Spi physics review

I'm clinical imaging, the wavelength measures between

0.1 to 0.8mm

in tissues that contain well-defined gas bodies, no effects have been observed for in situ peak rarefactional pressures below a mechanical index value less than approximately

0.4

what is the duty factor of CW Doppler

1

The typical range of frequency for diagnostic ultrasound imaging is

1 to 20 MHz

no biologic effects have been observed for unfocused beam having a free field SPTA intensities below

100 me/cm>2

The duty factor for continuous wave ultrasound is

100%

What is the total amount of attenuation that occurs if a 6.0-MHz sound beam travels through 4 cm of soft tissue

12dB

Which of the following is considered the speed of sound in soft tissue

1540m/s

Which of the following would be considered ultrasonic

1MHz

no effects have been observed for an unfocused beam having thermal index value of less than

2

what is the point at which Reynolds number predicts turbulence

2000

a reflector is 20 mm away from the transducer. how long does it take for sound to get back to the transducer

26us

which of the following frequency shifts would exhibit aliasing if the PRF is 5000Hz

3.0kHz

a sound wave travels 26 us to a reflector. how far away is the reflector assuming the medium in soft tissue

4.0cm

Identify the wave that is ultrasonic

4MHz

a stenosis of 75% in area is equal to what percent of stenosis in diameter

50%

with 6 bits, what is the largest number of different shades of gray that can be stored

64

the Doppler shift is lowest at what angle to flow

90 degrees

If the angel of incidence is 40'degrees, Shay is the angle of transmission at the interface of medical 1 has a propagation speed of 1320 m/s and medium 2 has a propagation speed of 1700 m/s

>40'degrees

which of the following is an outdated test object that used an acrylic tank filled with fluid that attempted to stimulate the speed of sound in soft tissue

AIUM test object

The major component of attenuation is

Absorption

which of the following is not a credential granting body for sonographers

American Institute of Ultrasound Medicine

which of the following is not an accrediting agency of sonography lab

American Registry of Diagnostic medical sonography

The maximum value of minimum value of an acoustic variable minus the equilibrium value of that variable describes

Amplitude

An increase in pulse repetition frequency would lead to

An increase in duty factor

As a sound wave travels through the human body, the intensity of the sound wave decrease as a result of

Attenuation, scattering, and absorption

What is the ability of the ultrasound system to image structures that are positioned parallel to the sound beam as separate structure

Axial resolution

What provides the potential energy in the cardiovascular system

Beating heart

Which of the following would have the highest propagation speed

Bone

the only certifying agency that offers credentialing exams for cardiac and vascular testing

CCI

Areas of high pressure and density are referred to as

Compressions

read zoom is a function of the

D-to-A converter

the echo information is taken from the memory and converted so it can be shown on the display in th

D-toA converter

And imaging depth increases, the pulse repetition frequency must

Decrease

What does increasing the PRF/scale setting on a spectral Doppler do

Decrease the potential of aliasing

The inertia of the medium describes

Density

which test object uses a moving belt, vibrating string or a fluid pump

Doppler phantom

The percentage of time that the ultrasound system is producing pulses of ultrasound describes

Duty factor

What do waves transfer from one location to another

Energy

Which is determined by sound source only

Frequency

The prefix centi denotes

Hundredths

what states that waves are the result of the interference of many wavelets produced at the face of the transducer

Huygens's principle

What is another term for gravitational potential energy

Hydrostatic pressure

As imaging depth increases, pulse repetition period

Increases

If pulse repetition frequency increases, the duty factor

Increases

What is essentially equal to the power of a wave divided by the area over which the power is distributed

Intensity

What is the change in intensity of the power decreases by half

Intensity is halved

Density and propagation speed are

Inversely related

What is the change in power if the amplitude triples

It increase nine times

All of the following are true about stiffness

It is defined as the ability of an object to resist compression Increasing stiffness increases propagation speed Stiffness may also be referred to as elasticity

True of wavelength

It is determined by both medium and sound source It is inversely related to frequency It is directly related to period

Density is typically measured in

Kilograms per centimeter cubed

Transducers have material within them that, when electronically stimulated, produces ultrasound waves. This is most likely

Lead zirconate titanite

Which of the following would have the lowest propagation speed

Lung tissue

Sound is technically a

Mechanical and longitudinal

Which of the following is an appropriate unit of measurement for propagation speed

