Finals Part 2 Flashcards
Under which of the following conditions is lateral resolution improved?
a. decreased beam diameter
b. decreased pulse duration
c. decreased imaging depth
d. decreased pixel size
e. decreased spatial pulse length
a. decreased beam diameter
In which way is an annular phase array transducer different than a linear phased array transducer?
a. the linear is steered mechanically
b. the linear can have multiple focal zones
c. the annular can create a sector shaped image
d. the linear has higher pulse repetition frequency
e. the annular is steered mechanically
e. the annular is steered mechanically
In which of these biologic tissues will sound waves p r o p a g a t e
most quickly?
a. tendon
b. blood
c. lung
d. fat
e. amniotic fluid
a. tendon
Which of the following best describes a sound beam?
a. electrical impulses
b. a collection of mechanical vibrations in the form of compressions and rarefactions
c. a wave that man can hear
d. electromechanical
e. ionic vibrations
a collection of mechanical vibrations in the form of compressions and rarefactions
You are performing a quality assurance study on an
ultrasound system using a
tissue equivalent phantom.
You make an adjustment using
a knob on the system console that changes the appearance
of reflector brightness from
fully bright to barely visible. What are you evaluating?
a. resolution
b. dynamic range
c. system sensitivity
d. vertical calibration
e. slice thickness
c. system sensitivity
Which of the following best describes the features of a sound wave and medium that determine the speed of sound in the medium?
a. density of the medium and stiffness of the medium
b. density of the medium and power of the sound beam
c. elasticity of the medium and frequency of the sound beam
d. stiffness of the medium and elasticity of the medium
e. pulse repetition period of the sound wave and density
of the medium
density of the medium and stiffness of the medium
while scanning in a water tank, what location in a sound beam has the highest intensity?
a. focal point
b. focal zone
c. Fresnel zone
d. Fraunhofer zone
e. half value depth
a. focal point
Which of these factors has
the greatest influence on pulse repetition period?
a. display depth
b. thickness of the PZT crystal
c. attenuation of the sound beam
d. impedance of the medium
e. display’s dynamic rang
a. display depth
Which of the following choices best describes an ideal
epidemiologic bioeffects study?
a. randomized and prospective
b. benefits outweigh the risks
c. retrospective and optimized
d. ideal and non-biased
e, prudent and safe
a. randomized and prospective
Which of the following will
result in the highest mechanical index?
a. high frequency and low power
b. high intensity and high frequency
.c low frequency and high signal amplitude
d. low intensity and low frequency
c. low frequency and high signal amplitude
Al of the following statements regarding in-vitro bioeffects are true EXCEPT:
a. In vitro bioeffects conclusions are clinically relevant
b. In vitro bioeffects are always real
.c In vitro bioeffects are very important
d. In vitro bioeffects may not
be applicable to clinical settings
a. In vitro bioeffects conclusions are clinically relevant
Under which circumstance is
the mechanical index highest?
a. high frequency and low p o w e r
b. high intensity and high frequency
c. low intensity and low frequency
d. low frequency and high signal amplitude
d. low frequency and high signal amplitude
Which of the following improves the signal-to-noise ratio?
a. dynamic range
b. frame averaging
c. gray scale
d. edge enhancement
e. receiver gain
b. frame averaging
Under which circumstance is cavitation most likely to occur?
a. high frequency and low power
b. high intensity and high frequency
c. low intensity and low
frequency
d. low frequency and high signal amplitude
d. low frequency and high signal amplitude
What is the accuracy of reflector depth position on an A-mode, B-mode or M-mode display called?
a. range resolution
b. horizontal calibration
c. axial resolution
d. s p e e d error artifact
e. depth calibration
e. depth calibration
Pre-processing occurs
a. when the patient is scanned
b. when images are transferred to the VCR
c. after the images are on the tape
d. when the image exits the
scan converter
a. when the patient is scanned
Post processing occurs when
the image
a. is played off o
f the VCR
b. entered the A/D converter
but before display
c. after ti leaves the A/D converter
d. after ti leaves the scan converter
b. entered the A/D converter
but before display
The region from the transducer to the minimum beam cross-sectional area is the
a. Fraunhofer zone
b. Fresnel zone
c. focus
d. Snell’s length
b. Fresnel zone
Biologic effects have not been documented below what intensity (SPTA)?
a. 100 W/cm
b. 100 mW/m2
c. 100 mW/cm2
d. 100 mW/cm3
c. 100 mW/cm2
What is the standard for communication between medical imaging computers?
