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Flashcards in System reverse Deck (44)
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1
reverse

basicas are interchangable between manufactureres

reduces scan time in a clinical setting

know your controls

Knobology

2
reverse

varies energy transmitted to patient

should be used at lowest level

ALARA limit

higher power=brighter image

Acoustic power/transmit power

3
reverse

operator controlled

determines electrical voltage to pulsar

low voltage=gentle PZT vibration

high voltage=forceful vibration

transmit power controls

4
reverse

creates electrical signals that excite the PZT crystals

only functions during transmission

operator controlled

0-500 volts

important in Bioeffects

Pulsar

5
reverse

0-500 volts

high =brighter image

also called output gain, accoustic power, energy output or transmitter output

Pulsar voltage

6
reverse

Thermal Index

Mechanical Index

Pulsar Standardization

7
reverse

random and persistant degradation

unwanted low level echoes

 

Noise

8
reverse

power increase raises ratio

quiality improves with increase

Signal to Noise ratio

9
reverse

determines time between voltage spikes

PRP Pulse repition Period

controlled by operator

 

pulser repitition

10
reverse

determines depth of scan

operator controlled

Pulse Repitition Period

PRP

11
reverse

continuous wave

vascular

Pulser single pulse

12
reverse

pulsed wave

imaging

Pulser numerous pulses

13
reverse

shorter listening time

shorter PRP

higher PRF

Shallow imaging 

14
reverse

longer listening time

longer PRP

lower PRF

Deeper imaging

15
reverse

recieves the electrical spike from pulser and distributes to the active elements in an array transducer

used advanced microprocessor tech to produce digital format

Bean Former

16
reverse

proteects the electrical components in the reciever

 

Beam Former Switch

17
reverse

prepares information from returning echoes for display

5 functions

 

Reciever

18
reverse

Amplification

Compensation

Compression

Demodulation

Reject

5 reciever functions

19
reverse

first function

affects all signal quality

receiver gain

measured in dB

adjustable

Gain/Overall Gain knob

Amplification

20
reverse

controls degree of echo amplification or brightness or image

too much can fill artifactual echoes into a fluid structure

too little can negate echo information

Gain Overall Gain

21
reverse

creates and image of uniform brightness

known as TGC Time Gain Compensation

DGC Depth Gain COmpensation

sompensates for the sound wave as it weakens or attentuates

Compensation

22
reverse

operator controlled

sliders on console

structures will be same brightness regardless of depth

TGC

DGC

23
reverse

3rd function

keeps image grayscale content with range of human eye (20 shades)

keeps electrical signal level within accuracy range

called log compression or dynamic range (DR) most common

dB

operator controlled

Compression

24
reverse

relative term that compares on one signal to another

important in quantifying strenght of sound beams, electrical signal strenght and brightness of image

notatoin is logarithmic

 

Decibels dB

25
reverse

4th function

two part process that changes electrical signals in reciever into a more suitable form for the CRt or monitor

rectifies and smooths electrical signal

NOT adjustable

no effect on image

Demodulation

26
reverse

5th function

controls whether low level signals will be displayed

low leve signasl can be diagnostic or noise

called threshhold or suppression

operator controlled

Reject

27
reverse

Adjustable

all signals affected identically

entire image gets brighter or darker

Amplification overview

28
reverse

Adjustable

signals treated differently bases on reflective depth

images will be uniformly bright from top to bottom

Compensation Overview

29
reverse

Adjustable

Signals treated differently depending on strenght

changes grayscale mapping

Compression Overview

30
reverse

NOT adjustable

prepares electrical signals to be suitable for display

NO effect on image

Demodulatoin Overview