Part 1 Flashcards
- What is the term for any sound that is less than the audible sound ?
a. Hypersound
b. Infrasound
c. Noise
d. Supersound
e. Ultrasound
B. INFRASOUND
- Which of the following is characteristics of diagnostic ultrasound?
a. It can be transmitted through a vacuum
b. It is a form of electromagnetic radiation
c. It is a mechanical longitudinal wave
d. It is a transverse wave
C.
- Audible sound is
a. Greater than 20,000 Hz
b. Greater than 20Hz and less than 20,000 Hertz
c. Less than 20 Hertz
d. Less than 200 Hertz
B.
- What is a longitudinal wave ?
A. A wave in which the oscillating energy is in the direction opposite of the wave motion
B. A wave in which the oscillating energy is in the direction of the wave motion
C. A wave in which the oscillating energy is in an oblique direction of the wave motion
D. A wave in which oscillating energy is perpendicular to the direction of the wave motion
E. A wave in which the oscillating energy is redirected in the direction of the wave motion
B.
- When an acoustic wave travels through a medium, the tissue molecules change concentration. What is the highest level of concentration called?
a. Compactness
b. B. compression
c. C. excitation
d. Ionization
e. Rarefaction
B.
- When an acoustic wave travels through a medium, the tissue molecules change concentration. What is the lowest level of concentration called?
a. Compactness
b. Compression
c. Excitation
d. Ionization
e. Rarefaction
E.
- As the frequency of wave increases, the wavelength will
a. Decrease
b. Decreased by one half
c. Increase
d. Double
e. Remain the same
A.
- Which of the following is a definition of period ?
a. The distance it takes for one complete cycle to occur
b. The. Distance it takes for the pulse to travel through the medium
c. The time it takes for one complete cycle to occur
d. The time it takes for one complete pulse to occur
e. The time it takes for the u/s pulse to travel through the medium
C.
- Ultrasound travels the slowest through which of the following
a. Bone
b. Fat
c. Lung
d. Soft tissue
e. Water
C.
- What is the approximate frequency that has a wavelength of 0.4 mm in soft tissue ?
a. 3.0 Hz
b. 3.0 kHz
c. 3.0 Mhz
d. 3.8 kHz
e. 3.8 MHz
E.
- The velocity of u/s in soft tissue is approximately
a. 330 m/s
b. 440 m/s
c. 1540 m/s
d. 4000 m/s
C.
- Stiffness of a medium is the opposite of its
a. Compressibility
b. Density
c. Hardness
d. Impedance
e. Resillency
A.
- If the compressibility of a material increases, the speed of sound will
a. Decrease
b. Double
c. Increase
d. Remain the same
e. Compressibility and speed of sound are not related
A.
- As the power of the beam increases, Intensity will
a. Decrease
b. Double
c. Increase
d. Quadruple
e. Remain the same
C
- If the frequency of a wave increases, the period will
a. Decrease
b. Double
c. Increase
d. Remain the same
e. Frequency & power are not related
A
- By doubling the amplitude, the intensity will
a. Decrease by half
b. Decrease by ¼
c. Increase by two
d. Increase by four
e. Remain the same
D
- What is the unit used to compare the ratio of intensities of two sound waves ?
a. Amplitude
b. Decibel
c. Frequency
d. Hertz
e. Rayl
B
- Amplification gain is set to 40dB. If the fain is reduced by one-half, what will the new gain be?
a. 4
b. 10
c. 20
d. 30
e. 37
E
- The number 6115 can be express as which of the following ?
a. 6.0 x 10^3
b. 6.1 x 10
c. 61.15 x 10^3
d. 6.115 x 10^3
e. 6.2 x 10
D
- Put the following metric prefixes in descending (largest to smallest) order:
a. Kilo,micro,mega
b. Mega, micro, kilo
c. Micro, kilo, mega
d. Kilo, mega, micro
C
- The amount of space from one end of an object to the other end of the object is the
a. Area
b. Circumfrence
c. Distance
d. Radius
e. Volume
C
- The formular for the volume of an object is
a. 2 (length + height)
b. Length x height x 0.523
c. 2 (length x heigh x width)
d. Length x height x width
e. Length x width x height x 0.523
E
- What is the speed of sound through bone ?
a. Equal to the speed of sound in air
b. Equal to the speed of sound in soft tissue
c. Greater than the speed of sound in air and soft tissue
d. Less than the speed of sound in air
e. Less than the speed of sound in soft tissue
C
- The redirection of a portion og the sound beam back to the transducer is known as
a. Boundary
b. Interface
c. Reflection
d. Refraction
e. Transmission
C
- Specular reflection occurs at a
a. Large tissue interface
b. Large and smooth tissue interface
c. Rough tissue interface
d. Small tissue interface
e. Small and smooth tissue interface
B
- The product of tissue density and u/s velocity is known as
a. Acoustic coefficient
b. Acoustic impedance
c. Interface
d. Reflectivity
e. Transmission
B
- A type of non-specular reflection that occurs at irregular or rough interfaces is known as
a. Deflection
b. Reflection
c. Refraction
d. Scatter
e. Transmission
D
- The use of contrast media in the body will
a. Decrease the amount scatter
b. Double the amplitude of the signal
c. Have little or no effect on the signal
d. Increase the amount of scatter
e. Double the amount of scatter
D
- An echo caused by the bending of the sound beam is known as
a. Diversion
b. Reflection
c. Scatter
d. Refraction
e. Transmission
D
- If the velocity in the second medium is greater than the first medium than the transmission angle will be
a. Equal to incident angel
b. Equal to the reflection angel
c. Less than the incidence angle
d. Greater than the incident angle
e. Cannot be determined from the information above
D
- More absorption takes place when using a transducer with a
a. Higher frequency
b. Lower frequency
c. Multihertz crystals ‘multiple crystals
d. One crystal
A
- The reduction of intensity of the ultrasound beam as it travels through tissue is known as
a. Acoustic impedance
b. Absorption
c. Attenuation
d. Reflection
e. Scatter
C
- Using a high frequency transducer will result in
a. Faster propagation speed
b. Greater attenuation
c. Less attenuation
d. Poor resolution
e. Slower propagation speed
B
- What is another name for anechoic
a. Echo-free
b. Echogenic
c. Homogenous
d. Hyperechic
e. Hypoechoic
A
What is another term for hyperechoic?
a. Anechoic
b. Echogenic
c. Hypoechoic
d. Isoechoic
e. Sonolucent
B
- The increase of echoes posterior to weakly attenuating structure is known as
a. Enhancement
b. Homogeneous
c. Heterogenous
d. Hyperechoic
e. Shadow
A
- The property of certan materials to create a voltage when they are mechanically deformed is called
a. Bandwidth
b. Curie temperature
c. Pzt effect
d. Electromagnetism
e. Transducer
C
- Axial resolution is equal to
a. ½ SPL
b. 2 x SPL
c. SPL divided by 4
d. SPL^2
A
- The formular for Q factor is
a. Frequency divided by SPL
b. Frequency divided by the bandwidth
c. Frequency multiplied by bandwith
d. 2 x (frequency multiplied by bandwidth)
B
- What is the most common type of man made material used in diagnostic imagine transducers?
a. Lead zircon
b. Lead zirconate titanate
c. Quartz
d. Rochelle salt
e. Crystal
B
- U/s crystals vibrate the
a. Amplitude mode
b. Diameter mode
c. Radial mode
d. Thickness mode
e. Elevational axis
D
- The use of damping in transducer design results in
a. Longer SPL
b. Longer pulse duration
c. Resonance
d. Shorter SPL
e. Wavelength
D
- The Fresnel zone is also known as the
a. Far field
b. Focal zone area
c. Image plane
d. Huygens wave
e. Near field
E
- The length of the near. Field can be increased by increasing ?