a. ALARA
b. PACS
c. D-to- A conversion
d. DICOM
e. A-to-D conversion
d. DICOM
The Curie temperature has which
effect?
a. the backing material delaminates from the active element
b. the glue binding the crystal &matching layer melts
c. the ferroelectric material is depolarized
d. the matching layer changes its impedance
c. the ferroelectric material is depolarized
What happens to venous blood flow to the heart during expiration?
a. increased
b. decreased .
c unchanged
b. decreased
Which of the following has a propagation speed closest to “soft tissue”?
a. muscle
b. fat
.c bone
d. air
a. muscle
In a B-mode display, which of the following axes are used for
the amplitude of the
reflection?
a. Z-axis
b. m-axis
c. x-axis
d. y-axis
e. time base axis
a. Z-axis
What is displayed on the x-axis of an M-mode image?
a. time
b. time-of-flight
c.reflector depth
d. echo intensity
e. red blood cell velocity
a. time
What is displayed on the y
axis of an m-mode image?
a. time
b. time-of-flight
c. echo intensity
d. red blood cell velocity
b. time-of-flight
sonographer’s education ends when they become registered. T or F
F
The dynamic range is the ratio
of the smallest to the largest.
that a system can process without distortion.
a. amplitude
b. frequency
c. p h a s e delay
d. spatial length
a. amplitude
When may a patient revoke their consent to be treated?
a. at any time
b. when ti is safe to terminate the procedure
c. never
a. at any time
f the intensity
is increased by 3dB, it:
a. doubles
b. triples
c. halved
d. quartered
a. doubles
What determines the frequency of
a sound beam from a pulsed transducer?
a. voltage applied to the PZT
b. PZT thickness
c. frequency of the system
d. PRF of the pulser
b. PZT thickness
While propagating, a sound wave is refracted. Finally, it returns to the transducer. The system processes the sound wave as if it has:
a. refracted and returned
b. traveled in a straight line, reflected & returned
c. traveled in a straight line, attenuated, reflected & returned
traveled in a straight line, reflected & returned
What measures the output of a transducer?
a. receiver
b.display .
c hydrometer
d. hydrophone
d. hydrophone
The impedance of tissue is
3 x 105 rayls and for the PZT crystal is 6 x 106 rayls. What is the best impedance for the matching layer?
a. 63×106
b. 3,600
.с 10,000
d. 9.5 × 105
.e 9×104
d. 9.5 × 105
Put in increasing order of propagation speed:
a. air, bone, water
b. bone, water, air
c. air, water, bone
d. water, air, bone
e. bone, air, water
c. air, water, bone
Which type of artifact appears most commonly with highly reflective objects?
a. reverberations
b. mirroring
c. shadowing
d. enhancement
e. defocusing
c. shadowing
What can pulsed Doppler
measure that continuous wave cannot?
a. duration
D. speed
c. velocity
d. location
e. frequency
d. location
What is the fraction of time that a transducer is transmitting?
a. duty factor
b. pulse duration
c. period
d. PRF spatial duration
a. duty factor
Which of the following clinical modalities has the lowest output intensity?
a. pulsed Doppler
b. continuous wave Doppler
c. power Doppler
d. duplex scanning
e. gray scale imaging
e. gray scale imaging
What is the location of the minimum cross-sectional area of the US beam called?
a. focus
b. Fraunhofer zone .
c far zone
d. near zone
a. focus
The dB is defined as the of two intensities.
a. sum
b. diference
c. product
d. ratio
d. ratio
I the power of a sound wave is increased by a factor of 8, how many decibels is this?
a. 3dB
b. 6dB
c. 9 ₫B
d. 8 dB
c. 9 ₫B
An ultrasound system is set at O dB and is transmitting at full intensity. What is the output power when the system is transmitting at 50% of full intensity?
a. -3 dB
b. -50 dB
c. 10 dB
d. 3 dB
e. -10 dB
a. -3 dB
An ultrasound
system is set at 0 dB and is transmitting at full intensity. What is the output power when the system is transmitting at 10% of full intensity?
a. 3- ₫b
b. -50 db
c. 40 dB
d. 3d8
e. -10 ₫b
e. -10 ₫b
The Doppler shift is the of two frequencies.
a. sum
b. difference .
c product
d. ratio
b. difference
What is propagation speed determined by?
a. wavelength
b. intensity & density
c. amplitude
d. density and elasticity
e. density and amplitude
d. density and elasticity
If 300,000 cycles occur in a second, what is the waves frequency?
