on anode side of tube. The energy
increases toward the cathode side. The right side of the
tube is typically the cathode |
|
How should you have your tube installed? (Which side up?) |
Anode |
|
Which side of the radiograph will be the sharpest? |
Anode |
|
Describe the use of "split
screens" |
Anode --> Thin part of the body
Cathode --> Thick part of the body |
|
That the Cathode side of the tube has more radiation
intensity (104%) and the Anode side has less radiation
intensity distribution (of only 97%) is called___? |
Anode Heel effect |
|
What are the associated charges with an anode and
cathode?
|
Anode (+), cathode (-) |
|
Where is the anode during an Lateral Thoracic |
Anode down |
|
Where is the anode during AP Thoracic |
Anode up |
|
Name one view which has a caudal tilt of the x-ray tube? |
AP coccyx |
|
Controlled area: |
Area where x-rays are taken |
|
Crossover exposure related to detail: |
As crossover increases, detail decreases |
|
Define ALARA |
As low as reasonably achievable |
|
Developer begins to age? |
As soon as it is mixed. |
|
How does collimation to the film
size or smaller effect the production of scatter radiation? |
As the collimated field size
decreases, compton scatter interactions also decrease (less
atom at the path of travel). |
|
If the film is severely underexposed how do you fix it? |
At least double mAs |
|
What is PBL? |
Auto collimation - positive beam limitation |
|
Automatic vs. manual processing chemical difference: |
Auto has hardener |
|
Selects the kVp? |
Autotransformer |
|
Increasing time and temperature in the developer solution
will increase? |
Average gradient, film contrast and increased fog. |
|
Describe how developer should be mixed. |
Avoid over oxygenating the liquid. Run it
down the side of the tank to minimize oxidation. |
|
Control badge monitors: |
Background and transport
radiation |
|
Comparing annual radiation exposure to the population in the U.S., most exposure comes from this source? |
Background: cosmic, terrestrial |
|
Which environments have the highest background radiation? |
Beach area and high mountain areas. |
|
What are the two methods to control scatter? |
Beam restriction or collimation and grids |
|
Why is there a floating lid on the developer replenisher chemistry? |
Because as the developer ages the oxidized developer tends to rise to the underbelly of the rust color and then settle back down
to the bottom of the container contaminating the liquid |
|
Why is a free electron in human tissue a worry? |
Because they are highly reactive and believed to be involved in degenerative diseases and cancers. |
|
A small focal spot produces? |
Better details. |
|
Improper grid radius results in this pattern of grid cutoff? |
Bilateral |
|
Developer converts silver halide crystals to? |
Black metallic silver |
|
The developer converts exposed silver crystal halide to? |
Black metallic silver |
|
The visible image of the radiograph is composed of? |
Black metallic silver grains. |
|
Dark room should not be painted this color? |
Black. Dark Rooms needs color to reflect safe light. |
|
What color of light do calcium
tungstate screens emit? What type film must be used with them?
|
Blue-violet.
Blue
sensitive film |
|
This occurs if screen-film contact is poor? |
BLUR! (geometric).
Remember Fog is a photographic issue. |
|
What 5 things is each technique chart specific for?
|
Body region, cassette/screen type (speed), grid vs. table
top, x-ray unit, FFD |
|
What type of tissue is most likely to undergo photoelectric absorption? |
Bone Enamel |
|
When improper SID is used on a grid, what does grid cut off look like? |
Both lateral side of the film are cut off an underexposed |
|
Improper SID used on focus grid; Pattern of grid cutoff looks like? |
Both sides are cutoff; so the film is underexposed |
|
Improper grid radius results in this kind of cut off? |
Both sides are underexposed. |
|
What are the two ways that diagnostic x-rays are
produced?
|
Bremsstrahlung radiation "breaking radiation" and
characteristic radiation. |
|
This x-ray production process
produces the majority of x-rays in the beam? |
Bremsstrahlung |
|
What is the predominant mode of radiography? |
Bremsstrahlung radiation |
|
Occurs when an electron penetrates the anode metal and
passes close to the nucleus of the tungsten atom where it is
deflected and slowed down by the attractive forces of the
nucleus? |
Bremsstrahlung radiation |
|
Occurs when an electron is slowed
down due to a nuclear force field? |
Bremsstrahlung |
|
When projectile electron is slowed by nuclear force field, these x-rays are called? |
Bremsstrahlung |
|
Intensifying screens are made up of? |
Calcium tungstate. |
|
What causes a dark band on the long edge of a film? |
Cassette hinge is defective or cassette cover not tightly
closed. |
|
Shadows of cassette hinges along one side will show up on
the film only when? |
Cassettes are inserted into the cassette tray backside
toward the front. |
|
Give
a disease example of RAD reduced
response that follows threshold response? |
Cataracts |
|
This side of the radiograph will exhibit the most blur? |
Cathode |
|
This side of the tube produces the most xrays? |
Cathode |
|
X-rays travel from _______ to _______ to make x-rays |
Cathode to anode |
|
Electrons travel from: |
Cathode to anode to make x-rays |
|
What is the cause of quantum
mottle? What does it look like? |
Caused by too few x-rays, low
mAs/fast speed film. Quantum mottle is the proper name for film graininess. |
|
What does a rectifier do? |
Changes AC current to DC current |
|
Which
of these methods produces X-rays when electrons shift energy levels/shells within the atom?
|
Characteristic
Radiation |
Occurs when the incoming electron strikes an orbital
electron and ejects it from its shell?
|
Characteristic Radiation |
|
What relationship between exposure and density is plotted on
a curve called? |
Characteristic curve |
|
What view would be benefited from short exposure time? |
Chest film (Careful not to see motion artifact/blur
film-hold breath) |
|
Full inhalation is used in which view? |
Chest view. |
|
Which type of examinations utilize longer FFD or SID? |
Chest and, lateral cervical . |
|
Coherent Scatters is also known as? |
Classical Scattering or unmodified scattering. |
|
Two purposes of fixing? |
Clear off undeveloped silver
halide and harden film |
|
Ammonium or sodium thiosulfate is used
to remove underdeveloped silver halide grains from the film.
The unexposed grains leave the film and dissolve in the
fixer. This is called? |
Clearing (The clearing activity
can recover the accumulated silver and then electroplate it
onto a metallic surface within the silver recovery unit). |
|
Which x-ray interaction is the
most likely to occur at energies below 10 KeV? |
Coherent Scatter |
|
Thompson (photon interacts with a single electron) &
Rayleigh are? |
Coherent Scattering types. |
|
Film Fog can be caused by? |
Coherent Scatter |
|
Oxidized developer looks like? |
Coke or used motor oil |
|
Where does a pregnant women wear
film badge (s)? |
Collar and waist over lead apron |
|
Name two things that can reduce Compton backscatter |
Collimating and lead in the back of the cassette |
|
2 devices used to reduce Compton scatter: |
Collimation and bucky or compression band |
|
Define Total Filtration |
Combination of added which is
equivalent to 2 mm of Al and inherent which is .5 mm from
the Pyrex tube itself therefore giving you 2.5 mm of Al
equivalent. |
|
Besides using the anode heel
effect properly there are two other options that may help to
produce a more uniform film density. They include? |
Compensating Filters
and
Slow Speed where area is thin; faster speed where is
thickest. |
|
What are the two types of digital imaging?
|
Computed radiography and digital radiography |
|
A partial transfer of energy upon collision is characterized
by the? |
Compton effect. |
|
Which x-ray interaction with
matter is related to the energy of the x-ray photon? |
Compton - increasing energy,
increases the probability of it occurring. It is totally
independent of atomic number of the material it is
interacting with.
Photoelectric - decreasing KVP increases the probability of
it occurring.
