Flashcards in Cerebrovascular Deck (80):
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)?
Elderly woman comes in w/ elevated , pulsatile mass in her neck, most common cause?
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?
A carotid duplex showed a 16-49% reduction, did not correlate with findings of MRA, carotid duplex showed a preocclusive lesion, what is the best rationale for this discrepancy?
MRA tends to overestimate the disease process
Best way to differentiate between ICA & ECA when scanning?
ICA flow is usually(normally) low-resistant, ECA high resistance. ICA is lateral and larger
A TDC ordered to evaluate intracranial circulation, what vessels being evaluated through the transforaminal window?
Vertebral & basilar arteries
In a TDC scan you will utilize which acoustic window?
Transforaminal window, the vessels in this window vertebral & basilar
At what depth would you most likely find siphon portion of the internal carotid artery(ICA)?
True about atherosclerosis:
It effects intimal, medial and adventitial layers of arterial wall, causes thickning, hardening and loss of elasticity, decreased perfusion, damage to endothelial wall. Atheromatous plaque does not contain: lipids,fibrin or platlets
A 56 yr old a year ago had a right carotid endarterectomy, comes in for yearly exam has no bruits bilaterally no signs/symptoms, what could the tech anticipate finding when scanning right ICA?
A PT is being worked up for a TIA, the most likely symptom would be?
Hemiparesis, associated w/ a lesion in the ICA or one of its terminal branches
Completing a carotid exam on a 64yr old complaining of syncopal episodes, study showed smaller right vertebral artery as compared to the left, what is the finding?
Findings are in normal limits
A 72 yr old man w/ an asymptomatic carotid bruit, his carotid exam shows stenosis of less than 50% diameter reduction, based on this what would the doctor order?
PT would be instructed to take aspirin a day
Best method to differentiate between ICA & ECA?
ICA is normally low resistant, ECA is high resistant
During a carotid exam the spectrum from the right ICA is aliasing, what steps are effective in correcting aliasing & provide accurate PSV's?
Go.from 7MHz transducer to a 5, decrease baseline &/or increase Doppler, alter scanning plane to make vessel more shallow
When performing a transcranial exam, what direction of flow is expected in the middle cerebral artery(MCA) compared to anterior cerebral artery(ACA)?
MCA flow is antegrade, ACA flow is retrograde
What signs/symptoms associated with lesion in the internal carotid artery?
Aphasia, amaurosis, unilateral paresis, or paresthesia, won't have syncope
A PT is scheduled for a coronary bypass grafting, has probable occlusion if the right ICA is documented in carotid exam, what mechanisms provide collateral flow to the right hemisphere & why PT is asymptomatic?
Right external carotid art branches to right periorbital branches off ophthalmic art, to distal ICA
A PT is evaluated for a vasospasm from subarachnoid hemorrhage secondary to a rupture aneurysm, what's true about utilizing TDC for this purpose?
Serial studies need to be done, TDC has mean velocity of >120 cm/sec is consistent w/ vasospasm
Atheromatous plaque may be described containing intra-plaque hemorrhage, what are theses findings?
Well defined anechoic or sonolucent area seen within the plaque
Completing a carotid exam complaining of syncopal episodes, study finds smaller vertebral artery compared to left, what the conclusion?
This is in normal limits
A 65 yr old PT has frequent episodes of vertigo, had a previous heart attack resulting in coronary art bypass, peripheral pulses are palpable, no bruits detected. PT has hypertension & smokes, what causes these symptoms?
Basilar artery is formed by the confluence of what vessels?
Basilar formed by confluence of right vertebral art & left vertebral art
When utilizing a TDC study, which acoustic window won't be used?
What intracranial vessels can not be evaluated through the transtemporal window?
What does Atheromatous plaque look like on b-mode?
Anechoic or sonolucent area seen within plaque
A PT w/ a probable occlusion of R. ICA is documented by carotid duplex, no signs/symptoms, how can this PT get adequate perfusion of the R. Hemisphere resulting In lack of symptoms?
Left ICA to left ACA to anterior communicating artery to right ACA and right middle cerebral artery.
Another PT w/ no history signs/symptoms has occlusion on R. ICA, what mechanism least likely provide collateral flow to R. Hemisphere?
The left posterior cerebral artery does not connect to left anterior cerebral artery
A TDC scan ordered for a routine work-up for previous CVA, during exam you detect a intracranial Arteriovenous malformation, what flow patterns support this?
Reduced flow in adjacent arteries, very high pulsatility, increased systolic & diastolic velocities, low resistant not high
A doctor would ordered a day, aspirin has:
ASA is a antiplatlet drug, decreases platlet aggregation
Areas in of flow separation happen how?
The inverse relationship between pressure & kinetic energy. When CCA terminates in the ICA & ECA, the blue flow pattern seen at take off of ICA represents blue color is normal of flow separation
Secondary to subarachnoid hemorrhage is?
Intracranial Vasospasm, vasospasms have episode of high velocities >120, serial test necessary
A low resistant vascular bed will have
A lot of flow in end-diastole
True about vertebral arteries:
Vertebral art carry blood in cephalad direction, R & L vertebral arteries are first main branch off the R & L subclavian art, R vertebral smaller than left, confluence of vertebral art form the basilar art. Vertebral arteries prodominantly supply blood to brain & lower resistant vascular bed
In a TDC study, it begins w/ the transtemporal window, what vessel wont be evaluated through this approach?
During a TDC what direction of normal flow in MCA compared to ACA?
MCA is antegrade, ACA is retrograde
A PT having a GABG, what mechanism can give adequate perfusion to R hemisphere that results in lack of symptoms?
L. ICA to L. ACA to anterior communicating artery to R. ACA and R. Middle cerebral artery
A PT has a auscultation of cervical carotid art to identify a bruit, including a palpitation process to check strength & symmetry, what is a result in stimulating the carotid sinus during palpitation?
A PT has a suspected VBI, what would be sign/symptom?
A TDC requires info on the vessels that compromise the circle of Willis & other intracranial arteries, what vessel normally has the highest velocity?
Middle cerebral artery
FMD is evident in carotid exam in distal?
ICA,carotid & renal
A PT evaluated for blurry vision bilaterally, what cerebrovascular disease process is this related to?
What's a sign/symptom for a PT w/ a recent TIA?
Hemipairesis, associated w/ a lesion in ICA or one of its terminal branches
What arteries do not connect?
The left posterior cerebral artery does not connect to the left anterior cerebral artery
A PT w/ PSV of 559 and EDV's 242 in the left ICA, what would be sign/symptom?
Right leg numbness, right arm weakness, left hemisphere S/S, least likely is temp vision loss
A PT has right arm weakness lasting 15 hours w/ complete resolution, what would these symptoms be classified as?
Transient ischemic attack(TIA)
What is expected w/ a S/S of right ICA lesion?
Temp vision loss of right eye
Most used transducer frequency in a TDC?
2 MHz pulsed Doppler probe
A TDC ordered, however the sonographer was unable to obtain diagnostic information, why?
Inadequate penetration of temporal bone from hyperostosis
EDV's of >140 is consistent with an?
80-99% diameter reduction