a. Damping
b. Frequency
c. Propagation speed
d. Prf
B
- The intensity of the u/s beam is more uniform in the
a. Focal zone
b. Fraunhfer zone
c. Fresnel zone
d. Near zone
e. Dead zone
B
- Destructive interference occurs when
a. Two waves are equal to each other
b. Two waves are in phase with each other
c. Two waves are out phase with each other
d. One wave is greater than the second wave
e. One wave is less than the second wave
C
- The length of the Fresnel zone increase when the
a. Frequency decreases
b. Frequency increases
c. Propagation speed decreases
d. Propagation speed increases
e. None of the above
B
- One method of external focusing requires the us of a (n)
a. Acoustic lens placed in front of the crystal
b. Acoustic lens placed behind the crystal
c. Concave shaped pzt elements
d. Delaying the electrical pulses
e. None of the above
A
- What is the focal point
a. Area of maximum narrowing of the beam
b. Area of maximum widening of the beam
c. One-half the distance of the focal length
d. Distance from the transducer to the focus
e. None of the above
A
- Another term for lateral resolution is
a. Axial resolution
b. Azmithul resolution
c. Cross-sectional resolution
d. Radial resolution
e. Elevational resolution
B
- Angular resolution is
a. Improved by longer wavelengths
b. Equal to axial resolution
c. Improved with focusing
d. Improved with increased amount of damping layer
e. Improved with layer frequency transducer
C
- What is pulse duration
a. Length of time require to complete one cycle
b. Length of time require to complete one pulse
c. The time from the beginning of one pulse to the beginning of the next
d. Number of pulses in the cycle
e. Space require to complete one pulse
B
- Pulse duration is equal to the product of the
a. u/s frequency x the number of cycles in a pulse
b. u/s frrquency x the number of pulses
c. u/s period x the number of cycles in a pulse
d. u/s period x the number of pulses in a cycle
e. u/s propagation speed x the nmber of cycles in the pulse
C
- The process of. Varying the voltage to transducer crystals to form a real-time pulse is called
a. Amplification
b. Apodization
c. Focusing
d. Refraction
e. Transmission
B
- How is beam steering accomplished in an annular transducer
a. Concentric ring design
b. Electronic delay
c. Mechanically
d. Phased delay
e. Sequential delay
C
- What type of image does a vector array produce?
a. Circular shaped image
b. Pie shaped image
c. Rectangular image
d. Trapezoidal shaped image
e. Square image
D
- Diving a normal crystal element into smaller elements is termed
a. Apodization
b. Beam steering
c. Channel
d. Aliasing
e. Sub dicing
E
- Linear array transducers use which of the following ?
a. Electronic beam focusing and electronic beam steering
b. Electronic beam steering & mechanical beam focusing
c. Electronic beam steering & electronic beam delay
d. Mechanical beam steering and electronic beam focusing
e. Mechanical beam steering and mechanical beam focusing
A
- Phased array transducer use which of the following ?
a. Electronic beam focusing and electronic beam steering
b. Electronic beam steering and mechanical beam focusing
c. Mechanical beam steering and electronic beam focusing
d. Mechanical beam steering and mechanical focusing
e. Sub dicing the crystal elements to electronically steer them
A
- Beam steering is accomplished by altering the
a. Acoustic lens placement
b. Electronic pattern for excitation of the crystals
c. Electronic pattern for focusing of the crystals
d. Mechanical pattern for excitation of the crystals
e. Mechanical pattern for focusing of the crystals
B
- Focusing of the Z-axis in a phased array transducer is accomplished by ?
a. Sub dicing the elements in the array
b. Electronically timing the delays to the elements
c. Electronically timing the delays of receiving echoes
d. Mechanically adding a lens in front of all the crystals in the array
e. Electronically timing the transmission of the pulse
D
- In soft tissue, the time it takes to receive an echo from an interface 10.0 cm into the body is
a. 0.13 usec
b. 1.3 usec
c. .13 usec
d. 130 usec
e. 130 msec
D
- The number of pulses occurring in one second is called ?
a. Duty cycle
b. Frequency
c. Pulse duration
d. PRF
e. PRP
D
- The fraction of time that the u/s system is actually transmitting a pulse is called ?
a. Duty cycle
b. PRF
c. PRP
d. Pulse duration
e. Q value
A
- The duty factor is equal to the
a. Pulse duration divided by the PRP
b. Pulse duration divided by the PRF
c. Pulse duration multiplied by the PRP
d. Pulse duration multiplied by the PRF
e. None of the above
A
- PRF and imaging depth are
a. Directly related
b. Equal
c. Indirectly related
d. Inversely proportional
e. Not related to one another
C
- Increasing the output power will
a. Decrease the amplitude of the reflections
b. Increase the amplitude of the reflections
c. Decrease the dynamic range
d. Increase the dynamic range
e. None of the above
B
- How will increasing the output power affect the patient ?
a. Decrease the exposure to the patient
b. Decrease the time of exposure to the patient
c. Increase the exposure to the patient
d. Increase the time of exposure to the patient
e. None of the above
C
- What is another name for output power control ?
a. Compensatior
b. Receive
c. Synchronizer
d. Monitor
e. Transmitter
E
- What component receives and processes the echo information?
a. Compression
b. Master synchronizer
c. Reliever
d. Rectifier
e. Transmitter
C
- What adjusts for the effects of attenuation?
a. Compressor
b. Master synchronizer
c. TGC
d. Transmitter
e. Amplifier
C
- Another name for the reject control is ?
a. Demodulator
b. Receiver
c. Threshold
d. Transmitter
e. Rectifier
C
- The process by which the negative half of the signal is eliminated is called
a. Demodulation
b. Enveloping
c. Rectification
d. Smoothing
e. Rejection
C
- Which of the following receiver functions cannot be controlled by the operator?
a. Threshold
b. Reject
c. Demodulation
d. Amplification
e. Compensation
C
- Changing the radio frequency signal into a video signal is known as
a. Demodulation
b. Enveloping
c. Rectification
d. Compression
e. Smoothing
A
- The component responsible for the PRF is the
a. Master synchronizer
b. Receiver
c. Reject
d. Transmitter
e. Compensator
D
- What is the term for the range of signal intensities from the smallest to largest value ?
a. Amplification
b. Compression
c. Compensation
d. Dynamic range
e. Threshold range
D
- When imaging depth is decreased, the PRP is
a. Increases
b. Decreases
c. Remains the same
d. Decreases by one half
e. Doubles
B
- Which of the following would decrease if the period of a wave increased?
a. Pulse duration
b. Frequency
c. PRP
d. PRF
e. SPL
B
- If the amplitude was reduced by 3 dB, the amplitude of the echo would be
a. Reduced to half of what it was
b. Reduced to one quarter of what it was
c. Enhanced two times what it was
d. Increased by half of what it was
e. Unchanged
A
- What does a duty factor zero represent
a. The u/s unit is operating in a continuous wave
b. The u/s unit is operating in a pulsed wave mode
c. The u/s unit is off
d. The u/s unit is operating in Doppler mode
e. Duty factor and the u/s unit are unrelated
C
- In which of the following is the amplitude height of the echo proportional to its strength?
a. A-mode
b. Bistable
c. B-mode
d. C-mode
e. 3D mode
A
- In M-Mode, the x-axis or vertical axis represents ?
a. Amplitude
b. Brightness
c. Depth
d. Time
e. None of the above
D
- A-mode stands for
a. Action
b. Amplitude
c. Average
d. Axial
e. None of the above
B
- If the echo amplitude increases, the echo brightness
a. Decreases
b. Decreased by ½
c. Doubles
d. Increases
e. Remains the same
D
- What is determined b the range equation ?
a. Amplitude of the echo
b. Brightness of the eco
c. Depth of the eco
d. Time of the eco
e. Speed of the eco
C
- The number of frames generated per second is called ?
