Ultrasound Physics Test Prep

Practice, practice, practice for the boards!

The mass (weight) you are imaging has a diameter of 35mm. This value can also be expressed as:

a. 350cm

b. 0.35cm

c. 3.5cm

d. 35m

e. 3.5m

c. 3.5cm

Which of the following is listed in increaseing order?

a. micro, milli, deci, kilo, mega

b. centi, milli, kilo, mega, nano

c. micro, kilo, milo, deci, mega

d. mega, kilo, milli, nano, centi

a. micro, milli, deci, kilo, mega

Which of the following sound waves is ultrasonic and most useful in diagnostic ultrasound?

a. 16,000 MHz

b. 5,000 Hz

c. 4 MHz

d. 1 MHz

4 MHz

Which of the following is not true regarding sound waves?

a. may be inaudible

b. carries energy from one location to another

c. transverse

d. comprised of compressions and rarefactions

c. transverse

What is a cyclical region of high density?

a. rarefaction

b. pascal

c. compression

d. power

c. compression

With regard to amplitude, all of the following are true except:

a. amplitude may have units of decibels

b. amplitude is related to power

c. amplitude is related to intensity

d. amplitude is the difference between the maximum and the minimum values of an acoustic variable

d. amplitude is the difference between the maximum and the minimum values of an acoustic variable

A sonographer adjusts the output of an ultrasound system by increasing the amplitude by a factor of 3. Which of the following statements is true?

a. power is increased by a factor of 3

b. power is increased by a factor of 9

c. frequency is increased by a factor of 9

d. intensity is increased by a factor of 3

b. power is increased by a factor of 9

Which of the following sound waves is audible?

a. 2 Hz

b. 9 MHz

c. 2,000 kHz

d. 4 kHz

d. 4 kHz

How many kilograms are contained in 40,000 grams?

a. 400

b. 4

c. 4,000

d. 40

d. 40

Which of the following best describes the interference of a pair of waves that are in phase?

a. inverted

b. constructive

c. huygens

d. duty factor

b. constructive

Which of the following parameters is determined by both the ultrasound system as well as the tissue through which the sound wave travels?

a. period

b. frequency

c. speed of sound

d. wavelength

d. wavelength

In soft tissue, what is the wavelength of 3MHz sound?

a. 2 seconds

b. 0.5 mm

c. 3 MHz

d. 1.5 millimeters

0.5 mm

Which term does not belong with the others?

a. decreased depth of view

b. decreased PRP

c. increased PRF

d. low duty factor

d. low duty factor

Soundwaves weaken in intensity, power and amplitude as they travel through the body. This process is known as:

a. negative decibels

b. backscatter

c. logarithims

d. attenuation

d. attenuation

Incidence refers to the angle that a sound wave hits a boundary. All of the following are types of incidence except:

a. normal

b. oblique

c. parallel

d. perpendicular

c. parallel

This term refers to the bending or change in direction of the sound beam as it propagates from one medium to another:

a. refraction

b. incidence

c. reflection

d. diffusion

a. refraction

Distance that a soundwave travels and attenuation are ____ related.

a. proportionally

b. directly

c.indirectly

d. not

b. directly

______ is the largest component of attenuation in which ultrasound energy is converted to another energy form, such as heat.

a. rayleigh scattering

b. decibels

c. absorption

d. impedance

c. absorption

True or false: sound needs a medium to travel, it cannot travel through a vacuum.

True

Acoustic ______ are used to describe the features of a sound wave.

a. factors

b. parameters

c. frequencies

d. effects

b. parameters

This feature of a soundwave is reported in units of time.

a. frequency

b. wavelength

c. intensity

d. period

d. period

The “Bigness” features of a sound wave all describe the strength or magnitude of the wave. All of the following are “ Bigness” features except:

a. speed of sound

b. amplittude

c. power

d. intensity

a. speed of sound

One feature of a sound wave is determined by both the source (transducer) and the medium. The equation for this feature is appropriately C/F. What is this feature?

a. period

b. wavelength

c. frequency

d. speed of sound

b. wavelength

In diagnostic ultrasound, continuous wave sound cannot create anatomic images, therefore ______ of acoustic energy are used to create every picture of anatomy.

a. stream lines

b. pulses

c. nyquist packets

d. power currents

b. pulses

All of the following are parameters of imaging transducers except:

a. propogation speed

b. duty factor

c. spatial pulse length

d. pulse duration

a. propogation speed

The time from the start of a pulse to the end of that pulse is termed:

a. frequency

b. period

c. pulse duration

d. velocity

c. pulse duration

True or false: by adjusting the depthof view of an ultrasound image, the sonographer can change some parameters of pulse wave sound such as PRP and PRF.

True

True or false: pulse repetition frequency and transducer frequency are the same thing.

