Deck 11: Equipment Design for Radiation Protection

Question 1

Fluoroscopic devices are capable of subjecting the patient,the equipment operator,and other personnel near the fluoroscopic equipment to substantial doses of ionizing radiation.These devices include
1)C-arm fluoroscopes.
2)fluoroscopes on stationary equipment with HLC mode used for interventional procedures.
3)biplane interventional fluoroscopic systems.

A)1 and 2 only
B)1 and 3 only
C)2 and 4 only
D)1,2,3,and 4

Answer 1

1,2,3,and 4

Question 2

During a fluoroscopic examination,a resettable cumulative timing device measures the x-ray beam-on time and sounds an audible alarm or in some cases 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

Answer 2

5 minutes

Question 3

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

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

Answer 3

100 mGya/min

Question 4

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 5

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,thus making image viewing very convenient for physicians providing patient care.
D)digital images cannot be accessed at any workstations by physicians.

Question 6

In digital radiography the number of different shades of gray that can be stored in memory and displayed on a computer monitor is termed

A)contrast matrix.
B)grayscale.
C)shadows.
D)pixels.

Question 7

The protective tube housing serves as a shield against _____________________ entering the x-ray tube,thereby preventing electric shock while also facilitating cooling of the x-ray tube.

A)the high voltage
B)the low voltage
C)lose inherent filter particles
D)collimator components

Question 8

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

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

Question 9

When performing a mobile radiographic 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 10

Digital radiography systems offer several advantages over computed radiography.Some of these include
1)lower dose.
2)ease of use.
3)immediate imaging results.
4)manipulation of the image.

A)1,2,and 3 only
B)1,2,and 4 only
C)2,3,and 4 only
D)1,2,3,and 4

Question 11

What is the purpose of radiographic beam filtration?

A)To reduce exposure to the patient's skin and superficial tissues by absorbing most of the higher-energy photons from the heterogeneous beam.
B)To reduce exposure to the patient's skin and superficial tissues by absorbing most of the lower-energy photons from the heterogeneous beam.
C)To reduce exposure to the patient's skin and superficial tissues by absorbing all of the higher-energy photons from the homogeneous beam.
D)To reduce exposure to the patient's skin and superficial tissues by removing all the lower-energy photons from the homogeneous beam.

Question 12

If the luminance of the collimator light source is adequate,the localizing light beam will satisfactorily outline the margins of the radiographic beam on the area of clinical interest on

A)infants only.
B)children only.
C)teenagers and adults only.
D)all patients.

Question 13

Total filtration of _______________________ for fixed x-ray units operating above 70 kVp is the regulatory standard.

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 14

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 15

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

A)Cone
B)Collimator
C)Filter
D)Extension cylinder

Question 16

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

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

Question 17

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 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 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 the need for body or part immobilization.
D)lead to a 50% reduction of technical exposure factors.

Question 20

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 21

When generator settings are changed from one mA and time combination to another,the most that linearity can vary is

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

Question 22

The control panel,where technical exposure factors are selected and visually displayed for 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 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

Luminance is determined by measuring the concentration of light

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

Question 25

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