Mosby chapter 4
Choose all that describe the outcome of using low kVp (choose 3): a. High contrast b. Few shades of gray c. Long-scale contrast d. Short-scale contrast e. Low contrast f. Many gray tones
a,b,d
What device is turned by a rotor? a. Anode b. mA meter c. Ionization chamber d. Step-up transformer
a. Anode
What device spins at 10,000-12,000 rpm? A. Anode B. mA meter C. Ionization chamber D. Step-up transformer
a. Anode
Choose all of the following statements that are accurate regarding electrostatic charges. a. Electrostatics is the study of electric charges at rest b. The movement of electrons from one object to another is called ionization c. Like charges attract, and unlike charges repel d. Electrostatic charges concentrate on a conductor in the are of greatest curvature e. Friction, contact, and induction are methods of ionization
a. Electrostatics is the study of electric charges ate rest d. Electrostatic charges concentrate on a conductor in the area of the greatest curvature
Distortion that occurs when the x-ray beam is angled along the long axis of a part is: a. Elongation b. Magnification c. Minification d. Misrepresentation
a. Elongation
The radiographic image is formed by: a. Exit rays striking the image receptor b. Laser light c. Cosmic rays d. Electrons and heat
a. Exit rays striking the image receptor
A primary advantage to digital fluoroscopy is: a. Postprocessing manipulation of the image b. Radiation dose to the patient is substantially lower c. No radiologist is needed d. Lower cost
a. Postprocessing manipulation of the image
The process of assigning a value to each pixel to represent a gray tone is called: a. Quantization b. Scintillating c. Nyquist frequency d. Sampling
a. Quantization
Waves of radiation are called: a. Sine waves b. Strong waves c. Signal waves d. Current waves
a. Sine waves
The accuracy of the timer must be within: a. 10% of the time chosen for exposures over 10ms b. 5% of the time chosen for exposures over 10ms c. 5% of the time chosen for exposures under 10ms d. 10% of the time chosen for exposures under 10ms
b. 5% of the time chosen for exposures over 10ms
The useful image acquisition area of an image receptor is: a. Detector element b. Detector size c. TFT size d. Dynamic range
b. Detector size
An image intensifier's conversion factor is expressed as the ratio of: a. The flux gain to the minification gain b. The luminance of the output phosphor to the exposure rate at the input phosphor c. The exposure rate at the output phosphor to the exposure rate at the at the input phosphor d. The size of the input phosphor to the size of the output phosphor
b. The luminance of the output phosphor to the exposure rate at the input phosphor
Frequency is defined as: a. Synonymous with wavelength b. The number of waves passing a point per unit time c. The number of waves striking the patient d. The number of exposures needed during an exam
b. The number of waves passing a point per unit time
Which of the following affects receptor exposure? a. Atomic mass of the x-ray tube anode b. X-ray tube angle c. Atomic number of the cathode filament
b. X-ray tube angle
What percentage of energy in the x-ray tube is converted to x-rays? a. 99% b. 75% c. 1% d. 100%
c. 1%
What device may be used to ensure consistency of radiographic quality from one exposure to the next? a. Electronic timer b. Step-up transformer c. Automatic exposure control d. High-frequency generator
c. Automatic exposure control
Receptor exposure was formerly called: a. Contrast b Detail c. Density d. Distortion
c. Density
What is the most commonly used AEC? a. Phototimer b. mA meter c. Ionization chamber d. Falling load generator
c. Ionization chamber
Exposure linearity must be accurate to within: a. 4 b. 5% c. 2% of SID d. 10%
d. 10%
When a quality control test is performed to ensure the penetrating ability of the x-ray beam is accurate, the result must be within this amount of the control panel setting? a. 2% of SID b. 4% c. 10% d. 50%
d. 50%
The smallest exposure change able to be captured by a detector is called: a. Spatial resolution b. Exposure latitude c. Pixel d. Contrast resolution
d. Contrast resolution
Visible differences in adjacent structures on a radiographic image describe: a. Receptor exposure b. Spatial resolution c. Signal loss d. Contrast resolution
d. Contrast resolution
The process of thermionic emission causes: a. Electrons to boil off the anode b. The anode to spin c. The cathode to cool quickly d. Electrons to boil off the filament
d. Electrons to boil off the filament
Digital imaging is driven by: a. kVp b. mAs c. IR speed class d. Exposure
d. Exposure
The test that measures the accuracy of adjacent mA stations is: a. Exposure reproducibility b. Spinning top test c. Pinhole camera d. Exposure linearity
d. Exposure linearity
What device always delivers the shortest exposure time possible? a. Anode b. mA meter c. Ionization chamber d. Falling load generator
d. Falling load generator
What device uses maximum heat storage ability of the tube to deliver mAs? a. Anode b. mA meter c. Ionization chamber d. Falling load generator
d. Falling load generator
What type of x-ray machine uses a continually decreasing mA for the shortest times possible? a. Ionization chamber b. Portable c. C-arm d. Falling load generator
