FQ1 Flashcards
The purpose of a rectifier is to:
convert AC to DC current
Which of these rectifiers is consistent with the ALARA concept?
high frequency
what is ionization?
the total removal of an ELECTRON from its atomic shell level
The radiographic density is excellent using 30 mAs at 73 kVp at 40’’ SID. What change in exposure factors is necessary when changing to 80’’ SID?
120 mAs, 73 kVp
The quality factor of x-ray is _______.
1
REM=RAD x ______.
QF
5 REM = __________ mrem.
5,000
Which x-ray interaction with matter is the most likely to occur in high atomic number matter?
photoelectric absorption
Which x-ray interaction with matter has a probability of occurrence if the x-ray is in the 10-60 keV range?
photoelectric absorption
Which x-ray interaction with matter has a probability of occurring when the x-ray energy is in the 60-125 keV range?
compton scatter
The original x-ray no longer exists when this x-ray interaction with matter occurs.
photoelectric absorption
“Fog” on the image is the result of this x-ray interaction with matter.
compton scatter
The exposure factors are correct when performing a 14’’ x 17” AP lumbar spine exam using 80 mAs at 73 kVp. If the x-ray beam is collimated to a 6” x 17” area the exposure factors should be:
120 mAs, 73 kVp
The optimum kVp range for images of the spine is in this range.
70-90 keV
The optimum kVp range for non Bucky images of the extremities is in this range
50-60 keV
The purpose of a “Bucky” grid is to:
reduce “fog” from compton scatter
Which of these grids would require the most exposure to the patient?
16:1
The x-ray beam may be angled in this direction when using a linear grid.
in the direction of the strips
Which of these grids requires that the SID be within a very specific range?
focused
Intensifying screens are used with film to:
reduce radiation exposure
Which of these imaging systems would you choose to image extremities?
100 speed
Which of these imaging systems will result in the most quantum mottle in the image?
1200 speed
A GBX safelight filter is:
red
An AP lumbar spine film is exposed properly using 30 mAs, 73 kVp with a 200 speed film screen combination. What exposure factors should be used if the film screen system is changed to a 600 speed system?
10 mAs, 73 kVp
Silver is recovered from this processing chemistry.
fixer
****** processing system should be *****, cleaned, replenished and servived every _____ weeks.
4
On the radiograph, radiographic density appears ________.
black
On a radiograph, high atomic number, dense anatomy appears
white
The total number of x-rays in the beam is controlled by selecting the _________.
mAs
Which of these sets of exposure factors will produce an image with the shortest scale of contrast?
62 kVp, 60 mAs
The intensity of radiation standing 3 feet from the tube housing is 100 mR/hr. What is the intensity of radiation if you step back to 6 feet?
25 mR/hr
The technique chart requires 30 mAs, 73 kVp for a 20 cm AP thoracic spine exam. What should the exposure factors be if there is a 6” space between the patient’s thoracic spine and the image receptor?
45 mAs, 73 kVp
The technique chart says that a 14 x 17” AP thoracic spine image will require 30 mAs, 73 kVp. If a decision is made to collimate down to a 4 x 4” spot view of T-6 what will the exposure factors need to be?
45 mAs, 73 kVp
As mA increases, the cathode filament:
gets hotter
Which of these will produce the most skin dose?
short SID
An image is so underexposed that it needs to be retaken when the exposure factors were 30 mAs, 73 kVp. The new exposure factors should be:
60 mAs, 73 kVp
Linearity is the ability to:
manipulate the mA x seconds for the same mAs and get the same result
According to Dr. Bushong, therapeutic absorption should not be considered with exposures below ____ RAD to the abdominal area of a pregnant woman.
10
The ten day rule suggests that x-rays of a female with reproductive ability should only be performed:
in the 10 days following the onset of menstruation
To be provided with dosimetry, education and possible reassignment of duty, a pregnant employee must:
declare the pregnancy in writing to the employer
Which of these can receive the most mR/week?
controlled area
A 16 year old is working for you for the summer. What is his/her annual MPD?
0.1 rem
If velocity is constant, when frequency increases, wavelength ________.
decreases
The filament/focal spot size is selected on the console by selecting the ______.
mA
Which of these would be best to use for 10 mAs if you are concerened that the patient may move during the exposure?
300 mA, 1/30 second
The mAs can be rounded up or down within _____% without a change in radiographic density.
