Physics Top 100 Flashcards
If sound waves of 2 MHz, 5 MHz and 7.5 MHz are transmitted through the heart, reflections from which frequency will arrive back to the transducer first?
Reflections from all three frequencies will have identical round trip times
Increasing the frequency will result in all of the following except decrease:
(a) period (b) pulse duration (c) wavelength (d) spatial pulse length (e) beam width (f) beam divergence (g) depth of penetration (h) duty factor (i) attenuation (j) axial resolution-numerically (k) lateral resolution-numerically
(i) attenuation
Decibel(s) are the units for all of the following except:
(a) amplitude (b) transmit gain (c) gain (d) attenuation (e) TGC (f) dynamic range (g) intensity
(g) intensity
Which of the following performs spectral analysis for conventional (PW, CW) Doppler?
(a) autocorrelation
(b) fast Fourier transform
(c) Bernoulli
(d) Huygen
(b) fast Fourier transform
The artifact which will result in an increase in echo amplitude is:
(a) shadowing
(b) enhancement
(c) reverberation
(d) propagation speed error
(b) enhancement
The artifact which may result in the inability to detect mitral regurgitation from the apical views in a patient with a mitral valve replacement is:
(a) enhancement
(b) shadowing
(c) reverberation
(d) side lobe
(b) shadowing
An increase in log compression will (blank) dynamic range.
(a) increase
(b) decrease
(c) not change
(d) cannot be predicted
(a) Increase
An increase in dynamic range will (blank) the number of shades of gray displayed?
(a) increase
(b) decrease
(c) not change
(d) cannot be predicted
(a) increase
Which of the following is not considered mechanical focusing?
(a) internal focusing
(b) external focusing
(c) acoustic lens
(d) receive
(d) receive
The best way to practice ALARA is to:
(a) increase transmit gain
(b) reduce scan time
(c) increase PRF
(d) utilize PW Doppler
(b) reduce scan time
An increase in packet size will (blank) the frame rate.
(a) increase
(b) decrease
(c) not effect
(d) cannot be predicted
(b) decrease
The placement of color flow on moving structures is called:
(a) ghosting- flash artifact
(b) reverberation
(c) grating lobe
(d) shadowing
(a) ghosting- flash artifact
The range for audible sound is:
(a) less than 20 Hz
(b) 20 Hz to 20 kHz
(c) greater than 20 kHz
(d) 2 MHz to 15 MHz
(b) 20 Hz to 20 kHz
The wavelength of a 1.0 MHz transducer is (blank), assuming soft tissue.
(a) 154mm
(b) 15.4 mm
(c) 1.54 mm
(d) .154 mm
(c) 1.54 mm
The AVERAGE speed of sound in soft tissue is:
(a) 1540 m/s
(b) 1.540 m/s
(c) 15.40 m/s
(d) 154.0 m/s
(a) 1540 m/s
How much sound energy is reflected at a soft tissue-air interface?
(a) 1%
(b) 50%
(c) 75%
(d) 99%
(d) 99%
An increase in overall gain will result in all of the following except:
(a) increase in image brightness throughout the display
(b) increase in output power
(c) increase in the amplification of returning signals
(d) decrease in the risk of bioeffects
(b) increase in output power
To increase the strength (amplitude) of weak amplitude echoes, the sonographer should increase:
(a) frequency
(b) PRF
(c) transmit gain
(d) gain
(d) gain
Reject eliminates:
(a) high amplitude signals
(b) low amplitude signals
(c) gray scale
(d) ring down
(b) low amplitude signals
The units for power are:
(a) W
(b) mW/cm squared
(c) dB
(d) Hz
(a) W
The units for wavelength are:
(a) mm
(b) cm squared
(c) dB
(d) Hz
(a) mm
The units for speed of sound are:
(a) m
(b) mm
(c) m/s
(d) Hz
(c) m/s
There have been no proven biological effects for unfocused transducer for intensities below:
(a) 1 W/cm squared
(b) 100 mW/cm squared
(c) 100 mW/cm squared SPTA
(d) 1,000 mW/cm squared SPTA
(c) 100 mW/cm squared SPTA
60 mm equals (blank) cm.
