Deck 13: Exposure Technique Selection

Question 1

Phototimer AEC detectors are usually exit-type devices because

A) the x-rays must exit the patient to get to the detectors
B) the x-rays must exit the grid to get to the detectors
C) the x-rays must exit the image receptor to get to the detectors
D) the x-rays must exit the table to get to the detectors

Answer 1

the x-rays must exit the image receptor to get to the detectors

Question 2

When using AEC, the kVp

A) is set higher than usual
B) is set lower than usual
C) is set as appropriate for the study
D) is determined by the AEC system

Answer 2

is set as appropriate for the study

Question 3

The predetermined level of radiation exposure needed to terminate the exposure when using AEC is set by

A) the radiologist
B) the technologist
C) the equipment service personnel
D) the manufacturer

Answer 3

the equipment service personnel

Question 4

There is typically a configuration of at least ______ AEC detectors in place

A) 2
B) 3
C) 4
D) 5

Question 5

An ionization chamber is a hollow cell that contains

A) water
B) lead
C) tungsten
D) air

Question 6

Using a lower mA station during an AEC examination results in

A) reduced patient exposure
B) increased exposure time
C) decreased exposure time
D) reduced patient exposure and increased exposure time

Question 7

The device that converts the light energy to an electrical signal is the

A) photodiode
B) photocathode
C) photomultiplier tube
D) photodiode and photomultiplier tube

Question 8

The shortest exposure time that a radiographic tube with AEC can have is the

A) mAs readout
B) back-up time
C) minimum response time
D) density controls

Question 9

AEC controls the amount of radiation reaching the IR by controlling the

A) time of exposure
B) mA
C) kVp
D) none of these

Question 10

The two types of detectors used in AEC are

A) image intensifiers and phototimers
B) phototimers and ionization chambers
C) ionization chambers and Geiger counters
D) direct and indirect capture

Question 11

These can be adjusted to increase or decrease the amount of radiation needed to terminate the exposure using AEC

A) mAs readout
B) back-up time
C) minimum response time
D) exposure adjustment

Question 12

The actual amount of exposure used for an image when AEC is being used is the

A) mAs readout
B) back-up time
C) minimum response time
D) density controls

Question 13

The maximum length of time that an exposure lasts when using AEC is the

A) mAs readout
B) back-up time
C) minimum response time
D) exposure adjustment

Question 14

Once the electric charge from an AEC detector reaches a preset point

A) the patient can leave
B) the kVp will be reduced to 0
C) the exposure will stop
D) All of these

Question 15

The primary purpose of AEC is to

A) reduce patient exposure
B) control the amount of radiation reaching the IR
C) control image contrast
D) eliminate the need for the radiographer to think critically

Question 16

Using a higher kVp during an AEC examination results in

A) a longer exposure time
B) a shorter exposure time
C) increased patient exposure
D) a shorter exposure time and increased patient exposure

Question 17

Today's AEC system is most likely use a(n)

A) ionization chamber
B) Geiger counter
C) phototimer
D) none of these

Question 18

The original type of AEC detector was the

A) ionization chamber
B) Geiger counter
C) phototimer
D) none of these

Question 19

When the x-rays enter the ionization chamber

A) atoms become ions
B) atoms give up electrons
C) electrons and positive ions become electricity
D) All of these

Question 20

Ionization chamber AEC detectors are entrance-type devices because the x-rays must

A) enter the detector after passing through the IR
B) enter the detector before entering the patient
C) enter the detector before getting to the IR

Question 21

When the radiographer has the opportunity to set the back-up time, it should be approximately _____________ of the expected exposure time

A) 50%
B) 150%
C) 250%
D) 600%

Question 22

If the radiographer is doing an upright chest using AEC but the table bucky is selected

A) the back-up time will be reached
B) the patient will be exposed to excessive radiation
C) the IR will be overexposed
D) All of these

Question 23

If the back-up time is set by the equipment, the exposure time should end when the mAs reaches

A) 100
B) 400
C) 600
D) 1000

Question 24

If the patient for an AP thoracic spine image is centered so that the spine is not over the top of the detector

A) the IR exposure will be excessive
B) the IR exposure will be insufficient
C) the mAs will compensate
D) the image will be too light

Question 25

When your patient for an AP abdomen is very heavy, using AEC results in

A) underexposure to the IR
B) overexposure to the IR
C) appropriate exposure to the IR
D) increased image contrast

Question 26

When there is a significant amount of scatter radiation reaching the detector, the exposure time will

A) be shorter than needed
B) be appropriate
C) be longer than needed
D) reach the backup mAs

Question 27

If the back-up time is shorter than the actual exposure time needed for a properly exposed image

A) the image receptor will be overexposed
B) the image receptor will be underexposed
C) the exposure will be appropriate
D) the x-ray tube will overheat

Question 28

In imaging a child, a short exposure time is needed for an examination using AEC. The mA setting should

A) be low
B) be mid-range
C) be high
D) It doesn't matter-the AEC device will control the exposure time

Question 29

With digital imaging using AEC, if an AP thoracic spine is imaged using an outside instead of center detector, the brightness in the area of interest will be _________________ and the patient will be underexposed. (Assume all other factors are appropriate.)

