How can we help?

You can also find more resources in our Help Center.

200 terms

Radiology Exam Review - Equipment & Maintenance

STUDY
PLAY
The advantages of large-format spot film cameras, such as 100-mm and 105-mm, over smaller-format cameras, such as 70-mm and 90-mm, include
1. improved image quality.
2. decreased patient dose.
3. decreased x-ray tube heat load.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(A) 1 only
Exposures less than the minimum response time of an AEC may be required when
1. using high mA.
2. using fast film / screen combinations.
3. examining large patients or body parts.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(B) 1 and 2 only
The function of a plumbicon and vidicon is to convert:
(A) x-ray photon energy to visible light energy
(B) light energy to x-ray photon energy
(C) light to an electrical signal that is sent to the TV monitor
(D) an electrical signal to a light signal that is sent to the TV monitor
(C) light to an electrical signal that is sent to the TV monitor
Which of the following would be appropriate cassette front material(s)?
1. Tungsten
2. Magnesium
3. Bakelite
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(C) 2 and 3 only
Tungsten alloy is the usual choice for the anode target material of radiographic equipment because it
1. has a high atomic number.
2. has a high melting point.
3. can readily dissipate heat.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
If an AP hip technique required 92 kVp with single-phase x-ray equipment, what kVp would produce a comparable image with three-phase equipment?
(A) 69
(B) 75
(C) 81
(D) 103
(C) 81
(With three-phase equipment, voltage never drops to zero, and x-ray emission is 12 percent greater. Therefore, if 92 kVp is used with single-phase equipment, 81 kVp (12 percent less) will be required with three-phase equipment.)
The rear intensifying screen within a cassette may intentionally be made somewhat thicker to
(A) compensate for photon absorption within the front screen.
(B) improve the resolution capability of the screens.
(C) reduce the amount of light reflectance.
(D) minimize crossover.
(A) compensate for photon absorption within the front screen.
As the x-ray tube filament ages, it becomes progressively thinner because of evaporation. The vaporized tungsten is frequently deposited on the window of the glass envelope. This may
1. act as an additional filter.
2. reduce tube output.
3. result in arcing and tube puncture.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
Several types of exposure timers may be found on x-ray equipment. Which of the following types of timers functions to accurately duplicate radiographic densities?
(A) Synchronous
(B) Impulse
(C) Electronic
(D) Phototimer
(D) Phototimer
In which of the following portions of the x-ray circuit is a step-down transformer located?
(A) High-voltage side
(B) Filament circuit
(C) Rectification system
(D) Secondary side
(B) Filament circuit
Which of the following functions to increase the mA?
(A) increase in charge of anode
(B) increase in heat of the filament
(C) increase in kVp
(D) increase in focal spot size
(B) increase in heat of the filament
In order to maintain image clarity in an image intensifier system, the path of electron flow from the photocathode to the output phosphor is controlled by
(A) the accelerating anode.
(B) electrostatic lenses.
(C) the vacuum glass envelope.
(D) the input phosphor.
(B) electrostatic lenses.
Radiographs from a particular single-phase, full-wave-rectified x-ray unit were overexposed, using known correct exposures. A spinning top test was performed at 200 mA, 0.05 s, and 70 kVp, and eight dots (dashes) were visualized on the finished film. Which of the following is indicated?
(A) The 0.05-s time station is inaccurate.
(B) The 200-mA station is inaccurate.
(C) A rectifier is not functioning.
(D) The processor needs servicing.
(A) The 0.05-s time station is inaccurate.

(The spinning top test is used to test timer accuracy or rectifier operation. Because single-phase, full-wave-rectified current has 120 useful impulses per second, a 1-s exposure of the spinning top should demonstrate 120 dots. Therefore, a 0.05-s exposure should demonstrate six dots. Anything more or less than that indicates that the time station needs calibration. If exactly one-half of the expected number of dots appears, one should suspect rectifier failure)
The essential function of the photomultiplier is to
(A) provide a brighter fluoroscopic image.
(B) automatically restrict the field size.
(C) terminate the x-ray exposure once the image receptor is correctly exposed.
(D) automatically increase or decrease incoming line voltages.
(C) terminate the x-ray exposure once the image receptor is correctly exposed.
Which of the following formulas would the radiographer use to determine the total number of heat units produced with a given exposure using three-phase, six-pulse equipment?
(A) mA × time × kVp
(B) mA × time × kVp × 3.0
(C) mA × time × kVp × 1.35
(D) mA × time × kVp × 1.41
(C) mA × time × kVp × 1.35
The number of heat units produced during a given exposure with single-phase equipment is determined
by multiplying mA × time × kVp.
Correction factors are required with three-phase equipment. Unless the equipment manufacturer specifies otherwise, heat units for three-phase, six-pulse equipment are determined
by multiplying mA × time × kVp × 1.35.
Heat units for three-phase, twelve-pulse equipment are determined
by multiplying mA × time × kVp × 1.41.
...
by multiplying mA × time × kVp × 3.0
What is the relationship between kilovoltage (kV) and the half-value layer (HVL)?
(A) As kV increases, the HVL increases.
(B) As kV decreases, the HVL decreases.
(C) If the kV is doubled, the HVL doubles.
(D) If the kV is doubled, the HVL is squared.
(A) As kV increases, the HVL increases.
The HVL of a particular beam is defined as
that thickness of a material that will reduce the exposure rate to one-half its original value.