False

This component of the ultrasound system determines the amplitude, pulse repetiton period, and pulse repetiton frequency of the ultrasound pusles.

a. transducer

b. pulser

c. recevier

d. master synchronizer

b. pulser

All of the following could be adjusted to change the overall image brightness except:

a. master synchronizer

b. pulser

c. transducer output

d. reciever gain

a. master synchronizer

Images with the highest accuracy are those with:

a. high signal to noise ratio

b. low signal to noise ratio

c. low thermal index

d. low mechanical index

a. high signal to noise ratio

Amplification, compensation, compression, demodulation, and reject are all function performed in the:

a. transducer

b. pulser

c. receiver

d. master synchronizer

c. receiver

True or false: to follow the ALARA principle, the sonographer should first adjust the output power when an image is too bright.

True

This term describes flow that is moving in steady streamlines that are aligned and parallel. This flow is typically found in normal physiologic states throughout the body.

a. turbulent

b. laminar

c. reynolds

d. eddy currents

b. laminar

According to the Bernoulli principles, the velocity of blood will be the highest at the narrowest part of a vessel but ______ will be the lowest.

a. pressure

b. turbulence

c. friction

d. pulse duration

a. pressure

To obtain an accurate measurement of a patient’s blood pressure we try to take it at the same level as the patient’s heart, or with them lying down. This is to eliminate the effects of:

a. ohm’s law

b. inertial energy loss

c. hydrostatic presssure

d. plug flow

c. hydrostatic pressure

When blood cells are moving towards the transducer the reflected frequency is higher than the transmitted frequency. This will result in:

a. a positive doppler shift

b. a negative doppler shift

c. no detectable doppler shift

d. a bidirectional doppler shift

a. a positive doppler shift

What happens to the venous flow in the legs during inspiration?

a. increases

b. decreases

c. reverses

d. no change

b. decreases

True or false: the terms speed and velocity mean the same thing.

False: speed is magnitude only, while velocity includes direction.

The ______ is the highest doppler frequency or velocity that can be measured with the appearence of aliasing.

a. reynolds number

b. ohm’s law

c. nyquist limit

d. doppler shift

c. nyquist limit

Color doppler can tell the sonographer all of the following except:

a. flow direction

b. mean velocity

c. flow pattern (laminar vs. turbulent flow)

d. blood viscosity

d. blood viscosity

A doppler angle of 90 degrees will result in:

a. the highest measurable doppler shift

b. the lowest measurable doppler shift

c. no doppler shift

d. an aliasing doppler shift

c. no doppler shift

If this image is seen while performing a color doppler exam, the control that should be adjusted:

a. color gain

b. volume

c. 2D gain

d. color baseline

a. color gain

Certain materials create a voltage when a pressure is applied to them. This is called the:

a. piezoelectric effect

b. damping element

c. low quality factor

d. curie point

a. piezoelectric effect

True or false: An imaging transducer with a main frequency of 3 MHz likely produces a sound pulse that contains frequencies ranging from 1MHz to 5 MHz.

True

Which method is recommended for cleaning the ultrasound transducers?

a. heat sterilization

b. chemical disinfection

c. increasing temperature to the curie point

d. we should never clean a transducer

b. chemical disinfection

Which of the following is not a region found in a sound beam?

a. fresnel zone

b. snell zone

c. focal zone

d. fraunhofer zone

b. snell zone

Which of the follwowing explains why a sound beam created by a transducer is hourglass shaped?

a. bernoulli’s principle

b. sheffield’s law

c. ohm’s law

d. huygens’ principle

d. huygens’ principle

With laminar flow, where is the blood velocity the highest?

a. at the boundary between the blood and the vessel wall

b. at the entrance to a stenosis

c. at the point of boundary layer separation

d. in the center of the lumen

d. in the center of the lumen

Which of the following signals is most likely to alias?

a. 9 MHz continuous wave sound

b. 2 MHz continuous wave sound

c. 2 MHz sound with a PRF of 3 kHz

d. 7 MHz sound with a PRF of 3 kHz

d. 7 MHz sound with a PRF of 3 kHz

All of the following describe or associated with pulsed wave doppler except:

a. aliasing

b. range specificity

c. transducer with a minimum of 2 active elements

d. limit on the highest doppler frequency that can be accurately measured

e. nyquist frequency

c. transducer with a minimum of 2 active elements

While performing doppler interrogation of a vessel aliasing is seen. Which of the following steps should the sonographer take to rid the display of aliasing?

a. change to a continueous wave transducer from a pulsed wave transducer

b. use a higher frequency transducer

c. relocate the transducer so that the beam is parallel to the direction of flow

d. relocate the sample volume further from the transducer

e. zero baseline shift

a. change to a continuous wave transducer from a pulsed wave transducer.