d. Falling load generator
The latest digital fluoroscopic units use: a. Nonionizing radiation b. CR cassettes c. Conventional image intensifiers d. Flat panel plates similar to DR
d. Flat panel plates similar to DR
The primary type of grid used in diagnostic imaging is: a. Crosshatch b. Parallel c. Rhombic d. Focused
d. Focused
The range of SIDs that may be used with a focused grid is called: a. Grid ratio b. Objective plane c. Anticutoff distances d. Grid radius
d. Grid radius
When AEC is used, increasing the KVP: a. Increases the exposure time b. Increases the image contrast c. Decreases the exposure time d. Has no effect on image quality
d. Has no effect on image quality
The x-ray beam is: a. Heterogenous - all rays possess the some energy b. Homogeneous - all rays posses the some energy c. Monoenergetic - all energies correspond to the kVp d. Heterogeneous or ployenergetic - consisting of many different energies (wavelengths)
d. Heterogeneous or polyenergetic - consisting of many different energies (wavelengths)
Which of the following is a graphical representation of pixel values? a. Dynamic range b. Luminance c. Look-up table d. Histogram
d. Histogram
In digital radiography inappropriate collimation causes: a. A fogged image b. Pixel unresponsiveness c. DICOM incompatibility d. Histogram analysis error
d. Histogram analysis error
To reduce patient dose, exposure technique in digital imaging should be adjusted by: a. Lowering kVp b. Increasing mAs c. Shortening SID d. Increasing kVp
d. Increasing kVp
Electromagnetic radiation travels: a. In waves along a straight path b. In circles c. Back and forth d. As electrons in waves along a straight path
a. In waves along a straight path
Which of the following describes the relationship between mAs and receptor exposure? a. Receptor exposure is directly proportional to mAs b. Receptor exposure is inversely proportional to mAs c. Receptor exposure is directly proportional to mAs2 d. mAs controls the number of electrons boiled off the anode and the number of x-rays produced
a. Receptor exposure is directly proportional to mAs
The 15% rule states that : a. Receptor exposure may be halved by decreasing kVp by 15% b. kVp should be 15% of the mAs selected c. Receptor exposure may be halved by increasing kVp by 15% d. At least a 15% change in mAs is required to make a change visible
a. Receptor exposure may be halved by decreasing kVp by 15%
If SID is reduced by one half, what must be done to mAs to maintain a constant receptor exposure? a. Reduce mAs to one fourth its original value b. Reduce mAs to one half its original value c. Increase mAs by four times its original value d. Increase mAs by two times its original value
a. Reduce mAs to one fourth its original value
Digital image receptors are more sensitive to: a. Scatter and background radiation b. Fluorescent lights c. Free electrons d. Free radicals
a. Scatter and background radiation.
A software function that evens the brightness displayed in the image is called: a. Smoothing b. Equalization c. Postprocessing d. Subtraction
a. Smoothing
Which device reduces voltage and provides current to produce an electron cloud or space charge at the filament? a. Step-down transformer b. Rectifier c. Cathode d. Timer
a. Step-down transformer
A transformer that has more turns in the secondary coil than in the primary coil is called a: a. Step-up transformer b. Solenoid c. Step-down transformer d. Filament transformer
a. Step-up transformer
Grid cutoff may be described as: a. Decreased density in the middle of the radiograph caused by the use of a parallel grid inserted upside down b. Decreased density on a radiograph as a result of absorption of image-forming rays c. Increased density in the center of a radiograph caused by the use of a focused grid inserted upside down d. Decreased density on the edges of a radiograph only
b. Decreased density on a radiograph as a result of absorption of image-forming rays
The smallest resolvable area in a digital imaging device is: a. Detector size b. Detector element c. Matrix size d. Focal-spot size
b. Detector element
The force with which the electron stream passes from cathode to anode is a result of ______________ passing through the x-ray tube? a. Current b. Kilovoltage c. Tungsten d. Heat
b. Kilovoltage
The CR reader unit scans the IP with a(n): a. Infrared light b. Laser c. Sonar d. Visible white light
b. Laser
The number of pixels making up the digital image is the: a. Pixel depth b. Matrix size c. Pixel pitch d. Field of view
b. Matrix size
Improper use of grids may result in an image artifact known as: a. SNR b. Moire pattern c. Elongation d. Foreshortening
b. Moire pattern
The active portion(s) of a CR IP is (are): a. ABC b. PSP c. DQE d. SNR
b. PSP
A material that absorbs x-ray energy and emits part of that energy as visible light is called: a. Diode b. Scintillator c. TFT d. Cathode
b. Scintillator
The two types of electromagnetic induction are: a. Autoinduction and mutual induction b. Self-induction and mutual induction c. Generated induction and self-induction d. Current induction an voltage induction
b. Self-induction and mutual induction
Elongation and foreshortening are examples of: a. Size distortion b. Shape distortion c. Motion d. Distortion caused by short SID and long OID