Classical - decreasing energy will lead to increase in
probability. |
|
Which interactions
with matter discussed are important in diagnostic level radiography? |
Compton Effect and Photoelectric
Effect |
|
Name of X-ray reaction with matter
and Fog? |
Compton Scatter |
|
Which x-ray interaction with
matter is most likely to occur at energies greater than 60
keV? |
Compton Scatter |
|
How does kVp effect the
production of scatter radiation? |
Compton scatter interaction
increases as kVp increases.
The ideal is no scatter as
Scatter leads to poor contrast, fog, and dull film.
Increasing kVp will give long scale of contrast and thus
lots of shades of gray. |
|
Thermionic emission or 99% of the energy are converted to
heat and dissipated by a rotation anode made of? |
Copper |
|
What is the anode made of and why? |
Copper with tungsten target. Copper because it's a good heat
conductor and anode is covered by tungsten because it as a
high atomic number and a high melting point. |
|
Why does the path the x-ray
travel matter? |
Concentration of chemistry |
|
The focusing cup is to? |
Concentrate the electron stream toward the anode. |
|
Differential absorption results in this photographic property? |
Contrast |
|
What are three examples of natural radiation?
|
Cosmic rays (sun), terrestrial (uranium, radon, thorium) and
internally deposited radionucliotides. |
|
Inside a cassette cabinet is? |
Counter weight balance. |
|
Why is density expressed in logarithm? |
To conveniently express large differences in small numbers. |
|
What is the function of the developer? |
Converting silver halide crystals to black metallic silver. |
|
What does a rectifier do? |
Converts AC to DC current |
|
State the unit that a physicist would use to describe ionizations in air in Systems? International nomenclature. |
Coulombs/kg |
|
What is the measurement of radiation exposure in air?
|
Coulombs (used to be Roentgen) |
|
Why do we leave the developer lid
open at night? |
Cross contamination of fixer and
developer due to condensation |
|
Why does a double-coated film
emulsion result in a decrease in sharpness? |
Cross over |
|
What chemical can replace sodium sulfite as a preservative
in automatic processing? |
Cycon |
|
Crescent or moon shaped areas on an x-ray film is caused by? |
Bending the film before exposure. |
|
What type of current is required
to produce x-rays? |
DC |
|
How do you ↓ Q. Mottel? |
↓system speed (↓ film screen speed) Or... Use higher MAS |
|
Effect of reflective layer on sharpness? |
Decrease |
|
Purpose of intensifying screens? |
Decrease patient exposure and
extend tube life? |
|
What are the two purposes of collimation? |
Decrease patient dose of radiation and decrease scatter
(thus improve radiographic quality) |
|
Describe the effect of oxidizing developer has on the density of films. |
Decrease density so films get lighter. |
|
If a tube overload occurs? |
Decrease mA, increase time |
|
What is the purpose of intensifying screens? |
Decrease patient exposure |
|
What is the purpose of the air gap technique? |
Decrease scatter |
|
As TFD increases what happens to
blur? |
Decrease TFD = SID |
|
With tube overload, what must be set? |
↓mA ↑time |
|
What is the advantage of a high
frequency grid? |
Decreased line visibility
and no need for a moving grid mechanism. |
|
As FFD, TFD, & SID Increases blur
does what? |
Decreases |
|
How can you decrease the heel effect? |
Decreases with small field size and increased film-focal
spot distance |
|
An increase of 10 kVp can be compensated by? |
Decreasing the exposure time by 1/2 (↑
10 kvp 1/2 mass) |
|
Poor screen film contact results in? |
Definition reduction. |
|
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 |
|
Males receiving radiation for
ankylosis spondylolisthesis: |
Develop leukemia |
|
Which type of x-ray equipment requires no cassette/image
storage device? |
DR digital x-ray unit. |
|
What is the processing order to "fix" a film? |
Fixer, Acidifier/activator (Acetic Acid),
Clearing agent (Ammonium thiosulfate), Hardener
(Potassium alum), and Preservative (Sodium sulfite) |
|
List the times for the various processes in a 90 second
Automatic Processor beginning with the Developer? |
Dev-20-25 sec, Fixer-20 sec, Wash-20 sec, Dry-25-30 seconds. |
|
This processing solution is alkaline? |
Developer |
|
What are Hydroquinone and Elon? What is their function? |
Developer. Act as reducing agent. |
|
Where is the hardener in auto developer? |
Developer and Fixer |
|
Which chemical prevents rapid oxidation of the developer? |
Sodium sulfite (Preservative). |
|
The function of the preservative is to? |
Prolong life of developer. |
|
What is radiographic contrast? |
Differential absorption of
tissues;
Results in different degrees of white and black on the film. |
|
Replenishment rates in automatic
processing are dependent on this? |
Direction of film travel thru film processor |
|
How is the grid ratio related to patient exposure? |
Directly |
|
Density SID Equation |
Directly Proportional (old/new = old2/new2) |
|
Kvp and compton scatter: |
Directly related |
|
Scratch marks of the films are usually caused by? |
Dirty rollers. |
|
This type of grid has strips that converge with angle of ray? |
Divergence |
|
Stochastic effect? |
Does not have a threshold |
|
Reproducibility: |
Doing the exact same exposure
over and over and getting the exact same results |
|
What
are advantages to have a \high
grid frequency? |
Don't need moving grid and no
lines on the film |
|
When you need to double the density,
what do you do to mAs? |
Double mAs |
|
An increase in the log exposure to the film of 0.3 always
increases film density by? |
Doubling |
|
Where should the anode side of the tube be placed when performing a lateral thoracic spine
radiograph? |
Down |
|
Which edge of the processor feed
tray should be used and why? |
Either the top or bottom edge.
To insure that the chemistry is evenly distributed over the entire film and to allow for the entire radiograph to be
developed. |
|
What is an X-ray? |
Electromagnetic Energy |
|
What is an
X-ray and elaborate? |
Electromagnetic energy is the transport of energy through space as a combination of electric and magnetic fields.
X-Ray wavelength is measure in billionths of an inch, thus has high frequency
and reacts with atoms |
|
What is another name for a single
x-ray in the beam? |
Electromagnetic Radiations;
Proton |
|
Radio waves, microwaves, ultraviolet, infrared, and visible
light are? |
Electromagnetic Radiation. |
|
Electrical energy in the x-ray system is used to produce
what? |
Electromagnetic energy which is converted to chemical energy
in the radiographic film or detector. |
|
In the x-ray tube, how are the
x-rays produced? |
Electrons are boiled off from
cathode to anode/ |
|
Describe how and when crossover
rollers should be cleaned. |
Every day.
Pull up the developer (rubber) and fixer (wood) rollers and using a plain old sponge to clean them. Have one color spong for the developer and one for the fixer. |
|
TLD badges
should be changed?
|
Every three months |
|
When heat is produced in
the tungsten
target, what type of reaction is that called? |
Excitation |
|
Is
heat production an excitation interaction or is it an
ionization interaction? |
Excitation |
|
Who receives somatic effects of
radiation? |
Exposed patient; these effects
are increased incidence of cancer, effects on the developing embryo, cataracts, and life span shortening. |
|
Use of a non-grid technique is implemented in? |
Extremity examinations. |
|
Where are compensatory filters
placed? |
Face of the collimator |
|
What is the result of film speed on image resolution?
|
Faster speed = shorter exposure time but less resolution,
Slower speed = longer exposure time but greater resolution. |
|
State 2 AKA's for SID? |
FFD and TFD |
|
The total amount of radiation received by a patient during
radiography is chiefly affected by___? |
Field size being exposed. |
|
Cathode's 2 primary parts: |
Filaments and focusing cup |
|
X-ray of a thin mesh wire is to detect? |
Film screen contact. |
|
Which part of the x-ray tube has to be heated if radiographs
were to be taken? |
Filament (tungsten) |
|
What are the four steps of film processing?
