Study guide 12-13 Flashcards Preview

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Flashcards in Study guide 12-13 Deck (33):
1

What transducer type is if the crystal is damaged there is no image

Mechanical

2

What is the typical value for electrical single in phased array transducer

10 nanoseconds ?

3

What transducer creates a beam that is focused in all planes and all depths

With 2-D array transducers, the sound beams are electronically focused in both the lateral and thickness planes ( used for 3D imaging) pg 191

4

What is the image shape for a vector array

Flat top/ trapezoid

5

What transducer has active elements in rings

Annular phased array

6

which transducer has active elements in straight lines

Linear (page 168 MW)

7

What is the advantage of a 1 ½ D array transducer ?

has numerous crystals arrange side by side. Has multiple crystals in the up and down direction.

8

What type of resolution is improved with a 1 ½ D array transducer ?

Improves elevational resolution

9

Transducer has active elements that are bowed

convex (page 168 MW)

10

Phased array always means

Adjustable, multifocuses

11

Liner switch or sequential has what type of steering

Phasing

12

Drop out from top to bottom what transducer has that type of crystal

Convex&Linear (AL pg 187)

13

Horizontal /side to side

Annular Phased array

14

What type of transducer Mechanically steered and fixed and singular focused

Mechanical transducer

15

The use of more active elements to receive reflections with a great time of flight is called what

Dynamic Aperture(AL????)pg 194

16

Displaying with both real time and Doppler is called what

Duplex (AL)

17

The ability to accurately locate moving structures at any particular instance is what type of resolution

Temporal

18

what will affect the pules in a single image

Number of focal points, sector size, line density

19

If the imaging depth of view is doubled what happens to the frame rate

it is halved (question 4 page 210 MW)

20

Sector size that will use fewer pulses

Narrow

21

What is the consequence from changing the density of one line to three lines

The spatial resolution will be improved which means improve the accuracy of each individual image

22

What is a frame rate/ how long it takes to create a frame

frame rate is the system's ability to create numerous frames each second, units Hz (page 198)

23

Lateral resolution improves which of the following

Multi focus and Dynamic Apperture

24

what low line density is and what type of imaging it creates

spacing between sound beams which are very wide spaces and it creates a better temporal resolution

25

What if we have a poor movie quality but a higher image quality

there are multiple focal zones reducing temporal resolution but bettering lateral resolution (page 203 MW)

26

with line density improves what type of resolution and which one decrease that other type

When line density improves spatial resolution increases, but temporal resolution decreases

27

If the imaging depth of the scan is 15 centimeters 100 lines what is the number of pluses making up the scan

100(AL) 213 #19&20

28

Sonographer using a phases array system turned of the multifocus system what action happenes

frame rate increases improving temporal resolution (MW)

29

if it takes 1/100 sec to create a frame then what is the frame rate (MW)

100Hz (MW)

30

spatial resolution, who has it? (MW)

Line Density

High line Density = improves spatial resolution
Low line Density = poor spatial resolution

31

what degrades temporal resolution (MW)

Low Frame Rate
deeper imaging
multiple focal points
wide sector
high line density

32

what limits frame rate (MW)

Sound of speed through the medium

33

what determines temporal resolution and how is it affected (MW)

Displays a high number of images per second improves temporal resolution

Temporal resolution is reduced when few images are displayed per second