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Flashcards in Transducers Continued Deck (31):
0

What controls the electronics that create the patterns of slope (steering) and curvature (focus)?

Beam Former

1

How does the beam former create slope and curvature?

incredible short time delays to create these patterns

2

Does the beam former do its job in the transducer or in the system?

in the system

3

The beam former works with .....

the electrical voltage

4

What shape does a sector transducer make?

pie shape

5

with a sector transducer how do the elements fire?

all at the same time

electronic focusing and steering (beam former)

6

How does a Vector array work?

combines linear sequential and linear phased

trapezoidal shape - flat top

multiple focal points - phased array

7

What is dynamic focusing?

reception or receiving focus (multizone)

transmission or transmitting focus (multizone)

8

Why is dynamic focusing important?

It improves the image

9

What is dynamic aperture?

more crystals listening

form of electronic focusing

focusing during reception

varying the number of elements to listen

improves LATERAL RESOLUTION

10

What helps with focusing?

dynamic aperture

dynamic focusing

11

What is a multidimensional array?

two dimensional array of small transducer elements

**its a MATRIX***

12

What transducer makes a thinner slice/narrower beam?

multidimensional array

improves elevational resolution

more elements side to side than up and down

13

of the arrays what are the different kinds of construction?

array

linear

curvilinear

annular

14

Of the arrays what are the operations?

sequencing or switched

phased

vector

15

what are the different kinds of spatial resolution?

axial

lateral

elevational

16

What is axial resolution?

longitudinal, axial, radial, range, depth

1/2 spatial pulse length

the smaller the better

17

What is lateral resolution?

lateral, angular, transverese, azimuthal

related to beam width... no math - just whatever the beam width is that is the lateral resolution

18

What is elevational resolution?

section thickness, partial volume, slice thickness

takes the beam and it doesn't appear as flat...the thickness improves the picture

creates a thicker slice of the image

19

What is detail resolution?

elevation resolution

disc shaped crystals

elevation resolution equal to lateral resolution with disc shaped crystals

reduces section thickness artifacts

20

What is volume imaging?

3-D and 4-D imaging

21

What is Keepsake Ultrasound?

3-D and 4-D imaging for fun....womb with a view type places

22

What are side lobes?

created by a Single element transducer

an artifact

extend off the main beam

off axis

degrade lateral resolution

(old transducers)

23

What is a Grating lobe artifact?

found in Array transducers

off axis

degrade lateral resolution

reduce image quality

24

How do you eliminate Side lobes and Grating lobes?

apodization

subdicing

variable or dynamic aperture (open and closes the beam)

25

what is apodization?

alters electrical spike voltages

improves Lateral resolution

26

what is subdicing?

sub elements - improves lateral resolution

27

What improves lateral resolution?

apodization

subdicing

variable or dynamic aperture (open and closes the beam to how it is needed)

28

go to ovel, eldeman, and kremkau

learn all different kinds/details about the transducer

29

compare curved arrays and annular arrays

curved annular

convex not produced
firing groups sector
ABD concentric circles
OB/GYN mechanically steering
electronic focus electronic focus
electronic steering

30

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