Lateral resolution*

Question 1

What are the AKAs for lateral resolution?

Answer 1

Lateral
Angular
Transverse
Azimuthal

Question 2

What improves lateral resolution?

Answer 2

-large diameter, thin PZT (high frequency)
-beam width (narrow focus, focal point) 1!
-high line density 2!
-multifocus or (add a focus!)
-dynamic aperture
-thin half value layer
-dynamic focusing

Question 3

what narrows a beam?

Answer 3

higher operating frequency

Question 4

what transducer will give you the best lateral resolution?

Answer 4

linear (sequential or switched) transducers and annular phased array

Question 5

how does dynamic aperture help improve lateral resolution?

Answer 5

it allows focusing at different depths

Question 6

what happens to your penetration when you increase your frequency?

Answer 6

your penetration will go down

Question 7

since increasing your frequency diminishes your far field, how can you use high frequency to improve lateral resolution?

Answer 7

dynamic aperture makes up for the lack of penetration in the far field due to the higher frequency

Question 8

when you use a smaller amount of crystals what will happen to your frequency and your focal depth?

Answer 8

both will decrease (focal depth/focus will be closer to the transducer)

Question 9

for deeper penetration with high frequency, what else would you want to pair it with?

Answer 9

a larger thin crystal

Question 10

what will degrade lateral resolution?

Answer 10

-low line density
-low frequency (small diameter, thick PZT crystals)
fewer focus
-increasing depth
-thick half value layer

Question 11

what has the biggest effect on lateral resolution?

Answer 11

the beam width or narrowing the beam