(a) 0.6 cm
(b) 6 cm
(c) 60 cm
(d) 600 cm
(b) 6 cm
The best example of a specular reflector is:
(a) organ parenchyma
(b) red blood cell
(c) contrast agitated saline
(d) common carotid artery
(d) common carotid artery
The primary cause of attenuation of ultrasound in soft tissue is:
(a) absorption
(b) reflection
(c) scatter
(d) diffraction
(a) absorption
The clinical imaging frequency range is:
(a) less than 20 Hz
(b) 20 Hz to 20,000 Hz
(c) greater than 20,000 Hz
(d) 2 MHz to 15 MHz
(d) 2 MHz to 15 MHz
Two structures parallel to the ultrasound beam are displayed as one reflector. This is referred to as:
(a) range ambiguity artifact
(b) grating lobes
(c) comet tail
(d) resolution artifact
(d) resolution artifact
Damping decreases all of the following except:
(a) spatial pulse length
(b) pulse duration
(c) bandwidth
(d) quality factor
(c) bandwidth
Which of the following depicts the motion of a reflector, the distance of the reflector and the motion of the reflector over time?
(a) A mode
(b) C mode
(c) M mode
(d) transmission mode
(c) M mode
The PRF is 12 kHz. The detected Doppler shift during a PW Doppler examination is 7,000 Hz. Will aliasing occur?
(a) yes
(b) no
(c) never
(d) cannot be predicted
(a) yes
An increase in the number of pixels in a B mode display will increase:
(a) frequency
(b) PRF
(c) frame rate
(d) spatial resolution
(d) spatial resolution
Preprocessing occurs before:
(a) pulser
(b) transducer
(c) receiver
(d) memory
(d) memory
Temporal resolution may be improved by all of the following except decrease:
(a) image depth
(b) field of view
(c) frequency
(d) line density
(c) frequency
The difference between the transmit frequency and the received frequency is called the Doppler:
(a) principle
(b) effect
(c) shift
(d) frequency
(c) shift
For color flow Doppler, turbulent flow is depicted as (a):
(a) red
(b) black
(c) blue
(d) mosaic
(d) mosaic
A change in the direction of sound as it crosses the boundary is called:
(a) reflection
(b) refraction
(c) reverberation
(d) rarefaction
(e) range ambiguity
(f) range discrimination
(b) refraction
All elements are fired but with a slight time delay in order to beam steer and beam focus is the description of:
(a) linear sequenced array
(b) sector phased array
(c) annular array
(d) convex sequenced array
(b) sector phased array
Which artifact is associated with low amplitude signals?
(a) enhancement
(b) propagation speed error
(c) shadowing
(d) comet tail
(c) shadowing
Which resolution is improved by decreasing beam width?
(a) axial
(b) lateral
(c) temporal
(d) contrast
(b) lateral
The propagation speed of a medium a sound wave is traveling is 1,400 m/s. The reflection from that medium will be placed:
(a) too far
(b) too close
(c) in the correct location
(d) cannot be predicted
(a) too far
Which type of cavitation is associated with micro streaming?
(a) stable
(b) transient
(c) both transient and stable cavitation
(d) cannot be predicted
(a) stable
Which of the following may be useful for the sonographer to use when trying to alter the focus of a fixed focus mechanical transducer?
(a) water path
(b) acoustic lens
(c) curved element
(d) transmit frequency
(a) water path
Which of the following transducer components is placed in front of the piezoelectric element?
(a) cable
(b) damping block
(c) electrical wire
(d) matching layer
(d) matching layer
How small is a Rayleigh scatterer?
(a) 1/4 wavelength
(b) 1/2 wavelength
(c) 3/4 wavelength
(d) 1 wavelength
(a) 1/4 wavelength
Which type of transducer is electronically fired and electronically focused but mechanically steered?
(a) linear sequenced array
(b) sector phased array
(c) annular array
(d) vector array
(c) annular array
The formula for wavelength is:
(a) propagation speed x frequency
(b) propagation speed/frequency
(c) 1/f
(d) SPL/2
(b) propagation speed/frequency
Axial resolution is improved by:
(a) damping
(b) increasing frame rate
(c) decreasing bandwidth
(d) increasing quality factor
(a) damping
The distance from the transducer to the focus is the:
(a) near field
(b) focus
(c) far field
(d) Fraunhofer
(a) near field
Which of the following type of transducer oscillates to create a cross sectional image?
(a) linear sequenced array
(b) sector phased array
(c) mechanical
(d) linear translating
(c) mechanical
The Nyquist limit is equal to:
(a) propagation speed x frequency
(b) propagation speed/wavelength
(c) PRF/2
(d) 4 x V (2) squared
(c) PRF/2
Which gain will increase the risk of bioeffects?
