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Flashcards in Chapter 4 Deck (57)
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1
Q

A-Mode

A

mode of operation in which the display presents echo amplitude versus depth

2
Q

Amplification

A

the process by which small voltages are increased to larger ones

3
Q

amplifier

A

a device that accomplished amplification

4
Q

analog

A

related to a procedure or system in which data are represented by proportional, continuously variable, physical quantities

5
Q

analog-to digital converter

A

a device that converts voltage amplitude to a number. ADC

6
Q

B mode

A

mode of operation in which the display presents a spot of appropriate brightness for each echo received by the transducer

7
Q

B scan

A

a B-mode image that presents an anatomic cross section through the scanning plane

8
Q

bandpass filter

A

see other

9
Q

beam former

A

the part of an instrument that accomplishes electronic bean scanning, apodization, steering, focusing, and aperture with arrays.

10
Q

bistable

A

having two possible states

11
Q

Bit

A

binary digit; one or zero

12
Q

channel

A

a single one or two way path for transmitting electric signal, in distinction from other parallel paths

13
Q

Cine loop

A

sequential display of all the frames stored in memory at a controllable frame rate

14
Q

coded excitation

A

a sophisticated form of transmission in which the driving voltage pulses have intrapulse variations in amplitude, frequency, and or phase

15
Q

compensation

A

equalization of received echo amplitude difference cause by different attenuations for different reflector depths

16
Q

compression

A

reduction in difference between small and large amplitudes. region of high density and pressure in a compressional wave.

17
Q

contrast resolution

A

ability of a gray scale display to distinguish between echoes of slightly different intensities

18
Q

demodulation

A

detection

19
Q

Depth gain compensation

A

see compensations. DGC

20
Q

detection

A

conversion of voltage pulses from radio frequency to video form.

21
Q

digital

A

related to a procedure or system in which data are presented by numeric digits

22
Q

digital to analog converter

A

a device that converts a number to a proportional voltage amplitude

23
Q

display

A

a device that presents a visual image derived from voltages received from an image processor

24
Q

dynamic range

A

ration of largest to smallest power that a system can handle, ration of the larges to smallest intensity of echoes encountered.

25
Q

elastrography

A

imaging tissue stiffness by tracking movement under mechanical stress

26
Q

flat-panel display

A

a back-lighted rectangular matrix of thousands of liquid crystal display elements.

27
Q

frame

A

a single image produced by one complete scan of the sound beam

28
Q

frame rate

A

number of frames of echo info stored each second

29
Q

gain

A

ratio of amplifier output to input electric power

30
Q

gray scale

A

range of brightnesses between black and white

31
Q

image memory

A

the part of the image processor where echo info is stored in image format

32
Q

image processor

A

an electronic device that manipulates and prepares image for visual presentation

33
Q

lateral gain control

A

gain controls that enable different gain values to be applies laterally across an image to compensate for differing attenuation values in different anatomic regions

34
Q

M mode

A

a B-mode presentation of changing reflector position versus time. (Motion)

35
Q

panoramic imaging

A

the extension of the field of view beyond the normal limits of a transducer scan plane

36
Q

persistence

A

averaging sequential frame together

37
Q

PACS

A

the system provides means for electronically communicating image and associated info to work stations and devices external to the sonographic instrument, the examining room, and even the building in which the scanning is done.

38
Q

pixel

A

picture element; the unit into which imaging info is divided for storage and display in a digital instrument

39
Q

postprocessing

A

image processing done after storage in the memory

40
Q

preprocessing

A

signal and image processing accomplished before storage in the memory

41
Q

radio frequency

A

voltages representing echoes in cyclic form

42
Q

real time

A

imaging with a rapid frame sequence display

43
Q

real time display

A

a display that, which a sufficient frame rate, appears to image moving structures or a changing scan plane continuously.

44
Q

refresh rate

A

the number of times each second that info is sent from the image memory to the display.

45
Q

scan line

A

a line produced on a display that represents ultrasonic echoes returning from the body.

46
Q

scanning

A

the sweeping of a sound beam through the anatomy to produce an image

47
Q

shear wave

A

see transverse wave

48
Q

signal

A

the physical representation of a message or info

49
Q

signal processer

A

an electronic device that manipulates electric signal in preparation for appropriate presentation of info contained in them

50
Q

spatial compounding

A

averaging of frames that view the anatomy from diff angles

51
Q

strain

A

the increase or decrease of the length of segment of a material, subjected to a stress, divided by its original lengh

52
Q

stress

A

a force per unit area applied to a material that compresses or stretches it

53
Q

temporal resolution

A

ability to distinguish closely spaced events in time, improves with increased frame rate

54
Q

TGC

A

equalization of echo amplitude differences caused by different attenuation for different reflector depths

55
Q

volume imaging

A

3D imaging

56
Q

young’s modulus

A

a measure of the hardness of a material . is it the ration of applied stress to the resulting strain in a material subjected to the stress.

57
Q

Freeze-rate

A

constant display of one of the frames in memory.