a. 3MHz
b. 30 kHz
c. 30 MHz
d. 3kHz
e. 0.3 MHz
e. 0.3 MHz
What may be a unit of amplitude?
a. cm
b. HZ
c. msec
d. watts
e, none of the above
a. cm
A Doppler exam is performed with a 5 MHz probe and a PRF of 15 kHz. Which of these Doppler shifts will create aliasing?
a. 2 kHz
b. 2.5 KHZ
c. 7 . 5 kHz
d. 14 kHz
d. 14 kHz
Which of the following choices determines the signal amplitude in the transducer of an ultrasound system?
a. reflected intensity of the sound beam
b. post processing
c. edge enhancement filtering
d. persistence
e. demodulation
a. reflected intensity of the sound beam
In an air-tissue interface, what percentage of the US si reflected?
a. 0%
b. near 0%
c 50%
d. near 100%
d. near 100%
Traveling through the same medium, fi the frequency is doubled, the
wavelength is
a. unchanged
b. doubled
.c halved
d. quartered
c. halved
Traveling through the same medium, if the frequency is doubled, the propagation speed is:
a .u n c h a n g e d
b. doubled
c. halved
d. quartered
a .u n c h a n g e d
True or False. Increasing the frequency increases the penetration depth.
F
True or False. Axial resolution
is affected by focusing.
False
If a manufacturer changed the lines per frame and kept the imaging depth the same, what else would change?
a . PRF
b. period
.c frame rate
c. frame rate
Which of the following has the greatest influence on temporal resolution?
a. propagation speed and the imaging depth
b. frequency of sound and the propagation speed
c. wavelength of sound & propagation speed
d. output power & frequency
a. propagation speed and the imaging depth
In a real time scanner, which of these choices determines the maximum frame rate?
a. depth of view
b. pixel size
c. attenuation coefficient
d. beam diameter
e. lateral resolution
a. depth of view
Multiple reflections that are equally spaced are called:
a. refractions
b. reverberations
c. shadows
d. comets
b. reverberations
What artifact has a grainy appearance and is caused by the interference effects of scattered sound?
a. spackle
b. reverberation
c. slice thickness
d. speckle
e. section thickness
d. speckle
Al of the following will
improve temporal resolution EXCEPT:
a. increased line density
b. single rather than multi focus
c. higher frame rate
d. shallower depth of view
e. slower speed of sound in a medium
a. increased line density
Impedance is the product
of ——- a n d ———
Density, Propagation Speed
The manufacturer increases the number of lines per frame. As a result, which of the following may have to be decreased?
a. frequency
b. frame rate
c. sector angle
d. imaging depth
e. power output
b. frame rate
c. sector angle
d. imaging depth
What component of a
transducer changes electrical to mechanical and mechanical back to electrical energy?
PZT, Crystal
Sonographers cannot affect
a patient’s exposure to acoustic energy.
False
Attenuation of US in soft tissue
is closest to:
a. 3 dB/1MHz
b. 1 dB/cm/10MHz
c. 2 dB/ cm
d. 0.6 dB/cm/MHz
d. 0.6 dB/cm/MHz
How many bits are needed to represent 1024 gray shades?
a. 1024
b. 8
c. 10
d. 3
e. 512
c. 10
(True or False) Gray scale can be changed by the sonographer.
T
The distance to a target is doubled. The time-of flight for a pulse to travel to the target and back is:
a. 4 times
b. 8 times
c. the same
d. 2 times
d. 2 times
If 3MHz sound has 2dB of attenuation in 1cm of tissue,
what is the amount of
attenuation of 6MHz
sound in 0.5cm of the same
tissue?
a. 5dB
b. 2dB
c. 10 d B
d. 1.5dB
b. 2dB
Volume has which of the following units?
a. cm
b. cm2
c. cm 3
d. cm 4
c. cm 3
Which of the following is proportional to the square of the amplitude?
a. period
b. attenuation
c. power
d. frequency
e. speed
c. power
What are typical clinical Doppler frequencies?
a. 1-10,000Hz
b. 1-10MHz
c. 2 - 1 , 0 0 0 k Hz
d. 40-45kHz
a. 1-10,000Hz
What Doppler angle is most inaccurate?
a. 15-30 degrees
b. 30-45 degrees
c. 45-60 degrees
d. 60-75 degrees
d. 60-75 degrees
Changing which of the
following would not cause any change in a hard copy image output?
