Cerebrovascular Flashcards
What is true about a carotid body tumor(CBT)?
CBT frequently feed by external carotid artery, surgical excision of CBT may require ligation or embolization of the fed ding vessels, CBT highly vascular structure, carotid body is normal part of anatomy, located just above carotid bifurcation, down not effect neurological deficit in the ipsilateral carotid distribution
Doing a carotid exam, spectrum from the right iCA is aliasing, how to correct this problem to obtain accurate PSV’s?
Alter scanning plane, to make vessel of interest more shallow, go from 7mhz transducer to the 5 MHz transducer, decrease baseline/Doppler scale
What is the angle of insonation, the angle I should duplicate:
As close to 60 degrees as possible, but not over
Basilar artery is formed by the confluence of what vessels?
Confluence of the right vertebral artery & left vertebral artery
A 75 yr old man complains of right arm weakness lasting most the day, what would these symptoms be classified as?
TIA(transient ischemic attack
How does the adventital layer of the internal carotid artery receive oxygen & nutrients and get rid of waste?
By the Vaso vasorum
In a TCD(transcranial Doppler exam) what windows are used?
Suboccipital, transtempral, transorbital. Not transfontanel
A PT in ICU had a TDC study, the tech unable to obtain relevant diagnostic info, most reason a study can’t be performed?
There is inadequate penetration of the temporal bone from hyperostosis
A PT w/ blurry vision, what cerebrovascular disease most likely to cause this symptom?
The symptom is most likely related to vertebrabasilar insufficancy
When completing a TCD study, what depth most likely to find the siphon portion of the internal carotid artery?(ICA)?
60-80 mm
Elderly woman comes in w/ elevated , pulsatile mass in her neck, most common cause?
Tortuous vessel
A TCD ordered to evaluate intercranial circulation, what vessels will be evaluated through the into transforminal window?
Vetebral & basilar arteries
ICA can be identified by all of the following characteristics:
ICA larger, ICA more lateral ECA, more flow in ICA at the end of diastole than ECA, ICA has no branches in the neck
True about vetebral arteries:
The R & L vertebral artery is the first main branch off the R & L subclavian, R vertebral artery usually smaller than left artery, vertebral arteries carry blood flow in a cephalad direction, confluence of the vertebral arteries form basiliar artery, vertebral art no blood supply to high resistant vascular bed
A PT is asymptomatic w/ a carotid bruit, duplex study found to have stenosis that equals a less than 50% diameter reduction based on this, what would doc most likely recommend?
Take an aspirin a day
Most likely to eliminate aliasing?
Switch to lower frequency transducer, when scanning make vessel more superficial, minipulate baseline/scale settings, switch from pulse to continuous wave
A PT is in for a TCD for a recent CVA, your findings are consistent w/ an intracranial Arteriovenous malformation?
Increased systolic & diastolic flow velocities, reduced flow in adjacent arteries , very low pulsatility indices & low resistant flow patterns
What type if transducer most frequently used for TDC exams?
2 MHz pulsed Doppler probe
A Cerebral angiogram study finds significant lesion on right ICA, stenotic portion vessel measuring at 2mm, what is the diameter?
67% a normal ICA measures at 6mm
Angiogram found a significant lesion on right ICA, approximate 70% diameter reduction, what would you expect in peak systolic velocities(PSV) & end diastolic velocities(EDV) measurements?
The carotid duplex would likely document PSVf of 346 cm/sec with EDV of 124. EDV of less of 140 cm/sec is consistent w/ an 80-98% reduction
Woman evaluated for vasospasm from a subarachnoid hemorrhage secondary to a ruptured aneurysm, what’s true about utilizing TDC for that purpose?
A mean velocity of >120 cm/sec is consistent w/ vasospasm
70 yr old man complains of right arm weakness lasting most the day, what would this symptom be classified as?
TIA , transient ischemic attack
An atherosclorosis plaque may be described as containing intra-plaque hemorrhage, what are the b-mode characteristics?
Well defined anechoic or sonolucent area seen with in plaque
A carotid duplex study on a PT w/ an acute onset of behavioral changes and right facial numbness, symptoms caused by a lesion in which vessel?
Left middle cerebral artery
Best way to differentiate between ICA & ECA when scanning carotid duplex?
ICA is low resistant, ECA is usually high resistant
In ICA terminates in which vessels?
Middle cerebral artery and anterior cerebral artery
What angel is assumed when performing TDC(transcranial Doppler) exam?
A zero angel of insonation is assumed
A 30 yr old PT is evaluated for vasospasm from subarachnoid hemorrhage secondary to a ruptured aneurysm, what’s true about utilizing TDC for this purpose?
A mean velocity of >120 cm/sec is consistent with vasospasm
A PT needs a coranary artery bypass grafting, no history of CVA/TIA, probable occlusion on R. ICA in current carotid duplex, what is least likely to provide collateral flow to the right hemisphere & explain why PT is asymptotic?
Left posterior cerebral artery does not connect to left anterior cerebral artery
During a TDC that requires in-depth knowledge of the vessels that comprise the Circle of Willis as well as other intracranial arteries, what vessels normally have highest velocities?
Middle cerebral artery
A 35 yr old in a motor vehicle accident w/ multiple abrasions & a left carotid bruit, what are these pathology findings?
You anticipate seeing evidence of a carotid dissection
A carotid duplex exam includes auscultation of the cervical carotid arteries to identify a bruit, also palpate to evaluate their strength & symmetry, what can be a result of stimulating the carotid sinus during palpation?
Bradycardia