Blood is moving thriugh the hepatic artery with a velocity of 2m/s. A 9 MHz transducer is used, and measures a doppler shift of 1.5 kHz. Then a 3 MHz transducer is used instead. What doppler frequency will be measured?

a. 1.5 kHz

b. 0.5 kHz

c. 2 m/s

d. 2 MHz

b. 0.5 kHz

Which of the following flow patterns is associated with murmurs, bruits, and thrills?

a. smooth

b. turbulent

c. pulsatile

d. laminar

b. turbulent

Which of the following characteristics best describe a velocity mode map?

a. the right side of the map is a different color from the left side

b. the colors vary from top to bottom and side to side

c. colors vary from side to side but not top to bottom

d. colors vary from top to bottom but not from side to side

d. colors vary from top to bottom but not from side to side

All of the following optimize the accuracy and reduce the likelihood of artifacts in a clinical doppler examination except:

a. decreases the PRF

b. increase the nyquist limit

c. shallower sample volume depth

d. 0 degree angle between the sound beam and the flow direction

a. decreases the PRF

Whats the direction of flow in this picture?

a. right to left

b. left to right

c. turbulent flow

d. cephalad to caudal

b. left to right

During a doppler exam, a sound beam reflects off of red blood cells. What’s the term for the process used to extract the doppler frequency from the high- frequency component of the reflected sound beam?

a. refraction

b. demodulation

c. angle correction

d. TFT

b. demodulation

Which of the following techniques is used to analyze continuous wave doppler and why?

a. autocorrelation, because it’s the most accurate

b. FFT, because it’s the most accurate

c. autocorrelation, because it’s fastest

d. FFT, because it’s computer based

d. FFT, becsause it’s computer based

Which of the following features would result in increased resistance to flow?

a. impedance

b. viscosity

c. incidence

d. intensity

b. viscosity

Which of the following reynold’s number is associated with turbulent flow?

a. 60

b. 2,400

c. 425,000

d. 1,200

b. 2,400

What is the maximum velocity limit without aliasing for a 3 MHz CW doppler unit operating at a depth of 4 cm?

a. 40cm/s

b. 200cm/s

c. 2.5m/s

d. 4m/s

e. none of the above

e. none of the above

You will see aliasing of the doppler spectrum occurs whenever the frequency shift exceeds:

a. twice the pulse repetition frequency

b. three times the pulse repetition frequency

c. one-third the pulse repetition frequency

d. one-half the pulse repetition frequency

e. one-fourth the pulse repetition frequency

d. one-half the pulse repetition frequency

What would be the most likely result from increasing the transmit frequency of the color doppler?

a. improved sensitvity to slow flow

b. improved penetration for imaging flow in deep tissues

c. reduced color doppler aliasing

d. improved visibility of complex flow hemodynamics

a. improved sensitivity to slow flow

What information does the z-axis (brightness) on the doppler spectrum provide?

a. velocity

b. bandwidth

c. amplitude

d. frequency shift

c. amplitude

What doppler technique does not provide range resolution?

a. color doppler

b. power doppler

c. pulsed wave doppler

d. continuous wave doppler

e. no doppler techniques can provide range resolution

d. continuous wave doppler

The doppler frequency shift is defined:

a. the difference between the doppler frequency and the imaging frequency

b. the difference between the transmitted and received frequencies

c. the time between the transmit and received pulses

d. the number of pulses per second

b. the difference between the transmitted and received frequencies

You are performing a carotid duplex exam with the following parameters: 5 MHz doppler frequency, 6 kHz PRF, 4 cm depth and 1.5 mm sample volume length. What is the aliasing frequency?

a. 6 kHz

b. 12 kHz

c. 3 MHz

d. 3 kHz

d. 3 kHz

When you switch from a 2.5 MHz to a 5 MHz transducer, the sound wavelength:

a. doubles

b. quadruples

c. halves

d. quarters

c. halves

If the number of cycles in a pulse is increased but the wavelength remains the same, which of the following is true?

a. the frequency is increased

b. the propagation speed is increased

c. the pulse duration is increased

d. the period is decreased

e. the bulk modulus is decreased

c. the pulse duration is increased

Which of the following represents the number 1234 in scientific notation?

a. 0.1234

b. 0.1234 × 10³

c. 1234 × 10^1

d. 1234 × 10

e. 1234 × 10³

e. 1234 × 10³

Which of the following terms denotes the time it takes for one cycle to occur?

a. frequency

b. amplitude

c. wavelength

d. period

e. pressure

d. period

The sound propagation speed in soft tissue is assumed to be:

a. 1.54 mm/µs

b. 1540 mm/s

c. 1.54 km/ms

d. 1540 mm/s

e. 154,000 cm/µs

a. 1.54 mm/µs

Which of the following would increase the spatial pulse length?