The more energetic the beam (the higher the kV), the greater the HVL thickness required to cut its intensity in half.
(((((((Therefore, it may be stated that kV and HVL have a direct relationship: As kV increases, HVL increases.))))))
In fluoroscopy, the automatic brightness control adjusts the
(A) kVp and mA.
(B) backup timer.
(C) mA and time.
(D) kVp and time.
(A) kVp and mA.
The automatic brightness control (ABC) functions to
maintain constant brightness and contrast of the output screen image, correcting for fluctuations in x-ray beam attenuation with adjustments in kVp and/or mA. ( in fluoroscopy)

(((There are also brightness and contrast controls on the monitor that the radiographer can regulate.)))
All of the following information is necessary to determine the maximum safe exposure using a radiographic tube rating chart, except the
(A) type of rectification.
(B) focal spot size.
(C) anode rotation speed.
(D) SID.
(D) SID.
SID
has no impact on anode heat load, but rather affects patient dose and film density
Which of the following causes pitting, or many small surface melts, of the anode's focal track?
(A) Vaporized tungsten on the glass envelope
(B) Loss of anode rotation
(C) A large amount of heat to a cold anode
(D) Repeated, frequent overloading
(D) Repeated, frequent overloading
Characteristic x-rays are produced when
(A) high-speed electrons are attracted by a tungsten nucleus and decelerated.
(B) orbital electrons move from an outer shell to fill an inner-shell vacancy.
(C) orbital electrons move from an inner shell to fill an outer-shell vacancy.
(D) an outer-shell electron is ejected from orbit.
(B) orbital electrons move from an outer shell to fill an inner-shell vacancy.
The device that receives the remnant beam, converts it into light, and then increases the brightness of that light is the
(A) cine camera.
(B) spot film camera.
(C) image intensifier.
(D) television monitor.
(C) image intensifier.
Off-focus, or extrafocal, radiation may be minimized by
(A) avoiding the use of very high kilovoltages.
(B) restricting the x-ray beam as close to its source as possible.
(C) using compression devices to reduce tissue thickness.
(D) avoiding extreme collimation.
(B) restricting the x-ray beam as close to its source as possible.
What is the device that directs the light emitted from the image intensifier to various viewing and imaging apparatus?
(A) Output phosphor
(B) Beam splitter
(C) Spot film changer
(D) Automatic brightness control
(B) Beam splitter
Which of the following is the correct formula for determining heat units for a three-phase, twelve-pulse x-ray machine?
(A) kVp × mA × time
(B) mA × kVp × mAs
(C) kVp × mAs × 1.35
(D) mA × time × kVp × 1.41
(D) mA × time × kVp × 1.41
Heat units for a single-phase x-ray unit are determined by using
using the formula HU = mA × kVp × time.
Heat units for a three-phase, six-pulse x-ray unit are determined by using t
using the formula HU = mA × kVp × time × 1.35.
Heat units for a three-phase, twelve-pulse x-ray unit are determined by using
using the formula HU = mA × kVp × time × 1.41.
High-mAs technical factors produce far more heat units than low-mAs technical factors.
(CarltHeat units for a three-phase, twelve-pulse x-ray unit are determined by using
tusing he formula HU = mA × kVp × time × 1.41.
Disadvantages of moving grids over stationary grids include which of the following?
1. They can prohibit the use of very short exposure times.
2. They increase patient radiation dose.
3. They can cause phantom images when anatomic parts parallel their motion.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(B) 1 and 2 only
The voltage ripple associated with a three-phase, twelve-pulse rectified generator is about
(A) 100 percent.
(B) 32 percent.
(C) 13 percent.
(D) 3 percent.
(D) 3 percent.
Voltage ripple
refers to the percentage drop from maximum voltage each pulse of current experiences
Voltage Ripple In single-phase rectified equipment -
the entire pulse (half-cycle) is used; therefore, there is first an increase to the maximum (peak) voltage value and then a decrease to zero potential (90º past peak potential). The entire waveform is used; if 100 kV were selected, the actual average kilovoltage output would be approximately 70.
Voltage Ripple in Three-phase rectification -
produces almost constant potential, with just small ripples (drops) in maximum potential between pulses. Approximately a 13 percent voltage ripple (drop from maximum value) characterizes the operation of three-phase, six-pulse generators.
Voltage Ripple in Three phase, twelve-pulse generators -
have about a 3.5 percent voltage ripple.
The contrast improvement factor of a grid will be greatest with
(A) high-ratio grids with many lines per inch.
(B) low-ratio grids with many lines per inch.
(C) high-ratio grids with fewer lines per inch.
(D) low-ratio grids with fewer lines per inch.
(C) high-ratio grids with fewer lines per inch.
Inadequate collimation, when using automatic exposure control, often results in
1. an underexposed radiographic image.
2. an overexposed radiographic image.
3. the timer not terminating soon enough.
(A) 1 only
(B) 1 and 3 only
(C) 3 only
(D) 2 and 3 only
(A) 1 only
Which of the following equipment is mandatory for performance of a myelogram?
(A) Cine camera
(B) 105-mm spot film
(C) Tilting x-ray table
(D) Tomography
(C) Tilting x-ray table
Capacitor discharge mobile x-ray units
1. use a grid-controlled x-ray tube.
2. are typically charged before the day's work.
3. provide a direct current output.
(A) 1 only
(B) 2 only
(C) 1 and 3 only
(D) 1, 2, and 3
(C) 1 and 3 only
A technique chart should be prepared for each AEC x-ray unit and should contain the following information for each type of examination:
1. Photocell(s) used
2. Optimum kVp
3. Backup time
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
Which of the following is (are) characteristics of the x-ray tube?
1. The target material should have a high atomic number and a high melting point.
2. The useful beam emerges from the port window.
3. The cathode assembly receives both low and high voltages.

