Mit 232 2D Instrumentation

Front 1

Transducer

Back 1

Turns electric into acoustic pulse
Sends US into tissues
Receives echoes
Turns acoustic into electric

Front 2

Electric to acoustic

Back 2

Converse piezoelectric effect

Front 3

Acoustic to electric

Back 3

Piezoelectric effect

Front 4

Pulser

Back 4

Receives timed signal from master synchronizer and produces voltage that is transmitted to the probe.

Front 5

Acoustic power

Back 5

Pulser
Transducer output
Output gain
Pulser power
Energy output
Transmitter power

Front 6

Output power set at 0 dB

Back 6

Machine will generate the maximum power it is capable of. (100%)

Front 7

CW Pulser

Back 7

Produces continuous electrical signal that is converted into continuous US wave.

Front 8

PW Pulser

PRF

Back 8

Creates an electrical spike that the transducer crystal later transfers into a single US pulse

Front 9

Array transducer
Sector probe
(Many crystals)

Back 9

Each crystal will receive it's own spike, requiring several spikes to generate one acoustic pulse.

Front 10

Determines the focusing and steering of the acoustic pulse

Back 10

The timing between electrical spikes

Front 11

Transmit zone

Back 11

In order to have many focal zones, the same area must be scanned separately for each focus

Front 12

Frequency

Back 12

Inversely proportional to penetration

Front 13

Harmonic Imaging
or
Fundamental frequency

Back 13

The echoes with the frequency that is divisible by the transducer frequency

Front 14

Tissue harmonic imaging

Back 14

No contrast

Front 15

Harmonic imaging
and
Color/power Doppler harmonic imaging

Back 15

Uses contrast

Front 16

Gain

Back 16

Adjustment control that increases the amplification of the received echoes

Front 17

Compensation

Back 17

TGC
The echo amplitude from the deep structures is smaller than amplitude of echoes from superficial structures

Front 18

Compression

Back 18

The difference between the strongest and weakest echo is too big

Front 19

Rejection

Back 19

Very low amplitudes have no clinical value and are associated with noise

Front 20

Demodulation

Back 20

Changes the shape of the electrical signal to be accepted by the display

Front 21

Rectification

Back 21

Turns negative voltage into positive

Front 22

Smoothing

Back 22

Places envelope around the bumps

Front 23

Analog

Back 23

Infinite number of values
Received and displayed

Front 24

Digital

Back 24

Set number of values
Used for storage

Front 25

Shades of grey on pixel

Back 25

Represents the amplitude of the returning echoes

Front 26

Shades

Back 26

2^Bits

Front 27

Grey Scale

Back 27

Assigns more bits (Shades of grey) per pixel

Front 28

Preprocessing
(Transducer, Receiver, AD Converter)

Back 28

Data processed before it is stored in scan converter

Front 29

Postprocessing
(Computer Memory, DA Converter, Display)

Back 29

Data processed after it has been stored in scan converter but before displaying

Front 30

Write Magnification

Back 30

Occurs when data is acquired.

Front 31

Increasing line density

Back 31

Better spatial resolution
Better lateral resolution

Front 32

Read Magnification

Back 32

Already stored image is being magnified.
More pixels are assigned to the echo received from location x.

Front 33

Smoothing
(Persistence)

Back 33

The system averages several frames to reduce "noise"