Milliliters per microsecond

Micro denotes

Millionth

Spatial pulse length can be calculated as

Multiplying the number of cycles times the wavelength

The attenuation coefficient in soft tissue is equal to

One half of the operating frequency

Pressure is typically expressed

Pascals

What is pressure measure in

Pascals or pounds per square inch

What is the name of the flat flow profile that is seen at the entrance of vessels

Plug flow

These are true about power

Power is proportional to amplitude squared Intensity is proportional to power Power is measured in milliwatts

Which of the following is defined as only the active time

Pulse duration

What is defined as the beginning of one pulse to the beginning of the next pulse. And Hereford includes both the "on" and "off" tkme

Pulse repetition period

The portion of the sound beam where molecules are pulled apart described an area of

Rarefaction

Camping of the sound beam

Reduces the spatial pulse length

The change in the direction of the original sound wave that occurs when sound interacts with two different tissue types that have a different propagation speed

Refraction

Which of the following describes the amount of refraction that occurs at an interface

Snell's law

If only the density of a medium increases, then the

Speed will decrease

Which of the following is described as the ability of an object to resist compression and related to the hardness of a medium

Stiffness

All the following are true of sound waves except

They are transverse

which of the following is representative of Ohm's law

V=IR

which of the following is a storage medium that uses a magnetic tape

VHS

All of the following relate to the strength of the sound wave except

Wavelength

Which is determined by sound source and medium

Wavelength

Which of the following is described as the distance over which one cycle occurs

Wavelength

which of the following is not a true statemtn

a larger aperture results in a shorter near zone lenght

which older mode is still used today in ophtalmology

a-mode

what is considered to be the primary reason why tissue heats as sound is attenuated in the human body

absorption

which of the following is a voluntary process that acknowledge an organizations competency and credibility according to standards and essentials set forth by a reliable source

accreditation

which of the following statement is not true concerning hand washing

alcohol-based hand rubs should be used to take place of hand washing

which of the following statements is false

aliasing does not occur with color doppler

which of the following is a technique used to reduce the presence of grating lobes

all the above

adjusting which of the following will have no effect on the measured frequency shift

amplitude

which of the following is not a synonym for axial resolution

angular

which of the following is the type of transducer that utilizes elements arranged in a concentric pattern

annular array

which types of transducers are no longer used

annular array transducers

which of the following is not a method of creating 3D images

annular array transduer

what term and philosophy relates the amount of exposure time for the sonographer and patient during a diagnostic ultrasound examination

as low as reasonable achievable

which of the following is not a characteristic of an unfocused single-element transducer

at the face of the transducer, the beam diameter is twice the size of the element thickness

which signal processing technique is used for color Doppler is not as accurate, but faster than the technique used for spectral doppler

autocorrelation

which resolution is best in clinical imaging

axial

which of the following is the ability to accurately identify reflectors that are arranged front to back and parallel to the ultrasound beam

axial resolution

in which mode is the strength of the reflector represented by the brightness of the dot

b-mode

which of the following shortens the length of the pulse by decreasing the number of cycles in the pulse

backin material

which of the following is the range of frequencies present within the beam

bandwidth

the strength of the voltage sent to each element is determined by the

beam former

provides the potential energy in the cardiovascular system

beating heart

a video display that is limited to only black and white, with no other shades of gray is called

bistable

which of the following would be best described as the failure of the hear to pump the proper amount of blood to the vital organs

cardiogenic shock

in the presence of a nonresponsive adult patient, which pulse should be evaluated

carotid

what is defined as the action of an acoustic field within a fluid to generate bubbles

cavitation

how are ultrasound transducers typically sterilized

cold-sterilization methods

as the sound beam travels it is attenuated. this explains the need to have which receiver function

compensation

what is the receiver function that adjusts the image because of the darker appearance of reflectors in the far field as a result of attenuation

compression

which type of interference results in a larger sound wave

constructive interferenec

which of the following transducers is not used for imaging

continuous-wave transducers

the AIUM test object can evaluate all of the following except

contrast resolution

what would be most likely means of transmission of tuberculosis from a patient to a sonogapher

coughing

which of the following electrical patterns produce electronic focusing of the ultrasound beam

curve

which of the following would be best utilized for imaging of deep stuctures in the abdomen

curved sequeneced array transducer

which of the following is the part of the transducer that stops the ringing of the element

