URR 4 Flashcards by Billie Harney

two areas are compared and one is less bright than the other, the tissue is less reflective than its comparison

hypoechoic

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two area are compared and one is brighter than the other; the tissue is more reflective than its comparison

hyperechoic

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aka echodense

hyperechoic

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Electronic focusing is used in addition to manufacturer set elevation place focus (lens)

focal zone position/number

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Is focal zone positioning/ number operator adjustable?

yes

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improves spatial resolution at the specified focal depth

focal zone position/number

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Multiple focal zones can significantly improve ____ resolution but will decrease _____ resolution

lateral
temporal

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_____ affects contrast resolution

dynamic range

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defined as the ratio of the smallest to the largest signal strength the system can receive and display properly

dynamic range

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describes the range of gray levels displayed on the image

dynamic range

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The ____ the dynamic range, the more shades of grey displayed on the image

larger

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Some vendors call this control of dynamic range, _____

compression

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Functionally, increasing the act of compression, will _____ dynamic range and the number of shades of grey displayed will be _____

decrease
reduced

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Functionally, decreasing the act of compression will _____ the dynamic range and the number of shades of grey will be _____

increase
increases

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Some vendors set their equipment functionality for compression as if it is like a volume know = turning it up ____ the feature and turning it down ____ the feature

increases
decreases

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Increasing depth requires ____ penetration which will ____ resolution

increased
reduce

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____ frequency probes offer the ability to scan deeper structures

lower

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number of images displayed per second

frame rate

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deeper imaging and multiple focal zones cause a ____ frame rate and will degrade ____ resolution

slower
degrade

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The ____ the structure you are imaging, the longer the time the pulse needs to reach it and return

deeper

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The pulses are emitted at a slower rate (lower ____) because they need to travel a longer distance

PRF

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If the pulses are transmitted and received at a slower rate, the rate that the image is produced will be ____

reduced

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Frame rates are ____ with a smaller field of view

higher

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Reducing the sector size will ____ the frame rate

increase

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can be applied prior to storage of image in the digital memory or before the image is "frozen"

pre-processing

Pre-procesing includes:

gray scale map color map edge enhancement 3D image acquisition

Allows the technologist to vary the echotexture of the displayed real time image

pre-processing

can be used on images stored in the digital memory and "frozen" images

post-processing

Post-processing includes the adjustment of:

gray scale map gain rejection dynamic range

Cine loop function is a _____ processing function

post

allows the technologist to manipulate images after they are captured

post processing

removal of low level echoes and non-diagnostic information

rejection

Does not affect "brighter" echoes, only low level reflection

rejection

Rejection is operator adjustable using the ___, ____, or ____ keys

reject threshold suppression

___ filter performs rejection function during Doppler evaluation

wall

aka compound imaging

spatial compounding

scan lines are electronically steered by transducer in different directions to evaluate structures using multiple pulses from several different angles

spatial compounding

Spatial compounding is only used on ____ arrays because it requires the ability to steer electronically

phased

During spatial compounding, frames are averaged together to improve:

signal-to-noise ratio

Spatial compounding reduces ___ and ___

speckle clutter

Spatial compounding improves ____ resolution

spatial

_____ resolution is degraded and frame rate is reduced due to increase in amount of reflected information that requires processing with spatial compounding

temporal

Spatial compounding reduces or eliminates ______

shadowing/enhancement

used for larger area/mass formations, extended FOV

panoramic view

used to demonstrate anatomy that will not fit on one single screen

dual screen

used for larger area/mass formations

trapezoidal FOV

image is shaded with color instead of greys

B-color

used to enhance a 2D image by accentuating certain shades in the image to assist in detecting subtle differences in tissues

B-color

microbubble contrast is used to enhance the Doppler signal from vessels

contrast imaging

During contrast imaging, AOI should be imaged for up to 1 minute or until:

peak arterial-phase enhancement

To evaluate washout during contrast imaging, imaging should then be performed at ___ minute and every ____ seconds until the ___ minute mark