b. Shape distortion
The amount of material needed to reduce the intensity of the beam by 1/10 is called: a. Half-value layer b. Tenth-value layer c. Total filtration d. Inherent filtration
b. Tenth-value layer
As the amount of beam filtration is increased: a. Contrast increases b. There is no effect on contrast c. Contrast decreases d. Contrast increases because the beam is harder
c. Contrast decreases
The best scatter cleanup is achieved with the use of: a. Air gap technique b. Focused grid c. Crosshatch grid d. Parallel grid
c. Crosshatch grid
What allows more anatomical structures to be captured during an exposure: a. Contrast resolution b. Spatial resolution c. Dynamic range d. MTF
c. Dynamic range
X-rays travel as bundles of energy called: a. Energy waves b. Phasers c. Electromagnetic bursts d. Photons
d. Photons
If SID is doubled, what may be said about receptor exposure? a. Receptor exposure doubles b. Receptor exposure is reduced by one half c. Receptor exposure is reduced by new mAs2 d. Receptor exposure is reduced to one fourth
d. Receptor exposure is reduced to one fourth
What regulates the duration of x-ray production? a. Step-down transformer b. Rectifier c. Cathode d. Timer
d. Timer
The portion of the image-intensifier tube that converts electron energy to visible light is the: a. Output phosphor b. Photocathode c. Input phosphor d. Detector element
a. Output phosphor
Where does thermionic emission occur? a. Step-down transformer b. Rectifier c. Cathode d. Timer
c. Cathode
Electricity is supplied to the imaging department by a: a. Motor b. Rectifier c. Generator d. Voltmeter
c. Generator
Most of the energy conversion in the x-ray tube produces: a. X-rays b. Light c. Heat d. Current
c. Heat
Wavelength is defined as the distance from: a. The x-ray tube to the patient b. The cathode to the anode c. The bottom of a wave to the top d. Peak to peak of the wave
d. Peak to peak of the wave
What converts light into a charge? a. Diode b. Cathode c. AC to DC converter d. Photodiode
d. Photodiode
Differential absorption of the x-ray beam is a function of: a. Compton interactions b. Atomic mass of anatomic structures c. mAs d. Photoelectric interaction
d. Photoelectric interaction
Electromagnetic induction is the process of causing an electrical current to flow in a conductor: a. When it is placed in contact with another conductor b. When it is placed in contact with an insulator c. When it is placed in contact with a superconductor d. When it is placed in the magnetic field of another conductor
d. When it is place in the magnetic field of another condutor
Fluoroscopy exposure rate may not exceed: a. 10 mGya per minute b. 100 mGya per minute c. 5 mGya per minute d. 1 mGya per minute
b. 100 mGya
Choose all that will result in higher spatial resolution (choose 3): a. Long SID b. Long OID c. Short SID d. Short OID e. Large focal spot f. Small focal spot
a,d,f
Quality assurance of digital imaging requires the uniformity of processing codes to ensure: a. Image appearance consistency b. Faster throughout c. Less heat loading on the anode d. Smoother integration into PACS
a. Image appearance consistency
The expression of image quality provided by a detector is called: a. MTF b. Matrix size c. SNR d. Nyquist frequency
a. MTF
Distortion may be described as: a. Misrepresentation of an anatomic structure on the image b. Foreshortening c. Elongation d. Magnification
a. Misrepresentation of an anatomic structure on the image
AECs may be tested using: a. Phantoms b. Images of real patients c. Analog meters d. Fluoroscopic screens
a. Phantoms
The number of pixels/mm in an image is called: a. Pixel density b. Bit depth c. Pixel pitch d. Matrix depth
a. Pixel density
Magnification is caused by: 1. Short SID 2. Long SID 3. Short OID 4. Long OID a. 2, 3 b. 1, 4 c. 1, 3 d. 1 only
b. 1, 4
The number of mAs used for analog fluoroscopy is: A. 300 to 500 B. 3 to 5 C. 10 to 12 D. 100 to 300
b. 3 to 5
High-frequency power: a. Is less effective that single-phase power b. Has almost no ripple c. Has more ripple that three-phase power d. is yet unproven
b. Has almost no ripple
What changes AC to DC? a. Step-down transformer b. Rectifier c. Cathode d. Timer
b. Rectifier
The increase in average photon energy when using three-phase, 12-pulse equipment compared with single-phase equipment is: a. 1.34% b. 41% c. 1.41% d. 35%
b.41%
The variation of x-ray intensity along the longitudinal axis of the x-ray beam describes: a. Beam collimation b. Positive beam limitation c. Anode heel effect d. X-ray emission spectrum
c. Anode heel effect
Smoothing software may result in: a. Enhanced fine detail b. Less distortion c. Loss of fine detail d. Increased distortion
c. Loss of fine detail
The appearance of digital images on technologists' monitors is: a. The same as on radiologists' monitors b. Substantially better than on radiologists' monitors c. Not as good as on radiologists' monitors
c. Not as good as on radiologists' monitors
If the exposure field is not accurately recognized, the histogram will contain data: a. Outside the exposure field, narrowing the histogram b. Inside the exposure field, widening the histogram c. Outside the exposure field, widening the histogram d. Inside the exposure field, narrowing the histogram