|
Film, developer, fixer, wash. |
|
What should be done instead of
using "split screens"? Why is this consistent with the concept of ALARA? |
Filters, to reduce exposure |
|
Define inherent filtration. |
Filtration the pyrex gives you |
|
The greatest radiation hazard to an embryo or fetus occurs
during the? |
First trimester. |
|
This processing solution is
acidic? |
Fixer |
|
Where does silver recovery happen? |
Fixer |
|
Where would you find the clearing agent, hardener, and preservative? |
Fixer |
|
Hypo is another name for? |
Fixer |
|
This processing chemistry must be passed through a device to reclaim silver? |
Fixer |
|
This processing solution is
considered an environmental hazard? |
Fixer b/c of the silver involved |
|
Sodium thiosulfate in a processing solution serves as a? |
Fixing agent (known as a clearing agent). |
|
After leaving the developer the film is transported into a
second tank, which contains_? |
Fixing contents |
|
What causes radiographs to stain
brown with age? |
Fixer problem / problem with
fixer retention |
|
What causes processed radiographs
to stain w/ age and turn brownish-yellow? |
Fixer retention |
|
Archival quality of film is
established in this stage of processing? |
Fixing |
|
What type of luminescence do our
screen exhibit? |
Fluorescence |
|
What are the four exposure factors involved in producing
a radiograph?
|
Focal film distance (FFD), kVp, mA, and time. |
|
At what specific point are x-rays
formed/produced in the tube? |
Focal spot on the target of the
anode |
|
Describe the make up of the
cathode? |
Focusing cup as well as the
short and long filaments |
|
What occurs if film screen
contact occurs? |
Fog and Blur |
|
What's most likely to
occur with
x-ray? |
Free radicals |
|
In the X-Ray tube X-Rays travel
from what to what? |
From cathode to anode |
|
Describe the use of a compensating
filter for a lateral spine shot. |
Utility if from L1 to L4 or 5 |
|
Name the projection which shows the L5 disc spaces with the
best clarity? |
Frontal lumbosacral spot. |
|
Which rectification is most
consistent with ALARA. |
Full Wave Rectification |
|
Which
of these types of rectifiers produces the highest contrast
radiograph? |
Full Wave Rectification |
|
Which of the types of energies in
the electromagnetic spectrum have the ability to ionize? |
Gamma and X-Ray |
|
Red safe light is considered
universal; name of safe light? |
GBX |
|
This color safe light is used
with other chromatic (green) film? |
GBX Red |
|
How is a safe light filter
installed? |
With the Gel substance on the outside so
you should be able to read the letters. |
|
What will happen to film if
developing temperature is to warm? |
Gets Darker |
|
What will happen to film if it
spends excess time in the developer? |
Gets Darker |
|
What are the general characteristics of an x-ray tube? |
Glass tube containing an anode and cathode. Cathode (-) end
has a coiled tungsten wire filament within a focusing cup. |
|
What happens to the original
x-ray following the Compton scatter interaction? |
Goes on to other reactions and
creates fog. |
|
What type of chiropractic
practice would require a relatively high grid ratio? |
Gonstead |
|
State the unit of absorbed dose
in Systems International nomenclature. |
Gray |
What is the measurement of an absorbed dose of radiation
(how much enters a patient)?
|
Gray |
|
Films improperly washed after fixing would result in? |
Greasy appearance. |
|
The advantage of a rotating anode over stationary anode
x-ray tube is? |
Greater tube capacity for heat. |
|
What color of light do rare earth
crystals typically emit? |
Green and Yellow |
|
Type of luminescence appropriate
for intensifying screens? |
Green/yellow, rare earth type |
|
What is the most common method of reducing scatter?
|
Grids |
|
A thin sheet of metal (lead) which has a high atomic number
and absorbs protons and electrons defines how a___works? |
Grid |
|
Where is the radiographic grid
placed? |
Grid is a.k.a. bucky so between
patient and film |
|
Efficiency of grid strongly dependent on? |
Grid ratio (Where efficiency = the cut in scatter) |
|
Height of lead strips divided by
width of lead strips is called? |
Grid ratio |
|
The formula of kVp x mAs x 1.3 would be used for calculation
of? |
Heat Unit. |
|
Glutaraldehyde is used to retard the swelling of the
emulsion necessary in automatic processors in which the film
is transported by a system of rollers. This is called? |
Hardener (During Developer stage) |
|
Aluminum chloride functions to shrink and harden the
emulsion. This process is called? |
Hardener (During the Fixer stage) |
|
In pediatric radiography, how should a child be stabilized? |
Have the parent/guardian hold the child still. |
|
Number of electrons that pass through the x-ray tube for any
given exposure is chiefly dependent on? |
Heat of the filament. |
|
Variation of the x-ray intensity along the tube axis is
known as the? |
Heel effect (One side strong the other side weaker) |
|
Grid ratio is? |
Height of
the lead strip divided by width of interspace |
|
The collimator functions to? |
Help reduce scattered radiation. |
|
What type of tissue most likely
to undergo photoelectric interaction? |
High atomic # |
|
Photoelectric absorption
interaction = |
High atomic # |
|
To maintain optimal film contrast in higher kVp exams,
___grid ratio is important. |
High |
|
Which type of rectification has
the highest energy beam, shortest exposure time? |
High frequency |
|
Which rectifier will provide
the least radiation exposure to the patient? |
HIGH FREQUENCY (30% less) |
|
Which x-ray generators produce highest energy photon
consistently? |
High frequency x-ray (Not single or triple phase and not
digital) |
|
Which rectifier will give the
least radiation to the patient? |
High frequency (about 30% less) |
|
Which of these types of
rectifiers produces a beam with the highest energy x-rays? |
High Frequency Rectification |
|
Which of these types of
rectifiers can be plugged in to a 110 outlet? |
High Frequency Rectification |
|
Which of these types of
rectifiers will extend the tube life? |
High Frequency Rectification |
|
Which of these types of
rectifiers reduces patient exposure by at least 30%? |
High Frequency Rectification |
|
What grid permits the least
degree of error? |
High Ratio in terms of lateral
angle |
|
Quantam mottle is caused by? |
High speed/screen film
combination |
|
What is the relationship between grid ration
and radiation exposure? |
Higher ratio, the more exposure.
Higher grid ratio, less consistent with ALARA |
|
Which is most consistent with
quantum mottle? |
Higher speed |
|
How is system speed related to detail? |
Higher speed, detail decreases |
|
Name the two persons responsible for plotting of the
characteristic curve? |
Huerter and Driffield |
|
Define manifest image? |
Image on film after processing. |
|
Define latent image? |
Image on film before developing |
|
To avoid being exposed to x-rays,
how long must you wait before entering the x-ray room, after
the exposure is terminated? |
Immediately |
|
In
humans, what type of ionization is most likely to occur? |
Indirect
effect. |
|
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 |
|
Where is the hardener found in
manual processing. |
In the fixer |
|
Automatic processing, where is
the hardener? |
In the fixer and developer. Please note that the fluids turn to a
gelatin emulsion when it is wet, turns to jello, so its also
in the developer to prevent this reaction. |
|
What are three things that can increase scatter? |
Increased patient size, increased kVp, and increased field
size. |
|
Doubling the FFD during X-ray examination requires___ to
maintain the same film density? |
Increase of the mAs by four times (2 x FFD x 4) |
|
How is film contrast related to
film latitude? |
Increase contrast - decrease
latitude
(Inversely related) |
|
A decrease in grid ratio will? |
Increase film density. |
|
How does mA effect radiographic density? |
Increased density (blackness)=mA controls number (quantity)
of electrons produced and has most effect on blackening.