damping material

which of the following is not true of damping

damping worsens axial resolution

what does increasing the PRF/scale setting on spectral Doppler do

decrease the potential of aliasing

which of the following would cause an increase in frame rate

decreased imaging depth

which of the following would not be considered a clinical complication of diabetes mellitus

decreased urine output

a proximal stenosis will look like what on the spectral waveform

delay in the systolic upstroke

which of the following would be decreased as a complication of diabetes that results from a severe lack of insulin, in which case the patients breath may have a sweet smell

diabetic ketoacidosis

in a standard cathode ray tube used to display ultrasound images, what are the charged particles that are emitted from a "gun" from the rear of the tube

electrons

which of the following is the resolution in the third dimension off the beam

elevational resolution

the health insurance portability and accountability act attempt to do all of the following except

encourage safe practices when dealing with patients; they also promote cleanliness in the health care setting

the useful artifact that one might se behind a weakly attenuating structure is

enhancement

which of the following best describes the components of the damping material

epoxy resin loaded with tungsten

which of the following is NOT a way in which venous blood is assisted in returning to the heart

expiration

some clinical manifestation of shock includes all of the following except

extreme thirst

which mathematical processing technique is used to analyze the data and produce a spectral waveform

fast fourier transform

the technique that uses made-up pixel information to replace areas between the scan lines where there is no actual signal information is

fill-in interpolation

Which of the following would be considered the narrowest part the sound beam

focus

the portion of the transducer that comes in contact with the patient is the

footprint

temporal resolution relates to relate to which of the following

frame rate

which of the following is not a component of spatial resolution

frame resolution

which of the following mat also be referred to as the far zone

fraunhofer zone

along with the crystal diameter, the divergence in the far field is also determined by which of the following

frequency

a technique that averages out the frequencies used to make the image to improve contrast resolution and reduce speckle is

frequency compounding

all of the following are true statements about the use of gloves except

gloves can be used to replace hand washing

personal protective equipment includes all of the following except

gluteraldehyde soaking solution

additional reflectors on the screen that are from extraneous sound waves off the primary axis of the beam

grating lobes

which of the following would not be considered a barrier technique

hand hygiene

which of the following would be considered the best way to prevent the spread of infection

hand washing

which of the following would not be considered a part of the classic presentation of cardiac arrest

headache

which of the following would not be considered a common virus that a health care worker would be exposed to

hepatitis k

A nosocomial infection is best described as

hospital-acquired infection

what is another term for gravitational potential energy

hydrostatic pressure

the diabetic syndrome characterized by excessive urination and dehydration is

hyperglycemic hyperosmolar nonketotic syndrome

when viewing sonographic images outside of the clinical arena, all of the following information are required to be removed except

image orientation

in a standing patient, where is the hydrostatic pressure the highest

in the feet

when a reflector moves toward the transducer, what will happen to the reflected frequency

increase

if the far field of the image is too dark, it is recommended that you

increase the receiver gain

which of the following would cause a decrease in temporal resoultion

increased line density

damping material produces all of the following exept

increased spl

which of the following will Not eliminate aliasing

increasing the frequency shift above the Nyquist limit

the output gain of the pulser determines the _____ of the acoustic pulse

intensity

which of the following could be a cause of anaphylactic shock

iodinated contrast agents

the harmonic signal

is produced by the patient

which of the following is false about color Doppler imaging

it can measure peak systolic and end diastolic velocites

in order to maintain flow as a constant, if the are of a vessel increases what must happen to the velocity

it decreases

which of the following is true of the diameter of the sound beam in the Fresnel zone

it decreases

what occurs as the Doppler angle is increased

it decreases the frequency shift

what can be said about the ensemble length of pulsed wave Doppler

it is about 10 to 20 pulses per scan line

which of the following is true about the frequency shift

it is in the audible range of sound

which of the following is true about the spectral Doppler envelope

it is thickened in the presence of turbulence

which of the following is true for continuous wave Doppler device

it must have at least two piezoelectric elements

what does the heart sterilization do to an ultrasound transducer

kills pathogens and destroys the transducer

human immunodeficiency virus is spread by all of the following means except

kissing

which of the following will decrease beam divergence in the far field

large crystal diameter, high frequency

which of the following will increase the near zone length

large crystal diameter, high frequency

which of the following transducers is also referred to as a sector or vector transducer

linear phased array

hepatitis denotes

liver inflammation

imaging transducers

low quality factors, wide bandwidths

which mode is interested in the movement of the reflectors along one scan line

m-mode

the part of the machine responsible for timing the reception of the pulses to determine their location is the

