Week 3 Quiz

Front 1

Anatomy of the sound beam

Back 1

Focus

Near zone

Focal length/near zone length

Far zone

Focal zone

Hint 1

Five terms describe the shape and regions of a sound beam.

Front 2

Focus/Focal Point

Back 2

Location where beam is be narrowest

Hint 2

Focus base zone

Front 3

Near zone

Back 3

Aka near field or fresnel zone. The region from the transducer to the focus

Hint 3

Closest to the diameter

Front 4

Focal length

Back 4

A.k.a. the focal depth or near zone length. the focal length is the distance from the transducer to the focus

Hint 4

Focal length

Front 5

Far zone

Back 5

A.k.a. far field or fraunhofer zone. The first one is a region that starts at the focus and extends deeper with then the fire zone the team diverges and spreads out.

Hint 5

Far zone

Front 6

Focal Zone

Back 6

Region around the focus where the beam is relatively narrow. Reflections arising from focal zones create images that are more accurate.

Hint 6

Focal zone

Front 7

What characteristics of a fixed focus transducer determine the focal depth depth?

Back 7

1. The transducer diameter

2. Frequency of the sound

Hint 7

Focal depth

Front 8

Deep focus?

Back 8

1. A large diameter PZT

2. High frequency

Hint 8

Less divergence

Front 9

Shallow Focus

Back 9

1. Small diameter PZT

2. Low frequency

Hint 9

More divergence

Front 10

True or false

Frequency and focal depth are directly related

Back 10

True

Hint 10

Deep focus

Front 11

True or false?

Transducer diameter and focal depth are directly related

Back 11

True

Hint 11

Shallow focus

Front 12

A clinically useful transducer with shallow focus

Back 12

1. Small diameter PZT

2. High frequency

Hint 12

Second option for a shallow focus

Front 13

What is the most shallow location of the sound beam?

Back 13

Near zone

Hint 13

Shallow

Front 14

What is the deepest location of the sound beam?

Back 14

The far zone or the Fraunhofer zone

Hint 14

Deep

Front 15

What is Huygens Principle?

Back 15

US transducers with large PZT crystals create some beams that are shaped like hourglass however small sound sources create beams that are vitiate this inconsistency between large and small sound sources and their beams was explained by Higgins known as his principal.

Hint 15

V shape

Front 16

What are V shaped waves known as?

Back 16

Spherical waves, the diffraction patterns, Huygens wavelets.

Hint 16

Small sources of some producing wavelets

Front 17

What is sound beam divergence?

Back 17

Describes a gradual spread of the ultrasound beam in the far Field

Hint 17

Divergence

Front 18

What determines the spread of the beam in the far field?

Back 18

1.transducer diameter 2.frequency of the sound

Hint 18

Determine divergence

Front 19

True or false? Crystal diameter and beam divergence are inversely related.

Back 19

True

Hint 19

Smaller diameter crystals produce beams that spread out or diverge more in the deep far zone

Front 20

True or false?

Frequency and beam divergence are inversely related.

Back 20

True

Hint 20

Lower frequency sound being spread out or diverge more in the deep far zone.

Front 21

True or false?

higher frequency sound improves lateral resolution in the far Field

Back 21

True

Hint 21

High frequency sound beams diverge less and the far Field.

Front 22

More Divergence

Back 22

1. small diameter

2. lower frequency

Hint 22

Deep focus

Front 23

Less Divergence

Back 23

1. Large diameter

2. higher frequency

Hint 23

Shallow focus

Front 24

What is resolution?

Back 24

The ability to create accurate images.

Hint 24

Resolution

Front 25

What are the units of axial resolution?

Back 25

Distance: mm, cm

Hint 25

Axial resolution

Front 26

What is axial resolution determined by?

Back 26

Spacial pulse length

Front 27

Synonyms of Axial resolution

Back 27

Longitudinal

Axial

radial

range

depth

Hint 27

LARRD

Front 28

What is the formula for Axial resolution?

Back 28

SPL/2 , SPL x C/ 2F

Hint 28

2 of them

Front 29

What is less ringing?

Back 29

A few cycles in a pulse

Hint 29

Less ringing

Front 30

What makes up better axial resolution?

Back 30

1. Shorter SPL

2. Shorter pulse duration

3. Higher frequency and shorter wavelength

4. Lower cycles per pulse a.k.a. less ringing

5. Lower numerical values a.k.a. numbers

Hint 30

5 of them

Front 31

What do lower numerical values of axial resolution indicate?

Back 31

Shorter pulses

Hint 31

Lower numbers mean?

Front 32

Higher frequency and less ringing

Back 32

Higher frequency and less ringing

Hint 32

2 things

Front 33

What is lateral resolution?