Increased mA |
|
How does kVp effect radiographic density?
|
Increased
density (blackness)=Controls
the voltage between cathode and anode. Increased kVp |
|
What occurs as kVp is increased?
|
Increased density (blackness) |
|
The purpose of the rotating anode is to? |
Increase the tube capacity for heat. |
|
Secondary radiation affecting the film is increased by? |
Increase in kilovoltage (Compton effect) |
|
As room temperature increases, the speed of the film? |
Increases |
|
Compton scatter increases with? |
Increase in kV, field size,
and decreased image distance |
|
When you need to double density
what do you do to KVP? |
Increase it by 15% |
|
Though kVp is not the
controlling factor of radiographic density, to double radiographic density using kV? |
Increase kV 15% |
|
What occurs when mA is increased?
|
Increased density (blackness) |
|
If MAS is reduced by 50%, how
much should you change KVP to get equal density? |
Increase KVP 15% |
|
Double radiographic density using
kvp? |
Increase kvp by 15% |
|
Describe effect of crossover on
blur? |
Increased Blur (crossover =
light striking through all parts of screen as it crosses
through). |
|
Why is it a problem to use a bucky if one isn't
needed? |
Increased Exposure |
|
What is the effect of increased and decreased time in
the developer on the exposure of the film?
|
Increased time = blacker, decreased time = lighter |
|
As KVP increases what happens to
Compton scatter? |
Increases - direct relationship
between the two |
|
Name one disadvantage to using a
grid? |
Increases patient exposure. |
|
What are two things that effect cosmic radiation?
|
Increases with altitude and latitude (north pole) |
|
How does collimation to the
smallest field size effect radiographic contrast? |
Increasing film size reduces
scatter radiation. |
|
Field size, thickness of the body part
and kVp all do what to scatter? |
Increase scatter-↑
body part thickness, ↑ Field size and to a lesser degree
↑ kVp, all
↑ Scatter (Low kVp increases
dose so in practice we maximize kVp. |
|
What is the Relationship between SID and Distortion? |
Indirect |
|
Which is most likely to occur in
human tissue? |
Indirect effect (Mutate to
change rather then directly changing genes) |
|
Describe the relationship between
photon, wavelength and energy? |
Indirect relationship |
|
Which shell level is ionized in
the photoelectric absorption interaction? |
Inner Shell |
|
Photoelectric effect involves? |
Inner Shell electrons-involved in diagnostic x-ray |
|
I/I*=(D*)2 / (D)2
= |
Inverse Square Law |
|
Double the FFD will give 1/4 of exposure? |
Inverse Square Law thus increase mass by 4 times |
|
One half of the FFD will increase exposure 4 times? |
Inverse Square law thus decrease mass by 4 times |
|
Triple the FFD will give 1/9 of the exposure? |
Inverse Square law |
|
One third of the FFD will increase exposure 9 times? |
Inverse Square law |
|
The film latitude varies___with film contrast? |
Inversely |
|
What is the relationship between
crossover exposure and blur? |
Inverse, decrease crossover =
increased blur |
|
Describe the relationship between SID
and magnification distortion? |
Inverse |
|
Describe the relationship between film screen
system speed and sharpness? |
Inverse |
|
How is a photons wavelength
related to its energy? |
Inverse |
|
What is the relationship between
x-rays and wavelength? |
Inverse |
|
What is the relationship between
voltage ripple and x-ray energy? |
Inverse (as ripple increases,
x-ray decreases) |
|
What is the relationship b/w frequency and
wavelength?: |
Inverse relationship |
|
What is the relationship between
Compton Scatter and collimator field size? |
Inverse, as you increase
collimation you decrease scatter. |
|
How is photon wavelength related
to it's energy? |
Inversely |
|
How is a photon related to its
energy? |
Inversely |
|
How are contrast and latitude related?
|
Inversely. High contrast = low latitude (few shades of
gray), low contrast = high latitude (increased number shades
of gray) |
|
What is the relationship between SID and
magnification? |
Inverse |
|
What is the Relationship between frequency
and wavelength? |
Inversely proportional |
|
Intensity Equation |
Inversely Proportional (old/new
= new2/old2) |
|
What agent is commonly used in studies of the vasculature? |
Iodine. |
|
State at least 2 advantages of
performing PA lumbar spine examinations instead of AP. |
It decreases radiation dose to
the gonadal region, decreases scatter and
Improves detail. |
|
Application of what principal/rule minimizes radiation
exposure dose to the patients? |
Inverse square law. |
|
As quality assurance of our X-ray units & darkroom
equipments___? |
It is acceptable to take experimental x-ray films of either
phantom parts or other objects first, run it through the
processor, before accepting the first patient. |
|
State at least 2 advantages of
tissue compression
|
It decreases the number of atoms
in the path of the travel of the x-ray.
Decreased patient thickness = Decreased Compton Scatter |
|
Where should the anode side of
the tube be placed when performing a lateral cervical spine
radiograph? |
It doesn't matter on a 10x12"
film at 40" |
|
Why is the processor lid left
open when the processor is off? |
It gives the liquid the
opportunity to cool off to room temperature and
allows the developer and fixer to rise to the top without
settling back down and avoids cross contamination of
developer to fixer. |
|
Purpose of using an airgap?. |
It increases OID, to decrease
scatter without using a grid |
|
What is a gamma ray? |
It is a high energy ray that
comes from inside the nucleus. |
|
What is differential absorption? |
It is the difference between
what is absorbed vs. what is transmitted.
Helps to determine radiographic contrast. |
|
What does kVp do inside the tube
to produce x-rays? |
It is the technical factor that
controls the energy of the electron. |
|
What happens to the original
x-ray following the photoelectric interaction? |
It is totally absorbed resulting in the bright areas on the radiograph |
|
How does placing the anode /
cathode side in the proper place affect the radiograph's
overall density? |
It produces uniformity in density |
|
What is radiographic density? |
It refers to the film's degree
of blackness. |
|
What is ionizing radiation capable of doing to an
orbital electron?
|
It can remove an orbital electron from the atom with which
it interacts - the result is an ion pair. This occurs when
an x-ray passes close to an orbital electron of an atom and
transfers enough energy to remove it. |
|
Which
Characteristic X-rays of tungsten are energetic enough to be
useful? |
K-Characteristic |
|
Which characteristic x-ray are
useful in tungsten target? |
K-shell |
|
For every degree
increase in the developer for manual
developing? |
You
have to add 15 more seconds |
|
Which exposure factor controls
differential absorption? |
kVp |
What exposure factor controls the voltage differential
between the cathode and anode?
|
Kilovoltage anode-cathode circuit (kVp) |
|
The exposure factor that produces the longest scale of
contrast? |
kVp |
|
Secondary radiation is increased with higher___? |
Kilovoltage (Increased compton effect) |
|
Why does high kVp give less contrast?