c. Outside the exposure field, widening the histogram
The number of electrons boiled off the cathode and consequently the number of x-rays produced are controlled by: a. kVp b. SID c. mAs d. OID
c. mAs
Which of the following terms describes the highest spatial frequency that can be recorded by a digital detector? a. Spatial resolution b. Contrast resolution c. MTF d. Nyquist frequency
d. Nyquist frequency
Choose all factors below that result in poor spatial resolution (choose 4): A. Long SID B. Long OID C. Large focal spot D. Small focal spot E. Patient motion F. Magnification
b,c,e,f
Three phase, 12 pulse full wave rectification produces: a. Direct current with 13% ripple b. Direct current with 4% ripple c. Direct current with 100% ripple d. Alternating current with 13% ripple
b. Direct current with 4% rippple
The relationship between kVp and receptor exposure may be described as: a. Directly proportional b. Direct, although not proportional c. Governed by the 15% rule d. Controlled by x-ray tube current
b. Direct, although not proportional
Receptor exposure may be defined as: a. Amount of remnant radiation striking the image receptor b. Dose area product c. DQE d. Differences in dark areas on a radiographic image
b. Dose area product
an indicator of the dose level needed to acquire an optimal image is: a. Detective quantum efficiency b. Dose area product c. Field of view d. Dynamic range
b. Dose area product
An artificial increase in display contrast at an edge of the image is: a. Smoothing b. Edge enhancement c. Contrast resolution d. Spatial resolution
b. Edge enhancement
A grid with lead strips and aluminum interspaces that are angled to coincide with the divergence of the x-ray beam is called: a. Parallel grid b. Focused grid c. Crosshatch grid d. Rhombic grid
b. Focused grid
Which of the following described the relationship between receptor exposure and the use of grids? a. Grids always reduce receptor exposure b. Grids reduce receptor exposure unless mAs are increased to compensate c. Grids reduce receptor exposure by only absorbing scatter radiation d. Receptor exposure increases as grid ratio increases
b. Grids reduce receptor exposure unless mAs are increased to compensate
Undesirable fluctuations in brightness are called: a. MTF b. Image noise c. Quantization d. Scintillation
b. Image noise
Which of the following measures tube current? a. Anode b. mA meter c. Ionization chamber d. Falling load generator
b. mA meter
The electricity provided to the radiology department is: a. 110 Hz or 220 Hz DC b. 110 Hz or 220 Hz DC c. 60 Hz AC d. 60 HZ DC
c. 60 Hz AC
In digital fluoroscopy, the image must be turned into digital form by what device? a. Digital-to-analog converter b. Flux capacitor c. Analog-to-digital converter d. DVD-ROM
c. Analog-to-digital converter
Mathematical codes used to generate the digital image are called: a. Binary codes b. Algorithms c. Binary digits d. Bytes
b. Algorithms
Quality assurance and maintenance of CR cassettes include cleaning and inspecting the plates at least: a. Daily b. Every 48 hours c. Every 3 weeks d. Weekly
c. Every 3 weeks
As radiation strikes matter: a. The energy of the rays is destroyed b. The energy of the rays is increased as they acquire the energy of the atoms c. The energy is transferred to the atoms according the law of conservation of energy d. The energy is converted to matter according to Einstein's theory
c. The energy is transferred to the atoms according to the law of conservation of energy
The use of filtration: a. Greatly reduces receptor exposure because of the absorption of short-wavelength x-rays b. Greatly reduces radiographic receptor exposure because of the absorption of high-energy x-rays c. Increases radiographic receptor exposure by removing long-wavelength x-rays d. Has little effect on receptor exposure because x-rays removed from beam are not image-producing rays
d. Has little effect on receptor exposure because x-rays removed from beam are not image-producing rays
Single-phase, full-wave rectification produces: a. Direct current b. Pulsating direct current c. Pulsating direct current with 120 pulses per second d. Pulsating direct current with 120 pulses per second and 100% ripple
d. Pulsating direct current with 120 pulses per second and 100% ripple
What device increases voltage approximately 500 times? a. Anode b. mA meter c. Ionization chamber d. Step-up transformer
d. Step-up transformer
The portion of contrast that is caused by variations in the anatomy or is secondary to pathological changes is called: a. Radiographic contrast b. Anatomic contrast c. Pathologic contrast d. Subject contrast
d. Subject contrast
Grid frequency is defined as: a. The same as grid ratio b. The amount of lead in the grid (expressed in terms of focusing distance) c. How often a grid is used d. The amount of lead in the grid (expressed as the number of lead strips per inch)
d. The amount of lead in the grid (expressed as the number of lead strips per inch)
When a predetermined level of ionization is reached in the ionization chamber, what does the machine do? a. The unit shuts off as a result of a malfunction b. The maximum allowable time has been reached c. The highest allowable dose to the patient has been reached d. The exposure is terminated
