vascular final review

Question 1

recanalization is what

Answer 1

a channel of blood flow that has formed through a blood clot. More indicative of what?

A chronic blood clot

Question 2

characterization systems type 1 and 2 vs type 3 and 4

Answer 2

type 1 and 2 are considered unstable (assoc with hemmorage and ulceration)

type 3 and 4 assoc with more benign, plaque is stable… more homogenous

Question 3

dense plaque may or may not

Answer 3

shadow

Question 4

low, moderate, or high pulsatility is based on the amount of

Answer 4

peripheral resistance those vessels are facing

Question 5

shifting hue method vs the changing shade method

Answer 5

shifting hue (the one we use) different colors = different frequencies

changing shade = lighter color as frequency increases

Question 6

deep vessels with fast moving blood… don’t use this

Answer 6

power doppler… its bad at identifying shit like this

Question 7

with the doppler equation, the only thing that is counterintuitive is “if angle theta increases, the frequency shift (other side of equation) … does what?

Answer 7

DECREASES

*everything else with equation checks out as far as that equation numerator/denominator rule goes… if its on top it directly affects the other side of equation… if its on bottom the relationship is inverse

here’s the equation
Δf = 2fₒVcosθ ÷ C

“change in frequency = two times the operation frequency of transdx multiplied by the velocity of source multiplied by the cosine of that angle, divided by the speed of US in soft tissue (constant)

Question 8

stenosis considered when diameter is this % and area is this %

Answer 8

diameter is 50% or a 75% area stenosis in an artery

Question 9

velocity mode, velocity is a function of this… not this

Answer 9

velocity is a function of the vessel, not the transdx

Question 10

sample volume gate is actually in ____ dimensions

Answer 10

3

Question 11

low pulsatility waveforms have a what and a what

Answer 11

broad systolic peak and forward flow through diastole
Carotid vertebral renal and celiac arteries
MONOPHASIC

Question 12

moderate pulsatility waveforms have a

Answer 12

tall sharp systolic peak and forward flow present throughout diastole… may be interrupted by early diastolic flow reversal
-external carotid artery

Question 13

example of high pulsatility

Answer 13

tall, narrow, sharp systolic peaks and reversed or absent diastolic flow
triphasic. waveform in peripheral arteries

Question 14

flow decelerates (systolic flow, so lower peaks) if severe arterial obstruction is

Answer 14

PROXIMAL to doppler exam, can measure using acceleration time

Question 15

what velocity increases with stenosis

Answer 15

diastolic velocity (waveform)

Question 16

diastolic velocity will only increase with _____ stenosis not ________

Answer 16

high not moderate stenosis

Question 17

with increase in stenosis, the difference between systole and diastole is

Answer 17

smaller

Question 18

Know waveforms of stenosis

Answer 18

Question 19

systolic velocity ratio compares

Answer 19

systolic velocity in stenosis vs systolic velocity PROXIMAL to stenosis

Question 20

@ 80% stenosis peak systole falls to

Answer 20

normal or subnormal levels

Question 21

poststenotic flow disturbance is how far beyond stenosis

Answer 21

1cm
(laminar usu 3 cm beyond)

Question 22

in relation to stenosis, proximal pulsatility of waveform is (before stenosis) ______ and distal pulsatility of waveform (beyond stenosis is )

Answer 22

pulsatility increases proximal to stenosis and is dampened distal to stenosis (tardus parvus)