Intracranial Cerebrovascular Doppler TEST

Question 0

What is TCD (transcranial doppler) based on?

Answer 0

hemodynamics (how is the blood flowing)

Question 1

What are they trying to evaluate in intracranial doppler?

Answer 1

The blood vessels in the Circle of Wilis

Question 2

Why was TCD initially developed?

Answer 2

to detect vasospasm following a subarachnoid hemorrhage

Question 3

Is TCD invasive?

Answer 3

non invasive

portable

painless

safe

inexpensive

REPEATABLE

Question 4

What does TCD do?

Answer 4

measures velocity

Identifies direction of flow

Question 5

What are the limitations of TCD?

Answer 5

operator dependent - steady hand

blind vessel identification

anatomic variants

skull difficult to penetrate

Question 6

Why do we do TCD?

Answer 6

occlusive Disease

cerebral emboli

hemorrhage

sickle cell disease

subclavian steal

head trauma

cerebrovascular disease

stroke

migraine headaches

aneurysms

AV fistula

vasospasm

evaluation of brain death

eval of collateral flow

Question 7

What are the two routes that blood is delivered to the brain?

Answer 7

internal carotids and vertebrals that form an anterior circulation and a posterior circulation respectively

Question 8

What is the circle of Willis?

Answer 8

ring that permits communication between the rt and lt cerebral hemispheres

and between anterior and posterior systems

Question 9

What does the circle of willis consist of?

Answer 9

A1 segments of the

two ACA’s

ACoA

two PCoA’s

two ICA’s

P1 segment of the two PCA’s

Question 10

What does the circle of willis actually do?

Answer 10

polygon shaped vascular ring

at the base of the brain

communication between rt and lt cerebral hemisphere

communication between ant and post systems

Question 11

What vessels are in the anterior circulation?

Answer 11

ICA

MCA (middle cerebral artery)

ACA (anterior cerebral artery)

ACoA

Question 12

What is the first branch off of the ICA?

Answer 12

Opthalmic artery

Question 13

Can the Opthalmic artery be scanned?

Answer 13

yes by TCD

Question 14

Why is the Opthalmic artery important?

Answer 14

Role in collateral pathways

Question 15

What is the carotid siphon?

Answer 15

portion of the ICA that forms two curves

Question 16

The ICA bifurcates into two terminal branches…what are they?

Answer 16

anterior cerebral artery

middle cerebral artery

very curved branches

Question 17

The anterior circulation is via the ___________ ___________ artery

Answer 17

anterior communicating artery ACOM

Question 18

Posterior circulation via the _____________ ____________ artery

Answer 18

Posterior communicating artery PCOM

Question 19

What is COW?

Answer 19

circle of willis

Question 20

Which artery cannot be visualized by TCD?

Answer 20

anterior communicating artery ACoA

Question 21

What do you use to perform TCD?

Answer 21

phased array

Pulsed doppler

CW can be used

2-5 MHz (for penetration)

0 degree angle

capture the entire circle of willis

Question 22

The real time display of all doppler shift frequencies over ______ is the doppler _________ waveform

Answer 22

time

spectral

Question 23

A ___________doppler shift is ___________the baseline

Answer 23

positive

above

Question 24

a __________doppler shift is _________the baseline

Answer 24

negative below

Question 25

During TCD imaging the doppler _________ should be _______ for adequate penetration

Answer 25

Power Increased

Question 26

What is key information for TCD?

Answer 26

depth

Question 27

the flow toward and away is most important which color is which

Answer 27

Blue - away Red- toward

Question 28

What are the four TCD windows?

Answer 28

transtemporal (above the ear) transorbital (eye) transoccipital, suboccipital submandibular (under the chin)

Question 29

FRom the transtemporal window, what vessels can you see?

Answer 29

MCA ACA MCA/ACA (bifurcation - butterfly sign) PCA ICA

Question 30

MCA courses adjacent to the ____________ _________

Answer 30

sphenoid wing

Question 31

PCA wraps around the ____________ ____________

Answer 31

cerebral peduncle

Question 32

Decrease ________for slower flow in the PCA and ACA

Answer 32

PRF (scale)

Question 33

Opthalmic artery is __________resistance

Answer 33

high

Question 34

Transtemporal arteries are _______resistance

Answer 34

low

Question 35

What do you do with the power for transorbital?

Answer 35

decrease the power ALARA - as low as reasonably acheivable.

Question 36

What artery gets reversed flow with stenosis in the ICA?

Answer 36

ophthalmic artery

Question 37

The trans/suboccipital window places the transducer....

Answer 37

on the posterior aspect of the neck inferior to the nuchal crest

Question 38

What do you see in the suboccipital area?

Answer 38

vertebral basilar distal ICA **Y sign** see slide 49 for picture

Question 39

How do you get good quality color doppler images?

Answer 39

increase color gain small sector width and color box for highest possible frame rates change color PRF color sensitivity and persistence settings (makes the color come out more than gray scale)

Question 40

What kind of flow are you looking for in TCD?

Answer 40

mean flow velocity - not peak

Question 41

Why is the color display important?

Answer 41

assists in the proper placement of sample

Question 42

know slides....

Answer 42

54 -55 look in Ipad pictures

Question 43

describe stenosis

Answer 43

increased velocities turbulence

Question 44

describe occusion

Answer 44

no flow insonating (sweeping) the vessel is key

Question 45

What are the doppler findings for Stenosis? occlusion? vasospasm? sickle cell anemia?

Answer 45

stenosis: increased velocities - turbulence occlusion: no flow - insonating vessel key vasospasm: increased velocities - sequential doppler sickle cell: increased velocities in the ICA MCA

Question 46

describe AV malformations and doppler

Answer 46

increase velocities low pulsatility turbulance

Question 47

how does age affect velocities?

Answer 47

lower with increasing age

Question 48

how does being female affect velocities?

Answer 48

slight increase

Question 49

What are the physiologic factors for non disease related intracranial changes in doppler?

Answer 49

age: lower velocities with ^ age sex: slight ^ velocities with females Hematocrit: velocities ^ with anemia heart rate/cardiac output

Question 50

What is a stenosis?

Answer 50

focal ^ in velocity local turbulence poststenotic dtop PRF ^

Question 51

antegrade means? retrograde means?

Answer 51

antegrade - up retrograde - down

Question 52

What is vasospasm?

Answer 52

vasoconstriction of the arteries complication of hemorrhage ^ velocity

Question 53

What can cause hemorrahge?

Answer 53

ruptured aneurysm vascular tumor head trauma

Question 54

If there is an aneurysm, what two things might you see with color doppler?

Answer 54

color flow appearing in an unexpected area wider color area

Question 55

What is a subclavian steal?

Answer 55

associated with stenosis or occlusion of subclavian artery vertebral becomes collateral

Question 56

When you have a subclavian steal, which artery get "stolen" from?

Answer 56

basilar

Question 57

What happens to the vertebral artery with a subclavian steal?

Answer 57

retrograde flow causes patient to experience neurologic symptoms of brain stem ischemia

Question 58

If you have an innominate or subclavian artery obstruction, what is the difference in systolic pressure between arms?

Answer 58

> 20 mmHg obstruction on the side of lower pressure

Question 59

If you have an emboli what will you hear/see?

Answer 59

high intensity signal hear a chirp see a spike

Question 60

What do you do to detect an emboli?

Answer 60

Use main MCA transient signal higher amplitude unidirectional audio sound - snap

Question 61

What is sickle cell disease?

Answer 61

inherited blood disorder cerebral infarction associated with occlusion