Characteristics of Ultrasound System

Question 1

a single element transducer requires what kind of focusing and steering

Answer 1

mechanical

Question 2

transducer frequency is ____ to penetration and ____ to resolution

Answer 2

inversely proportional to penetration and directly related to resolution

Question 3

high frequency transducers have ___ penetration and ___ resolution

Answer 3

poor penetration and improved resolution

Question 4

what three things are inversely proportional to the transmitted frequency

Answer 4

beam width spatial pulse length and pulse duration

Question 5

___: usually constructed of 5 concentric ring shaped piezoelectric elements that produce a cylindrical beam

Answer 5

annuar array

Question 6

annular array has a ___ shaped image

Answer 6

sector

Question 7

annular array requires what kind of steering

Answer 7

mechanical

Question 8

circular elements allow for electronic focusing in all planes at all depths providing what

Answer 8

optimal lateral resolution at all depths of the image

Question 9

___: elements are arranged in a linear pattern

Answer 9

sequential linear array

Question 10

___: groups of elements are fired at varied times to produce, focus and steer the beam

Answer 10

phased linear array

Question 11

linear arrays have what kind of focusing

Answer 11

electronic

Question 12

what kind of focusing and steering does a curved array ahem

Answer 12

electronic

Question 13

___: contains a large number of linearly arranged rectangular piezoelectric elements

Answer 13

sector phased array

Question 14

which transducer allows multiple focal points at different depths

Answer 14

sector

Question 15

narrow sector widths have a lower line density increasing ___ and ___ but decreasing ___

Answer 15

increasing frame rate and temporal resolution but degrading spatial resolution

Question 16

___: combine a sequence of linear array and phased array techniques to provide a trapezoidal imaging format

Answer 16

vector array

Question 17

what does DICOM stand for

Answer 17

digital imaging and communication in medicine

Question 18

what does PACS stand for

Answer 18

picture archival and communication system

Question 19

what does NAS stand for

Answer 19

network attached storage

Question 20

what does RIS stand for

Answer 20

radiology information system

Question 21

what does HIS stand for

Answer 21

hospital information system

Question 22

harmonic frequency = what

Answer 22

2 times the fundamental frequency

Question 23

___: scanned lines are electronically stirred by the transducer in different directions to evaluate structures using multiple pulses from several different angles

Answer 23

spatial compounding

Question 24

what is the only transducer that can use spatial compounding

Answer 24

phased

Question 25

what kind of resolution is improved with spatial compounding

Answer 25

spatial

Question 26

what resolution is reduced with spatial compounding

Answer 26

temporal resolution

Question 27

gain adjusts what

Answer 27

amplitude of returned reflection

Question 28

___: created uniform brightness from top of image to bottom

Answer 28

TGCs

Question 29

___: adjusts the brightness of the entire image

Answer 29

gain

Question 30

focal zones improves ___ at the specific focal depth

Answer 30

spatial resolution

Question 31

multiple focal zones improve___ but decrease ___

Answer 31

improve lateral resolution but decrease temporal resolution

Question 32

___: ratio of the smallest to the largest signal strength the system can receive and display properly

Answer 32

dynamic range

Question 33

the larger the dynamic range the ___ shades of grey on the image

Answer 33

more

Question 34

dynamic range affects ___ resolution

Answer 34

contrast

Question 35

___: removes the low level echoes from a 2d image or doppler tracing

Answer 35

rejection

Question 36

reducing rejection will do what to the image

Answer 36

more shades of grey

Question 37

increasing depth decreased what

Answer 37

resolution

Question 38

what frequency transducers have the ability to scan deeper structures

Answer 38

lower

Question 39

___: number of images displayed per second

Answer 39

frame rate

Question 40

if from rate decreases what happens to temporal resolution

Answer 40

decreases

Question 41

___: eliminates low frequency doppler shift from display

Answer 41

wall filter

Question 42

___: highest velocity in the artery during a cardiac cycle

Answer 42

peak systolic

Question 43

___: peak flow velocity in the artery at the end of the cardiac cycle

Answer 43

ende diastolic

Question 44

how do you calculate resistive index

Answer 44

PSV-EDV divided by PSV

Question 45

the greater the difference between peak and end the higher the ___

Answer 45

RI

Question 46

how to figure out pulsatility index

Answer 46

PSV - EDV / PSV + EDV

Question 47

___: the maximum frequency that can be displayed is 1/2 PRF

Answer 47

nyguist limit

Question 48

what can cause mirror imaging on doppler

Answer 48

over use for doppler gain