(a) transmit
(b) receive
(c) gain
(d) overall gain
(a) transmit
Which of the following is considered the memory of an ultrasound instrument?
(a) pulser
(b) transducer
(c) receiver
(d) beam former
(e) digital scan converter
(f) display monitor
(e) digital scan converter
A Doppler high pass filter eliminates:
(a) high amplitude signals; high velocity flow
(b) Low amplitude signals; high velocity flow
(c) high amplitude signals; low velocity flow
(d) low amplitude signals; low velocity flow
(c) high amplitude signals; low velocity flow
Spectral broadening suggests:
(a) laminar flow
(b) turbulent flow
(c) flow away from the transducer
(d) flow towards the transducer
(b) turbulent flow
With pulsed wave Doppler axial resolution:
(a) improves
(b) degrades
(c) is not affected
(d) cannot be predicted
(b) degrades
Which color is usually used in a color flow Doppler variance map to indicate turbulent flow?
(a) red
(b) yellow
(c) orange
(d) black
(e) blue
(f) cyan
(g) green
(g) green
Multiple echoes, equally spaced originating from a gas bubble is called:
(a) comet tail
(b) ring down
(c) slice thickness artifact
(d) multipath
(b) ring down
An increase in red blood cell velocity will (bank) the Doppler shift.
(a) increase
(b) decrease
(c) not change
(d) cannot be predicted
(a) increase
The primary advantage of CW Doppler is:
(a) range resolution
(b) range discrimination
(c) range ambiguity
(d) range gating
(e) absence of a sampling rate
(e) absence of a sampling rate
A high pressure, high density zone in a sound wave is called:
(a) compression
(b) rarefaction
(c) reflection
(d) refraction
(a) compression
The range for ultrasound begins at:
(a) 20 Hz
(b) 20,000 Hz
(c) 2 MHz
(d) 15 MHz
(b) 20,000 Hz
How much sound energy is transmitted at a fat-muscle interface?
(a) 1%
(b) 50%
(c) 75%
(d) 99%
(d) 99%
Which instrument control affects the amplitude of the outgoing signal?
(a) gain
(b) receiver gain
(c) TGC
(d) transmit gain
(e) overall gain
(d) transmit gain
The echoes in the far field of the display are too weak. Which control would be best to use to amplify the echoes returning from the far field?
(a) transmit gain
(b) rejection
(c) compression
(d) TGC
(d) TGC
Which of the following is used to convert Doppler shift information into color?
(a) high PRF
(b) fast Fourier transform
(c) autocorrelation
(d) time interval histogram
(c) autocorrelation
All of the following are ways to avoid aliasing except:
(a) increase the velocity scales
(b) decrease image depth
(c) increase transmit frequency
(d) shift the baseline
(e) increase the angle of incidence
(f) use CW Doppler
(c) increase transmit frequency
Which number system is used in the digital scan converter?
(a) decimal
(b) binary
(c) combination of decimal and binary
(d) cannot be predicted
(b) binary
The number of pulses created per second is called:
(a) f
(b) T
(c) wavelength
(d) PRF
(d) PRF
The best way to increase the near field length of an ultrasound beam is to:
(a) increase transducer diameter
(b) increase frequency
(c) focus
(d) increase PRF
(a) increase transducer diameter
The range of frequencies produced by a damped piezoelectric element is called:
(a) fundamental frequency
(b) Q factor
(c) near field
(d) bandwidth
(d) bandwidth
Fundamental frequency divided by bandwidth equals:
(a) wavelength
(b) harmonics
(c) propagation speed
(d) quality factor
(d) quality factor
Clinical imaging transducers are:
(a) wide bandwidth; high Q factor
(b) narrow bandwidth; low Q factor
(c) wide bandwidth; low Q factor
(d) narrow bandwidth; high Q factor
(c) wide bandwidth; low Q factor
Power divided by area equals:
(a) amplitude
(b) power
(c) intensity
(d) beam uniformity ratio
(c) intensity
Increasing the wavelength will (blank) the frequency.