a. Flicker
b. Frame rate
c. Frequency
d. Scan line density
e. Frame pulses
B
- The major limitation in scanning speed is
a. Frequency
b. Number of focal zones
c. Number of scan lines needed per frame
d. Time it takes for the sound wave to propagate through tissue
e. Transducer selection
D
- The ability to resolve two elements related by time is
a. Frame rate
b. Resolution
c. Spatial resolution
d. Temporal resolution
e. Time space continuum
D
- Higher frame rate and temporal resolution are
a. Directly related
b. Equal
c. Indirectly related
d. Not related
e. Reciprocals of eachother
A
- Frame rates can improved by
a. Decreasing the depth
b. Increasing the number of scan lines
c. Increasing the number of focal zones
d. Increasing sector angle
A
- The human eye can detect flicker at frame rates
a. Equal to 15-20 frames per second
b. Greater than 15-20 frames per second
c. Less than 15-20 frames per second
d. 30-60 frames per second
e. Greater than 20 but less than 30 frames per second
C
- Maximum depth X lines per frame X number of focal zones x frame rate is less than
a. 7700
b. 15,400
c. 77,000
d. 154,000
e. 777,000
C
- The image depth controls the
a. Frequency
b. Propagation speed
c. PRF
d. Resolution
e. Wavelength
C
- The relationship between spatial resolution and temporal resolution can be described as
a. Directly related
b. Indirectly related
c. Spatial resolution is only related to contrast resolution
d. Temporal resolution has no affect on either spatial or contrast resolution
e. Temporal resolution is only related to contrast resolution
B
- The solid state computer memory that stores the echo information as a binary digit is called an
a. Analog scan converter
b. Cathod ray tube
c. Central processing unit
d. Digital scan converter
e. Monitor
D
- The term for picture element is
a. Matrix
b. Pictel
c. Pixel
d. Word
e. Bit
C
- The smallest unit used in computer storage is a
a. Bit
b. Byte
c. Pixel
d. Word
e. Matrix
A
- The number 101101 is equal to
a. 33
b. 73
c. 45
d. 113
e. 44
C
- The number of pixels in the matrix and spatial resolution are
a. Directly related
b. Equal
c. Indirectly related
d. Not related
e. Related to contrast resolution only
A
- The number of shade os gray that can be displayed by a scan converter is determined by
A. 2n where n = the number of bits
B. 2n where n = the number of bytes
C. 2n where n = the number of pixels
A
- The electron beam is directed across the monitor by a process called
a. Contrast scanning
b. Raster scanning
c. Resolution scanning
d. Voltage scanning
e. Smoothing
B
- The assignment of display brightness to numbers derived from memory is
a. Contrast processing
b. Persistence
c. Post-processing
d. Pre-processing
e. Raster scanning
C
- The assignment of the analog sinal level to a digital level before storage in memory is called
a. Contrast processing
b. Persistence
c. Pre-processing
d. Digitization
e. Apodization
D
- Write magnification is a type of
a. Contrast processing
b. Persistence
c. Post processing
d. Preprocessing
e. Receiver function
D
- To record an image, thermal processors use
a. Chemicals
b. B. photographic film
c. Paper
d. Video tape
e. Magenetic fields
C
- Which of the following types of recording devices can be erased and rewritten?
a. Magneto-optical disks
b. Photgraphic film
c. Thermal paper
d. Transparent film
e. Translucent film
A
- A computer network for the acquisition, display, and storage of images is called
a. ACR
b. MO
c. PACS
d. VHS
e. BIT
C
- The electronic transfer of images from one location to another is called
a. MO
b. PACS
teleradiology
c. Transradology
d. Conversion
C
- The physical principles associated with the study of blood circulation is
a. Hemodynamics
b. Resistance
c. Thermodynamics
d. Viscosity
e. Pressure gradients
A
- Within the circulatory system, pressure differences & flow rates are
a. Directly related
b. Equal
c. Indirectly related
d. Not related
e. Only related to velocity
A
- The energy level difference between two points is termed
a. Energy gradient
b. Flow
c. Resistance
d. Viscoicty
e. Intertia
A
- The quantity of blood moving through the vessel per unit of time is called
a. Laminar flow
b. Plug flow
c. Velocity flow rate
d. Volume flow rate
e. Resistance
D
- Disturbed flow occurs when the Reynolds number meets or exceeds
a. 1000
b. 2000
c. 3000
d. 5000
e. 4000
B
- Constant flow velocity across the vessel is termed as
a. Disturbed flow
b. Laminar flow
c. Parabolic flow
d. Stenosis
e. Plug flow
E
- Flow characterized by cross currents and multiple velocity components is called
a. Laminar flow
b. Parabolic flow
c. Plug flow
d. Turbulent flow
e. Antegrade flow
D
- The gravitational weight of a column of blood that extends from the heart to a level where blood pressure is determined is
a. Body pressure
b. Hemodynamics
c. Hydrostatic pressure
d. Venous hemodynamics
e. Arterial resistance
C
- Venous pressure & flow are affect by
a. Hemodynamics
b. Respiration
c. Velocity of blood
d. Viscosity
e. Inertia
B
- The most inaccurate Doppler shift occurs when the angle is
a. 0
b. 45
c. 75
d. 90
e. 60
D
- Rayleigh scattering occurs when the
a. Concerntration of RBC is high
b. Frequency used in Doppler is higher than used in imaging
c. RBC are smaller than the wavelength of the sound beam
C
- If the RBCs are moving toward the transducer, the received frequency is
a. Equal to the transmitted frequency
b. Higher than the transmitted frequency
c. Lower than the transmitted frequency
B
- As the angle between the transducer & flow decreases, the Doppler shift will
a. Decrease
b. Increase
c. Remain the same
B
- The type of Doppler system that uses two crystals is termed as
a. Aliasing
b. Continous wave
c. Pulsed wave
B
- The term applied when only the information from the selected gate will be processed is
a. Nyquist limit
b. Range resolution
c. Spatial resolution
d. Temporal resolution
e. Range ambiguity
B
- Aliasing occurs when the Doppler shift exceeds the
a. Imaging depth
b. Nyquist limit
c. PRF
d. PRP
e. Resistance
B
- Noise in the doppler signal that is generally caused by high amplitude doppler shifted echoes is called
a. Clutter
b. Demodulation
c. Range ambiguity
d. Smoothing
e. Laminar
A
- The wall filter used in doppler is a type of
a. Aliasing control
b. Compressiuon control
c. Gain control
d. Reject control
e. Power control
D
- Signal processing of the Doppler signal is accomplished by the
a. Autocorrelation technique
b. FAST fourier Technique
c. Time domain correlation
d. Power domain correlation
B
- A faster but less accurate signal process used in color Flow doppler is called
a. Aliasing
b. Autocorrelation
c. Fast Fourier Transform
B
- The termed used to describe the number of pulses use to intteroagte a single color line of sight is called
a. Packet size
b. Pulse size
c. Sample
d. Variance
A
- The attribute of colors that permits classification into a color is termed as
a. Ensemble
b. Hue
c. Intensity
d. Saturation
e. Variance
B
- Increasing the packet size increases color sensity and accuracy and
a. Decreases frame rate
b. Decreases time
c. Increases temporal resolution
A
- The type of doppler that does not rely on the reflectors velocities is
a. Color power mode
b. Spectral doppler
c. Color flow doppler
A
- A feature that appears on the image but does not correspond to an anatomical structure is called
a. Aliasing
b. Artifact
c. Interference
d. Resolution
B
- The artifact that interferes with the ability to detect low contrast objects is known as
a. Acoustic speckle
b. Comet tail
c. Mirror image
A
- The artifact that occurs from thickness of the scanned tissue volume perpendicular to the scan plane is called
a. Elevation resolution
b. Contrast resolution
c. Lateral resolution
A
- Mulitple equally spaced reflections on the image decreasing in intensity is called
a. Reverberation
b. Width focusing
c. Shadowing
d. Mirror image
A
- A type of reverberation artifact due to a large acoustic impedance mismatch is called
a. Reverberation
b. Multipath
c. Comet tail
d. Acoustic speckle
C
- The type of artifact associated with propagation speed erros is
a. Acoustic speckle
b. Focal banding
c. Shadowing
d. Refraction
D
- Acoustic energy emitted in a direction different than from the main axis of the sound beam is called
a. Range ambiguity
b. Focal banding
c. Side lobes
d. Multipath
C
- If the speed of sound is greater than 1540 m/s the echo will be placed
a. Lateral to the transducer
b. Too close to the transducer
c. Too far from the transducer
d. At an increasd section thickness
e. At a decreased section thickness
C
- The absence or reduced intensity of echo information distal to a reflector is called
a. Aliasing
b. Banding
c. Enhancement
d. Shadowing
e. Multipath
D
- An example of an artifact helpful in diagnoses is
a. Banding
b. Focusing
c. Multipath
d. Shadowing
e. Propagation speed error
D
- The extension of color beyond the region of flow to the adjacent tissue is called
a. Aliasing
b. Bleeding
c. Clutter
d. Noise
e. Enhancement
B
- Low level echo image artifacts caused by other electrical equipment are called
a. Aliasing
b. Banding
c. Filtering
d. Noise
e. Rejection
D
- The routine, periodic evaluation of the u/s system is termed as
a. Preventative maintenance
b. Quality assurance
c. Quality management
B
- The middle rod group of the AIUM phantom scanned from the top measures the
a. Axial resolution
b. Depth calibration accuracy
c. Lateral resolution
d. Sensitivity
A
- The testing device composed of a serioes of 0.75 m diameter stainless steel rods arranged in groups suspended in fluid is the
a. AIUM 100 mm test object
b. Tissue phantom
c. Doppler tissue phantom
A
- The measure of the weakest echo signal that can be visualized on the image is called
a. Contrast resolution
b. Dead zone
c. Sensitivity
d. Speckle
C
- The region where no imaging can take place is called the
a. Contrast zone
b. Dead zone
c. Sensitivity zone
B
- How often should sonographers perform routine preventive maintenance?