(A) 1 only
(B) 2 only
(C) 1 and 2 only
(D) 1, 2, and 3
(D) 1, 2, and 3
Which of the following circuit devices must be connected in parallel?
(A) Filament ammeter
(B) Milliammeter
(C) Voltmeter
(D) Rectifiers
(C) Voltmeter
(so as to be able to measure the potential difference between two points.)
The total brightness gain of an image intensifier is a result of
1. flux gain.
2. minification gain.
3. focusing gain.
(A) 1 only
(B) 2 only
(C) 1 and 2 only
(D) 1 and 3 only
(C) 1 and 2 only
The Brightness Gain of image intensifiers is 5000 to 20,000. This increase is accomplished in two ways.
1st) as the electron image is focused to the output phosphor, it is accelerated by high voltage (this is flux gain).
2nd) the output phosphor is only a fraction of the size of the input phosphor, and this decrease in image size represents another Brightness Gain, termed Minification Gain.
Total Brightness Gain
is equal to the product of Minification Gain and Flux Gain.
A quality control program includes checks on which of the following radiographic equipment conditions?
1. Reproducibility
2. Linearity
3. Positive beam limitation/automatic collimation
(A) 1 only
(B) 1 and 2 only
(C) 1 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
(The accuracy of all three is important in order to ensure adequate patient protection. )
Reproductivity
means that repeated exposures at a given technique must provide consistent intensity.
Linearity
means that a given mAs, using different mA stations with appropriate exposure time adjustments, will provide consistent intensity.
Positive Beam Limitation (PBL)
Is Automatic Collimation
and must be accurate to 2 percent of the SID. Light-localized collimators must be available and must be accurate to within 2 percent.
In which of the following examinations would a cassette front with very low absorption properties be especially important?
(A) Abdominal radiography
(B) Extremity radiography
(C) Angiography
(D) Mammography
(D) Mammography

it uses such low kVp levels, cassette/image receptor front material becomes especially important.
As electrons impinge on the target surface, less than 1 percent of their kinetic energy is changed to
(A) x-rays.
(B) heat.
(C) gamma rays.
(D) recoil electrons.
(A) x-rays.
Which of the following materials is most likely to be used for mammography filtration?
(A) Rh
(B) Al
(C) Cu
(D) W
(A) Rh
(Dedicated mammographic x-ray tubes will have either a Rhodium (Rh) or Molybdenum (Mo) target.)
Rh
Rhodium
Al
...
Cu
...
W
...
The input phosphor of the image intensifier tube functions to convert
(A) kinetic energy to light.
(B) x-rays to light.
(C) electrons to light.
(D) fluorescent light to electrons.
(B) x-rays to light.
Mo
Molybdenum
X-ray tube life may be extended by
1. using low-mAs/high-kVp exposure factors.
2. avoiding lengthy anode rotation.
3. avoiding exposures to a cold anode.
(A) 1 only
(B) 1 and 2 only
(C) 1 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
What x-ray tube component does the number 5 in Figure 5-3 indicate?
(A) Anode stem
(B) Rotor
(C) Stator
(D) Focal track
(Saia, p 424)
(A) Anode stem
# 8 is the rotating anode with its beveled focal track at the periphery and its stem (at #5).
A photostimulable phosphor plate is used with
(A) computed radiography.
(B) radiographic intensifying screens.
(C) fluoroscopic intensifying screens.
(D) image intensified fluoroscopy.
(A) computed radiography.
Computed Radiography (CR) does not use traditional intensifying screens or film. Rather,
The CR cassette contains a photostimulable image plate (IP) which functions as the image receptor (rather than film emulsion). Upon exposure, the IP stores information. The cassette is placed into a special scanner / processor where the IP is scanned with a laser light and the stored image is displayed on the computer monitor. (
Radiation-sensitive automatic exposure control devices are known as
(A) automatic beam restrictors.
(B) ionization chambers.
(C) sensors.
(D) backup timers.
(B) ionization chambers.
(1 type of AEC devices)
An incorrect relationship between the primary beam and the center of a focused grid results in
1. an increase in scattered radiation production.
2. grid cutoff.
3. insufficient radiographic density.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(C) 2 and 3 only
Which of the following devices converts electrical energy to mechanical energy?
(A) Motor
(B) Generator
(C) Stator
(D) Rotor
(A) Motor
Two principal parts of an induction motor.
1.) Stator
2.) Rotor
Generator
converts mechanical energy into electrical energy.
If one rectifier were malfunctioning, the resulting mAs would be
(A) one-fourth that expected.
(B) one-half that expected.
(C) twice that expected.
(D) four times that expected.
(B) one-half that expected.
"half-waving"
When radiographs demonstrate half the expected density and the mA meter registers half the selected milliamperage, rectifier failure is generally suspected. The equipment is said to be "half-waving" because the inverse voltage is not being rectified to useful voltage.
Light-sensitive automatic exposure control devices are known as
(A) phototimers.
(B) ionization chambers.
(C) sensors.
(D) backup timers.
(A) phototimers.
Star and wye configurations are related to
(A) autotransformers.
(B) three-phase transformers.
(C) rectification systems.
(D) automatic exposure controls.
(see Fig. 5-10, on page 288-Selman)
(B) three-phase transformers.
star and wye (or delta)
refer to the configuration of transformer windings in three-phase equipment.

Instead of having a single primary coil and a single secondary coil, the high-voltage transformer has three primary and three secondary windings - one winding for each phase
(see Fig. 5-10, on page 288 - Selman).
Autotransformers
operate on the principle of self-induction and have only one winding.