|
kVp photons are less discriminating and pass through all
materials easily with less difference between tissues |
|
Technical factor that controls
wavelength of x-rays in the beam? |
kVp |
|
What is the wavelength of an
x-ray dependent on? |
kVp |
|
What factors control x-ray
energy? |
kVp |
|
What is the
highest energy X-ray in the beam dependent on? |
kVp |
|
State the formula for heat units? |
kVp x mA x time |
|
What is the formula for heat
units? |
kVk x MAS |
|
Radiographic contrast is
controlled by? |
kvp/mAs relationship |
|
Where should the compensating
filter be placed for a lateral lumbar? |
L1-L3 |
|
Radiosensitivity of tissues depends on
the degree of undifferentiation in cells. Lymphocytes
more sensitive then nerve tissues for example. |
Law of Bergonie & Tribondeau
(Lymphocytes are more undiffertiated) |
|
When does the anode heel effect
become important in terms of film size and source image
distance (SID). |
Large film sizes at short SID |
|
How does increasing the distance from the film affect the
sharpness of the image on a large and small focal spot? |
Large
focal spot = fuzzier and more distorted while a small focal
spot = still sharp image, |
|
What are the two filament sizes and how does filament size
determine the focal spot size (how compact the x-ray beam
will be)? |
Large and small. A small compact beam gives a sharper image
but can tolerate less heat. |
|
Which view best depict lumbar IVF's? |
Lateral view |
|
Describe a radiograph taken at
the improper grid radius? |
Laterally underexposed (white) |
|
Radiation that comes from tube
housing in areas other than port? |
Leakage |
|
What is the radiation that comes
from the tube housing (other from the port) of the tube? |
Leakage radiation |
|
For any given film dose, skin entrance dose for the patients
is___when the films are taken with a longer FFD? |
Less. |
|
Two benefits to using compensating filtration? |
Less exposure to the patient and a more uniform density on the film |
 Why is a cross hatch grid not
recommended? |
Less room for error, and you
have to aim the
beam perfectly, no angling in any direction, much more
sensitive to short or long
SID's |
|
What is the level of female
exposure for which there is no risk of having an
abortion/getting an abortion? |
Less than 10 RAD |
|
Define LD 50/30? |
Lethal dose mean 50% of
population dies in 30 days |
|
Men who had ankylosing
spondylosis had an increase in? |
leukemia |
|
Shortest latent period of
cancers? |
Leukemia |
|
Name two radiation induced
malignancies? |
Leukemia and thyroid cancer |
|
Of Radical induced cancers, which
has shortest latent period? |
Leukemia only 7 yrs. |
|
Name two more radiation induced
malignancies? |
Leukemia, skin, bone, lung,
thyroid, and breast cancer. |
|
State the wave equation? |
Light = wavelength x frequency |
|
How do you know the dead man
switch exposure is terminated? |
The light goes off |
|
How do you know x-rays are
produced and are terminated? |
The light goes off |
|
Describe the appearance of grid cut
off due to lateral exposure? |
Light on one side |
|
Dust on an intensifying screen
results in? |
Little white specks. |
|
What reduces scatter radiation? |
Longer FFD, use of the air gap technique or use of a grid. |
|
This type of contrast is produced
by High KVP, Low MAS techniques: |
Long Scale |
|
What does the term film latitude
mean? |
Longer scale - tolerate error |
|
Secondary radiation usually has___wavelength than the
primary radiation? |
Longer |
|
Which view demonstrates the lung apex the best? |
Lordotic chest (Pancoast tumor) |
|
What procedure is used to perform a pulmonary examination? |
Lordotic view |
|
Shallow breathing is recommended in which view? |
Lateral thoracic spine to blur out the ribs. |
|
Full exhalation is recommended in which view? |
Lower ribs. |
|
Two probabilities that an
electron will undergo photoelectric absorption interaction? |
Low energy and high atomic
number |
|
Tube overload corrected by? |
Lower mA and increase time |
|
The exposure factor that produces the least heat units would
be? |
Lowest time |
|
List the variation in cell sensitivity from most to least
sensitive? |
Lymphocyte, erythrocyte, epithelium, endothelium, con
tissue, bone, muscle nerve, brain. Nerve and brain
cells not turned over so less sensitive. |
|
The exposure factor that produces the the greatest film
density? |
mA |
|
What factor is selected to select
filament size? |
mA |
|
The focal spot size is dependent
on this exposure factor? |
mA |
|
Air gap technique produces? |
Magnification of body parts. |
|
One disadvantage to grids? |
Significantly higher patient exposure. |
|
What are two sources of ionizing radiation?
|
Man made and natural. |
|
Define linearity? |
Manipulating the MA and time to get the same MAS |
|
Electrical unit that controls total number of x-rays? |
mAs |
|
What is the controlling factor for
Radiographic density? |
mAS |
|
What controls the number of x-rays in the beam? |
mAS |
|
This exposure factor controls the quantity of the x-rays in the beam? |
mAs |
|
The # of x-rays in beam is controlled by? |
mAs |
|
When collimating down "significantly", what must be done to maintain radiographic density? |
mAs must be increased by 50% |
|
State the formula for heat units? |
mAs x kVp |
|
LD 50/30: |
Means lethal dose where 50% of exposed population dies within 30 days |
|
The view that shows the ankle mortise joint the best is? |
Medial Oblique. |
|
Reduction of silver bromide into metallic silver during
development is by? |
Metol and hydroquinone which are reducing agents. |
|
Film badge reports express occupationally exposed persons dosage in these units? |
Millirem seivert |
|
Purpose of control badge? |
Monitors transport RAD |
|
How often are film badges
monitored? |
Monthly |
|
Collimated field size and scatter
production? |
More collimation, less scatter |
|
A Bucky is also known as a? |
Moving grid |
|
Ability to manipulate mA and time and get the same image? |
Linearity: |
|
What charge is on the focusing cup? |
Negative |
|
What is the disadvantage of using a grid? |
Need to increase mAs 2 to 3 times when using grids vs
non-grids. |
|
Which view best demonstrates a posterior dislocation of a metacarpal bone? |
Neutral lateral view. |
|
As film is removed from the developer, development
continues because of soaked up solution by the emulsion.
To stop this action and prevent overdevelopment and
fogging of film, acetic acid is a? |
Neutralizer also called activator |
|
Film badges should___ be worn by radiation workers when
going to medical or dental x-ray's themselves? |
Never |
|
How often must lead walls be replaced? |
NEVER; it is impossible to contain an X-ray |
|
Is a gamma ray always higher energy than an x-ray? |
No |
|
Will you, as a chiropractor, ever
use gamma rays in your practice? |
No |
|
Will exposure to x-radiation leave matter radioactive? |
No |
|
Do all of the x-rays in the beam have the same energy? |
No, it's Heterogeneous |
|
10:25 rule of thumb for fetal
radiation exposure and abortion. |
No fetus should be aborted if haven't received more than 10 RAD,
11-25 gray area (parent's decision) and over 25 advised to abort. |
|
Describe an x-ray photon in terms of mass, charge and velocity? |
No mass or charge and moves at speed of light. |
|
Severity of symptoms depends on the number of exposures
called? |
Non-stochastic effect because there is a threshold for
somatic disease. |
|
Is it really the x-ray that
interacts with the film emulsion to produce the image? |
No, chemical processing is
needed in order to convert the invisible latent image into a
visible image. |
|
Does the power company provide DC
current? |
No, only AC |
|
Do all of the electrons have the same velocity as they pass from cathode to anode? Why? |
No. When the electrons from the cathode hit the tungsten anode
they suddenly stop and give up their energy. |
|
What should be used to clean an
intensifying screen? |
Non lint screen cleaner |
|
Describe electromagnetic energy in terms of:
Mass, Charge and Velocity |
None, None, Speed of Light |
|
Hormesis: |
Notion that some radiation may
be actually good for you. |
|
Pair product interacts with? |
Nucleus or nuclear interaction-not in diagnostic but found
in x-ray treatment |
|
