Mock 2

Question 1

compression is a mechanism that allows adjustment of

Answer 1

the number of shades of gray displayed

Question 2

a continuous wave doppler transducer would provide optimal ability to detect and display

Answer 2

high velocity flow

Question 3

what are the benefits of using CW doppler?

Answer 3

it has a sample volume along the entire line of sight and will not alias

Question 4

according to poiseuille’s law, what has the greatest impact on flow?

Answer 4

the lumen diameter

Question 5

a sound wave is traveling in the body and moves from muscle to air. what percentage of sound will be transmitted through?

Answer 5

0.5%
there is a very large acoustic impedance difference

Question 6

what technique allows calculation of blood velocity?

Answer 6

duplex imaging

Question 7

how is duplex imaging used?

Answer 7

the velocity is calculated using the angle of insonation which is determined by the image

Question 8

when decreasing the listening time by decreasing the depth, what is the only parameter that will change?

Answer 8

pulse repetition period

Question 9

what is the wavelength and resolution when the frequency is higher?

Answer 9

shorter wavelength and better resolution

Question 10

what are the 3 important references in a transverse wave?

Answer 10

peak, trough, rest

Question 11

what is interpolation?

Answer 11

a method to fill in gaps due to the increased distance between the scan lines in the far field when using a sector or curvilinear array

Question 12

what is quality factor?

Answer 12

a unitless number related to bandwidth
the main frequency divided by the bandwidth

Question 13

what does quality factor involves?

Answer 13

the pulse duration and the prp which includes the transmit and receive(listening) time

Question 14

what percentage of a sound wave will be transmitted from one soft tissue to another?

Answer 14

99%, the small difference in impedance will result in msotly transmitted

Question 15

what control has the greatest effect upon signal:noise ratio?

Answer 15

output power

Question 16

what does a 3-D array acquires data from?

Answer 16

a voxel or volume element
3D acquired data from all three planes

Question 17

what is the relationship of resistance and viscosity?

Answer 17

directed related

Question 18

if viscosity of fluid in a pathway is decreased by more than 50% what will happen to resistance?

Answer 18

it will decrease

Question 19

what is the relationship between propagation velocity and tissue density?

Answer 19

they are inversely related

Question 20

what happens to velocity when tissue density goes up?

Answer 20

velocity goes down

Question 21

what is the first control to adjust when color ghoosting is present?

Answer 21

color doppler gain

Question 22

what mechanical index will result in a typical B-mode linear reflection?

Answer 22

<0.1

Question 23

what has the ability of a test to detect disease when present?

Answer 23

sensitivity

Question 24

what test has the ability to identify normalcy (no disease present)?

Answer 24

specificity

Question 25

what causes more divergence?

Answer 25

the more shallow the focus, the greater the divergence

Question 26

what would result in a sound beam that diverges to the greatest extent in the far field?

Answer 26

low frequency and small diameter active element

Question 27

what contrast are useful for organ edge delineation and organ perfusion? and why

Answer 27

untargeted contrast, because they travel with the blood and therefor useful to evaluate perfusion

Question 28

the use of a tissue equivalent phantom in a quality assurance program to test image accuracy would be considered

Answer 28

objective because it provided data that is measurable and repeatable even when repeated by different operators

Question 29

an objects kinetic energy is determined by

Answer 29

mass and speed

Question 30

what is the value of calculating specificty?

Answer 30

it tells you how often a positive ultrasound exam is correct

Question 31

what is the value that indicates how often a positive test is correct?

Answer 31

positive predictive value

Question 32

what contrast are useful for organ edge delineation and organ perfusion?

Answer 32

targeted because they bind with a respective target which can then be identified with ultrasound

Question 33

during when the diaphragm lowers what does it result in?

Answer 33

increased intra-abdominal pressure

Question 34

given the propagation speed and wavelength how do you find the frequency?

Answer 34

wavelength = propagation speed/frequency

Question 35

what is the primary pump that drives blood around the entire system?

Answer 35

left ventricle

Question 36

in diagnostic imaging, what is most important about wavelength?

Answer 36

it determines our resolution we cannot resolve structures of less than 1 wavelength