d. The exposure is terminated
The speed of x-rays is based on: a. mAs b.kVp c. Size of the patient d. The fact that they are a form of electromagnetic radiation
d. The fact that they are a form of electromagnetic radiation
Bit depth is equal to: a. 2n (n equals the number of bits) b. 4096 shades of gray c. Pixel pitch d. Bits times bytes
a. 2n (n equals the number of bits)
As speed class increases: a. The likelihood of noise increases b. The likelihood of noise decreases c. Patient exposure increases d. Sharpness increases
a. The likelihood of noise increases
Choose all that are true concerning grids (choose 3): a. Contrast improvement factor is the measure of the ability of a grid to enhance contrast b. Grid selectivity is the ratio of primary radiation transmitted through the grid to secondary radiation transmitted through the grid c. Grids are used when part thickness is less than 10cm d. GCF is the amount of increase in kVp necessary when converting from nongrid to grid technique e. The primary purpose of grids is radiation protection f. The main function of grids is to prevent Compton scatter from reaching the IR g. Grids prevent the production of scatter
a, b, f
Choose all of the following that are accurate (choose 6): a. A magnetic field always surrounds an electrical charge ins motion b. Current flows back and forth in AC c. Current flows in one direction in DC d. The volt is the unit of electrical current e. A conductor allows the flow of electrons f. The ampere is the unit of electromotive force g. The volt is the unit of potential difference h. The path of electrical current is called the ciruit
a,b,c,e,g,h
Choose all of the following statements that are accurate pertaining to the role of kVp in radiographic image production (choose 3). a. As kVp is increased, penetrating ability of the x-rays of the x-rays increases b. As kVp is increased, more x-rays exit the patient to strike the image receptor c. As kVp increases, receptor exposure increases d. As kVp decreases, receptor exposure remains constant because mAs controls receptor exposure
a,b,d
The electricity provided to the radiology department operates at: a. 120 pulses per second b. 60 pulses per second c. 110 pulses per second d. 220 pulses per second
a. 120 pulses per second
A radiographic image with few gray tones, primarily exhibiting black and white, would be described as having what type of contrast? 1. Long scale 2. Short scale 3. Low 4. High a. 2 and 4 b. 1 and 3 c. 1 and 4 d. 2
a. 2 and 4
When a nongrid technique using 10 mAs and 75 kVp is changed to a 12:1 grid using 75 kVp, what new mAs must be used to create the same image? a. 50 mAs b. 2 mAs c. 40 mAs d. 120 mAs
a. 50 mAs
The filament is kept warm by: a. A standby current from the time the x-ray machine is turned on b. Insulating oil c. Lead housing d. Current produced only during exposure
a. A standby current from the time the x-ray machine is turned on
What is the source of bremsstrahlung and characteristic rays? a. Anode b. mA meter c. Falling load generator d. Step-up transformer
a. Anode
X-rays are produced as incident electrons collide with inner shell electrons in target atoms by a process called: a. Characteristic b. Photoeletric c. Bremsstrahlung d. Compton
a. Characteristic
Excessive processing of the digital image may: a. Degrade visibility of anatomy b. Provide additional anatomic information c. Enhance visibility of desired anatomy d. Increase patient dose
a. Degrade visibility of anatomy
Quantum noise limits ability to see: a. Detail b. Contrast c. Fatty tissue d. Additive pathologies
a. Detail
What type of current is required for proper operation of the x-ray tube? a. Direct b. Falling load c. Alternating d. Fluctuating
a. Direct
Three phase, 6 pulse full wave rectification produces: a. Direct current with 13% ripple b. Direct current with 4% ripple c. Direct current with 100% ripple d. Alternating current with 13% ripple
a. Direct current with 13% ripple
The test that measures the accuracy of successive exposures is: a. Exposure reproducibility b. Spinning top test c. Pinhole camera d. Exposure linearity
a. Exposure reproducibility
Total brightness gain achieved using an image intensifier equals: a. Flux gain times minification gain b. Diameter of input phosphor times diameter of output phosphor c. Intensification factor - brightness without an image intensifier divided by brightness with an image intensifier d. Total light emitted at the photocathode
a. Flux gain times minification gain
The primary purpose of filtration is: a. Radiation protection b. Removal of short-wavelength (soft) rays c. Hardening the beam for imaging d. Removal of long-wavelength (hard) rays
a. Radiation Protection
A step-down transformer: a. Steps down voltage b. Steps down current c. Step up voltage d. Steps up resistance
a. Steps down voltage
Effective quality control and quality assurance programs are required for accreditation by: a. The Joint Commission b. Joint Review Committee on Education in Radiologic Technology c. American Healthcare Radiology Administrators d. American Registry of Radiologic Technologists
a. The Joint Commission
Beam part receptor alignment latitude describes: a. The latitude of collimation that still allows the software to detect collimated edges b. The alignment that maintains ALARA requirements c. Exposure latitude d. Acceptable distortion of the image