A) gray
B) light
C) dark
D) appropriate

Question 30

If the AEC detectors are not completely covered by the part being imaged and are exposed to primary radiation

A) the patient will be overexposed
B) the exposure will terminate very quickly
C) the IR will be exposed to the appropriate amount of radiation
D) none of these

Question 31

When using AEC, destructive pathologic conditions can cause

A) overexposure
B) decreased absorption
C) excessive overexposure
D) increased absorption

Question 32

When imaging a patient's right hip, which detector(s) should be activated?

A) right detector only
B) right and left detector
C) center detector only
D) all three detectors

Question 33

Which of the following is the most critical aspect of successfully performing an examination using AEC?

A) Centering the anatomy of interest over the detector
B) Using the right mA
C) Using the right kVp
D) Setting the best back-up time

Question 34

AEC devices should be calibrated

A) when the unit is first installed
B) at regular intervals
C) when there is a change in the type of IR being used
D) All of these

Question 35

The Quality control test of the AEC device to see that exposures for a given set of factors and selected detector result in mR readings within 5%, is known as:

A) reproducibility;
B) linearity
C) reciprocity
D) accuracy

Question 36

When using AEC with digital imaging, errors resulting in overexposure to the IR result in

A) images that have insufficient brightness
B) images with appropriate brightness
C) overexposed patients
D) images with appropriate brightness and overexposed patients

Question 37

The AEC minimum response time may pose a problem when

A) a long exposure time is needed
B) the patient can easily hold still for the exposure
C) the patient is unable to hold still for the exposure
D) All of these

Question 38

Anatomically programmed technique is a system in which the radiographer selects

A) AEC settings
B) mAs and kVp settings
C) preset settings based on the part being imaged
D) preset settings based on the size of the patient

Question 39

The reason to have a back-up time is to

A) protect the patient from excessive exposure
B) make sure the right mAs is used
C) keep the tube from excessive heat-loading
D) protect the patient from excessive exposure and keep the tube from excessive heat-loading

Question 40

The detector(s) selected for an image should be

A) the center detector because that is where the central ray is going
B) the two or three detectors that are covered by the part being imaged
C) the ones that are superimposed by the anatomic structure of interest
D) all three so that the system can work properly

Question 41

The amount of electric charge produced in an AEC detector depends on the amount of radiation absorbed by the detector.

Question 42

Pre-established guidelines used by the radiographer to select standardized manual or AEC exposure factors for each type of radiographic examination are called

A) anatomical programming
B) exposure technique charts
C) mA reciprocity
D) quantum noise detectors

Question 43

___________________ identify optimal kVp values and alter the mAs for variations in part thickness

A) Fixed kVp-variable mAs
B) Variable kVp-variable mAs
C) Fixed kVp-Fixed mAs
D) Variable kVp-fixed mAs

Question 44

Which of the following patient conditions require a change in technical factors?
1) Plaster casts
2) Obesity
3) Additive disease

A) plaster casts and obesity only
B) plaster casts and additive disease only
C) obesity and additive disease only
D) plaster casts, obesity, and additive disease

Question 45

Using the plus or minus exposure adjustments should be done frequently to produce quality images with AEC.

Question 46

When using AEC, the exit radiation is converted into an electrical signal.

Question 47

With digital imaging using AEC, what factor is decreased if an AP thoracic spine is imaged using an outside instead of the center detector? (Assume all other factors are appropriate.)

A) exposure time
B) increased; subject contrast
C) spatial resolution
D) brightness

Question 48

With digital imaging using AEC, if an AP thoracic spine is imaged using 110 kVp instead of 80 kVp, the patient exposure is _______________________. (Assume all other factors are appropriate.)

A) higher
B) unchanged
C) lower
D) excessive

Question 49

With digital imaging using AEC, what factor is increased if an AP thoracic spine is imaged using an outside instead of the center detector? (Assume all other factors are appropriate.)

A) subject contrast
B) brightness
C) spatial resolution
D) quantum noise

Question 50

Different radiographic projections and patient positions of the same anatomic part do not require modification of the exposure factors.

Question 51

If an AEC has three detectors, only one of the three can be selected for an exposure.

Question 52

Phototimer AEC devices convert the radiation to light energy.

Question 53

It is safe to assume that anatomically programmed techniques have been developed to produce the best quality images with the least amount of exposure.

Question 54

The AEC system will automatically adjust to changing image receptor types.

Question 55

The mAs readout is of little value because there is no need to set manual exposure factors.

Question 56

With digital imaging using AEC, if an AP thoracic spine is imaged with the central ray passing 3 inches to the right of the spine, the right lung exposure is _________________. (Assume all other factors are appropriate.)

A) excessive
B) insufficient
C) sufficient
D) too long

Question 57

With digital imaging using AEC, if an AP thoracic spine is imaged with the exposure adjustment changed from 0 to +2, the exposure time is _______________________. (Assume all other factors are appropriate.)

A) longer
B) shorter
C) unchanged
D) insufficient

Question 58

Collimation is not required when AEC is used.

Question 59

AEC and phototiming are accurate terms that can be used in place of automatic exposure control.