Chapter 10 key terms

Question 1

ability to distinctly identify two structures that are very close together

side by side perpendicular to the beam

Answer 1

lateral resolution

Question 2

ability to distinctly identify two structures that are very close together

fron to back parallel to the beam

Answer 2

axial resolution

Question 3

angular

transverse

azimuthal resolution

Answer 3

lateral resolution synonyms

Question 4

axial gives distance between object in depth

Lateral gives distance side to side

Answer 4

axial vs lateral

Question 5

concentration of asound energy into a narrow beam and thus improving lateral resolution

Answer 5

focusing

Question 6

external

internal

phased array

Answer 6

methods of focusing

Question 7

beam diameter in near field and focal zone narrows

focus is moved closer to the transducer

beam diameter beyond the focal zone widens

size of the focal zone is reduced

Answer 7

effects of focusing

Question 8

.77 x # of cycles in pulse / Freq=

Answer 8

axial resolution (mm)

Question 9

spatial pulse length/2=

Answer 9

axial resolution (mm)

Question 10

wavelengthx # cycles in pulse/2=

Answer 10

axial resolution (mm)

Question 11

axial resolution is determined by two factors

Answer 11

less ringing

higher freq

Question 12

lateral resolution =

Answer 12

beam diameter

Question 13

axial resolution orientation

Answer 13

front to back

parallel to beam

Question 14

Axial nemonic

Answer 14

LARRD

Question 15

axial resolution determined by

Answer 15

pulse length

Question 16

Axial resolution best with

Answer 16

short pulse

highest freq and fewest cycles

Question 17

Axial resolution change

Answer 17

same at all depths

does not change

Question 18

axial resolution best in near field with

Answer 18

`shortest pulse

Question 19

axial resolution best in far field with

Answer 19

shortest pulse

Question 20

lateral resolution orientation

Answer 20

side by side

perpendicular to beam

Question 21

lateral resolution mnemonic

Answer 21

LATA

Question 22

lateral resolutoin determined by

Answer 22

beam width

Question 23

lateral resolutin best with

Answer 23

narrowest beam

Question 24

lateral resolution changes

Answer 24

with depth, best at focus

Question 25

lateral resolutoin best in near field with

Answer 25

smallest diameter crystal

Question 26

lateral resolutoin best in far field with

Answer 26

larger diameter and highest freq

(lkess divergence)

Question 27

external

internal

phased array

Answer 27

types of focus

Question 28

focus with a lens

Answer 28

external

Question 29

focus with a curved avtive element

Answer 29

internal

Question 30

focused with the electronics of the ultrasound system

Answer 30

phased array

Question 31

beam diameter in near field and focal zone is reduced

focal depth is shallower

beam diameter in the far zone increases

focal zone is smaller

Answer 31

effects of focusing

Question 32

frequency of electrical signal from ultrasound system

Answer 32

freq continuous wave

Question 33

thickness of ceramic and speed of sound in ceramic

Answer 33

freq pulsed wave

Question 34

diameter of ceramic and freq of sound

Answer 34

focal length

Question 35

diameter of cereamic and freq of sound

Answer 35

beam divergence

Question 36

beam width

Answer 36

lateral resolution

Question 37

shorter spatial pulse length

shorter pulse duration

higher freq (shorter wavelength)

fewer cycles per pulse (less ringing)

lower numerical values

Answer 37

better axial resolution