a. The latitude of collimation that still allows the software to detect collimated edges
What is atomic mass? a. The number of protons plus the number of neutrons b. The number of photons c. The number of electrons d. The number of protons plus the number of electrons
a. The number of protons plus the number of neutrons
Choose all that are properties of x-rays (choose 6): a. Electrically negative b. Affect film emulsion c. Scatter and produce secondary radiation d. Invisible to the human eye e. Travel at the speed of light (186,000 miles per hour) f. Posses wavelengths between 1 Å and 5 Å g. Travel in bundles of energy photons h. Can ionize matter and gases I. Can be focused by collimators j. Cause phosphors to fluoresce
b,c,d,g,h,j
Given an original technique of 30 mAs and 80 kVp what will produce a radiograph with double the density? a. 60 mAs, 90 kVp b. 30 mAs, 92 kVp c. 15 mAs, 80 kVp d. 30 mAs, 70 kVp
b. 30 mAs, 92 kVp
Exposure reproducibility must be accurate to within: a. 4 b. 5% c. 2% of SID d. 10%
b. 5%
The feature that automatically adjusts kVp and mA during fluoroscopy is called: a. AEC b. ABC c. DQE d. SNR
b. ABC
When making an exposure, the radiographer should: a. Hold the rotor for several seconds before pressing "expose" b. Activate the rotor and exposure switch in one continuous motion c. Begin the rotor while a student is still positioning the patient d. Activate the rotor while estimating how fast the anode is spinning
b. Activate the rotor and exposure switch in one continuous motion
What is the smallest particle of an element that retains the characteristics of the element? a. Mole b. Atom c. Molecule d. Quark
b. Atom
The x-ray beam changes as it travels through the patient by a process called: a. Filtration b. Attenuation c. Electrification d. Annihilation
b. Attenuation
A variable transformer that is used to select kVp for the x-ray circuit is the: a. Step-up transformer b. Autotransformer c. Step-down transformer d. Rectifier
b. Autotransformer
Self-induction is used in the operation of what device? a. Step-up transformer b. Autotransformer c. Step-down transformer d. Electronic timer
b. Autotransformer
The available gray scale of an imaging system is determined by: a. Pixel pitch b. Bit depth c. Exposure latitude d. Image latitude
b. Bit depth
The thicker part of anatomy should be placed under which aspect of the x-ray tube? a. Central ray b. Cathode c. Anode d. Collimator
b. Cathode
The strength of the magnetic field in a transformer is increased by: a. Coiling the wires and placing them in adjoining machines b. Coiling the wires and letting their magnetic fields overlap c. Keeping the wires very straight, increasing their effectiveness d. Replacing the wires with diodes
b. Coiling the wires and letting their magnetic fields overlap
The actual patient does as measured by a meter embedded in the collimator is: a. RAD - radiation absorbed dose b. DAP - dose area product c. REM - radiation equivalent man d. Doubling dose
b. DAP - dose area product
Heat is produced in the x-ray tube as: a. Electrons break apart while striking the anode b. Electrons interact with the target material c. The anode stops spinning d. The rectifier operates
b. Electrons interact with the target material
Quality assurance and maintenance of CR cassettes include erasing plates at least: a. Daily b. Every 48 hours c. Every 3 months d. Weekly
b. Every 48 hours
The range of receptor exposures that provides a quality image is called: a. Detector latitude b. Exposure latitude c. Histogram d. Dynamic range
b. Exposure latitude
Examples of particulate radiation are: a. X-rays, gamma rays, and cosmic rays b. Helium nuclei and beta particles c. Electrons, protons, and meteorites d. X-rays and quarks
b. Helium nuclei and beta particles
More uniform penetration of anatomic structures occurs when what level of kVp is used? a. Low b. High c. kVp does not effect penetration d. Level at which photoelectric interaction predominates
b. High
In digital fluoroscopy, what equipment should be used to view the image? a. Conventional view box b. High-resolution monitor capable of displaying millions of pixels c. High-definition television d. Plasma television required
b. High-resolution monitor capable of displaying millions of pixels
A high SNR provides an image with: a. Poor spatial resolution b. Higher spatial resolution c. Poor contrast d. Higher distortion
b. Higher spatial resolution
Wavelength and frequency are: a. Directly proportional to each other b. Inversely proportional to each other c. Inversely proportional to the square of their distance d. Unrelated to each other
b. Inversely proportional to each other
Optimal spatial resolution may be created using which of the following factors? a. Large focal spot b. Narrow pixel pitch c. Long OID d. Short SID
b. Narrow pixel pitch
The law stating that the outer shell of an atom can contain no more than eight electrons is called: a. Ohm's law b. Octet rule c. Octagon rule d. Electron binding energy
b. Octet rule
The portion of the image-intensifier tube that converts visible light to electrons is the: a. Output phosphor b. Photocathode c. Input phosphor d. Anode
b. Photocathode