master synchronizer

which of the following facilitates the transmission of sound beam from the element into the patients skin

matching layer

the calculation used to assist in evaluating the likelihood of cavitation to occur is referred

mechanical index

nonthermal mechanisms may be also referred to as

mechanical mechanisms

which of the following transducers uses a motor for sterring the beam

mechanical transducers

sonographers should verify the patients wristband information for identifying markers. this includes which of the following

medial record number

which of the following would most likely manifest as a weeping skin lesion that is swollen and infected

methicillin-resistant staphylococcus aureus

sound bouncing off of a strong reflector and producing an image on the wrong location on the display is

mirror image artifact

in the exercising patient, the distal arterioles are dilated. what type of flow pattern would most likely be demonstrated on spectral Doppler within the proximal vessels

monophasic

what would be the most likely means of transmission of the human immunodeficiency virus from a patient to a sonographer

needle stick

which of the following would not be considered a transmission barrier that would help prevent the transporting of pathogens from the infected person to the general environment

needles

which of the following statements is true concerning the biologic effects of diagnostic ultrasound

no effects caused by exposure from present diagnostic ultrasound instruments have been reported in human patients in the absence of contrast agents

which of the following would not be a subcategory of distributive shock

nosocomial shock

along with the image depth, which of the following also determines the frame rate

number of lines per frame

which of the following would be most likely caused by an arterial stenosis

obstructive shock

what is the fewest number of crystals a PW Doppler device may have

one

in an unfocused, single-element transducer, the focal point of the sound beam measures how much of the total beam width

one half

which of the following may result if the spectral Doppler gain is too high

overmeasurment of the velocities

which of the following represents the resistive index

peak systolic velocity minus the end diastolic velocity divided by the peak systolic velocity

what is the component of the ultrasound machine used to detect positive versus negative frequency shifts

phase quadrature

which of the following produces a pie-shaped image

phased array

which of the following I defined as changing the timing of the shocking of the elements in order to shape and steer the beam

phasing

what is the name of the flat flow profile that is seen at the entrance of the vessels

plug flow

which of the following is required in order for a pathogen to be transmitted from one individual to another

portal of exit

which of the following occurs in the D-to-A converter

postprocessing

which type of Doppler does not rely on the frequency shift but instead relies on the strength of the shift

power doppler

which of the following has to be increased in order to see an increase in flow volume

pressure gradient

which of the following is a methodical way of evaluating equipment performance on a routine basis to ensure proper and accurate equipment function

preventive maintenance

if a patient does not speak English, or the national language, the sonographer should

provide an interpreter

when you adjust the output power control, you affect the following system component:

pulser

which of the following is defined as forces exerted by a sound beam on an absorber or reflector that can alter structures

radiation forces

which of the following is defined as the minimum distance two reflectors can be, parallel to the beam, and still appear on the screen as dots

range resolution

which part of the us machine does not affect the amount of energy entering the patient

receiver

what receiver function converts the negative portion of the signal to positive

rectifcation

which of the following tasks is incorporated in the process of demodulation

rectification

the part of the receiver that reduces low- level system noise is the

rejection

all of the following are goals for a quality assurance program except

report equipment malfunctions anually

an infectious agent needs to initially have which of the following to grow and survive

resevoir

an artifact that occurs when a sound beam bounces back and forth between two strong reflectors creating a step-ladder like appearance is

reverberation

Comprehensive preventative maintenance must be performed at least

semiannually

which of the following is the systems ability to detect weak echos

sensitivity

what term is defined as the bodys pathologic response to illness, trauma, or severe physiologic or emotional stress

shock

which of the following is a property of power doppler

signal is obtained by detecting amplitude of shift

an advantage of coded excitation is improved

signal-to-noise ratio

what type of errors will cause artificial echoes to appear within a cystic structure

slice thickness

you are using a transducer that produces a beam with a very wide elevational plane. which of the following problems are you most likely to encounter as a result

slice thickness artifact

which of the following is the test object that evaluates the elevation resolution, or the thickness portion, of the sound beam perpendicular to the imaging plane

slice thickness phantom

who among the following is responsible for ensuring an effective quality assurance program