Back 33

The ability to identify two structures that are close when they are side-by-side or perpendicular to the sound beams mean axis.

Hint 33

LR

Front 34

What are the units of lateral resolution?

Back 34

Distance: MM, CM

Hint 34

Lateral resolution

Front 35

What is lateral resolution determined by?

Back 35

The width of the sound beam

Hint 35

Aka diameter

Front 36

What are the synonyms for lateral resolution?

Back 36

Lateral, Angular, Transverse Azimuthal

Hint 36

LATA

Front 37

Where is lateral resolution best at?

Back 37

At the focus for the beam is the narrowest or end of near zone.

Hint 37

LR

Front 38

What is the formula for a lateral resolution?

Back 38

Diameter of the sound beam or width of the sound beam.

Hint 38

2 of them means the same.

Front 39

Which is better, axial resolution or lateral resolution?

Back 39

Axial

Hint 39

Shorter pulses

Front 40

Which resolution is front to back or parallel?

Back 40

Axial resolution

Hint 40

Parallel

Front 41

Which resolution is side-by-side or perpendicular?

Back 41

Lateral resolution

Hint 41

Perpendicular

Front 42

What is focusing?

Back 42

Concentrate sound into new Ruby to improve lateral resolution

Hint 42

Focusing

Front 43

What is external focusing?

Back 43

A lens is placed in front of the PZT. Can be used on a fixed conventional or mechanical focusing.

Hint 43

External

Front 44

What is internal focusing

Back 44

Use with a curved active element or PZT it concentrates the sound energy into a narrow or tighter beam. Fixed conventional or mechanical

Hint 44

Internal

Front 45

Phased array focusing

Back 45

Electronics focus to sound beam. focusing characteristics of a beam adjustable, can only be used on multi element transducers never on single Crystal transducers.

Hint 45

Phased array

Front 46

For modifications of focusing

Back 46

1. Beam diameter in Nearfield and focal zone is reduced.

2. Focal depth is shallower

3. beam diameter in the far zone increases

4. focal zone is smaller

Hint 46

Effects of focusing

Front 47

Old Transducer

Back 47

-fixed Focus

-cannot move focus

-can not add/remove Focus

-non-adjustable

-Two ways of focusing external (lens) and internal

Hint 47

Old

Front 48

Modern transducer

Back 48

-electronic

-Phased Arrays

-adjustable

-Change focus

-move focus and Nearfield and Farfield

Hint 48

Modern

Front 49

A mode- Amplitude

Back 49

Appears as a series of upward spikes displays are created as a sound pulse is emitted by the transducer, that moves at a constant speed. When reflection returns to the transducer it’s processed and moving dot is deflected upwards.

Hint 49

Display mode

Front 50

What kind of spikes does A mode have?

Back 50

Strong echoes = tall spikes

Weak reflections = short spikes

Hint 50

Spikes

Front 51

X axis represents what in a mode?

Back 51

Depth

Hint 51

Time of flight

Front 52

Y axis represents what in a mode?

Back 52

Reflection amplitude

Hint 52

Y axis

Front 53

B-Mode - Brightness

Back 53

Appears as a line of dots very brightness created as some pulse is emitted by transducer. Invisible dot moves at a constant speed across display. When reflection returns to transducer it’s processed and invisible dot is turned on.

Hint 53

Display mode 2

Front 54

What does B mode indicate?

Back 54

Strength of reflection

Hint 54

B mode

Front 55

The x axis of B mode represents what?

Back 55

Reflector of depth

Hint 55

Time of flight

Front 56

z axis of B mode represents what?

Back 56

Amplitude

Hint 56

Info routed from olliscope

Front 57

True or false?

The first form of grayscale imaging is B mode.

Back 57

True

Hint 57

Grayscale

Front 58

Appears as a group of horizontal wavy lines. Created as sound pulses are omitted by transducer reflections move at constant speed from left to right. Very squiggly lines representing the

Back 58

Appears as a group of horizontal wavy lines. Created as sound pulses are emitted by transducer. reflections move at constant speed from left to right. Very squiggly lines representing the Changing depth of reflecting surfaces.

Hint 58

M mode

Front 59

X axis on Mode represents what?

Back 59

Time

Hint 59

Motion

Front 60

Y axis of M mode represents what?

Back 60

Reflector depth

Hint 60

Motion

Front 61

True or false? A line that moves up and down on the display indicate that a reflector is moving closer to or farther away from the transducer on M mode.

Back 61

True

Hint 61

M mode

Front 62

What is the M mode mostly used for?

Back 62

Fetal heart rate

Hint 62

Motion organs