a. Weekly or biweekly
b. Monthly
c. Every 3 months
d. Every 6 months
e. Annually
A
- Quality assurance is usally performed
a. Daily
b. Monthly
c. Weekly
d. Yearly
e. Biweekly
B
- A testing device that has a gel-like substance with cystic structures suspended in it is called
a. AIUM test object
b. String test phantom
c. Hydrophone
d. Test phantom
e. Doppler test objecvt
D
- The acoustic variable defines as force divided by area ia called
a. Intensity
b. Pascals
c. Pressure
C
- The amount of energy flowing through a unit area ia called
a. Intensity
b. Pressure
c. Force
A
- To reduce the acoustic exposure to the patient, the sonographer should
a. Decrease the output control
b. Decrease receiver gain
c. Increase receiver gain
A
- If the power is doubled, the intensity will be
a. Halved
b. Doubled
c. Quartered
d. Tripled
B
- IF the amplitude is doubled, the intensity will
a. Decrease by ½
b. Decrease by ¼
c. Double
d. Increase by a factor of 4
D
- Which of the following units are used to measure intensity?
a. Milliwats per centimeter
b. Milliwatts per centimeter squared
c. Watts per meter squared
B
- The instrument that measures the intensity of the sound beam is a
a. Hydrophone
b. Phantom
c. Scale
d. Test object
A
A sonogram-her switches to a higher frequency transducer, What effect will that have on aliasing?
a. increased risk of aliasing
b. decreased risk of aliasing
c. transducer frequency does not effect aliiasing
A
As a result of _____ the propagation speed increases
a. increasing stiffness & increasing frequency
b. increasing stiffness & increasing elasticity
c. decreasing compressibility & decreasing density
c
All of the following are true except
a. two waves with identical frequencies must interfere constructively
b. out of phase waves interfere destructively
a
The effects on soft tissues on US are called
a. bioeffects
b. acoustic propagation properties
c. biologic effects
b
If there is no Doppler shift, which of the following is true?
a. the vessel is occluded
b. 90 degree angle of incidence
c. spectral gain is to low
d. more than one above
d
A new referring physician wants to know how often your positive studies are correct, which of the following calculations would best answer your question
a. negative predictive value
b. positive predictive value
c. sensitivity
d. specificity
e. accuracy
b
The calculation used to identify the likelihood of cavitation
a. thermal index
b. mechanical index
c. acoustic cavitation
b
A sonographic technique used to evaluate stiffness of mass or tissue
a. bulk moduls
b. elastography
c. edge enhancement
d. frequency compounding
b
The power in a beam is 1 watt and the area is 5cm^2. What is the beams intensity
a. 5 w/cm^2
b. 1 cm ^2
c. 0.2 w/cm^2
d. 1 watt
c
Sound travels at the same velocity in TWO different media. The density of medium A is HALF that of medium b. Which of the following statements is true.
a. the impedance of medium A is four times that of medium b
b. the Reynolds number of medium a is twice that of medium b
c. the impedance of medium A if half that of Medium B
c
Some u/s systems use a great number of active receive elements as echoes return from greater depths, what is this called
a. harmonic imaging
b. dynamic aperture
c. multidimensional arrays
c. two dimensional imaging
e. phased array
b
By definition , US is sound having a frequency greater than \_\_\_\_\_ cycles per second, that is sound above the audible range a. 10,000 b, 20,000 c. 30,000 d. 40,000
b
Which of the following is not a property of acoustic waves
a. pressure & particle velocity are in phase
b. the wave force is attenuated by converting the energy in the pressure wave
d. there is movement of the material
d.
Which of the following types of tissue would have the lowest propagation velocity
a. air
b. fat
c. blood
d. , water
a
When C2 > C1 (C = Speed of medium(, refraction can occur when the angle of incidence is ____ than the angle off transmission
a. less then
b. equal to
c. greater than
A.
Acoustic couplings are needed b/c they reduce the impedance between the
a. damping material & active element
b. matching layer & active element
c. transducer & skin surface
c
Arrange in decreasing order
a. deci, centi, milli, micro, nano
b. milli, centi, deci, micro, nano
c. centi, milli,micro,nano,deci
a.
Which of the following u/s modalities has highest intensity value
a. M-mode
b. Pulsed wave
c. continuous wave
b
The color flow doppler artifact associated with the superimposition of color on moving tissue is a. aliasing b. ghosting c, reverberation d. shadowing
B.
What is the best angle for imaging & doppler
a. 90 degrees & 70 degrees
b. 45 degree & 60 degrees
c. 90 degree and 60 degree
c
What will the axial resolution be when SPL is 10 mm
a. 10 mm
b. 5 mm
c, 2.5 mm
b
Name the disadvantage if continuous doppler
a. range resolution
b. range specificity
c. range ambiguity
c
You are performing a sonographic examination of the tissue harmonics operating mode. What advantage will you obtain over conventional imaging
a. improves contrast resolution & signal to noise ratio
b. decreased penetration
c. improved temporal resolution
a.
You notice a loss of detail in the lateral dimension of the us image, what can you do to improve this
a. decrease number of focal zone
b. increase scan line density
c, decrease transducer frequency
b.
Nyquist limit describes
a. penetration limit of US
b. transmit lines of pulsed us
c. sampling frequency needed for detecting doppler signal unambigiously
c
IF you wish to improve border definition what imaging enhancement would you use
a. edge enhancement
b. speckle reduction
c. lower line density
a.
The rapid technique used in most doppler systems to obtain means doppler frequency shift is
a. FFT
b. phase qudrature
c. autocorrelation
c
The presence of spectral window on the Doppler wave is affected by all of the following except
a. SV gate
b. doppler gain
c. high pass filter
d. turbulent flow
c.
Name the imaging technique which improves image quality, continues to display information from older images on the most current frame with reduced frame rate is
a. spatial compounding
b. persistence (temporal)
c. coded excitation
d. edge enhancement
b.
What Reynolds number would indicate turbulent flow & laminar flow
a. <1500, >2000
b. <2000 & >2000
c. >2000 & <1500
c.
When you change the transmit frequency which one of the following is altered
a. number of cycles per second
b. speed at which sound wave propagates through a medium
c. pulsed transmitted per sound
a.
During doppler interrogation of the carotid artery you detect spectral mirroring which of the following is a common causes of this artifact
a. doppler angle of interrogation is 90 degrees
b. high pass filter set to high
c. doppler gain to set low
a.
Steering the color window to the right or left produces a ___ frame rate
a. double
b. quadrupled
c. unchanged
d. halved
c.
Increasing ensemble length ___ color sensitivity & accuracy and _____ frame rate
a. improves, increases
b. degrades, increases
c. degrades , decreases
d. improves, decreases
d.