Three-phase x-ray equipment often has three autotransformers.
(Selman, p 163)
Radiation that passes through the tube housing in directions other than that of the useful beam is termed
(A) scattered radiation.
(B) secondary radiation.
(C) leakage radiation.
(D) remnant radiation.
(C) leakage radiation.
Scattered Radiation
radiation that has been deviated in direction while passing through a part. It may include secondary Ratiation
Secondary Radiation
The results from the scattering of primary x-rays. Secondary radiation often accounts for fogging of radiographic film.
Remnant Radiation
is that which emerges from the patient to form the radiographic image.
Tube Head Construction
Must keep Leakage Radiation to less than 0.1 R/h at 1 m from the tube.
Fogging
Haziness or clouding of diagnostic X-ray films due to aging of unexposed film, or leakage of radiation or light onto the film before its development
The device used to test the accuracy of the x-ray timer is the
(A) densitometer.
(B) sensitometer.
(C) penetrometer.
(D) spinning top.
(D) spinning top

(May be used to test timer accuracy in single-phase equipment).
Spinning Top
A spinning top is a metal disc with a small hole in its outer edge that is placed on a pedestal about 6 in high. An exposure is made (e.g., 0.1 s) while the top spins. Because a full-wave-rectified unit produces 120 x-ray photon impulses per second, in 0.1 s the film should record 12 dots (if the timer is accurate).
Densitometer
...
Sensitometer
...
Penetrometer
...
Which of the following are features of fluoroscopic equipment that are designed especially to eliminate unnecessary radiation to patient and personnel?
1. Protective curtain
2. Filtration
3. Focal spot
(A) 1 only
(B) 1 and 2 only
(C) 1 and 3 only
(D) 1, 2, and 3
(B) 1 and 2 only
Which of the following techniques is used to evaluate the dynamics of a part?
(A) Fluoroscopy
(B) Stereoscopy
(C) Tomography
(D) Phototiming
(A) Fluoroscopy
Which of the following combinations would pose the least hazard to a particular anode?
(A) 1.2-mm focal spot, 92 kVp, 1.5 mAs
(B) 0.6-mm focal spot, 80 kVp, 3 mAs
(C) 1.2-mm focal spot, 70 kVp, 6 mAs
(D) 0.6-mm focal spot, 60 kVp, 12 mAs
(A) 1.2-mm focal spot, 92 kVp, 1.5 mAs
The image intensifier's input phosphor differs from the output phosphor in that the input phosphor
1. is much larger than the output phosphor.
2. emits electrons and the output phosphor emits light photons.
3. absorbs electrons and the output phosphor absorbs light photons.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(A) 1 only
Electrical devices that allow current to flow in only one direction are called
(A) resistors.
(B) rheostats.
(C) rectifiers.
(D) transformers.
(C) Rectifiers.

(Solid-state diodes are the rectifiers used in x-ray equipment because they allow current flow in only one direction.)
Resistors
such as rheostats, may be used to vary circuit current or voltage.
Transformers
operate on the principle of mutual induction and function to change the current and voltage values.
Fractional-focus tubes, with a 0.3-mm focal spot or smaller, have special application in
(A) magnification radiography.
(B) fluoroscopy.
(C) tomography.
(D) image intensification.
(A) magnification radiography.

(may beused to demonstrate small, delicate structures that are difficult to image with conventional radiography.)
Advantages of 100-mm spot filming over cassette spot filming include
1. less patient exposure.
2. lower film cost.
3. practical storage.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
The source of electrons within the x-ray tube is
(A) electrolysis.
(B) thermionic emission.
(C) rectification.
(D) induction.
(B) Thermionic Emission.
- the liberation of valence electrons from the filament atoms
Electrolysis
describes the chemical ionization effects of an electric current.
Rectification
s the process of changing AC to unidirectional current.
Induction
...
A backup timer for the AEC serves to
1. protect the patient from overexposure.
2. protect the x-ray tube from excessive heat.
3. increase or decrease master density.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(B) 1 and 2 only
Which of the following information is necessary to determine the maximum safe kVp, using the appropriate x-ray tube rating chart?
1. mA and exposure time
2. Focal spot size
3. Imaging-system speed
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(B) 1 and 2 only
Which of the illustrations in Figure 5-2 depicts the ionization-chamber type of automatic exposure control?
(A) Figure A.
(B) Figure B.
(C) Both are ionization-chamber-type AEC.
(D) Neither is ionization-chamber-type AEC.
(Saia, p 306)
(A) Figure A.

-there is an ionization chamber just beneath the tabletop above the cassette/image receptor (A).
If 92 kV and 12 mAs were used for a particular abdominal exposure with single-phase equipment, what mAs would be required to produce a similar radiograph with three-phase, six-pulse equipment?
(A) 36 mAs
(B) 24 mAs
(C) 8 mAs
(D) 6 mAs
(C) 8 mAs
In order to produce similar density, only two-thirds of the original mAs would be used for three-phase, six-pulse equipment (2/3 × 12 = 8 mAs).

With three-phase, twelve-pulse equipment, the original mAs would be cut in half. (Saia, p 333)
Advantages of battery-powered mobile x-ray units include their
. ability to store a large quantity of energy.
. ability to store energy for extended periods of time.
. lightness and ease of maneuverability.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(B) 1 and 2 only
2 main types of mobile x-ray equipment
1.) Capacitor Discharge
Light -easy to maneuver