sonographer

the maximum heating of tissue is related to the sound beams

spatial pulse temporal average

what is it called when an acoustic field causes motion of fluids

streaming

which of the following does the Doppler phantom not typically evaluate

subtle tissue differences

universal or standard precautions apply to all of the following except

sweat

in order to add more spectral Doppler waveforms to the display, what setting on the machine should be adjusted

sweep speed

which of the following is represented as time, or the ability to display structures in real time

temporal resolution

which type of resolution is an accurate representation of moving structures

temporal resolution

contrast resolution

the ability to see differences in shades of gray

what happens as the frequency of the transducer increases

the amount of scatter is increased

what is the name for the smaller amount of digital storage

the bit

in B-mode imaging, the stronger the return echo

the brighter the dot on the display

which of the following is not true o the linear sequenced array transducer

the elements are arranged in a ring

which of the following best described the frame rate

the frame rate is equal to the pulse repetition frequency divided by the lines per frame

when imaging in tissue harmonic imaging

the fundamental frequency is filtered out

which of the following is true concerning the frequency and the near zone length

the higher the frequency, the longer the near zone length

which of the following will be seen with a stationary reflector

the incident frequency is equal to the reflected frequency

artifacts related to propagation speed occur because

the machine assumes 1540m/s for all tissue

what does the brightness of the dots that make up the spectral display represent

the number of red blood cells present

in the exercising patient, what is the response to peripheral resistance with arteriolar dilatation

the peripheral resistance decreases

what is the smallest element in a digital picture called

the pixel

which of the following describes the result of destructive interference

the resulting wave is smaller than the orginial wave

which of the following best describes transient cavitation

the type of cavitation when larger bubbles are produced and subsequently rupture

which of the following is not a true statement about a mechanical transducer

there are no moving parts

which of the following is a true statement

there are two fields in a frame

which of the following is true about CW doppler

there is a large sample volume that obtains signals from all the vessels within

assuming flow is constant, what happens in a region of blood vessel narrowing

there is an increase in the velocity along with corresponding decrease in pressure

what happens to a digital image when the pixel density is increased

there is more spatial detail

what is said to occur when the window of the spectral Doppler display is filled in

there is spectral broadening

when compared to 2D graysale imaging, which of the following color Doppler statements is true

there is worse temporal resolution

what happens if blood flow is sampled in the center of laminar flow

there will be higher velocity than if sampled toward the edges

the calculation used to predict the maximum temperature elevation in tissues as a result of attenuation of sound is the

thermal index

the m-mode imaging, what is along the x-axis

time

all of the following are considered to be part of nonthermal mechanisms of biologic effects except

tissue heating

the test object that mimics the acoustic properties of human tissue and is used to ensure proper equipment performance

tissue-equivalent phantom

which of the following test phantoms should be stored in an airtight container and in a controlled temperature

tissue-equivalent phantom

sound waves through a large quantity of muscle tissue. the reflector will be displayed

too close to the transducer

which of the following is seen wit continuous-wave instrumentation

transducer frequency matches that of the oscillator

which of the following forms of cavitation has the most potential for inducing biologic damage

transient

what is the term for pressure difference between the inside of a vein and the tissue outside

transmural pressure

what must be known in order to calculate to a reflector

travel ,time, speed

a shadow occurs when sound

travels through an area of increased attentuation

what is it called when the 2D image, color Doppler image, and spectral Doppler are displayed simultaneously

triplex mode

which of the following is best described as an airborne disease that is spread by bacteria released from an infected individual when that person coughs, sneezes, speaks, or sings

tuberculosis

which of the following is not transmitted via contact with infectious blood or accidental needle sticks

tuberculosis

an image with one bit of memory has how many shades of gray

two

which of the following will result in aliasing

undersampling of the blood flow

which of the following would be considered one of the most common nosocomial infection

urinary tract infections

to produce a transducer with a higher frequency one should

use a thinner piezoelectric element

how does a cathode ray tube steer the charged particles emitted by the electron so that they sweep across the front screen

using a magnetic field

the test used to evaluate the depth of reflectors from a transducer is called

vertical depth calibration

which of the following indicates the maximum depth of visualization

vertical distance

the smallest component of a 3D image is the

voxel

the end diastolic component is missing on a spectral waveform. which of the following should be adjusted to fix this

wall filter

when is the Doppler shift highest

when the beam is parallel to the direction of flow

which of the following would be considered an advantage of a curved linear array over a phased array transducer

wider near field

which type of zoom offers a high quality zoom but must be selected while the image is live

write zoom