URR Intracranial Arteries

Question 1

indications for intracranial arteries?

Answer 1

-assess vasospasm/vasoconstriction cause by subarachnoid hemorrhage
-stoke
-TIA
-intracranial stenosis/occlusion
-collateral flow
-AV malformation
-vasospasms
-monitoring for surgery
-shunt detection
-sickle cell anemia for peds
-suspected brain death

Question 2

limitations of intracranial arteries?

Answer 2

-hyperostosis
-time consuming
-incorrect vessel identification
-vasospasm can be mistake for stenosis
-cannot eval for aneurysm
-patient coooperation

Question 3

thickening of cranial bones?

Answer 3

hyperstosis

Question 4

most common type of indication for intracranial artery doppler?

Answer 4

assess vasospasm/vasoconstriction cause by subarachnoid hemorrhage

Question 5

limitations of TCD?

Answer 5

-inacurate vessel identifcation
-no imaging capabilities
-requires experience
-hyperostosis

Question 6

what is the transtemporal window used for?

Answer 6

-used to eval MCA, ACA, PCA, and terminal ICA
-patient supine
-notch towards patient nose

Question 7

in the transtemporal window, how the the MCA flow?

Answer 7

towards the transducer

Question 8

in the transtemporal window, how does the ACA flow? P1, P2?

Answer 8

away from transducer
-toward
-away

Question 9

what does the suboccipital (transoccipital) window do?

Answer 9

-evals vertebral and basilar
-patient decub
-probe at the base of the neck and angle cephalad
-basilar flow away from transducer

Question 10

what does the transorbital (opthalmic) window do?

Answer 10

-evals opthalmic artery and carotid siphon
-patient supine
-output should be at min
-notch should be medially towards the nose
-flow towards the transducer

Question 11

what does the submandibular window do?

Answer 11

-evals dist ICA and siphon
-flow away from probe
-patient supine

Question 12

flow velocities normally go how as people age?

Answer 12

decrease

Question 13

MCA velocities?

Answer 13

10 years old=70 cm/sec
70 years old=41 cm/sec

Question 14

normal ACA/MCA

Answer 14

<1.2

Question 15

normal MCA/ICA

Answer 15

1.1-3.0

Question 16

basilar a / extracranial vert a

Answer 16

<2.0

Question 17

normal PI

Answer 17

.5-1.1

Question 18

PI will do what prox to obstruction and what distal to obstrcution?

Answer 18

increase, decrease

Question 19

difference greater than what in the same vessel on opposite sides indicates disease?

Answer 19

30%

Question 20

stenosis is most common in what vessels?

Answer 20

MCA, siphon, and terminal ICA

Question 21

resistnance does what in flow prox to obstrcution?

Answer 21

increase

Question 22

periorbital doppler?

Answer 22

-CW doppler eval of the frontal artery ( a branch of opthalmic)
-8-10 MHz pencil probe in inner canthus of eye
-normal flow toward the probe
-compression of the infraorbital, facial, and superficial temporal As is performed on both sides while evaling flow

Question 23

in the periorbital doppler if the flow is away from the probe, what is going on?

Answer 23

obstruction in ipsilat ICA

Question 24

if compression of 1 artery causes decreased or reversed flow in the frontal artery, that vessel is what?

Answer 24

being used as collateral to fill the frontal artery
-can only determine if there are patent collaterals

Question 25

-most emerge during fetal development -headache or seizures -complications include hemorrhage, cerebral ischemia, cerebral aneurysm, brain damage or stroke -risk factors include gender (more common in males) and fam hx

Answer 25

intracranial arteriovenous malformations

Question 26

Large AVM usually identified on fetal US or at birth

Answer 26

vein of galen defect

Question 27

Unilat vascular AVMs that involve brain, orbits, and facial structures

Answer 27

Wyburn Mason Syndrome

Question 28

treatment of Intracranial AVMs?

Answer 28

surgical resection, embolization, and radio therapy

Question 29

complication in patients with subarachnoid hemorrhage, usually slow bleed?

Answer 29

Vasospasm

Question 30

vasoconstriction of intracranial arteries?

Answer 30

vasospasm

Question 31

flow velocities in MCA, ACA, PCA usually do what with subarachnoid hemorrhage?

Answer 31

increase -MCA mean velocity over 200 cm/sec and 120 cm/sec indicates severe reduction -PI> 1.2 indicates vasospasm

Question 32

vasospasm usually occurs when during the start of a hemorrhage?

Answer 32

w/in 14 days of the start of the hemorrhage -record highest mean MCA and terminal ICA

Question 33

vasospasm can be treated how?

Answer 33

vasodilator

Question 34

opening in the intercranial septum fails to close after birth

Answer 34

patent foramen ovale

Question 35

how to look at patent foramen ovale?

Answer 35

-patient supine, performs valsalva -adjetated saline injected -microbubbles enter lungs -if ovale is patent , bubbles will cross into the left heart and enter arch, then cerebrovascular system

Question 36

if shunt present in patent foramen ovale, what happens?

Answer 36

emboli can be seen in MCA w/in few seconds after injection -high intensity transient signals (HITS) are vis as bright spikes on doppler -also may cause "chirping sounds"

Question 37

if bubbles are seen in the intracranial arteries with foramen ovale?

Answer 37

there must be a right ->left shunt in the heart to send the bubbles into the atrial system -valsalva may be used to push flow across the PFO into the left atrium

Question 38

of HITS recorded is directly related to what in the patent foramen ovale?

Answer 38

size of shunt

Question 39

sickle cell anemia can cause what?

Answer 39

increase PSV in cranial vessels and increase risk of stroke ->200 cm/sec is abnorm for terminal ICA and MCA and indicates increase risk of stroke for children

Question 40

TCD monitoring during carotid endarterectomy ?

Answer 40

-CA clamed during procedure and ipsilateral MCA evaled -used to monitor cerebral emboli and to help determine if shunt is necessary -unilat monitoring of the ipsilat MCA -if MCA flow present >10 cm/sec after clamping, adequate collat flow is present

Question 41

TCD monitoring used during open heart surgery with bypass?

Answer 41

used to assess cerebral flow during extracorporal bypass which can lead to hyperfusion of cerebral vessels -bilat MCA monitoring -microemboli monitoring

Question 42

TCD monitoring during ICU monitoring?

Answer 42

-monitor critically ill patients with head issues -bilat MCA monitoringT

Question 43

TCD monitoring during brain death?

Answer 43

peaked MCA waveform with moderate flow regversal in diastole