2.) Battery-Powered.
Very heavy - capable of storing a large mAs capacity for extended periods of time. These units frequently have a capacity of 10,000 mAs, with 12 h required for a full charge.
Double-focus x-ray tubes have two
(A) port windows.
(B) anodes.
(C) filaments.
(D) rectifiers.
(C) filaments.
Which of the following modes of a trifield image intensifier will result in the highest patient dose?
(A) Its 25-in mode.
(B) Its 17-in mode.
(C) Its 12-in mode.
(D) Diameter does not affect patient dose.
(C) Its 12-in mode.
A light-absorbing dye is frequently incorporated during the manufacture of screens to
(A) reduce the diffusion of fluorescent light.
(B) decrease film contrast.
(C) increase screen speed.
(D) increase the useful life of the screen.
(A) reduce the diffusion of fluorescent light.
If exposure factors of 85 kVp, 400 mA, and 0.12 s yield an output exposure of 150 mR, what is the mR/mAs?
(A) 0.32
(B) 3.1
(C) 17.6
(D) 31
(B) 3.1
In the example given, 400 mA and 0.12 s were used, equaling 48 mAs. If the output for 48 mAs was 150 mR, then 1 mAs is equal to 3.1 mR (150 mR ¸ 48 mAs = 3.1 mR/mAs).
Radiographs from a particular three-phase, full-wave-rectified x-ray unit, made using known correct exposures, were underexposed. A synchronous spinning top test was performed using 200 mA, 1/12 s, and 70 kVp, and a 20º arc is observed on the test film. Which of the following is most likely the problem?
(A) The 1/12-s time station is inaccurate.
(B) The 200-mA station is inaccurate.
(C) A rectifier is not functioning.
(D) The processor needs servicing.
(A) The 1/12-s time station is inaccurate.
During cinefluorography, the camera shutter is open
(A) between frames.
(B) when the film moves.
(C) during exposures.
(D) all the time.
(C) during exposures.
The most frequent use of cinefluorography is for cardiac catheterizations. Cine film may be 16 or 35 mm in size. Cine cameras operate very much like movie cameras;
To determine how quickly an x-ray tube will disperse its accumulated heat, the radiographer uses a(n)
(A) technique chart.
(B) radiographic rating chart.
(C) anode cooling curve.
(D) spinning top test.
(C) anode cooling curve.
A parallel-plate ionization chamber receives a particular charge as x-ray photons travel through it. This is the operating principle of which of the following devices?
(A) Automatic exposure control
(B) Image intensifier
(C) Cine film camera
(D) Spot film camera
(A) Automatic exposure control (AEC)
Which of the following circuit devices operate(s) on the principle of self-induction?
1. Autotransformer
2. Choke coil
3. High-voltage transformer
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(B) 1 and 2 only
Periodic equipment calibration includes testing of the
1. focal spot.
2. mA.
3. kVp.
(A) 1 only
(B) 1 and 3 only
(C) 2 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
A particular AP thoracic measurement is 25 cm. What tomographic sections are indicated if we desire one midline and one each anterior and posterior to midline?
(A) 8, 9, and 10 cm
(B) 10, 11, and 12 cm
(C) 12, 13, and 14 cm
(D) 14, 15, and 16 cm
(C) 12, 13, and 14 cm

(If a part measures 25 cm, the midline is 13 cm (there are 12 cm anterior to the 13-cm level and 12 cm posterior to the 13-cm level), so the required series of cuts would be at 12, 13, and 14 cm.)
Congruence of the x-ray beam with the light field is tested using
(A) a pinhole camera.
(B) a star pattern.
(C) radiopaque objects.
(D) a slit camera.
(C) radiopaque objects.