Which occupation expose the worker to the least amount of occupational exposure
but seems counterintuitive? |
Nuclear power plant employees |
|
Visualization of grid lines on an exposed radiograph
suggest? |
Off-centering of the grid in relationship to the tube. |
|
Which view show the Sacroiliac joint the best? |
Oblique lumbopelvic spine. |
|
From a PA view of the hand, how is the thumb being
projected? |
Obliquely. |
|
What is contained inside the large transformer besides the
coils? |
Oil |
|
State 2 of the 3 grid motions? |
Oscillating, reciprocating |
|
Where should personnel wear a
dosimeter? |
On a collar (and on the outside
of an apron if wearing one) |
|
Literally, where are compensating
filters placed in system? |
On collimator |
|
Personnel dosimeter should be
warn? |
On the collar or outside the
apron |
|
Where are compensating filters
placed? |
On the face of the collimator |
|
Where is the film's expiration
date located? What is the result of using film that is out
of date? |
On the packaging, fogging. |
|
How often should the entire
processor be drained, cleaned and replenished? |
Once a month. The most it should
go is 6 weeks. Costs roughly $100
per clean up. |
|
Describe grid cut off with
lateral angulation error? |
One side underexposed |
|
What is the 10 day rule? |
Non-urgent diagnostic radiography of the abdomen should be
confined to the pre-ovulatory phase of the menstrual cycle,
i.e., the ten days following the first day of the last
menstrual period, on the assumption that ovulation occurs at
about mid-cycle. |
|
Another way to explain 10 day rule? |
10-day interval following the onset of menstruation (1st ten
days of menstrual cycle) |
|
10 day rule from Appendix 4 page 74 Radiologic Health Branch
California DHS? |
10 or 14 days after the onset of menses it is improbable
that a woman would be pregnant and thus are safer times to
perform X-ray examinations. |
|
What is the difference between X-ray and gamma
ray? |
Origin (gamma ray comes from
nucleus). |
|
Which shell level is ionized in
the Compton scatter interaction with matter? |
Outer Shell-as found in
diagnostic x-ray. |
|
In Compton scattering the photon interacted with the? |
Outer Shell |
|
If a technologist wears a lead apron, the dosimeter should
be worn? |
Outside of the apron. |
|
What would the image look like if
the developer was too hot? |
Overexposed (Creates Developer
Fog. |
|
What would the image look like if
the developer was too concentrated? |
Overexposed (Fog) |
|
Poor film screen contact can be created by? |
Warped cassettes, loose hinges and foreign objects inside. |
|
Tungsten is
used as a target material. It has electron shells from
"K" near the nucleus out to___? |
P |
|
Electron transmission in tungsten
produces highest characteristic x-rays? |
P to K |
|
The Characteristic X-ray with the
most KEV of energy occurs with this electron transition? |
P TO K |
|
This electron transition in
tungsten produces the highest energy x-ray? |
P to K transition |
|
Which electron transition in
tungsten makes highest energy x-ray? |
P-K |
|
Of Par, high, rare earth, short focal film distance or
combination screens, which allows for the best definition
and details? |
Par speed screen. |
|
Which view demonstrates the pars? |
Oblique |
|
What type of grid should you buy
if you are using both 14x36 @ 72 SID and 14x17 @ 40 SID? |
Parallel |
|
There are 3 types of grids - name
them |
Parallel Linear, Crosshatch,
Focused Linear |
|
Compare particular matter to
electromagnetic in path through matter. |
Particular has shorter path in
matter. |
|
TheTunnel view of the knee should be take? |
With the patient prone. |
|
The transmission of the x-ray beam through a thick
protective barrrier is closely related to___of the tube? |
Peak operating potential (Peak kVp) |
|
Calibration of the x-ray unit? |
Penetrometer |
|
Describe degree and direction
with crosshatch grid: |
Perpendicular and no angle |
|
Describe the degree and direction
that can be used with a single cross hatched grid? |
Perpendicular, no degrees |
|
Which x-ray interaction with
matter is more likely to occur with high atomic number
tissues? |
Photoelectric Absorption |
|
Which x-ray interaction with
matter is most likely to occur at energies between 10-60 keV? |
Photoelectric Absorption |
|
What x-ray interaction results in
inner shell ionization? |
Photoelectric absorption |
|
Interaction w/ matter that
results in inner shell ionization? |
Photoelectric absorption |
|
What happens to the X-Rays in
photoelectric interaction? |
Photoelectric absorption |
|
White areas on film are a result
of this X-Ray with matter? |
Photoelectric absorption |
|
In this interaction the photon is
totally absorbed? |
Photoelectric absorption
interaction |
|
Use of contrast agent in diagnostic x-ray (Barium) is
dependent on their ability to enhance___? |
Photoelectric effect |
|
Photon interacts with bound inner
shell electron,electron is liberated from the atom
(ionization), with Photon disappearance is called? |
Photoelectric effect
(Electrons in higher energy shells cascade down to fill
energy void of inner shell). |
|
Describe classical scatter in
terms of energy loss and change of direction? |
Photon strikes the atom, it
interacts with the outer shell and gives up no energy but
does change direction |
|
Describe pair production? |
Photon hits the nucleus an disappears
but and electron and positron are created. |
|
What is the film base made of? |
Polyester-Plastic |
|
Define what a PBL? |
Positive Beam Limitation, its a
collimator |
|
Sodium sulfite helps protect the reducing agent from
oxidation because of their contact with air. It also
reacts with oxidation products to reduce their activity.
This is called a? |
Preservative (During Developer and Fixer in Automatic
Processing) |
|
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 receive up to 10
times the exposure of
the uncontrolled area |
|
Define grid radius? |
Proper SID range or (Grid
radius applies to focused linear grids) it is the
distance from the surface of the grid to the point above the
grid where all of the strips would meet. |
|
What two things does kVp control?
|
Quality and quantity of electrons (energy) |
|
Proper name for film graininess? |
Quantom Mottel |
|
State the unit that a physicist would use to describe ionizations in air in classical nomenclature? |
R |
|
State the unit of absorbed dose
in classical nomenclature. |
RAD-Radiation Absorbed Dose |
|
State the formula for Rem. Rem =
_____ x _____. |
RAD x QF |
|
What is the formula for REM? |
rad x quality factor |
|
Define leakage radiation. |
Radiation other than the primary
beam |
|
Orthocromatic film matches with
these screens. |
Rare earth |
|
State three other names for the
Coherent scatter interaction: |
Rayliegh, Thompson, and
Classical |
|
What is remnant radiation? |
Rays that interact, make the
image. Transmitted and scattered rays |
|
State 2 of 3 grid Motions: |
Reciprocate, Single Stroke,
Oscillating |
|
What color safe light do you need
for orthochromatic film screens? |
RED |
|
Color safe light required to be used
w/ rare earth film screen combos? |
RED |
|
What color do safe lights need to
be? |
Red |
|
This color safe light filter is
required for rare earth film screen combinations? |
Red, GBX |
|
X-ray films are least sensitive to___light? |
Red |
|
Crystals of the Intensifying screens do not usually
emit___light. |
Red |
|
The primary purpose of a filter used in diagnostic x-ray
machines is to? |
Reduce the skin dose |
|
What is the purpose of radiographic grid? |
Reduce Compton Scatter |
|
What is the advantage of using
air gap technique? |
Reduce patient exposure |
|
What is the main purpose for
intensifying screen? |
Reduce patient exposure |
|
Three advantages of tissue compression? |
Reduce scatter, less exposure, improves contrast, improves detail, can decrease ovarian
disease |
|
Exhausted developer will have? |
Reduced alkalinity. |
|
What is the processing order to "develop" a film? |
Reducer/developer (phenidone, hydroquinone),
Accelerator/activator (Sodium carbonate),
Preservative (Sodium Sulfite), Restrainer
(Potassium bromide), and Hardener (glutaraldehyde). |
|
Chemical reduction of exposed silver
bromide grains to convert them into visible metallic silver.