The smallest area represented in a digital image is the: a. Image matrix b. Pixel c. Voxel d. Bit
b. Pixel
In many cases, digital fluoroscopy eliminates which of the following? a. The need for a radiographer b. Postprocedure "overhead" images c. Image acquisition d. Accurate positioning
b. Postprocedure "overhead images
What is located in the x-ray circuit between the high-voltage transformer and the x-ray tube? a. Step-down transformer b. Rectifier c. Cathode d. Timer
b. Rectifier
Which of the following is comped of solid-state silicon based diodes? a. Step-down transformer b. Rectifier c. Cathode d. Timer
b. Rectifier
Activating the rotor: a. Accelerates a procedure b. Reduces tube life c. Keeps it oiled d. Keeps the cooling fan activated
b. Reduces tube life
The primary controlling factors of receptor exposure are: a. kVp and mAs b. mAs and SID c. SID and OID d. SID, OID, FSS
b. mAs and SID
Choose all that describe the outcome of using high kVp (choose 3): a. High contrast b. Few gray tones c. Long-scale contrast d. Short-scale contrast e. Low contrast f. Many gray tones
c,e,f
Which of the following maintains image brightness over a wide range of exposures? a. AEC b. Bit depth c. Automatic rescaling d. Detector size
c. Automatic rescaling
X-rays are produced as incident electrons are slowed going past he nuclei of target atoms by a process called: a. Classical d. Photoelectric c. Bremsstrahlung d. Compton
c. Bremsstrahlung
The x-ray emission spectrum consists of: a. Brems and characteristic rays b. Discrete spectrum (produced by brems rays) and continuous spectrum (produced by characteristic rays( c. Discrete spectrum (produced by characteristic rays) and continuous spectrum (produced by brems rays) d. X-rays and electrons, both per of the electromagnetic spectrum
c. Discrete spectrum (produced by characteristic rays) and continuous spectrum (produced by brems rays)
Which of the following is surrounded by a negatively charged focusing cup? a. Step-down transformer b. Rectifier c. Filament d. Timer
c. Filament
The intensity of radiation is inversely proportional to the square of the distance between the source of radiation an the person receiving it. This describe the: a. Square law b. Reciprocity law c. Inverse square law d. Octet law
c. Inverse square law
Which of the following governs the relationship between SID and receptor exposure? a. Reciprocity law b. 15% rule c. Inverse square law d. Ohm's law
c. Inverse square law
Which of the following is located between the patient and the image receptor? a. Anode b. mA meter c. Ionization chamber d. Falling load generator
c. Ionization chamber
as speed class decreases: a. The likelihood of noise increases b. Noise in unaffected c. Patient exposure increases d. Sharpness decreases
c. Patient exposure increases
Marks on the focal track of the anode resulting from bombardment of electrons are called: a. Melts b. Bullet marks c. Pitting d. Cracks
c. Pitting
The space from the center of a pixel to the center of the adjacent pixel is called: a. Pixel density b. Bit depth c. Pixel pitch d. Matrix depth
c. Pixel pitch
Programs that deal with the safe and reliable operation of equipment and programs that address all aspects of the delivery of radiology services are called: a. Quality assurance and quality control b. Total quality improvement c. Quality control and quality assurance d. Total quality management
c. Quality control and quality assurance
As beam restriction increases (becomes tighter): a. Receptor exposure increases b. Receptor exposure increases as a result of focusing of x-rays c. Receptor exposure decreases d. Receptor exposure is not affected
c. Receptor exposure decreases
Resolution of the television system that may be measured using the following tool(s): a. Wire mesh set b. Line pairs/millimeter resolution tool along with a kVp meter c. Resolution test pattern d. Resolution test pattern, wire mesh test, or line pairs/millimeter resolution tool
c. Resolution test pattern
What is the transformer used to boost voltage to kilo-voltage levels called? a. Autotransformer b. Step-down transformer c. Step-up transformer d. Low-voltage transformer
c. Step-up transformer
Grid ratio is defined as: a. The ratio of the lead strips to the space between them b. The thickness of the lead strips divided by the thickness of the aluminum interspaces c. The ratio of the height of the lead strips over the distance between the lead strips d. The ratio of the distance between the lead strips over the height of the lead strips
c. The ratio of the height of the lead strips over the distance between the lead strips
At what speed do x-rays travel? a. The speed of light - 186,000 miles per hour b. The speed of the incident electrons - 93,000 miles per second c. The speed of light - 186,00 miles per second d. Infinite speed
c. The speed of light - 186,000 miles per second
The primary advantage of three-phase power is that: a. Voltage drops to zero only 6 times per second b. Voltage drops to zero only 12 times per second c. Voltage never drops to zero d. Voltage is always at peak value
c. Voltage never drops to zero
The input phosphor of the image-intensifier tube converts: a. Electron energy to x-ray energy b. X-rays and heat to visible light c. X-ray energy to visible light d. X-ray energy to an electronic image