(To test the congruence of the light and x-ray fields, a radiopaque object such asa paper clip or a penny is placed at each corner of the light field before the test exposure is made. After processing, the corners of the x-ray field should be exactly delineated by the radiopaque objects)
An automatic exposure control device can operate on which of the following principles?
1. A photomultiplier tube charged by a fluorescent screen
2. A parallel-plate ionization chamber charged by x-ray photons
3. Motion of magnetic fields inducing current in a conductor
(A) 1 only
(B) 2 only
(C) 1 and 2 only
(D) 1, 2, and 3
(C) 1 and 2 only
In the radiographic rating charts shown in Figure 5-6, what is the maximum safe kVp that may be used with the 1-mm focal spot, single-phase x-ray tube, using 300 mA and 1/50 s exposure?
(A) 80 kVp
(B) 95 kVp
(C) 105 kVp
(D) 112 kVp
(Chart - Selman, p 145)
(C) 105 kVp
The number 2 in Figure 5-5 indicates the
(A) effective focal spot.
(B) actual focal spot.
(C) focal track.
(D) thermionic emission.
(Selman, pp 138-139)
(A) effective focal spot.
Excessive anode heating can cause vaporized tungsten to be deposited on the port window. This can result in
1. decreased tube output.
2. tube failure.
3. electrical sparking.
(A) 1 only
(B) 2 only
(C) 1 and 2 only
(D) 1, 2, and 3
(D) 1, 2, and 3
In order to be used more efficiently by the x-ray tube, alternating current is changed to unidirectional current by the
(A) filament transformer.
(B) autotransformer.
(C) high-voltage transformer.
(D) rectifiers.
(D) rectifiers.
Which of the following voltage ripples is (are) produced by single-phase equipment?
1. 100 percent voltage ripple
2. 13 percent voltage ripple
3. 3.5 percent voltage ripple
(A) 1 only
(B) 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(A) 1 only
Target angle will have an effect on the
1. severity of the heel effect.
2. focal spot size.
3. heat load capacity.
(A) 1 only
(B) 2 only
(C) 1 and 2 only
(D) 1, 2, and 3
(D) 1, 2, and 3
Together, the filtering effect of the x-ray tube's glass envelope and its oil coolant are referred to as
(A) inherent filtration.
(B) added filtration.
(C) compensating filtration.
(D) port filtration.
(A) inherent filtration.
When using the smaller field in a dual-field image intensifier,
1. a smaller patient area is viewed.
2. the image is magnified.
3. the image is less bright.
(A) 1 only
(B) 1 and 3 only
(C) 2 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
Extended film processing of 3 minutes can be valuable for which of the following procedures?
(A) macroradiography
(B) mammography
(C) computed tomography
(D) computed radiography
(A) macroradiography
Which of the following will occur as a result of a decrease in the anode target angle?
1. Less pronounced anode heel effect
2. Decreased effective focal spot size
3. Greater photon intensity toward the cathode side of the x-ray tube
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(C) 2 and 3 only
Patient dose during fluoroscopy is affected by the
1. distance between the patient and the input phosphor.
2. amount of magnification.
3. tissue density.
(A) 1 only
(B) 3 only
(C) 2 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
A mobile C-arm unit can provide
1. fluoroscopic images.
2. dynamic images.
3. static images.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
All of the following x-ray circuit devices are located between the incoming power supply and the primary coil of the high-voltage transformer except the
(A) timer.
(B) kV meter.
(C) mA meter.
(D) autotransformer.
(C) mA meter.
Which of the following devices is (are) component(s) of a typical fluoroscopic video display system?
1. Videotape recorder
2. TV camera
3. TV monitor
(A) 1 only
(B) 1 and 3 only
(C) 2 and 3 only
(D) 1, 2, and 3
(C) 2 and 3 only
Decreased x-ray tube output can be attributed to
1. a roughened focal track.
2. tungsten deposits on the glass envelope.
3. excessive anode rotation.
(A) 1 only
(B) 2 only
(C) 1 and 2 only
(D) 1, 2, and 3
(C) 1 and 2 only
A device used to ensure reproducible radiographs, regardless of tissue density variations, is the
(A) phototimer.
(B) penetrometer.
(C) grid.
(D) rare earth screen.
(A) phototimer.
During a fluoroscopic exam, x-ray photons exiting the patient then travel to which of the following?
(A) output phosphor
(B) focusing lens
(C) input phosphor
(D) photocathode
(C) input phosphor
The procedure whose basic operation involves reciprocal motion of the x-ray tube and film is
(A) cinefluorography.
(B) spot filming.
(C) tomography.
(D) image intensification.
(C) tomography.
Which of the following systems function(s) to compensate for changing patient/part thicknesses during fluoroscopic procedures?
(A) Automatic brightness control
(B) Minification gain
(C) Automatic resolution control
(D) flux gain
(A) Automatic brightness control
A slit camera is used to measure
1. focal spot size.
2. intensifying-screen resolution.
3. SID resolution.
(A) 1 only
(B) 1 and 2 only
(C) 1 and 3 only
(D) 1, 2, and 3
(Fig. 5-9) ( (Bushong, p 431)
(A) 1 only
Delivery of large exposures to a cold anode or the use of exposures exceeding tube limitation can result in
1. increased tube output.
2. cracking of the anode.
3. rotor bearing damage.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(C) 2 and 3 only
Features of x-ray tube targets that function to determine heat capacity include the
1. rotation of the anode.
2. diameter of the anode.
3. size of the focal spot.
(A) 1 only
(B) 1 and 2 only
(C) 1 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
The transition of orbital electrons from outer to inner shells gives rise to
(A) Compton scatter.
(B) pair production.
(C) bremsstrahlung radiation.
(D) characteristic radiation.
(D) characteristic radiation.
A high-speed electron entering the tungsten target is attracted to the positive nucleus of a tungsten atom and, in the process, is decelerated. This results in
(A) characteristic radiation.
(B) Bremsstrahlung radiation.
(C) Compton scatter.
(D) photoelectric effect.
(B) Bremsstrahlung radiation.
Referring to the anode cooling chart in Figure 5-7, if the anode is saturated with 300,000 heat units (HU), how long will the anode need to cool before another 160,000 heat units can be safely applied?
(A) 3 min
(B) 4 min
(C) 5 min
(D) 7 min
(Chart - Selman, p 147)
(B) 4 min
Components of digital imaging include
1. computer manipulation of the image.
2. formation of an electronic image on the radiation detector.
3. formation of an x-ray image directly on the image receptor.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(B) 1 and 2 only
How is the thickness of the tomographic section related to the tomographic angle?
(A) The greater the tomographic angle, the thicker the section.
(B) The greater the tomographic angle, the thinner the section.
(C) The less the tomographic angle, the thinner the section.
(D) The tomographic angle is unrelated to section thickness.
(B) The greater the tomographic angle, the thinner the section.
Which of the following will serve to increase the effective energy of the x-ray beam?
1. Increase in added filtration
2. Increase in kilovoltage
3. Increase in milliamperage
(A) 1 only
(B) 2 only
(C) 1 and 2 only
(D) 1, 2, and 3
(C) 1 and 2 only
The technique that is used to improve diagnostic quality by removing superimposed anatomic details from an x-ray image is called
(A) xeroradiography.
(B) subtraction.
(C) CT.
(D) MRI.
(B) subtraction.
is used most frequently with angiographic films.
All of the following are associated with the anode except
(A) the line focus principle.
(B) the heel effect.
(C) the focal track.
(D) thermionic emission.
(D) thermionic emission.
Moving the image intensifier closer to the patient during fluoroscopy
1. decreases the source-image distance (SID).
2. decreases patient dose.
3. improves image quality.
(A) 1 only
(B) 1 and 2 only
(C) 1 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
(see Fig. 5-8). (Fosbinder & Kelsey, pp 265-267)
If a radiograph exposed using an AEC is overexposed because an exposure shorter than the minimum response time was required, the radiographer generally should
(A) decrease the mA.
(B) use the minus density.
(C) use the plus density.
(D) decrease the kVp.
(A) decrease the mA.