How many level of information does a single bit store
a. one
b. two
c. four
b
Which of the following electrical patterns produces electronic focusing of the ultrasound
a. curve
b. slope
c. width
d. length
a
How is slice thickness imrpoved
a. using 1 & 1/2 D array transducer
b. using 1 D array transducer
c. using 1/2 D array transducer
d. all of the above
a
All of the following result from the use of backing material in transducer except
a. reduced SPL
b. high sensitivity
c. shorter pulse duration
d. wide bandwidth
b
What is the wavelength of a 3 MHz sound pulse in soft tissue.
a. 1.54 mm
b. 0.51 mm
c. 0.49 mm
d. 1.54km
b.
Which answer provides the best expiration for the reason the frame rate decreases
a. the color doppler pulse length is longer
b. there are more focal zones when color is active
c. the system accuracy resources are challanged
d. more pulses are fire on each line of sight
d.
You have decreased the scan line density, what technique will be employed to fill in the empty data between the scan lines
a. rejection of the gray
b. fill in the doppler window
c. interpolation
d. persistence
c
Which of the following transducers have the best axial resolution
a. 2.5 MHz, 4 cycles/pulse
b. 4.5 MHz, 6 cycles/ pulse
c. 4.5 Mhz, 2 cycles/pulse
c
Name the transducer which uses mechanical steering & focusing technique
a. mechanical transducer
b. linear sequential
c. annular phased
d. phased array transducer
c.
Which of the following controls on the US systems will reduce artifacts
a. wall filter
b. overall gain
c. persistence
d. nyquist limit
a
What is the accuracy of reflector depth position on A mode, B mode, M mode
a. horizontal calibration
b. depth callibration
c. range resolution
d. axial resolution
b
When the depth of view is set to 5cm what will be the PRP
a. 130 microsec
b. 65 microsec
c. 55 microsec
d. 50 microsec
b
What is the thickness of the active element
a. half wave length thick
b. quarter wave length thick
c. one wavelength thick
a
What is the frequency of the sound beam from a continuous wave transducer when the transmitter creates a 10Mhz electrical frequency
a. same as transmitter frequency
b. half to transmitter frequency
c. half of the active element
a
Dynamic receive focusing uses
a. mechanical means to focus them
b. time delays to excite array elements
c. time delays before echo signals from array elements are continued
c.
What conditions are necessary for refraction to occur at an interface between two media
a. unequal impedance and normal incidence
b. diff propagation speeds & oblique incidence
b
Which of the following indicates how a test provides the correct results regardless whether the result is positive or negative
a. accuracy
b. specificity
c. sensitivity
d. positive predictive value
a
Aliasing is helpful in the US because it allows us to
a. quickly detect regions where blood flow velocity is too high
b. quickly detect where pressure energy is high
a
Which artifact results in improper side by side positioning of reflections
a. multipath
b. comet tail
c. refraction
c
A monographer adjust an u/s scan to the depth of view from 5 to 10 cm what happens to frame rate
a. it is halved
b. it doubles
c. it increases from 5 to 10 Hz
a
Which of the following doppler modes does not use Doppler frequency shift information to generate the signal?
a. spectral doppler
b. color. doppler
c. power doppler
c
All of the following statements are true regarding temporal resolution except
a. increased temp resolution is associated with a high PRF
b. decreased temporal resolution is associated with a shorter pulse duration
b
Under which circumstance is cavitation likely to occur
a. high frequency and low power
b. low intensity & low frequency
c. low frequency & high pressure
c.
Which of the following is the cause of slice thickness artifact
a. decreased attenuation of the sound beam at reflector
b. curved reflectors in the path of the sound beam
c. beam dimension greater in size than reflector
c
The following transducers have a constant output power, which of the following will give the best lateral resolution in the far zone
a. 4 Mhz, 9 mm diameter
b. 4 Mh, 6 mm diameter
c. 4 Mhz, 12 mm diameter
c.
Transducer a has a longitudinal resolution of 4mm, transducer B has a longitudinal resolution of 6mm, transducer c has a longitudinal resolution of 3mm, which transducer has the poorest longituational resolution a. A b. B C. c d. cannot be predicted
b
All of the following will increase SPL except
a. increasing wavelength
b. decreasing frequency
c. increasing # of cycles in a pulse
d. increasing receiver gain
d
Increasing the imaging depth affects all of the except
a. axial resolution
b. PRP
c. PRF
d. Duty factor
a
Which fo the following receiver function amplified all the return signals regardless of depth
a. amplfication
b. compression
c. compensation
d. rejection
a
Preprocessing is performed by the
a. transducer
b. receievr
c. analog to digital converter
d. digital to analog converter
c
The best example for Rayleigh scatter is
a. diaphragm
b. heart wall
c. liver parenchyma
d. red blood cell
d
All of the following are true statements concerning doppler regulation except
a. an increase in transmitted frequency will result in an increase in the doppler shift
b. sound speed of soft tissue is considered. constant
c. a decrease in RBC velocity will increase the detected doppler shift
c
the monographer needs to make an accurate lateral dimension measurement of a structure. For the best result monographers should place the structure
a. close to transducer
b. away from transducer
c. in the focal region
c
The doppler shift is in which range of sound
a. medical diagnostic u/s
b. audible sound
c. infrasound
d. ultrasound
b
All of the following artifacts places errenous reflections at the same depth as true reflector except
a. refraction
b. side lobes
c. mirror image
d. grating lobe \
c
An u/s system is set at 0 DB & is transmitted at full intensity, what I the output power when the system is transmitting at 50% of full intensity
a. -3DB
b. -10DB
c. 3dB
d. 10dB
a
The image on the ultrasound system is too bright, which of the following tencique is best to correct this problem
a. decrease output power
b. adjust TGC
c. decrease reject
d. decrease receiver gain
a
Enhancement artifact appears on an ultrasound scan. Which of the following statement is true about the structure immediately above artifact
a. there is to little absoprtion
b. attenuation propertjes to low
b
With phased array transducers transmitted sound beam is steered by the
a. mechanically sweeping the pot elemtns
b. varying the timing of pulses to individual pzt elements
c. varying the frequency of the pulses to individual Pat elements
B
Which of the following preserves the pixel density when enlarging the image
a. read zoom
b. write magnification
c. postprocessing magnification
b
Which testing device is used to measure acoustic output power
a. tissue phantom
b. AIUM test phantom
c. doppler flow phantom
d. hydrophone
d.
Law of interference is
a. Bernoulli’s principle
b. snells law
c. Huygens principle
d. pouislles law
c
What type of wave is sound
- mechanical transverse
- mechanical longitudinal
- transverse longitudinal
- lateral wave
mechanical longitudinal
The frequency ranges for ultrasound are:
<20 Hz
20 to 20,000 Hz
> 20 kHz
> 2000 Hz
- 20 to 20,000 Hz
The speed of sound in soft tissue is
1.54 mm/s
1540 m/s
1540 km/s
1.54 m/µs
1540 m/s
Which of the following transuders fires the elements in groups?
Linear sequenced array
Phased array
Mechanical sector
Linear phased array
Linear sequenced
The units for wavelength is
millmeters
Hertz
microseconds
milliliters
Wavelength units are millimeters
Enhancement is caused by
Strongly reflecting structures
Propagation speed errors
Snell’s law
Weakly attenuating structures
Weakly attenuating structures cause enhancement
The wavelength in a material having a propagation speed of 1.5 mm/µs employing a transudcer frequency of 5.0 MHz is:
- 3 mm
- 3 cm
- 6 mm
- 0 mm
0.3 mm
wavelength = c/f
1.5 mm/µs / 5 MHz = 0.3 mm
An ultrasound transducer converts
electrical energy into light and heat
electrical energy into mechanical energy
mechanical energy into radiation
sound into ultrasound
An ultrasound transducer converts electrical energy into mechanical energy and vice versa
Arrange the following media in correct order from the lowest attenuation to the highest
(a) air, fat, muscle bone
(b) muscle, fat, air, bone
(c) bone, muscle, fat, air
(d) muscle, air, fat, bone
Lowest attenuation to highest
(c) bone, muscle, fat, air
Arrange the following media in terms of propagation speed from lowest to highest
(a) air, fat, muscle, bone
(b) bone, fat, air, muscle
(c) bone, muscle, fat, air
(d) muscle, air, fat, bone
Propagation speed from lowest to highest:
(a) air, fat, muscle, bone
If frequency doubles, what happens to the wavelength?
increases fourfold
increases twofold
decreases by one half
frequency has no relationship to wavelength
If frequency doubles, wavelength decreases by one half
Frequency and wavelength are inversely related
What happens to intensity if the amplitude of a signal is halved?