a. TGC
b. overall gain
c. output power
d. display brightness & contrast
e. depth of view
d. display brightness & contrast
A quality assurance program:
a. is not needed in small labs
b. is very time consuming and expensive
c. is needed by all labs
d. cannot be
performed by sonographers
c. is needed by all labs
What is the actual time that an US machine is creating a pulse?
a. duty factor
b. period
c. pulse period
d. pulse duration
d. pulse duration
The angle of incidence of an US beam is perpendicular to an interface. The two media have the same propagation speeds. What process cannot occur?
a. refraction
b. reflection
c. transmission
d. attenuation
a. refraction
What component of the US unit contains the memory bank?
a. transducer
b. receiver
c. display
d. scan converter
d. scan converter
An US wave travels through two media and has attenuation of 3 dB in the first and 5 dB in the second. What is the total attenuation?
a. 15 dB
b. 8 dB
c. 3 / 5 dB
d. 5/8 dB
b. 8 dB
According to the AIUM
statement on bioeffects, there have been no confirmed bioeffects below intensities of watts per square centimeter SPTA.
a. 10
b. 0.01
c. 0.1
d.1
e.1 0 0
c. 0.1
Fill-in of an anechoic structure s u c h as a cyst is known as all of the following EXCEPT?
a. partial volume artifact
b. slice thickness artifact
c. section thickness artifact
d. ghosting artifact
d. ghosting artifact
What si the range of frequencies created by medical diagnostic Doppler transducers?
a. 4-10Hz
b. 10-20MHz
c. 1-10 kHz
d. 2-20Hz
e. 2 - 10MHz
e. 2 - 10MHz
(True or False) Doppler shifts
are always created when the
source and receiver are in motion relative to each other.
False
What is the significance of gray scale variation in the spectrum of a pulsed wave Doppler display?
a. it represents the number of
red blood cells creating the reflection
b. it represents the velocity of red blood cells
c. it represents the speed of red blood cells
d. it represents the convergence of red blood cell lamina
e. ti determines the ensemble length
it represents the number of
red blood cells creating the reflection
Which one of the following sets of properties of a test phantom is most relevant when assessing depth calibration accuracy?
a. reflector spacing and reflection coefficient
b. attenuation and speed of US in the medium
c. reflector spacing and US attenuation in the medium d. reflector reflection coefficient and US attenuation in the medium
e. reflector spacing and propagation speed
e. reflector spacing and propagation speed
From a safety stand point, which of the following methods is best?
a. low transmit output and high receiver gain
b. high transmit output and low receiver gain
c. high near gain and low far gain
.d low near gain and high far gain
e. high reject and high transmitter output
a. low transmit output and high receiver gain
The relative output of an US instrument is calibrated in dB and the operator increases the output by 60 dB. The beam intensity is increased by which of the following?
a. 5%
b. two times
.c twenty times
d. one hundred times
e. one million times
e. one million times
What is the most typical Doppler shift measured clinically?
a. 3.5MHz
b. 3,500,000Hz .
c 2kHz
d. 1,000kHz
e. 20,000Hz
c 2kHz
(True or False) Doppler shifts always occur fi the source and receiver are in motion relative to each other.
False
(True or False) Doppler shifts always occur fi the source and observer are in motion relative to each other and the angle between the mo
tion and the sound beam is 90°.
False
(True or False) Doppler shifts always occur fi the source and observer are in motion relative to each other and the angle between the motion and the sound beam is not 90 degrees.
True
When the sound source and
the receiver are not moving directly toward or away from each other, the angle b e t w e e n t h e m enters
into the calculation of Doppler shift.
a. average
b. slope
c. sine
.d cosine
.d cosine
The range equation relates distance from the reflector
to ——and ——-
a. time-of-flight, distance
b. frequency, wavelength
c. time-of-flight, propagation speed
d. propagation speed, density
c. time-of-flight, propagation speed
In soft tissue:
Distance traveled =
———- *round trip time
.a propagation speed
b. wavelength
.c period
d. PRF
a. propagation speed
What is another name for
longitudinal resolution?
a. axial
b. Depth
c. Lateral
d. Transverse
a. axial
b. Depth
With the presence of—— we see more boundaries than there are reflecting surfaces.
a. reverberations
b. shadowing
c. enhancement
d. arrays
a. reverberations
What is the name of the
receiver function that corrects
for attenuation?
Compensation
The process of reducing the difference between the
smallest and largest voltages
is called
Compression
If the lines per frame is
increased while the imaging
depth is unchanged then:
a. frame rate increases
b. number of shades of gray decreases
.c the frame rate decreases
d. this cannot happen
c. the frame rate decreases