a. increased PRF

B. decreased number of transmit pulses per frame

c. increased number of transmit pulses per second

d. increased number of transmit pulses per line

e. increased number of cycles per pulse

e. increased number of cycles per pulse

In which of the following is the velocity of sound the lowest?

a. bone

b. tendon

c. amniotic fluid

d. kidney

c. amniotic fluid

A sound wave is propagating in soft tissue. The wavelength is 0.77 mm. What is the frequency of the sound beam?

a. 77 MHz

b. 1.54 MHz

c. 2 MHz

d. 2 kHz

c. 2 MHz

Which prefix equals 10^-6 ?

a. micro

b. milli

c. mega

d. centi

e. none of the above

a. micro

A sonographer is scanning a pt with a 3 MHz probe and then replaces it with a 6 MHz probe. All of the following statements are false except:

a. the 3 MHz beam will have a longer wavelength than the 6 MHz beam

b. the 6 MHz beam will have a longer period than the 3 MHz beam

c. the 6 MHz beam will travel at a lower speed than the 3 MHz beam

d. the 3 MHz beam will have a higher frequency than the 6 MHz beam

a. the 3 MHz beam will have a longer wavelength than the 6 MHz beam

Which of the following terms describes deep imaging?

a. increased PRF

b. High duty factor

c. long PRP

d. decreased depth of view

c. long PRP

When you change the transmit frequency, which of the following is altered?

a. displacement amplitude of the particles in the medium

b. speed at which the sound wave propagates through the medium

c. number of cycles per second

d. pulses transmitted per second

c. number of cycles per second

The rapid technique used in most color doppler systems to process and display the mean doppler frequency shift is:

a. fast fourier transform

b. phase quadrature

c. autocorrelation

d. variance

c. autocorrelation

Given the image, is the flow being sampled by the doppler sample gate moving towards or away from the transducer?

Towards

Regarding this image, the angle of the beam to the vessel is approximately:

a. 0 degrees

b. 60 degrees

c. 90 degrees

d. 45 degrees

c. 90 degrees

What info is colorized in an image using power doppler?

a. flow velocity

b. doppler signal amplitue

c. frequency bandwidth

d. acoustic power

b. doppler signal amplitude

According to Poiseuille’s equation, what will happen to flow if pressure difference increases?

a. flow rate will increase

b. flow will become pulsatile

c. flow rate will decrease

d. flow will become turbulent

a. flow rate will increase

If you increased the doppler angle during an exam what would be the expected result?

a. doppler frequency shift would decrease

b. aliasing would be increased

c. flow velocity would increase

d. sound velocity would increase

a. doppler frequency shift would decrease

This term describes the ability to create accurate images.

a. focus

b. pulse inversion imaging

c. spatial pulse length

d. resolution

d. resolution

The best image quality comes from what frequency transducer?

a. high

b. low

c. intense

d. less than 20 hertz

a. high

Which of the following is not a type of resolution?

a. fixed

b. lateral

c. transverse

d. axial

a. fixed

Focusing ____resolution.

a. degrades

b. intensifies

c. improves

d. shortens

c. improves

True or false: while scanning the sonographer can actively adjust (change) axial resolution.

False; axial resolution is determined by the spatial pulse length and is not actively adjustable by the sonographer during scanning.

The ability to distinguish two structures lying close together front-to-back or parallel to the sound beam is ______.

a. axial resolution

b. lateral resolution

c. temporal resolution

d. spatial resolution

a. axial resolution

If there are more cycles in a pulse, the numerical value of range resolution is

a. greater

b. lesser

c. the same

a. greater

If a new pulsed transducer has many more cycles in it’s pulse, the image accuracy

a. improves

b. degrades

c. remains the same

b. degrades

(high or low) frequency transducers generally have the best range resolution?

High

Which transducer has the poorest axial resolution?

a. 1.7 MHz and 4 cycles/pulse

b. 2.6 MHz and 3 cycles/pulse

c. 1.7 MHz and 5 cycles/pulse

2.6 MHz and 2 cycles/pulse

c. 1.7 MHz and 5 cycles/pulse

In soft tissue, 3 MHz transducer has a 3 cycle pulse and a pulse length of 1.5 mm. What id the axial resolution?

a. 3 mm

b. 1.5 mm

c. 0.75 mm

d. 6 mm

c. 0.75 mm

What is the lateral resolution at a depth of 8cm?

4.5 mm. At the end of the near zone, the beam diameter is one-half the transducer diameter.
Ch. 10 pg. 151

What is the lateral resolution at a depth of 16 cm?
a. 1cm
b. 9mm
c. 5mm
d. 14mm

b. 9 mm. At a depth of twice the near zone, the beam is as wide as the transducer.
Ch. 10 pg. 151

What is the best estimate for the resolution at 7 cm?
a. 1cm
b. 9mm
c. 5mm
d. 14mm

c. 5mm
Ch. 10 pg. 151