30%
The controlling factor of radiographic density is the:
mAs
The controlling factor of radiographic contrast is:
kVp
Which of these has the most detrimental effect on the recorded detail in the image?
motion
Why is there lead in the back of a cassette?
to absorb backscatter radiation
The film is underexposed. This means that it is too _____.
light
The image is so underexposed that it must be taken over again. What must be down to the exposure factors?
at least double the mAs
The geometric sharpness of detail is the same when using 25 mA, 75 mA or 150 mA on the small filament.
T/F?
true
A patient who is very muscular will require an increase in kVp.
T/F?
true
SID is also known as:
- FFD
- TFD
- OID
- OFD
1 & 2
[FFD & TFD]
Which of these standard chiropractic images can make use of the air gap technique to reduce patient exposure?
lateral cervical spine
Use of a long ______ will decrease magnification distortion.
SID
Use of a long _____ will increase magnification distortion.
OID
kVp controls the __________ in the beam.
energy
Differential absorption of x-rays results **** image property.
contrast
Which of these would contribute the most toward achieving ALARA?
change from a 200 speed film-screen to a 600 speed
What should be used to clean an intensifying screen?
bandage gauze
When closing down a processor, it is important to be certain:
that the water is turned off and the drain is open
When anatomy is of various thickness, the use of _______ to achieve a uniform image density it is consistent with the concept of ALARA.
compensating filters
Radiographic film emulsion is made of:
silver halide suspended in gelatin
The radiographic film base is made of:
mylar
An average 10:1 ratio grid requires this change in exposure factors.
increase mAs x 4
The grid ratio is the:
the height of the lead strips to the width of the interspace strips
When developing a fixed kVp technique chart, for every 4 cm increase in tissue thickness the mAs should be:
increase 100%
If a film totally exposed to white light or x-ray and then processed it will appear black.
T/F?
true
(#73 unreadable) …………..and then ……….. will appear black
T/F?
false
This method of x-ray production occurs when electrons shift energy levels within an atom.
characteristic
This method of x-ray production occurs when a high speed electron is accelerated and then decelerated when attracted to the nuclear force field.
bremsstrahlung
For useful characteristic x-rays to be formed in a tungsten atom the kVp must be:
≥ 70 kVp
A stochastic effect from radiation exposure needs no threshold of dose to occur.
T/F?
true
The annual whole body MPD for occupationally exposed people is:
5 REM
The MPD for a pregnant employee is:
0.5 REM per gestation period
A pregnant radiation worker should wear two dosimeters. One should be on the collar outside the lead apron and one should be at the waist under the lead apron.
T/F?
true
Film badge dosimeters should be sent in for monitoring every _________.
month
The three “cardinal principles” of radiation protection are:
time, distance, shielding
The purpose of the control badge dosimeter is to monitor background and transportation exposure to radiation and it should be kept next to the machines console.
T/F?
false
Human cells are capable of recovery from radiation effects.
T/F?
true
Highly proliferative, poorly differentiated cells are very resistant to radiation effects.
T/F?
false
***** radiation sensitive cell is the _______.
lymphocyte
Short term radiation effects are exhibited in patients who have been exposed to diagnostic x-ray.
T/F?
false
Long term radiation effects may be exhibited in people exposed to diagnostic x-ray.
T/F?
true
Biologic effects from x-ray exposure are the result of _________.
ionization
The ______ trimester is the most risky to the fetus from exposure to ionizing radiation.
first
An abortion should be recommended to a pregnant woman who has had any diagnostic x-ray exposure to the abdominal area.
T/F?
false
The anode side of the image will display the least radiographic density.
T/F?
true
The anode side of the tube should be __________ when performing an AP thoracic spine.
up
The purpose of using the anode heel effect properly is to:
produce a uniform radiographic density
According to the LNT dose response model, the level exposure below which there is no possible biologic damage to a human is ________.
0 rad
You are 26 years old. Your cumulative MPD is _____.
26 REM
The required total filtration of the x-ray beam is ______ aluminum equivalent.
2.5 mm
The dose response curve labeled “A” defines the LNT model.
T/F?
true
Which of these dose response curves indicates that a threshold of exposure to radiation would be required before a response would be expected?
B
Using the diagram of the x-ray tube: the letter A is pointing to the:
filament
Using the diagram of the tube: the letter C is pointing to the:
rotor
Using the diagram of the x-ray tube: the letter E is pointing to the
the focal spot