Phenidone for mid to lower gray scale and hydroquinone for
dense, or dark areas. This is? |
Reducer in the Developer stage |
|
Relationship between the
reflective layer and screen speed? |
Reflective layer and screen
redirect isotropic rays going away from the film. more light
makes it to the film, so the speed of the system is greater. |
|
State the unit for occupational
exposure in classical nomenclature? |
Rem |
|
Dose or radiation equivalent
in man? |
Rem = unit of radiation-Roentgen-equivalent-man |
|
Describe a long latitude film. |
Responds to a wide range of useful densities, but it has specific characteristics. |
|
Potassium bromide is used in an x-ray processing solution as
a? |
Restrainer (In Developer). |
|
What is the function of the potassium bromide mentioned
above? |
Restrainer use to moderate the rate of development. |
|
Voltage occurring at different
speeds at peak? |
Ripple |
|
Classical x-ray unit for intensity of x-ray in air? |
Roentgen |
|
What does developer roller look like? |
Rubbery and the other one is Wood |
|
Old formula for determining the maximum cumulative exposure for a occupationally exposed person? |
S(n-I8) |
|
Why is the inverse square law important?
|
Safety issue = increased distance = less intensity and less
exposure to staff. |
|
What is continued emission of light after the energy has been turned off from the crystal? |
Screen lag, or afterglow. |
|
What is the major source of radiation exposure to
restraining personnel and cause of poor radiographic
detail?
|
Scatter |
|
Grids and Air Gap Technique (gap between pt and film) help
control? |
Scatter radiation |
|
Secondary barriers are built to be exposed to___? |
Scattered radiation and leakage radiation. |
|
According to Gurney-Mott theory, this is the latent image formation center? |
Sensitivity spec |
|
The greater the grid ratio, the greater is the? |
Secondary radiation absorbed. |
|
State
the advantage of using small focal spot size? |
Sharper
image |
|
Name
4 RAD protection devices? |
Shielding, collimation, Increased developed system speed, opt. KVP,
filters, intensifying screens |
|
Use of high speed intensifying screens instead of direct
film exposure results in? |
Shorter exposure time required. |
|
Chest x-ray exam should have? |
The shortest exposure time, higher kVp than a thoracic spine
exam and never excessively collimate. |
|
Apply higher kVp to x-ray tube produces? |
Shorter wave length x-ray's. |
|
Describe the relationship b/w x-ray wavelength and energy? |
Shorter the wavelength, higher the energy...therefore inverse |
|
List
other types of electromagnetic energies in order of their
energies relative to x-ray? |
Shortest
to longest wavelength:
Gamma, X-Ray, UV, Visible Light, Infrared, Micro, Radio |
|
Describe
SID and sharpness relationship? |
SID
increases, sharpness increases |
|
State
the unit for occupational exposure in Systems International
nomenclature? |
Sievert |
|
What is the measurement of radiation dosage?
|
Sievert (Sv) |
|
What
is the unit of occupational exposure in SI? |
Sievert |
|
Film
emulsion has these crystals suspended in gelatin? |
Silver
halide crystals |
|
What will form if fixer is not washed off?
|
Silver sulfide (brown color) |
|
Focal
spot size is dependant on? |
Size
of the filament |
|
Cathode
has two primary parts, what are they? |
Small
and large filament and focusing cup |
|
Use of small focal spot produces? |
Smaller penumbra |
|
Geometric un-sharpness can be diminished by what two
methods?
|
Smaller focal spot and shorter object film distance. |
|
Which chemical prevents rapid oxidation of developer? |
Sodium sulfite (preservative) |
|
What chemical governs the reducing activities of the
developer? |
Sodium Carbonate |
|
State
the wave equation? |
Speed
of light = wavelength x frequency |
|
What
does an Electromagnetic induction motor do? |
Spins
the anode (has a rotor and stator) |
|
What
is the focal spot? |
Spot
on the anode target where x-rays are produced |
|
Black
tree light defects have been found due to low humidity and ___________? |
Static
Electricity |
|
What causes spider-like marks on the films? |
Static Electricity. |
|
What
may appear on the film if the humidity is too low? |
Static,
tree, crown, etc. |
|
What are the two types of radiation injury?
|
Stochastic and deterministic (non-stochastic) |
|
Occurs by chance (random), probability increases with dose
but severity is independent of dose, occurs in exposed and
unexposed people? |
Stochastic characteristic effects
(Example - cancer, genetic defects) |
|
This
type of effect is a random effect from chronic low dose
exposure? |
Stochastic |
|
Random effects such as cancer are
called? |
Stochastic |
|
70 year old suseptible so no threshold called? |
Stochastic effect. |
|
Why
is it important to have ↑mAs, ↓time? |
Stop
motion |
|
Charge
on the focusing cup? |
Strong
negative |
|
Define
total filtration? |
Sum
of adherent + added filtration |
|
For an AP view of the elbow, how would the wrist be
positioned? |
Supinated. |
|
When an A-P thoracic is
performed, which part of the body should the anode side of
the tube be placed? |
T1-T6, the thinnest part of the
body |
|
What is the function of the
fixer? |
Takes the emulsion and hardens
it. It clears and hardens the film. It
cleans off the unexposed/undeveloped halide crystals off the
film. They are dissolved off. When we do silver recovery to
get it back and keep it out of streams of water we pass the
fixer through a silver recovery device. |
|
State the aka's for source image
distance? |
Target film distance and Focal
film distance (TFD & FFD) |
|
What is a TVL? |
Tenth value layer, thickness of
a material that will reduce the intensity of the beam to one
tenth it's value |
|
Linearity? |
The ability to change mA and
time and get the same amount of mAs |
|
Define ionize? |
The ability to give an atom or
group of atoms a net electric charge by adding or removing
one or more electrons |
|
Latitude? |
The ability to make mistakes. |
|
Which side of a radiograph will
exhibit the least radiographic density? |
The anode |
|
What is radiographic density? |
The blacks on the film |
|
This side of the radiograph will
have the most blur, what side is it? |
The cathode |
|
Replenishment rates are dependent
on? |
The direction of film |
|
How much chemistry goes in versus
how much goes out depends on? |
The direction of film feed on
tray |
|
The central ray is aimed in this
direction using a linear grid? |
The direction of the
strips...usually cephalic/caudal, vertical |
|
What is the energy unit of a proton?
|
The electron volt (eV) |
|
|
The emission and transfer of radiation in space |
|
A cathode has two primary parts,
what are they? |
The filaments and the focusing
cup. |
|
Silver is reclaimed from? |
The fixer |
|
What determines the energy of the
x-ray? |
The frequency of the x-ray
wavelength. |
|
Law of triboneau and Buscuia? |
The more highly proliferative
the more sensitive |
|
Define hormesis? |
The notion that some radiation
maybe good for you |
|
What is the difference between
gamma rays and x-rays? |
The only difference is their
origin.
X-Ray = Electron Cloud &
Gamma = Nucleus |
|
What is the difference between
x-rays and gamma rays? |
The origin |
|
What would the film look like if
all of the x-rays interacted with the emulsion and the film
was then processed? |
The portion next to the film
base remains largely unexposed/black. |
|
The anode side of the tube can be
located by? |
The positive label,
listening for the spin and
finding the wire for the AC current. |
|
What does the mA circuit control?
|
The quantity of electrons produced in focusing cup |
|
How does focal film distance effect radiographic
density?
|
The smaller the FFD, the greater the intensity of the beam
and therefore greater resolution. |
|
Blackening of a film can be due to? |
The speed of the film, a low grid ratio and photon energy
reaching the film. |
|
What makes an x-ray photon higher
energy than a microwave? |
The wavelength is shorter. |
|
Gurney-Mott theory describes? |
Theory of latent image and
manifest image formation. |
|
What happens to the original
x-ray following the Coherent scatter interaction? |
There is a change in direction
but no change in energy, therefore no ionization. |
|
What is the unique mutation to
radiation exposure? |
There is no unique mutation |
|
How
are Characteristic X-Ray's produced? |
These are produced when outer
shell electrons fill inner shell vacancies due to the
projectile electron hitting an electron and ejecting it from
an inner shell. |
|
What is the only similarity
between particulate radiations that result from
radioactivity and x-ray? |
They can ionize |
|
What is the relationship between photon energy and
frequency? What happens to photon energy when
frequency is increased?