Quartered
Quadrupled
Halved
No change
Amplitude halved will result in intensity quartered
amplitude = intensity
Which of the following would be used to desribe the percentage of time that sound is on?
Intensity
Amplitude
SPTA
Duty factor
Duty factor is the percentage of time the sound is being transmitted
A 3 dB gain would indicate an increase in intensity by:
2 times
4 times
8 times
10 times
3 dB results in doubling of intensity (or power)
Ignoring the effects of attenuation, the intensity of the ultraosund beam is usually greater at the focal zone because of
- Decreased attenuation
- The smaller beam diameter
- Diffraction effects
- A shorter duty factor
Ignoring the effects of attenuation, the intensity of the ultrasound beam is usually greater at the focal zone because of the smaller beam diameter
Attenuation denotes
Progressive weakening of the sound beam as it travels
Density of tissue and the speed of sound in the tissues
The redirection of the ultrasound back to the transducer
Bending of the transmitted wave after crossing an interface
Attenuation denotes progressive weakening of the sound beam as it travels
Which of the following has the lowest intensity
SPTP
SATP
SPTA
SATA
SATA is the lowest of the intensities
What is the definition of the beam uniformity ratio?
The spatial intensity divided by the spatial peak intensity
The spatial peak intensity divided by the spatial average intensity
The temporal average intensity divided by the spatial average intensity
The temporal peak intensity divided by the spatial peak intensity
Beam uniformity ratio = Spatial peak / Spatial average
Continuous wave Doppler has a duty factor of
<1%
100%
>100%
50%
CW Doppler has a duty factor of 100%
The spatial pulse length is defined as the product of the _____ and the number of _____ in a pulse?
cycles, frequency
frequency, velocity
wavelength, cycles
frequency, wavelength
SPL = wavelength x cycles
With phased array transducers, the transmitted sound beam is steered by:
Mechanically sweeping the piezoelectric elements
Mechanically rotating the piezoelectric elements
Varying the timing of pulses to the individual piezoelectric elements
Varying the frequency of pulses to the individual piezoelectric elements
With phased array transducers, the transmitted sound beam is steered by varying the timing of pulses to the individual piezoelectric elements
Phased array transudcers operate y shocking the elements with minute time differences in between
If the gain of an amplifier is 18 dB, what is the new gain if the power is reduced by half?
15 dB
9 dB
36 dB
0.5 dB
15 dB
If the power is reduced by half is it sht esame as a change of -3 dB,
therefore 18 dB - 3 dB = 15 dB
Which of the following is true?
SPTA is always equal to or greater than SPTP
SPTP is always equal to or greater than SPTA
SATA is always equal to or greater than SATP
SPTA is equal to or greater than SPTP
SPTP is always equal to or greater than SPTA
Peaks are always higher than averages. SPTP is the highest intensity, SATA is the lowest
If the amplitude of a wave is increased threefold, the power will
Decrease threefold
Increase threefold
Increase ninefold
Increase sixfold
Amplitude increased threefold, power increases ninefold
Amplitude = Power2
Ultrasound attenuates an average of ____ dB/cm of travel for each megahertz of frequency
1
- 7
- 33
- 25
Average rate of attenuation in soft tissue = 0.7 dB/cm/MHz
If the intensity transmission coefficient is 0.74, the intensity reflection coefficient will be:
- 06
- 00
- 26
- 04
If the intensity transmission coefficient is 0.74, the intensity reflection coefficient will be 0.26
Acoustic impedance is defined as the product of:
The mismatch between two interfaces
A change in velocity at oblique incidence
The speed of sound in tissue and density of the tissue
The wavelength and frequency
Acoustic impedance is defined as the product of the speed of sound in tissue and density of the tissue
Impedence = density x propagation speed
Rayleigh scattering is an example of:
A reflector whose size is smaller than the wavelength
A reflector whose size is significantly larger than the wavelength
A specular reflection
A type of side lobe artifact
Rayleigh scattering is an example of a reflector whose size is smaller than the wavelength
Think: RBC
If medium 2 impedance is equal to medium 1 impedance:
100% of the intensity will be reflected
100% of the intensity will be transmitted
The reflection and the transmission coefficients will be equal
The answer cannot be determined without values given
If medium 2 impedance is equal to medium 1 impedance, 100% of the intensity will be transmitted
What is the total attenutaion of a 3.5 MHz pulse after passing through 2 cm of soft tissue?
7 dB
3.5 dB
17 dB
1.75 dB
3.5 dB is the total attenuation
Total attenuation (dB) = 1/2 f x path length (0.5 x 3.5) x 2 = 3.5 dB
The thinner the piezoelectric element
The lower the frequency
The higher the frequency
The higher the amplitude
The lower the amplitude
The thinner the piezoelectric element, the higher the frequency
The unit for impedance is:
dB
mW/cm2
Rayls
No units
The unit for impedance is Rayls
A sound beam encouters an interface at a 90° angle. If the speed of sound in the first tissue is 1540 m/s and the speed of sound in the sound tissue is 1450 m/s, which of the following numbers most closely approximates the angle of beam transmission?
<90°
90°
>90°
Need the impedance to compute angle of transmission
> 90°
There can be no refraction when sound hits a reflector at 90° to the interface
ALARA stands for
As low as reasonably achievable
As long as reasonably acceptable
As little as reasonably allowable
As long as reasonably achievable
ALARA stands for
As low as reasonably achievable
As long as reasonably acceptable
As little as reasonably allowable
As long as reasonably achievable
A decibel (dB) describes the:
Ratio of two sound intensities
Sum of two sound intensities
Amount of scattering
Velocity of the sound wave
Decibel (dB) describes the ratio of two sound intensities
The correct equation for Snell’s law is
(a) R = (Z2-Z1)2 / (Z2+Z1)2
(b) Z = pc
(c) sin θt = (C2/C1) x sin θi
(d) Fd - 2fvcosθ/c
Snell’s law
(c) sin θt = (C2/C1) x sin θi
Snell’s law describes refraction at an interfac
The attenuation coefficient of sound in soft tissue can be defined by which of the following equations?
One half the frequency times the path length
Frequency/6
Frequency/2
Frequency x 2
Attenuation Coefficient (soft tissue) = Frequency / 2
The intensity transmission coefficient is equal to:
1 + intensity reflection coefficient
1 - intensity reflection coefficient
The square of the angle of transmission
(Intensity transmission coefficient) / 2
Intensity Transmission Coefficient = 1 - Intensity Reflection Coefficient
ITC = 1 - IRC
The range equation explains
side lobes
distance to reflector
attenuation
calibration
Range equation explains distance to reflector
Range equation (d=ct/2) provides the distance to the reflector
The typical factor for attenuation coefficient for 6 MHz ultrasound in soft tissue is:
3 dB/cm
1 cm/cm/Hz
3 dB/cm2
2 dB
3 dB/cm
Attenuation coefficient = Frequency / 2
= 6 MHz / 2 = 3dB/cm
What must be known in order to calculate distance to a reflector?
Attenuation, propagation speed, density
Attenuation, impedance
Travel time, propagation speed
Density, propagation speed
Travel time and propagation speed is needed to calculate distance to the reflector
Specular reflections:
Occur when the interface is larger than the wavelength
Occur when the interface is smaller than the wavelength
Arise from interface smaller than 3 mm
Are not dependent on the angle of incidence
Specular reflections occur when the interface/border is larger than the incident wavelength
What is the reflected intensity from a boundary between two materials if the incident intensity is 1 mW/cm2 and the impedances are 25 and 75?
