Deck 11: Equipment Design for Radiation Protection

Question 1

Digital radiography images can be accessed:

A)at only one workstation at a time,thereby decreasing convenience for physicians providing patient care.
B)at no more than two workstations at a time,thereby decreasing convenience for physicians providing patient care.
C)at several workstations at the same time,making image viewing very convenient for physicians providing patient care.
D)digital images cannot be accessed at any workstations by physicians.

Answer 1

at several workstations at the same time,making image viewing very convenient for physicians providing patient care.

Question 2

Depending on the area of the body being examined with a fluoroscopic image intensification system,for adult patients,a range of ______ kVp is generally used.

A)30 to 60
B)60 to 75
C)75 to 110
D)110 to 140

Answer 2

75 to 110

Question 3

Compared with the traditional material in the front of a cassette (aluminum or cardboard),the cassette front containing the carbon fiber absorbs approximately ______ as much radiation,resulting in a __________ dose for the patient because ________ radiographic techniques are required to produce the recorded image.

A)four times,higher,higher
B)three times,higher,higher
C)twice,higher,higher
D)half,lower,lower

Answer 3

half,lower,lower

Question 4

Federal government specifications recommend a minimum total filtration of _______________ for stationary (fixed) fluoroscopic x-ray units operating above 70 kVp.

A)1.0-mm aluminum equivalent
B)1.5-mm aluminum equivalent
C)2.0-mm aluminum equivalent
D)2.5-mm aluminum equivalent

Question 5

During a fluoroscopic examination,a resettable cumulative timing device times the x-ray beam-on time and sounds an audible alarm or temporarily interrupts the exposure after the fluoroscope has been activated for what length of time?

A)1 minute
B)3 minutes
C)5 minutes
D)10 minutes

Question 6

Computed radiography,because of its higher exposure latitude,makes grid use on the pediatric population:

A)absolutely necessary for all radiographic examinations.
B)less necessary than was previously believed.
C)necessary only for extremity examinations.
D)unnecessary for any examination.

Question 7

Sharper size restriction of the radiographic beam is achieved when a cone or cylinder is:

A)longer.
B)shorter.
C)made of aluminum.
D)made of durable plastic.

Question 8

When obtaining a dorsoplantar projection of a foot,which of the following types of filters should be used to provide a greater uniform density of the anatomy?

A)Bilateral wedge filter
B)Trough filter
C)Thoraeus filter
D)Wedge filter

Question 9

Current federal standards limit entrance skin exposure rates of general-purpose intensified fluoroscopic units to a maximum of ______________ measured at tabletop with the image intensifier entrance surface at a prescribed 30 cm above.

A)100 mGya/min
B)300 mGya/min
C)500 mGya/min
D)600 mGya/min

Question 10

When the speed of screen-film systems doubles,for example,when changing from a 200-speed to a 400-speed system,patient radiation exposure is ______ by approximately ______.

A)increased,25%
B)increased,50%
C)reduced,25%
D)reduced,50%

Question 11

CR imaging has greater ____________ flexibility than conventional screen-film radiography.

A)kilovoltage
B)milliamperage
C)time of exposure
D)x-ray beam collimation

Question 12

In standard image intensification fluoroscopy,an x-ray beam half-value-layer (HVL) of 3 to 4.5 mm aluminum is considered acceptable when peak kilovoltage ranges from:

A)50 to 60.
B)60 to 70.
C)70 to 80.
D)80 to 100.

Question 13

When an exposed computed radiography imaging plate is ready to be processed,an imaging reading unit is used to scan the photostimulable phosphor imaging plate with a helium-neon laser beam.This process results in the emission of violet light that is changed into an electronic signal by a device called a:

A)charge-coupled-device array.
B)photodiode.
C)photomultiplier tube.
D)scintillator.

Question 14

A radiographer uses a high-speed,rare-earth screen-film system with optimal technical exposure factors to obtain PA and lateral radiographs of a 2-year-old child's chest.To maximize reduction of radiation exposure to the patient following adequate immobilization,the radiographer should:

A)collimate the x-ray beam so that it is only slightly larger than the margins of the image receptor and shield the child's reproductive organs.
B)collimate the x-ray beam so that it is no larger than the margins of the image receptor and shield the child's reproductive organs.
C)collimate the x-ray beam so that it is smaller than the margins of the image receptor and shield the child's reproductive organs.
D)collimate the x-ray beam so that it is smaller than the margins of the image receptor and not shield the child's reproductive organs.

Question 15

What is the purpose of radiographic beam filtration?

A)To decrease beam hardness,thereby reducing patient skin dose and the dose to superficial tissues
B)To increase beam hardness,thereby reducing patient skin dose and the dose to superficial tissues
C)To eliminate short wavelength radiation to reduce the radiation received by the patient's skin and superficial tissues
D)To increase beam hardness,thereby increasing patient skin dose with only a slight increase to superficial tissues

Question 16

Which of the following is not an x-ray beam limitation device?

A)Aperture diaphragm
B)Collimator
C)Filter
D)Extension cylinder

Question 17

When using digital fluoroscopy systems,making use of the last-image-hold feature can:

A)be an effective dose reduction technique.
B)eliminate the need to collimate the primary beam.
C)eliminate increased involuntary patient motion.
D)eliminate increased voluntary patient motion.

Question 18

When a fluoroscopic image is electronically amplified by the use of an image intensification system,which of the following benefits results?
1)Increased image brightness
2)Saving of time for the radiologist
3)Patient dose reduction

A)1 and 2 only
B)1 and 3 only
C)2 and 3 only
D)1,2,and 3

Question 19

When performing a mobile fluoroscopic procedure,to reduce the radiation exposure to the patient,the radiographer must use a minimal source-skin distance of:

A)15 cm.
B)30 cm.
C)38 cm.
D)45 cm.

Question 20

To visualize smaller and lower contrast objects during interventional procedures,high-level-control fluoroscopy uses exposure rates that are ____________ those normally used in routine fluoroscopy.

A)higher than
B)lower than
C)the same as
D)none of the above because smaller and lower contrast objects cannot be visualized by fluoroscopy during interventional procedures

Question 21

Luminance is determined by measuring the concentration of light:

A)at only one particular point of the field of view.
B)over a particular field of view.
C)at only one particular point of the field of view and then squaring the number.
D)over a particular field of view and then squaring the number.

Question 22

Of the following procedures,which involve extended fluoroscopic time?
1)Biliary drainage
2)Stent and filter placement
3)Urinary or biliary stone removal

A)1 and 2 only
B)1 and 3 only
C)2 and 3 only
D)1,2,and 3

Question 23

Which of the following materials is commonly used in the tabletop of a radiographic examination table to make the tabletop as radiolucent as possible so that it will absorb only a minimal amount of radiation,thereby reducing the patient's radiation dose?

A)Carbon fiber material
B)Formica
C)Granite
D)Slate

Question 24

The control panel,where technical exposure factors are selected and seen on indicators by the equipment operator,must be located:

A)at the foot end of the radiographic examining table.
B)at the head end of the radiographic examining table.
C)behind a suitable protective barrier that has a radiation-absorbent window that permits observation of the patient during any procedure.
D)behind any regular wall that has a regular glass window that permits observation of the patient during any procedure.

Question 25

When settings are changed from one mA to a neighboring mA station,the most that linearity can vary is:

A)0%.
B)10%.
C)20%.
D)50%.