CMI 354 - TEST 2

What is the angle of insonation for a lower extremity arterial exam, extracranial carotid exam, transcranial doppler

60 or less

45-60

0

What is a carotid body tumor?

Rare

1-1.5mm mass of vascular tissue located in the adventitia of the carotid bifurcation

controls blood pressure and pH

blood supply comes from ECA

What is the circle of Willis, and what does it connect?

intracranial communication channel

connects the anterior and posterior circulatory systems

TIA?

Stroke in evolution?

RIND?

Completed stroke?

Brain death?

transient ischemic attack symptoms last from a few minutes to hours; 6% stroke risk; usually caused from heart or carotid artery emboli

symptoms come and go; unstable

last longer than TIA slightly longer than 24hr recovery; brain tissue is damaged but there is complete recovery

no progression or resolution of symptoms; considered stable

increasing pulsatility with end diastole reaching zero; reverberatory flow where forward and reverse flow are equal

Know the difference between normal vertebral artery vs retrograde vertebral artery

1. retrograde

2. vertebral artery

Where would you commonly find a pseudoaneurysm?

right common femoral artery

Label

1. transorbital

2. transtemporal

3. transcervical

4. transforaminal

What vessels can you see in these windows?

transorbital, transtemporal, transcervical, transforaminal

Ophthalmic artery and carotid siphon

MCA,TICA,ACA,PCA

CCA,ECA,ICA

vertebral and basilar arteries

Where direction does MCA go to transducer?

toward

Where direction does TICA go to transducer?

toward

What direction does ACA go to transducer?

away

What direction does PCA(p1) go to transducer?

toward

What direction does PCA(P2) go to transducer?

away

What direction does OA go to transducer?

toward

What direction does carotid siphon go to transducer?

toward

What direction does ICA go to transducer?

away

What direction does VA go to transducer?

away

What direction does BA go to transducer?

away

What are the characteristics of the ICA?

higher pitched and more continuous than ECA

less pulsatile with increased diastolic flow

does not touch baseline

low resistance

tri,bi,monophasic are not used to decribe cerebral vasculature

normal: <125cm/s; no visible plaque or intimal thickening

ICA/CCA ratio <2.0

What are the characteristics of the ECA?

lower pitched

more pulsatile than ICA

touches the baseline

high resistance

branch usually seen

Is the normal flow of the vertebral artery suppose to be antregrade or retrograde?

antregrade flow

What is the blood pressure in the subclavian steal?

>15-20mmHg pressure gradient in systolic pressure compared to contralateral side

Subclavian steal can ?

cause reversed flow in ipsilateral verterbral artery - subclavian “steals” from the vertebral artery

Label

1. anterior communicating artery

2. circle of willis

3. posterior communicating artery

4. basilar artery

5. left internal carotid artery

6. left vertebral artery

7. left subclavian artery

8. left common carotid artery

9. aortic arch

10. brachiocephalic artery

11. right subclavian artery

12. right vertebral artery

13. right common carotid artery

14. right internal carotid artery

15. posterior cerebral artery

16. opthalmic artery

17. middle cerebral artery

18. anterior cerebral artery

What is an aneurysm?

abnormal bulge, swelling, or ballooning in the weakened wall of an artery

vessel dilation >3cm

What makes up a true aneurysm vs a pseudoaneurysm?

true- dilation of all three layers of arterial wall

pseudo- pulsating hematoma; hole in arterial wall allows blood to escape under pressure into a contained area

What are the characteristics of the CCA?

waveform is a combo of ICA and ECA

filling in of spectral window is consistent with multiple frequencies and turbulent flow

What are the characteristics of vertebral arteries?

same characteristics as ICA - low resistance and antegrade flow

stenosis generally occurs at the vessel origin at the subclavian artery

normal PSV =30-50cm/s

What is a subclavian steal

severe stenosis or occulusion of the subclavian art prox to the origin of the vertebral art

most common on left side

patients are asymptomatic

flow resistance in the vertebral artery increases because its feeding a higher resistane bed of the upper extremity

What is the first major branches of the ICA and ECA?

ophthalmic artery

superior thyroid artery

What does the ICA and ECA supply blood to?

anterior brain, eyes, forehead, and nose; 70-80% of blood in the ICA comes from CCA

neck,face,and scalp

What risk factors are there for cerebrovascular disease?

hypertension

hyperchloesterolemia

diabetes

What is a temporal tap and what does it identify?

a technique where the superficial temporal artery is tapped while using doppler ultrasound

ECA

What is takayasu’s arteritis and temporal arteritis?

chronic inflammation that results in narrowing of the arteries; known as the pulse less disease

inflammation of the distal superficial temporal artery; servere headache and/or sudden unilateral blindness

What is a transcranial doppler?

low frequency pulsed doppler transducer with spectral analysis and M-mode to evaluate intracranial vessels

Cerebrovascular disease may be overestimated when?

artifact is mistaken for plaque

accelerated flow is mistakenly attributed to stenosis

inappropriate doppler angle used

Cerebrovascular disease may be underestimated when?

fails to appreciate very low-level echoes of soft plaque

missed accelerated flow

high bifurcation-harder to thoroughly evaluate ICA

inappropriate doppler angle used

When they clean out a artery what is it called?

angioplasty

hollow tube is threaded through a blood vessel

small balloon on the tip of the catheter it is inflated to push the plaque to the side of the vessel so blood flow can resume

What is turbulent flow and what are other causes than plaque buildup?

disorganized blood flow with multiple velocities and frequencies causing spectral broadening on doppler ultrasound

vessel tortuosity

sharp bends

branching or bifurcations

increased blood flow velocity

% stenosis: normal 1-15%, 16-49%

PSV=<125CM/S

EDV= N/A

% stenosis: 50-79%

PSV=>125cm/s

EDV= <140cm/s

% stenosis 80-99%

PSV=>125cm/s

EDV=>140cm/s

Where does the right CCA, left CCA, vertebral arteries arise from?

brachiocephalic artery

aortic arch

subclavian arteries

What does the CCA bifurcate into?

ECA and ICA

What happens to the ECA waveform during a temporal tap?

a sawtooth pattern appears on the doppler waveform

Antegrade flow or retrograde flow?

antegrade flow

Antegrade flow or retrograde flow?

retrograde flow