Because too long an exposure time results in excessive density, the best way to compensate is to decrease the milliamperage
The advantage(s) of collimators over aperture diaphragms and flare cones include(s)
1. the variety of field sizes available.
2. more efficient beam restriction.
3. better cleanup of scattered radiation.
(A) 1 only
(B) 1 and 2 only
(C) 1 and 3 only
(D) 2 and 3 only
(B) 1 and 2 only
When a pair of intensifying screens are mounted inside a cassette, a thicker screen may be mounted
(A) inside the front of the cassette.
(B) inside the lid (rear) of the cassette.
(C) with a water-soluble paste.
(D) using a more pliable adhesive.
(B) inside the lid (rear) of the cassette.
During a fluoroscopic examination, the milliamperage is
(A) less than 5
(B) 10 to 20
(C) 50 to 75
(D) 100 to 500
(A) less than 5
Which of the waveforms illustrated in Figure 5-1 represents single-phase, full-wave-rectified equipment?
(A) Figure 1
(B) Figure 2
(C) Figure 3
(D) Figure 4
(Kelsey & Fosbinder, pp 74-75, 83-85)
(B) Figure 2
#2 represents single-phase, full-wave-rectified current; the negative half-cycle is rectified to a useful positive half-cycle.
How many half-value layers will it take to reduce an x-ray beam whose intensity is 78 R/min to an intensity of less than 10 R/min?
(A) 2
(B) 3
(C) 4
(D) 8
(B) 3

HVL may be used to express the quality of an x-ray beam. The HVL of a particular beam is that thickness of an absorber that will decrease the intensity of the beam to one-half its original value. If the original intensity of the beam was 78 R/min, the first HVL will reduce it to 39 R/min, the second HVL will reduce it to 19.5 R/min, and the third HVL will reduce the intensity to 9.75 R/min.
Circuit devices that will conduct electrons in only one direction are
1. resistors.
2. valve tubes.
3. solid-state diodes.
(A) 1 only
(B) 1 and 3 only
(C) 2 and 3 only
(D) 1, 2, and 3
(C) 2 and 3 only
What is the device that is used to absorb scattered radiation produced in the patient before it reaches the image receptor?
(A) Photomultiplier
(B) Beam restrictor
(C) Ionization chamber
(D) Grid
(D) Grid
Which of the following will improve the spatial resolution of image-intensified images?
1. A very thin coating of cesium iodide on the input phosphor
2. A smaller-diameter input screen
3. Increased total brightness gain
(A) 1 only
(B) 1 and 2 only
(C) 1 and 3 only
(D) 1, 2, and 3
(B) 1 and 2 only
In the production of characteristic radiation at the tungsten target, the incoming electron
(A) ejects an inner-shell tungsten electron.
(B) ejects an outer-shell tungsten electron.
(C) is deflected, with resulting energy loss.
(D) is deflected, with resulting energy increase.
(A) ejects an inner-shell tungsten electron.
Which of the following terms describes the amount of electric charge flowing per second?
(A) Voltage
(B) Current
(C) Resistance
(D) Capacitance
(B) Current
Dedicated radiographic units are available for
1. chest radiography.
2. head radiography.
3. mammography.
(A) 1 only
(B) 2 only
(C) 1 and 2 only
(D) 1, 2, and 3
(D) 1, 2, and 3
If the primary coil of the high-voltage transformer is supplied by 220 V and has 200 turns, and the secondary coil has 100,000 turns, what is the voltage induced in the secondary coil?
(A) 40 kV
(B) 110 kV
(C) 40 V
(D) 110 V
(B) 110 kV
The high-voltage, or step-up, transformer functions to
Increase voltage to the necessary kilovoltage. It decreases the amperage to milliamperage. The amount of increase or decrease depends on the transformer ratio, that is, the ratio of the number of turns in the primary coil to the number of turns in the secondary coil. The transformer law is as follows:
To determine secondary V,

.Vs Ns
¾ = ¾
.Vp Np

To determine secondary I:

.Ns Ip
¾ = ¾
.Np Is
The brightness level of the fluoroscopic image can vary with
1. milliamperage.
2. kilovoltage.
3. patient thickness.
(A) 1 only
(B) 1 and 2 only
(C) 1 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
The minimum response time of an automatic exposure control (AEC)
(A) is the time required to energize the intensifying phosphors.
(B) is its shortest possible exposure time.
(C) functions to protect the patient from overexposure.
(D) functions to protect the tube from excessive heat.
(B) is its shortest possible exposure time.
When the radiographer selects kilovoltage on the control panel, which device is adjusted?
(A) Step-up transformer
(B) Autotransformer
(C) Filament circuit
(D) Rectifier circuit
(B) Autotransformer
The radiograph illustrated in Figure 5-4 was made using a single-phase, full-wave-rectified unit with a timer and rectifiers that are known to be accurate and functioning correctly. What exposure time was used to produce this image?
(A) 1/10 s
(B) 0.05 s
(C) 1/12 s
(D) 0.025 s
(B) 0.05 s
spinning top is used
What x-ray tube component does the number 7 in Figure 5-3 indicate?
(A) Anode stem
(B) Rotor
(C) Stator
(D) Focal track
. (Saia, p 424)
(B) Rotor
#6 and 7 are the stator and rotor -the two components of an induction motor, whose function it is to rotate the anode.
The image intensifier's input phosphor is generally composed of
(A) cesium iodide.
(B) zinc cadmium sulfide.
(C) gadolinium oxysulfide.
(D) calcium tungstate.
(A) cesium iodide.
The photoelectric process is an interaction between an x-ray photon and
(A) an inner-shell electron.
(B) an outer-shell electron.
(C) a nucleus.
(D) another photon.
(A) an inner-shell electron.
Which of the following contribute(s) to inherent filtration?
1. X-ray tube glass envelope
2. X-ray tube port window
3. Aluminum between the tube housing and the collimator
(A) 1 only
(B) 1 and 2 only
(C) 1 and 3 only
(D) 1, 2, and 3
(B) 1 and 2 only
All of the following are components of the image intensifier, except the
(A) photocathode.
(B) focusing lenses.
(C) TV monitor.
(D) accelerating anode.
(C) TV monitor.
The type(s) of radiation produced at the target is (are)
1. photoelectric.
2. characteristic.
3. bremsstrahlung.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(C) 2 and 3 only
A three-phase timer can be tested for accuracy using a synchronous spinning top. The resulting image looks like a
(A) series of dots or dashes, each representative of a radiation pulse.
(B) solid arc, with the angle (in degrees) representative of the exposure time.
(C) series of gray tones, from white to black.
(D) multitude of small, meshlike squares of uniform sharpness.
(B) solid arc, with the angle (in degrees) representative of the exposure time.
If the distance from the focal spot to the center of the collimator's mirror is 6 in, what distance should the illuminator's light bulb be from the center of the mirror?
(A) 3 in
(B) 6 in
(C) 9 in
(D) 12 in
(B) 6 in