- 25 mW/cm2
- 33 mW/cm2
- 50 mW/cm2
- 0 mW/cm2
0.25 mW/cm2
Reflection Equation used:
Ir = Ii x [(Z1 - Z1) / (Z2 + Z1)]2
The layer of material within the transducer which has an intermediate impedance between the transducer element and human tissue is known as the
Filler medium
Damping medium
Acoustic medium
Matching layer
Matching layer
The matching layer has an impedance between that of the piezoelectric element and the skin in order to improve transmission of sound into the patient.
Which of the following relates bandwidth to operating frequency?
Near zone
Piezoelectric crystal
Quality factor
Far zone
Quality factor
Quality factor = operating frequency/bandwidth
The piezoelectric effect can best be described as
Density of tissue and the speed of sound in the tissues
Mechanical deformation that results from a high voltage applied to the face of the crystal that in turn generates a pressure wave
Having a damaging effect on crystal due to high voltage
The decrease in intensity that results from the application of damping material
The piezoelectric effect can best be described as mechanical deformation that results from a high voltage applied to the face of the crystal that in turn generates a pressure wave
Piezoelectric effect occurs when electricity is applied and a pressure wave is generated
Which of the following are most commonly used in ultrasound transdcuers?
Lead zirconate titanate
Barium sulfate
Expoxy loaded with tungsten
Quartz
Lead zirconate titanate (PZT) is most commonly used in modern day transducers
Diffraction refers to:
Spreading out of the ultrasound beam
Conversion of sound to heat
Redirection of a portion of the sound from a boundary beam
Bending of the sound beam crossing a boundary
Diffraction refers to spreading out of the ultrasound beam
Diffraction occurs as a result of Huygen’s principle and is a spreading of the wavefront.
The method of sterilizing transducers is:
Heat sterilization
Steam
Cold sterilization
Autoclave
Ultrasound transducers must be cold sterilized
A transducer with which frequency would have the thickest element(s)?
2 MHz
3.5 MHz
5 MHz
7.5 MHz
2 MHz would have the thickest element
The thicker the element the lower the frequency
Which of the following is best defined as the ability to discriminate between two closely spaced reflectors?
Definition
Range accuracy
Spatial resolution
Amplification
Spatial Resolution
is the ability to discern two closely spaced reflectors as individual reflectors
Which of the following is an effect of focusing?
Improved lateral resolution
Improve axial resolution
Increased beam divergence
Higher frequency
Focusing improves lateral resolution and is unrelated to axial resolution
Bandwidth is
A source of artifacts
A potential shade of gray
The range of frequencies produced by the transducer
Undesirable interference or noise
Bandwidth is the range of frequencies produced by the transducer
Within the same medium using the same transducer, decreasing the ______ decreases the beam diameter in the ______
(a) Frequency, far zone
(b) Wavelength, far zone
(c) Frequency, near zone
(d) Intensity, far zone
Within the same medium using the same transducer, decreasing the wavelength decreases the beam diameter in the far zone
Decreasing the wavelength will increase the frequency and thereby decrease divergence in the far field
The acoustic impedance of the transducer’s matching layer:
Is chosen to improve transmission into the body
Is chosen to have increased internal reflections
Determines the frequency
None of the above
Matching layer(s) impendance is chosen to improve transmission of sound into the body
If the amount of damping decreases, the bandwidth:
Stays the same
Increases
Decreases
Damping the bandwidth are unrelated
If amount of damping decreases, the bandwidth decreases
Bandwidth is the range of frequencies present within the beam.
Damping is the process of reducing the number of cycles of each pulse in order to improve axial resolution
The region where the sound beam is the smallest is referred to as the:
Fresnel spot
Focus
Near field
Far field
Focus
or focal zone is the smallest region of the sound beam
The near zone length is determined by
The number of focal zones
Frame rate
Pulse repetition frequency
Transducer frequency
Near zone length is determined by both transducer frequency and element diameter
The type of transducer that utilizes concentric rings is called
Sequential array
Phased array
Annular array
Spatial array
Annular array
has elements arranged into concentric rings
A wave’s initial intensity is 2 mW/cm2. There is an increase of 10 dB. What is the final intensity?
4 mW/cm2
8 mW/cm2
12 mW/cm2
20 mW/cm2
20 mW/cm2
An increase of 10 dB is equal to a change of 10 times the initial intensity
Which of the following is described best as a transducer that has multiple elements in a curved shape?
Annular array
Mechanical sector
Curvilinear
Linear array
Curvilinear
(aka curved, convex) transducer has multple elements on a curvature
What is the name of the control that compensates for attenuation related to path length?
Near gain
Far gain
TGC
Reject
TGC or compensation or time gain compensation
is what compensates for attenuation related to path length
The echoes are stored before final display by the
Receiver
Scan converter
Demodulator
Transducer
The scan converter stores the echo information in the memory before it is sent to the display
What portion of the ultrasound system drives the transducer?
Pulser
Receiver
Scan converter
TGC controls
The pulser is responsible for producing the voltages that drive the transducer
What component of the ultrasound system contains the digital-to-analog converter?
Scan converter
Pulser
Receiver
Display
e scan converter contains the analog-to-digital converter, memory, and digitial-to-analog converter
How many different shades of gray can the human eye discern at one time?
16
32
64
100
100 different shades of gray
is discernable with the human eye
Most current ultrasound systems have _____ shades of gray available.
4
32
64
256
Most current ultrasound systems have
256 shades of gray
How many shades of gray can be displayed with 4 bits of memory?
2
4
8
16
16 shades of gray
can be displayed with 4 bits of memory
Shades of gray = 2n
(n = number of bits per pixel in memory)
The spatial resolution capabilities of the system are mainly functions of the:
Pulser
Transducer
Receiver
Display
The transducer determines the spatial resolution of the system
The echo intensity on a grayscale of 32 shades is represented by the binary number:
10101
1010
100000
110000
The number 32 in binary is 100000
Preprocessing of the information that is fed to the scan converter:
Enlarges each pixel to provide a magnified image
Determines the CRT brightness assigned to store grayscale levels
Determines the assignment of echoes to predetermined gray levels
Determines the grayscale emphasis of stored gray levels
Preprocessing the information that is fed to the scan converter determines the assignment of echoes to predetermined gray levels
Which of the following do grasycale systems typically use as a means of signal dynamic range reduction?
Rejection
Compression
Relaxation
Elimination
Compression
is typically used to reduce dynamic range
Compression is the opposite of dynamic range. Increasing the compression reduces the dynamic range
Compression
is typically used to reduce dynamic range
Compression is the opposite of dynamic range. Increasing the compression reduces the dynamic range
Area is expressed by
cm2
If the frequency of a transducer is increased, which of the following will decrease?
Wavelength
Propagation Speed
Pulse Repetition Frequency
Pulse Repetition Period
Wavelength
Frequency and wavelength are inversely related.
With tissue harmonic imaging,
(a) The propagating pressure wave causes the sound to appear as a sinusoidal waveform
(b) The proagating pressure wave causes the sound to appear as a synovial waveform
(c) There are increased artifacts in the near field
(d) There are decreased artifacts in the near field
With tissue harmonic imaging (THI), there are decreased near-field artifacts
Which of the following is in the range of infrasound?
1.5 kHz
15 Hz
25 Hz
1 MHz
15 Hz is within the range of infrasound
Infrasound: <20 Hz
Audible sound: 20 Hz - 20,000 Hz
Ultrasound >20,000 Hz
Which of the following is in the range of audible sound?
15 Hz
18 kHz
25,000 Hz
2 Hz
18 kHz is in the range of audible sound
Infrasound: <20 Hz
Audible sound: 20 Hz - 20,000 Hz
Ultrasound >20,000 Hz
Which of the following can be changed by the operator?
Frequency
Wavelength
Propagation speed
Pulse repetition frequency
Pulse repetition frequency can be changed by the operator
PRF is changed by adjusting depth
Which of the following is the time it takes for one cycle to occur?
Period
Frequency
Wavelength
Pulse repetition period
Period
Think: Time!