c. X-ray energy to visible light
The collimator must be accurate to a level of: a. ±4% of SID b. ±5% of SID c. ±2% of SID d. ±10% of SID
c. ±2% of SID
Calculating heat units for three-phase, 12-pulse equipment requires the use of ______ as a constant; calculating heat units for single-phase equipment requires the of _____ as a constant; calculating heat units for three-phase, 6-pulse equipment requires the use of _____ as a constant. a. 1.0, 1.35, 1.41 b. 1.35, 1.0, 1.41 c. Calculating heat units does not require the use of a constant because all x-rays posses the some ionizing potential d. 1.41, 1.0, 1.35
d. 1.41, 1.0, 1.35
kVp must be accurate to within: a. 1 of the amount on the control panel setting b. 5% of the control panel setting c. 2% of SID d. 10% of the control panel setting
d. 10% of the control panel setting
The increase in average photon energy when using three-phase, 6-pulse equipment compared with single-phase equipment is: a. 1.35% b. 41% c. 1.41% d. 35%
d. 35%
Distortion that occurs when the x-ray beam is angled against the long axis of a part is: a. Elongation b. Magnification c. Minification d. Foreshortening
d. Foreshortening
Spatial resolution is: a. Photographic representation of the part being radiographed b. Controlled by kVp c. Controlled by mAs d. Geometric representation of the part being radiographed
d. Geometric representation of the part being radiographed
The adjustment in technical factors required when using beam restriction is: a. Increase kVp b. Decrease kVp to reduce the number of Compton interactions taking place c. Decrease mAs to reduce the number of Compton interactions taking place d. Increase mAs to compensate for the number of rays removed from the primary beam
d. Increase mAs to compensate for the number of rays removed from the primary beam
What effect does beam restriction have on contrast? a. Decreases contrast by focusing the x-ray beam b. Decreases contrast because of higher kVp level used c. Increases contrast by focusing the x-ray beam d. Increases contrast because of reduction in the number of Compton interactions that occur
d. Increases contrast because of reduction in the number of Compton interactions that occur
What effect does the use of radiographic grids have on contrast? a. Decreases contrast b. Increases contrast c. No effect on contrast d. Increases contrast by absorbing scatter radiation
d. Increases contrast by absorbing scatter radiation
Use of technique charts: a. Is unnecessary for any exam because of AECs b. Does not require that the part thickness be measured with calipers c. Is usually based on fixed mAs and variable kVp d. Is helpful when manual techniques are used
d. Is helpful when manual techniques are used
Voltage coming to the x-ray machine is kept constant through the use of a(n): a. Autotransformer b. Step-down transformer c. Rectifier d. Line voltage compensator
d. Line voltage compensator
The function of contrast is to: a. Make the image appear sharper b. Compensate for uneven anatomic structures c. Brighten the image d. Make detail visible
d. Make detail visible
mAs directly control: a. The energy of the x-ray emission spectrum b. The quality and quantity of x-rays produced at the cathode c. The quality and quantity of x-rays produced at the anode d. The quantity of x-rays produced at the anode
d. The quantity of x-rays produced at the anode
Digital systems operate at what speed class? a. 200 b. 400 c. 100 d. The speed class chosen by the radiographer
d. The speed class chosen by the radiographer
Which device is electronic, with a setting as low as 0.001? a. Step-down transformer b. Rectifier c. Cathode d. Timer
d. Timer
Which of the following statements regarding filtration is true? a. Total filtration must not be less than 2-mm aluminum equivalent b. Total filtration must remove all soft rays from the beam c. Total filtration (added + compensating) must not be less than 2.5-mm aluminum equivalent d. Total filtration (not less than 2.5-mm aluminum equivalent) = inherent filtration (glass envelope, tube housing, oil) + added filtration (aluminum)
d. Total filtration (not less than 2.5-mm aluminum equivalent) = inherent filtration (glass envelope, tube housing, oil) + added filtration (aluminum)
Lower spatial resolution may be caused by which of the following factors? a. Short OID b. Long SID c. Small focal spot d. Wide pixel pitch
d. Wide pixel pitch
Use of the air gap technique: a. Works because x-rays are absorbed in the air between the patient and the film b. Should occur when possible c. May cause some magnification because of decreased OID d. Works because scatter radiation travels in divergent paths and misses the IR as a result of increased OID
d. Works because scatter radiation travels in divergent paths and misses the IR as a result of increased OID
The primary controlling factor(s) of contrast is (are): a. mAs, which control the energy of the x-rays produced b. kVp, which primarily controls the quantity of x-rays produced at the target c. Focal-spot size, which controls the quantity and quality of x-rays produced d. kVp and bit depth
d. kVp and bit depth
Which of the following devices is prereading? a. Step-down transformer b. Rectifier c. Timer d. kVp meter
d. kVp meter