1 30-60 6

3 phases of contrast imaging

arterial portal venous delayed

starts 10-20 seconds after injection and lasts 20-25 seconds

arterial

follows the arterial phase and lasts until approximately 2 minutes after injection

portal venou

from the end of portal venous phases until unequivocal clearance of microbubbles from circulation at 4-6 minutes

delayed phases

_____ imaging only displays the areas filled with contrast and removes surrounding structures

pulse inversion

Contrast imaging requires the use of ____, ____, and ____

harmonic imaging low mechanical index proper focal zone placement

____ MI settings with burst microbubbles

high

Especially helpful in evaluating benign liver masses, hemangioma, focal nodular hyperplasia, HCC, and liver mets

contrast imaging

Most benign masses demonstrate contrast enhancement during the ____ and ____ phase of circulation

arterial venous

Benign nodules usually demonstrate _____ enhancement

isovascular

Malignant tumors usually demonstrate _____ enhancement

hypervascular

Most malignant masses demonstrate contrast enhancement during the _____ phase, but rapid contrast washout during the _____ phase

arterial venous

Complications of contrast administration include:

vasovagal response anaphylactic shock

sudden hypotension and bradycardia, causes drop in blood flow to the brain, pallor, dizziness, syncope,

vasovagal response

feeling of impending doom, hypertension, tachycardia, sweating, erythema

anaphylaxis

Reflections are received and processed at twice the fundamental frequency

harmonic imaging

US system transmits at a _____ frequency

fundamental

Creating image using sound reflections at 2X the fundamental frequency

harmonic imaging

Harmonic frequency = ___ fundamental frequency

Harmonic imaging results from:

non-linear behavior of the sound waves

Harmonic imaging improves image ____ and ____ resolution for lower frequency transducers needed for penetration

lateral contrast

The harmonic beam is ____, ___ side lobes, ____ lateral resolution, ___ clutter, with ____ contrast resolution

narrower smaller better less improved

requires acquisition of images from 3 planes: sagittal, coronal, transverse

3D/4D imaging

3 planes used with 3D/4D imaging

sagittal coronal transverse

Manual acquisition of 3D/4D imaging requires the Sonographer to"

sweep through structure in three planes

Automatic acquisition in 3D/4D imaging requires:

dedicated 3D transducer

3D/4D imaging generates:

volume data sets

3D/4D imaging is used for:

volume rendering of mass for size and surface characteristics volume calculations of fluid filled structures

used to demonstrate solid cast of a structure (good for displaying vessels without surrounding tissues)

inversion mode

Always measure the ___, ___, and ___ dimensions of an organ or mass

length width AP

demonstrates average flow velocities

color Doppler

Flow direction with color Doppler is displayed according to"

color map

____ patterns indicate turbulence

Mosaic

Mosaic patterns indicate turbulence which can be caused by:

normal anatomy (bifurcation) abnormalities incorrect machine settings

Color visualization increases with ____ and ____

infection malignancy

adjusts the diplayed amplitude of the reflected sound waves from the flowing blood

Color gain

Proper color Doppler gain setting involves:

increasing gain until blossoming is noted and then decreasing to just below that level

Over-gaining color Doppler can lead to:

noise/flash artifact

The optimum angle between the sample box and the blood flow is ___ degrees or ____ to the flow

0 parallel

The ____ function is used to make the sample box more parallel to the flow

steering

adjusts the amount of flow evaluated in a specific location

sample volume width

____ sample sizes produce more accurate color Doppler information with faster frame rates and improved temporal resolution

smaller

used to evaluate flow in specific locations

sample volume depth

_____ superficial structures provide better color display with faster frame rates and improved temporal resolution

refers to the number of samples taken during evaluation

color packet size

_____ packets are higher line density but lower frame rates and decreased temporal resolution

larger

eliminates low frequency Doppler shifts from display

wall filter

used to reduce color ghosting

wall filter

used to demonstrate positive and negative shifts appropriately without aliasing

baseline