|
They are directly related. Increasing frequency corresponds
to an increase in energy. If frequency doubles, energy
doubles. |
|
What is the relationship between frequency and wavelength? |
They are inversely related as c is a constant. C=frequency x
wavelength |
|
Define Half Value Layer - HVL? |
Thickness of certain material that attenuate radiation to
one half of the original dose. |
|
What are the three variables in a technique chart?
|
Thickness of region, kVp, and mAs. |
|
What are characteristics of non-stochastic effects?
|
Threshold dose, below which there is no effect. Severity
proportional to dose above threshold. Example - cataracts,
erythema, main problem in radiation accident. |
|
Careless manual handling of films with excessive bending of
the film cause? |
Thumbnail or crescent shaped dark shadows on films. |
|
3 examples of things associated
with ALARA? |
Time, distance, shielding
(cardinal principals) |
|
How much more time does the film stay in the fixer than
the developer?
|
Twice as much time. |
|
Why do we have contrast in an
image? How does that happen? |
To allow for increased clarity,
detail and resolution on the film.
Occurs as a result of some x-rays being absorbed and others
interacting with silver metallic crystals creating
radiographic density via differential absorption. |
|
Why is the film loading bench
grounded? |
To avoid static |
|
Why is the water tank in the
processor drained when it is off? |
To avoid the possibility of
stagnation and algae growth. The fixer will
be retained in the emulsion causing a smell and also turns a
sepia color (looks like a rust/nicotine stain) |
|
Why is the direction of film
transport through the processor considered important? |
To avoid to much chemistry being
concentrated in one area of the film. |
|
Why is there lead in the back of
the cassette? |
To prevent backscatter |
|
List at least 3 consumer products
that contribute to background exposure? |
Tobacco, Television, Combustible
Fuels |
|
If X-Rays turn yellow or stain
with age what cause that? |
Too much fixer |
|
Where is the floating lid? |
Top of developer in replenishing
tank |
|
Floating lid is in the
replenishment tank? |
True |
|
If you have a fixed kVp chart
then you must have a mAs that will change? |
True |
|
For every 4cm of tissue thickness
increase mAs should be doubled? |
True |
|
Long latitude films respond to a
wide range of useful density? |
True |
|
By federal law the machine must
have total of 2.5mm lead equivalent? |
True |
|
Which part of the x-ray tube has to be heated if radiographs
were to be taken? |
Tungsten filament |
|
The disk of the anode is made up of___? |
Tungsten |
|
What is the x-ray tube target
made of? |
Tungsten |
|
Describe grid cut off SID is too
Long? |
Underexposed on both sides |
|
Describe grid cut off SID is too
Short? |
Underexposed on both sides |
|
Describe grid cut off when CR is
off center? |
Underexposed on one side |
|
Focus grid with lateral
angulation? |
Underexposed one side |
|
What would the image look like if
the developer was too
Cold? |
Underexposed/Underreactive |
What would the image look like if
the developer was too
Diluted? |
Underexposed/Underreactive |
What would the image look like if
the developer was too
Oxidized? |
Underexposed/Underreactive |
|
Grid cutoff is? |
Undesirable absorption of
primaries |
|
Latent image is? |
Undeveloped, unprocessed image
in the corner |
|
Type or grid cutoff that would
occur if the central ray was off centered to a focused grid? |
Unilateral |
|
Where should the anode side of
the tube be placed when performing a lateral lumbar spine
radiograph? |
Up |
|
Where should the anode side of
the tube be placed when performing an AP thoracic spine
radiograph? |
Up |
|
If
compensating filter is used on a lat lumbar spine where
should it be, up or down? |
Up |
|
Where should the anode side of
the tube be placed when performing a full spine radiograph
on a 14 x 36" film? |
Up |
|
If a compensating filter is used
on a lateral lumbar exposure, in what direction should the
thinnest part of the filter be pointing? |
Up (want the thinnest part of
the filter on the thinnest part of the patients body.) |
|
Percentage of time a primary beam
is aimed at a particular wall is called it's? |
Use factor |
|
How do you clean intensity
screens? |
Use
manufactures' cleaner and
gauze. |
|
Describe the appearance of
oxidized developer? |
Used motor oil. |
|
What allows various patient structures to be recognizable
on x-ray images? |
Varying attenuating capability of the different body tissue
to incoming photons. |
|
State the wave equation? |
Velocity = Frequency X
Wavelength |
|
Which way do you angle CR with
linear grid? |
Vertically |
|
Lead glove is important for radiographer during? |
Videofluoroscopy. |
|
What is the clinical significance of the heel effect? |
Want to position thorax and abdomen toward the cathode
side since they need higher energy to penetrate.
|
|
Why is the use of "split screens"
considered obsolete? |
Way too much exposure to the
patient. |
|
List
the order from most sensitive to
least sensitive tissues? |
WBC, Epithelial cells, muscle
and nerve cells |
|
Which filter is useful for the dorsoplantar view of the
foot? |
Wedge filter |
|
What film will show flat feet? |
Weight bearing lateral. |
|
Define ionize? |
When an electron is totally
removed from an atom. |
|
When to use a gonad
shield? |
When it won't interfere with
shooting. |
|
When is the exposure terminated
when using the dead man's switch? |
When you remove your finger from
the switch. |
|
Describe reproducibility
relative to radiology? |
When you take the same exposure
over and over again; you should get the same results. |
|
Describe grid cutoff? |
Where the primary beam gets
absorbed by the grid. |
|
How does a radiographically dense
area appear on the radiograph? |
Wherever the body tissue is the
most dense, that's where the radiographic density is the
least dense. i.e. Most white = least radiographically dense.
Mass per volume of black metallic silver |
|
What color should your dark room
be painted? |
White or a light color. |
|
Dust on an intensifying screen
will cause what visual effect? |
White specks on the film. |
|
When an artifact is demonstrated
on a film as a result of something on the screen, what color
will it appear? Will it be sharp or blurred? Why? |
White, Sharp, because it is
close to the film. |
|
Only 1% of the energy is converted to___while 99% is
converted to heat? |
X-ray |
|
What are three examples of ionizing radiation?
|
X-rays, gamma rays, and ultraviolet light |
|
Coulombs/kg measure these types of
radiation only? |
X-ray and gamma-ray. |
|
Compare the mass of an x-ray to an alpha
particle: |
X-ray has no mass |
|
Compare the mass of an x-ray to
that of an alpha particle |
x-rays have less-they
have no mass |
|
Compare
wavelengths of X-rays to radio waves? |
X-rays have shorter wavelengths |
|
How are radiographic density and
anatomic density related? |
X-Rays that absorb vs. X-Rays
that transmit.
They are opposites-Inversely related. |
|
10 day rule: |
X-Ray after 10 days following 1st
day of period |
|
Where is the central ray for an AP full spine film? |
Xyphoid process (T10-T12) |
|
Compare wavelength of X-Rays to radiowaves? |
X-rays have short wave length |
|
For the tunnel view of the knee taken PA, is there tube tilt
and if so to what degree? |
Yes. 45 degree caudal tilt. |
|
Can pregnant women take X-Rays? |
Yes |
|
Can human cells recover from RAD
damage? |
Yes |
|
Does non-stochastic effects have
a threshold? |
Yes they do |
|
Why would you not want to
purchase a crosshatch grid? |
You can't angle the central ray. |
|
In Bremsstrahlung X-Ray
production, X-Ray energies range from? |
Zero To Peak Energy Electron. |
