Dmso 1302, Sec 5, Review

Front 1

Define dynamic receive focusing

Back 1

- Depends on reflector depth.

- Returning echoes are put in time delay.

- Occurs during reception.

- Performed automatically.

Front 2

Define apodization?

Back 2

— Reduces side and grating lobes strength.

— Stronger electrical signals excite the inner crystals.

— progressively weaker electrical spikes excite the outer crystals.

Front 3

Define subdicing:

Back 3

— PZT are divided into electrically joined sub-elements.

— act as one crystal to reduce grating lobes.

Front 4

Identify how modern transducers reduce side and grating lobes.

Back 4

Apodization and Subdicing

Front 5

identify electrical Spike lines used in beam steering and beam focusing

Back 5

— Spike's travel down the wire and excite the active element.

— soundbeam is steered if the spike line has a slope.

— sound beam is focused if the spike pattern is curved

Front 6

List the transducer types that utilize eletric beam steering and beam focusing.

Back 6

— Linear Phased Array

— Linear Sequential Array

— Convex, Curved, & Curvilinear Array Transducers

Front 7

Identify the relationship between axial resolution and transducer frequency.

Back 7

— Shorter Pulse Length = improved axial resolution.

— Higher Frequency = shorter wavelength

Front 8

Define slice thickness

Back 8

Elevational resolution, above and below the plane

Front 9

Identify which transducers are capable of multiple transmit focal zones.

Back 9

— Annular Phased Array

— Linear Phased Array

Front 10

List ways 1 ½ dimensional arrays improve resolution.

Back 10

— Create thinner beams with improved slice thickness resolution over a greater range of depths.

— improving elevational resolution (slice thickness) w/ 700 elements

Front 11

Identify how linear array transducers are focused and steered.

Back 11

Electronically focused and steered, time delay

Front 12

Identify what type of resolution is improved when a linear sequential array is focused.

Back 12

Lateral

Front 13

Define phasing and electronic beam steering.

Back 13

— Phasing = electronic steering & focusing

— Bean Steering = Redirection of the sound beam

Front 14

Beam steering is accomplished by?

Back 14

Delaying the voltage applied to the crystals

Front 15

Type of transducer that is mechanically steered but electronically focused

Back 15

Annual phased array

Front 16

What type of resolution is related to transducer frequency

Back 16

Axial resolution

Front 17

The use of focusing on linear sequential array transducer improves which type of resolution

Back 17

Lateral resolution

Front 18

Type of transducer that fires a small group of crystals to form a single

Back 18

Linear sequential

Front 19

Which array pattern will we use for superficial images

Back 19

Linear array

Front 20

Which type of transducer fires off all elements to create a single sound pulse

Back 20

Linear Phased Array

Front 21

Which type of transducers have elements arranged in a bowl or arched line

Back 21

Curved

Front 22

Dynamic received focusing introduces varying electrical

Back 22

Delays during reception

Front 23

Which transducer has the greatest number of elements

Back 23

Linear phased array 100-300 elements

Front 24

Primary purposes for varying the voltage is to?

Back 24

Remove grating lobes

Front 25

What type of transducer uses multiple focal zones to create each scan line of the image

Back 25

Annular phased array

Front 26

When a crystal has been divided into thinner segments

Back 26

Sub dicing

Front 27

Electronic pattern used for focusing

Back 27

Curvature

Front 28

Electronic beam steering in linear phased array is a process called

Back 28

Phasing

Front 29

The electronic Spike line is blank in an unfocused beam

Back 29

Straight

Front 30

Type of resolution degraded by side lobes

Back 30

Lateral

Front 31

Image shape of vector array

Back 31

Trapezoidal

Front 32

Focusing technique for mechanical transducers

Back 32

Fixed

Front 33

Blank resolution is another name for slice thickness

Back 33

Elevational

Front 34

Image shape of the linear sequential array

Back 34

Rectangular

Front 35

Sound beam is blank if the electronic Spike line is curved

Back 35

Focused

Front 36

Type of transducer affected by grating lobes

Back 36

Array

Front 37

The sound beam is blank if the electronic Spike line is sloped

Back 37

Steered

Front 38

Means always adjustable or multi focused

Back 38

Phased array

Front 39

Transducer with a small footprint

Back 39

Vector

Front 40

Used to reduce the strength of grading and side lobes

Back 40

Apod ization

Front 41

Blank shaped crystals provide the thinnest ultrasound slices

Back 41

Disc

Front 42

Type of transducer affected by side lobes

Back 42

Single element

Front 43

Annular array utilizes blank transmit focal zones

Back 43

Multiple

Front 44

Electronic pattern used for sound beam steering

Back 44

Slope

Front 45

Type of transducer that uses mechanical steering

Back 45

Annular transducer

Front 46

The best resolution of phased array transducer

Back 46

Axial

Front 47

Image of shape of linear phased array transducer

Back 47

Fan