The length of the pulse is the
Period
Wavelength
Pulse repetition frequency
Spatial pulse length
Wavelength
Think: length
Assuming oblique angle of incidence, if the propagation speed of medium 1 is greater than the propagation speed of medium 2, what will the angle of transmission be?
Greater than the angle of incidence
Less than the angle of incidence
Equal to the angle of incidence
Propagation speed does not influence the angle of transmissio
Less than the angle of incidence
If propagation speed of medium 1 > propagation speed medium 2, then the angle of transmission will be less than the angle of incidence
A 5 MHz wave travels through 5 cm of soft tissue. If a 3.5 MHz transducer is selected instead, what happens to the propagation speed of the medium?
Increases
Decreases
No change
Not enough information given
No change
Propagation speed is only determined by the medium (specifically the stiffness and density)
The slowest propagation speed is found in which medium?
Bone
Air
Muscle
Liver
The slowest propagation speed of sound is through
air
Air < Liver < Muscle < Bone
Which of the following represents the strength of a beam?
Frequency
Intensity
Q-Factor
Duty Factor
Intensity
is a parameter that represents the strength of the beam
Which of the following is the unit of pressure amplitude?
W/cm2
mm
mW
Pascal
Pascal
is the unit for pressure amplitude
Which of the following is the unit of intensity?
W/cm2
mW
Pascal
W/cm
W/cm2
is the unit of intensity
Think: intensity is the concentration of energy (W) in an area (cm2)
What else changes with a change in amplitude?
Resonating frequency
Output power
Wavelength
Spatial pulse lengt
A change in amplitude will change the
output power
Which of the following will increase the acoustic exposure to the patient?
Increased receiver amplification
Increased time gain compensation
Decreased pulse repetition frequency
Increased output gai
Increased output gain
will increase the acoustic exposure to the patient
Remember ALARA
Which operator control adjusts the intensity of the transmitted pulse?
Receiver gain
Depth of scanning
Power (dB)
Time gain compensation (TGC)
Power (dB)
Increasing the power increases the intensity of the transmitted pulse
What happens to the power if the intensity is doubled?
No change
It doubles
It quadruples
It is halved
If intensity is doubled, power doubles.
Intensity = Power
Intensity = Amplitude2
The number of pulses that occur in 1 second is the:
Pulse repetition frequency
Pulse repetition period
Pulse duration
Duty factor
Pulse repetition frequency (PRF)
is the number of pulses per second
What is along the x-axis on a spectral Doppler waveform?
Depth
Amplitude
Time
Velocity
Time
is on the x-axis of the spectral waveform
What is the unit of spatial pulse length?
µs
m
m/s
m/s2
Spatial pulse length (SPL) unit is m
What testing device is used to measure acoustic output (intensity) level?
Tissue phantom
AIUM test phantom
Doppler flow phantom
Hydrophone
Hydrophone
is used to test output intensity
What is the principle that states sound waves are the result of the interference of many wavelets produced at the face of transducer?
Doppler’s principle
Bernoulli’s principle
Huygen’s principle
Poiseuille’s principle
Huygen’s principle
sound waves are the result of the interference of many wavelets produced as the face of the transducer
In what mode is the amplitude of the return echo represented by spikes along the y-axis of the image?
M-mode
C-mode
B-mode
A-mode
A-mode
displays the amplitude of reflectors along the y-axis
In B-mode imaging, amplitude is located on the
___-axis of the image
x
y
z
c
z-axis
In B-mode imaging, amplitude is the brightness of the dot, which is considered the z-axis of the image
Which of the following determines the radial resolution of a system?
PRF
Impedance
SPL
Duty factor
Radial/axial resolution is determined by the spatial pulse length (SPL).
The shorter the pulse used, the better the axial resolution
The axial resolution can be improved by decreasing the ________ or increasing the _________.
(a) impedance pulse duration
(b) number of cycles in a pulse, wavelength
(c) propagation speed spatial pulse length
(d) number of cycles in a pulse, frequency
(d) number of cycles in a pulse, frequency
The axial resolution can be improved by decreasing the number of cycles in a pulse or increasing the frequency
two reflectors are 1.3 mm apart in a plane that is parallel to the beam. The SPL of the transducer is 2.6 mm. These two reflectors:
Will show up as one dot in the screen
WIll show up as two dots on the screen
WIll not show up on the image at all
Will have poor lateral resolution
These two reflectors will show up as two dots on the screen
In what zone does beam divergence occur?
At the face of the transducer
Focal zone
Fraunhofer zone
Fresnel zone
Divergence occurs in the far/Fraunhofer zone
The large the aperture,
The shorter the near zone
The longer the near zone
The more divergence there is in far field
The shorter the Fresnel zone
The larger the aperature/element diameter, the longer the near zone
The ability to resolve two reflectors that lie parallel to the beam is the ______ resolution of a sytem
axial
lateral
elevational
temporal
Axial
Resolution of two echoes parallel to the beam is the axial resolution
The more focal zones used,
The better the temporal resolution
The worse the temporal resolution
The better the axial resolution
The better the SPL
The more focal zones used, the worse the temporal resolution
In the most common type of transducers, the slice-thickness plane is focused:
Using a lens
Using a matrix array
Electronically
Using a 2D technology
The slice-thickness plane is focused with a lens in most modern transducers
If sound travels through a large quantity of water and then encounters a reflector, the reflector will appear:
Too far away
Too close
In the correct location
Not enough information to tell
Too far away
What is the maximum temperature increase below which there should be no thermally induced biologic effects?
95 °C
10 °C
4 °C
2 °C
Maximum temperature increase below 2 °C
is safe / should have no thermally induced biologic effects
Two sound beams with different frequencies are traveling through the same medium. Which beam will travel faster?
The higher frequency sound
The lower freqeuency sound
Both will travel at the same speed
Cannot be determined
Both will travel at the same speed
Think: frequency and propagation speed are unrelated
A video display that is limited to only black and white, with no other shades of gray, is called:
Binary
Monochrome
Bistable
Unichrome
Bistable image:
image that is only black and white
What is the name for the smallest amount of digital storage?
The bit
The pixel
The byte
The megabyte
The bit/binary digit is the smallest unit of digital memory
In the Fresnel zone,
The beam diameter is a constant
The beam diameter diverges
The beam area increases with distance from the transducer
The beam area decreases with distance from the transducer
In the Fresnel zone, the beam area decreases with distance from the transducer
Information that travels to the scan converter from the receiver is initially in what format?
Analog
Digital
Both
Neither
Analog
Receiver information is in analog form
Which of the following is true about color Doppler?
Each pixel can be both color and grayscale at the same time
Each pixel can be either grayscale or color
Pixels cannot be colorized
The gain determines the color priority of the pixel
Each pixel can be either grayscale or color,
they cannot be both at the same time
Which of the following preserves the pixel density when enlarging the image?
Read zoom
Write magnification
Max zoom
Postprocessing magnification
Write magnification
enlarges the image before the image is stored in digital memory, thus preserving the pixel density
Write is while scanning/live
Read is postprocessing so quality is what it is
What is the relationship between amplitude and frequency?
Directly related
Inversely related
No relation
Sometimes they are related, sometimes not
Amplitude and frequency have no relation
What is the relationship between spatial pulse length and pulse duration?
Directly related
Inversely related
No relation
Sometimes they are related, sometimes not
Spatial pulse length (SPL) and pulse duration are
directly related
Which of the following is true about axial resolution?
It decreases with depth
It increases with depth
It does not vary with depth
It is best at the focal zone
Axial resolution does not vary with depth
If the ______ is increased, the flow increases.
Pressure differential
Resistance
Length of vessel
Viscosity of blood
If the pressure differential is increased, the flow increases
Which law describes the relationship between flow and the presssure differential, viscosity, and length?
Bernoulli’s law
Poiseuille’s law
Snell’s law
Doppler’s law
Poiseuille’s law
is the relationship between flow, pressure differential, viscosity and length
The most common type of flow found in the body is:
Plug
Turbulent
Laminar
Chaotic
Laminar flow
is the most common type of flow found in the body
