Echo Instrumentation Flashcards Preview

Physics SON-111AB-2B1 > Echo Instrumentation > Flashcards

Flashcards in Echo Instrumentation Deck (32)
Loading flashcards...
1
Q

Amplification

A

Also known as receiver gain or overall gain, which increases amplification at all depths

2
Q

Analog

A

describes a device or system that represents changing values as continuously variable physical quantities

3
Q

Analog-to-Digital Converter

A

convert the analog radio frequency (RF) signal to a digital RF signal sampled at a predetermined rate (typical ranges are from 20MHz to 160MHz) and at a predetermined number of bits (typical ranges are from 10 bits to 16 bits)

4
Q

Beam Former

A

The part of an instrument that accomplishes electric beam scanning, Apodization, steering, focusing, and aperture with arrays

5
Q

Bistable

A

Having two possible states

6
Q

Bit

A

Binary digit

7
Q

Cathode-ray tube

A

A display device that produces an image by scanning an electron beam over a phosphor-coated screen

8
Q

Coded Excitation

A

extends the bounds of this tradeoff by increasing signal-to-noise ratio (SNR) through appropriate coding on transmit and decoding on receive

9
Q

Compensation

A

Also known as TGC used to increase amplification at varying depths

10
Q

Compression

A

Compression decreases the difference between the largest and the smallest voltages or echo amplitudes

11
Q

Contrast Resolution

A

Ability of a gray scale display to distinguish between echoes of slightly different amplitudes or intensities

12
Q

Demodulation

A

Conversion of echo voltages from radio frequency (RF) to video form; Also known as detection

13
Q

Depth Gain Compensation

A

Same as compensation; also called TGC

14
Q

Digital-to-analog converter

A

(DAC) A device that converts a digital number to a proportional voltage amplitude

15
Q

Dynamic Range

A

Ratio of the largest to the smallest amplitude or power that a system can handle

16
Q

Frame Rate

A

the number of sonographic images stored into memory per second

17
Q

Gain

A

Ratio of amplifier output to input electric power

18
Q

Gray Scale

A

Range of brightness between white and black

19
Q

Image Memory

A

After echo data is acquired and converted to proper video format image frames are stored in image memory

20
Q

Image Processor

A

An electronic device that reformats echo data into image form

21
Q

Persistence

A

Frame Averaging

22
Q

PACS

A

Picture archiving and communications systems

23
Q

Pixel

A

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

24
Q

Postprocessing

A

Signal processing done after data emerge from scan converter memory and before display

25
Q

Preprocessing

A

Image processing done before echo data are stored in image memory

26
Q

Real-time

A

Imaging with a rapid-frame-sequence display

27
Q

Real-time Display

A

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

28
Q

Scan Converter

A

Temporarily stores images during scanning, for viewing and recording

29
Q

Signal Processor

A

picks up amplified signals from the receiver and carries out operations such as filtering, amplitude detection, and signal compression

30
Q

Spatial Compounding

A

This form of image compounding reduces image noise and speckle, and increases tissue plane definition

31
Q

Temporal resolution

A

the ability to distinguish closely timed events as separate events; and to correctly display rapidly moving structures

32
Q

Time Gain Compensation

A

Same as compensation; Also known as DGC