he bulb's emitted beam of light is deflected by a mirror placed at an angle of 45º in the path of the light beam. In order for the projected light beam to be the same size as the x-ray beam, the focal spot and the light bulb must be exactly the same distance from the center of the mirror.
n Figure 5-6, which of the illustrated x-ray tubes permit(s) an exposure of 400 mA, 0.1 s, and 80 kVp?
1. Tube A
2. Tube B
3. Tube C
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(Selman, p 145)
(B) 1 and 2 only
Which of the following devices is used to control voltage by varying resistance?
(A) Autotransformer
(B) High-voltage transformer
(C) Rheostat
(D) Fuse
(C) Rheostat
In Figure 5-6, what is the maximum safe mA that may be used with 0.1 s exposure and 120 kVp, using the three-phase, 2-mm focal spot x-ray tube?
(A) 400
(B) 500
(C) 600
(D) 700
(Selman, p 145)
(C) 600
Typical examples of digital imaging include
1. magnetic resonance imaging (MRI).
2. computed tomography (CT).
3. pluridirectional tomography.
(A) 1 only
(B) 1 and 2 only
(C) 1 and 3 only
(D) 1, 2, and 3
(B) 1 and 2 only
Which of the following combinations will present the greatest heat-loading capability?
(A) 17º target angle, 1.2-mm actual focal spot
(B) 10º target angle, 1.2-mm actual focal spot
(C) 17º target angle, 0.6-mm actual focal spot
(D) 10º target angle, 0.6-mm actual focal spot
(Selman, pp 145-146)
(C) 17º target angle, 0.6-mm actual focal spot
The most commonly used types of automatic exposure control devices are the
1. ion chamber.
2. photomultiplier tube.
3. cathode ray tube.
(A) 1 and 2 only
(B) 1 and 3 only
(C) 2 and 3 only
(D) 1, 2, and 3
(Fig. 5-11). (Shephard, pp 275-276)
(A) 1 and 2 only
The functions of a picture archiving and communication system (PACS) include
1. storage of analog images.
2. acquisition of digital images.
3. storage of digital images.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(C) 2 and 3 only
With three-phase equipment, the voltage across the x-ray tube
1. drops to zero every 180º.
2. is 87 to 96 percent of the maximum value.
3. is at nearly constant potential.
(A) 1 only
(B) 2 only
(C) 1 and 2 only
(D) 2 and 3 only
(D) 2 and 3 only
Rare earth phosphors that may be used in intensifying screens include
1. cesium iodide.
2. gadolinium oxysulfide.
3. lanthanum oxybromide.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(C) 2 and 3 only
Accurate operation of the AEC device is dependent on
1. the thickness and density of the object.
2. positioning of the object with respect to the photocell.
3. beam restriction.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(C) 2 and 3 only
The total number of x-ray photons produced at the target is contingent on the
1. tube current.
2. target material.
3. square of the kilovoltage.
(A) 1 only
(B) 1 and 2 only
(C) 2 and 3 only
(D) 1, 2, and 3
(D) 1, 2, and 3
If a high-voltage transformer has 100 primary turns and 35,000 secondary turns, and is supplied by 220 Volts and 75 A, what are the secondary voltage and current?
(A) 200 A and 77 V
(B) 200 mA and 77 kVp
(C) 20 A and 77 V
(D) 20 mA and 77 kVp
(B) 200 mA and 77 kVp

The high-voltage, or step-up, transformer functions to increase voltage to the necessary kilovoltage. It decreases the amperage to milliamperage. The amount of increase or decrease is dependent on the transformer ratio¾the ratio of the number of turns in the primary coil to the number of turns in the secondary coil. The transformer law is as follows:
To determine secondary V,

.Vs Ns
¾ = ¾
.Vp Np

To determine secondary I:

.Vs Ip
Which of the following image recording methods will require the greatest patient dose?
(A) Cassette-loaded spot film
(B) 105-mm spot film
(C) 35-mm cine
(D) Videotape
(C) 35-mm cine
What component of the x-ray tube is a graphite disc with a tungsten-rhenium track at its periphery?
(A) Filament
(B) Focusing cup
(C) Anode
(D) Stator
(C) Anode
A spinning top device can be used to evaluate
1. timer accuracy.
2. rectifier failure.
3. the effect of kVp on contrast.
(A) 1 only
(B) 2 only
(C) 1 and 2 only
(D) 1, 2, and 3
(C) 1 and 2 only
Figure 5-5 illustrates the
(A) anode heel effect.
(B) reciprocity law.
(C) line focus principle.
(D) inverse square law.
(C) line focus principle.

it illustrates that the actual focal spot (number 1) is always larger than the effective, or projected/apparent, focal spot (number 2).
Anode Heel Effect.
...
Reciprocity Law.
...
Inverse Square Law.
...
All of the following devices are likely to be located on the typical x-ray unit control panel, except a(n)
(A) mA meter.
(B) kVp selector.
(C) timer.
(D) filament ammeter.
(D) filament ammeter.
Which of the following occurs during bremsstrahlung radiation production?
(A) An electron makes a transition from an outer to an inner electron shell.
(B) An electron approaching a positive nuclear charge changes direction and loses energy.
(C) A high-energy photon ejects an outer-shell electron.
(D) A low-energy photon ejects an inner-shell electron.
(B) An electron approaching a positive nuclear charge changes direction and loses energy.