(a) increase
(b) decrease
(c) not change
(d) cannot be predicted
(b) decrease
All of the following directly effect frame rate except:
(a) depth of penetration
(b) field of view width
(c) number of focuses
(d) line density
(e) beam width
(e) beam width
A reflection will occur at the boundary of two media if the acoustic impedances of the two media are:
(a) equal
(b) different
(c) unchanged
(d) cannot be predicted
(b) different
The Doppler shift is in the:
(a) infrasound range
(b) audible range
(c) ultrasound range
(d) clinical imaging frequency range
(b) audible range
A mechanical transducer utilizes:
(a) transmit focus
(b) receive focus
(c) fixed focus
(d) dynamic aperture focusing
(c) fixed focus
The transducer frequency is primarily determined by the transducer element:
(a) diameter
(b) thickness
(c) propagation speed
(d) type
(b) thickness
There is an increase in intensity by 10 dB. The new intensity has increased by (blank) times.
(a) 10
(b) 100
(c) 1,000
(d) 10,0000
(a) 10
A strongly focused transducer implies a:
(a) short focal length; decreased beam divergence
(b) medium focus length; increased beam divergence
(c) long focal length; no beam divergence
(d) short focal length; increased beam divergence
(e) medium focal length; decreased beam divergence
(d) short focal length; increased beam divergence
Harmonics is associated with all of the following except:
(a) improves lateral resolution
(b) reduces side lobes and grating lobes
(c) increases the frame rate
(d) reduces near field reverberations
(c) increases fram rate
An increase in log compression will result in an increase in (blank) and an (bank) in gray shades.
(a) dynamic range; increase
(b) frequency; decrease
(c) power; no change
(d) intensity; increase
(a) dynamic range; increase
All of the following are associated with sound waves except:
(a) amplitude
(b) power
(c) intensity
(d) phase
(e) propagation speed
(f) mass
(f) mass
B-Mode displays reflector:
a) amplitude and distance (time
(b) amplitude and velocity
(c) power and direction
(d) depth and speed
(a) amplitude and distance (time)
An increase in the number of pixels on the display monitor will improve:
(a) temporal resolution
(b) spatial resolution
(c) frequency
(d) brightness
(b) spatial resolution
Propagation speed is primarily determined by:
(a) frequency
(b) harmonics
(c) bandwidth
(d) bulk modulus
(d) bulk modulus
Increasing the transmit gain increases all of the following except:
(a) amplitude
(b) power
(c) intensity
(d) pressure
(e) beam width
(f) depth of penetration
(g) brightness of all echoes throughout the display
(h) mechanical index (MI)
(i) risk of bioeffects
(j) frequency
(j) frequency
How much sound energy is transmitted at a soft tissue-air interface?
(a) 1%
(b) 50%
(c) 75%
(d) 99%
(a) 1%
Spatial pulse length = number of cycles in a pulse x (blank)
(a) frequency
(b) period
(c) wavelength
(d) propagation speed
(c) wavelength
What will occur when an electrical wire becomes detached from a piezoelectric element in a linear sequenced array?
(a) increase flicker
(b) increase frame rate
(c) black radial lines on the display
(d) decreased aperture
(c) black radial lines on the display
The correct depth placement of reflectors depends primarily upon:
(a) frequency
(b) period
(c) power
(d) propagation speed
(d) propagation speed
Which of the following transducer components reduces the impedance difference between the piezoelectric element and the skin surface?
(a) cable
(b) electric wire to the piezoelectric element
(c) matching layer
(d) damping material
(c) matching layer
All of the following will increase the color flow Doppler frame rate except decrease:
(a) field of view
(b) line density
(c) color gain
(d) packet size
(c) color gain
Which of the following will increase the color flow jet area displayed?
(a) increase color gain
(b) increase velocity scale
(c) increase frequency
(d) increase scan time
(a) increase color gain
Which of the following is correctly organized by increasing propagation speed:
(a) air, bone, soft tissue
(b) soft tissue, air, bone
(c) air, soft tissue, bone
(d) bone, soft tissue, air
(c) air, soft tissue, bone
Blood flow with multiple velocities moving in multiple direction is:
(a) laminar flow
(b) inlet flow
(c) turbulent flow
(d) parabolic
(c) turbulent flow
With color flow Doppler aliasing will never occur with normal flow.
(a) yes
(b) no
(c) dependent on flow direction
(d) cannot be predicted
(b) no
The most common type of transducer used in echocardiography is:
(a) linear sequenced array
(b) sector phased array
(c) convex phased array
(d) mechanical
(b) sector phased array
