Quiz 4: Phantoms, QA, and Harmonics

what is the most likely part of the machine to break or degrade?

transducer

what are the two categories of QA devices

used to test instrument operation/performance

used to measure acoustic output

instrument operation/performance evaluates

diagnostic function

entire US system

acoustic output testing evaluates

bioeffects and safety

beam former and TDR

performance tests include

detail res

contrast res

penetration

DR

TGC

depth and distance accuracy

__________________ contain a circulation pump, vibrating strings, or moving belt

doppler phantoms

doppler phantoms are used to asses...

PW

CW

color doppler

power doppler

what are the different types of doppler phantoms

flow phantoms

string phantoms

vibrating plate (sensitivity) phantoms

what does a doppler phantom consist of

imaging face

medium

flow conduit

pump

reservoir

blood mimicking fluid

what can the flow phantom be used to eval

directional discrimination

flow velo

sensitivity

max pen

location of flow

a string phantom uses controlled movement of a ___________ via a motor to create ______________________

string

reproducible velocities

what can string phantoms be used to eval

PV accuracy

gate depth accuracy

spectral broadening

vibrating plate phantoms create a doppler signal by ________________ of US beam through small vibration of target plate

phase modulation

beam profile/slice thickness phantoms are used to evaluate ______________________________

elevational res

2D and 3D phantoms can be used to eval

detail res

sensitivity

contrast res

dead zone

dimensional measurement accuracy

when the transducer is placed at the top of the phantom _____________________ can be evaluated

axial res

when the traducer is placed at the side of the phantom ______________________ can be evaluated

lateral res

the multi-purpose tissue/cyst phantom can be used to test...

dead zone

detail res

depth accuracy

measurement accuracy

contrast res

penetration

The AIUM 100 mm test object measures

axial res

lateral res

caliper accuracy

dead zone

what is used to evaluate the dead zone

pins at the top of test object close to TDR

what is the tissue equivalent phantom used to eval

penetration tests

the tissue equivalent phantom is similar to _____________ parenchyma

liver

tissue equivalent phantoms contain properties similar to soft tissue such as

speed of sound

attenuation

scattering

echogenicity

what are tissue equivalent phantoms made of

graphite filled aqueous gels and urethane rubber

___________ is needed to obtain and maintain lab accreditation

QA

what are the five goals of QA

proper operation of systems

detect gradual changes in image quality

minimize downtime

reduce number of non-diagnostic scans

normal sensitivity

setting for QA testing so exams can be compared to eachother

what is the dead zone

region closest to the transducer where images are inaccurate

the dead zone extends from the ___________ to the ______________________

TDR to shallowest depth

higher FRQ TDR have _____________ dead zones

thinner

registration accuracy

place reflections in proper positions while imaging from different orientations

range accuracy

place reflectors at correct depths

HIFU testing phantom

high intensity focusing ultrasound

the ___________________ the slice the better the resolution

thinner

the AIUM suggest ______________________ calibration of equipment

annual

what is PM by sonographer

cleaning TDR/machines

checking cords are intact

routine cleaning of vent

Contrast agent increases the signal of blood by about ______________ when it is injected into the heart or blood vessels

30dB

Pulse inversion ____________ the pulses and ___________ them together

inverts

adds

Harmonics is better in the __________ field but is even better at the ___________ and will optimize ___________ resolution significantly

mid

focus

lateral

Harmonics is used during the _____________________ NOT during ______________________

transmission

receiving

The second harmonic

what is used when creating the image which is double what we started with

Static elastography is used with _______________________ and seeing how a mass respond to it

transducer compression

High intensity focused ultrasound is

purposely using high intensity beams to destroy masses

Cancers are __________ when looking at elastography

stiff

Cystic masses are likely ____________

benign

volume dataset

series of 2D image slices complied together to form a 3D image

2D

single slice; 2 dimensions vertical and horizontal

3D images are created by

stacking a series if 2D images into a volume dataset

the 3D image is the ________________ of the stacked 2D images

depth

4D is the..

live acquisition of volume datasets

the forth dimension is _____________

time

4D is also known as

real time 3D sonography

3D and 4D technology provides

more information for better diagnoses

if you have artifact in the 2D image you will have artifact in __________-

3D

you should make sure that your ROI box is only covering the _________________

area of interest

use of contrast agent increases the ______________________________

acoustic impedance mismatch

harmonica allows the TDR to receive at _____________ FRQ and transmit at a ___________________ FRQ

high

low

higher FRQ = ____________ penetration

less

lower FRQ = ____________ resolution

less

A harmonic image is produced by transmitting at 1.5 MHz and receiving at __________________

3MHz

A harmonic image is produced by transmitting at 2MHz and receiving at __________________

4MHz

in order to use harmonics you need a _____________________ TDR

broadband

how is harmonics produced?

non-linear (based in how US wave travels)

the harmonic beam is much ___________________ which means...

thinner

it will pick up less noise in the nearfield and improve lateral resolution

harmonic signals reduce energy in ____________________

grating lobes

harmonic imaging reduces _____________________ and ___________________

clutter and reverberation artifact

S-harmonics on the samsung machine uses _________________________ which overcomes the ______________________ degradation

pulse/phase inversion

axial res

normal harmonics ________________ PD which _________________ axial res

increases

decreases

harmonics helps to improve the ______________________-

signal to noise ratio

contrast harmonics

harmonic signals from microbubbles introduced into the body via contrast agent

what are the advantages of harmonics

improved lateral resolution

improved signal to noise ratio

less clutter

less reverberation

less grating lobes

what are the disadvantages of harmonics

decreased axial resolution

how does virtual beamforming work?

all elements are fired at once creating a broad unfocused pulse then restrospective software receives large returning data and processing it through GPU

GPU

postprocessing graphics unit

virtual beamforming overcomes

beam divergence

slice thickness

beam breakage

lobe artifacts

what are the benefits of virtual beamforming

detail res

contrast res

temporal res

increased FR

improved sensitivity

improved penetration

reduces artifacts

virtual beamforming uses

big data > enhanced DSP > bit-by-bit frame creation

porelastography

images capture fluid motion in tissues

-used in lymphatic clinics

elastography is most commonly used in

breast

HIFU can be used for

focal drug delivery

destroy tumor tissue

destroy fat tissue