Cerebrovascular Test Q&A Flashcards
80-99% stenosis. critical
Peak systolic velocity: >250 cm/s
End diastolic velocity: >100 cm/s
Systolic velocity ratio: >3.7
Diastolic velocity ratio: >5.5
A contralateral ICA occlusion may cause what to the ipsilateral side?
increased flow to the side with the lesser stenosis. causes PSV to be higher than expected. (pg 80)
The carotid body assists in regulating all what?
blood to the internal and external carotid arteries
What are the warning signs of a stroke?
aphasia
dysphasia- impairment of speech, arrange words
dysphagia
dysarthria- slurring due to lack of muscle control
lateralized paresthesia- tingling and numbness
hemiparesis- lateralized weakness
hemiplegia- lateralized paralysis
transient monocular blindness (TMB)
amaurosis fugax- shade being drawn (pg 33)
Most common visualized branch of the ECA is what?
superior thyroid (pg 36)
The inability to speak or express oneself?
aphasia (pg 33)
The innominate artery divides into two arteries, what are they?
common carotid and subclavian (pg 35)
60-79% stenosis, severe
Peak systolic velocity: >130
End diastolic velocity: >40
Systolic velocity ratio: >1.8
Diastolic velocity ratio: >2.6
vertebral- basilar symptoms
drop attacks
syncope
vertigo
dizziness
diplopia
binocular blindness (pg 33)
An abnormal spectral waveform from the ICA suggests what?
stenosis
Vertebral arteries bilaterally are typically the same, this means they are____
antegrade (pg 92)
The Doppler sample volume should be kept where in the vessel?
in the middle of the lumen (pg 55)
when plaque is present, sample at site of max stenosis (pg 75)
Vertebral waveform
A systolic velocity recorded from the origin of the ICA is < 125 cm/s, according to the chart, what does this tell us?
40-59% stenosis, moderate
What is retrograde and what are the causes?
reverse of flow within a vessel
subclavian steal
occlusion
What disorder has symptoms resolved but not within 24 hrs?
reversible ischemic neurologic deficit (RIND)
(pg 33)
CCA waveform
Transient partial or complete loss of vision is what?
binocular blindness (pg 33)
What are ultrasound findings of an ICA occlusion?
Use color Doppler at normal and low PRF
Establish no flow in multiple sites
ICA may be contracted inappearence
Rule out technical problems
ECA may function as a collateral pathway to the distal ICA. Facial and superfical temporal arteries are well developed. Blood flow in a retrograde fashion to reconsitute. ECA waveform changes and may demonstrate low resistance. (pg 76)
The union of vertebral arteries forms to join what vessel?
basilar artery (pg 35)
What is CVA and what does it cause?
Cerebrovascular accident
completed brain stroke (pg 33)
The degree of stenosis at the origin of the ICA is determined by?
NASCET (pg 69)
A difference of 20 mmHg of pressure between both arms suggests disease of what vessel?
subclavian stenosis on the side with low pressure (pg 94)
40-59% stenosis, moderate
peak systolic velocity: <130
End diastolic velocity: <40
systolic velocity ratio: <1.8
diastolic velocity ratio: <2.6
ischemia
an inadequate blood supply to an organ or part of the body, especially the heart muscles
An ultrasound finding of a Doppler signal from the ECA, what kind of flow?
high resistance (pg 53)
contralateral
relating to the side of the body opposite to that on which a particular structure or condition occurs.
ipsilateral
belonging to or occuring on the same side of the body
0-39% stenosis, mild
Peak systolic velocity: < 110 cm/s
End diastolic velocity: < 40 cm/s
Systolic velocity ratio: < 1.8
Diastolic velocity ratio: < 2.6
Name the disorder that symptoms occur and are resolved within 24 hrs?
transient ischemic attack (TIA) (pg 33)
If you see a sonolucent area within plaque, what could it represent?
intraplaque hemorrhage (pg 84)
When determing the ICA/CCA ratio, the CCA should be determined from what portion of the CCA?
mid/distal CCA (pg 52)
100% occlusion
No flow
What is there to know about tortuous vessels?
composed of twists and turns
associated with fibromuscular dysplasia
fibrous thickening of the intima, media, or adventa
usually bilateral
associated with hypertension
prox and dist ICA spared
more common in women
A normal flow disturbance along the posterior surface of the bulb is what separation?
external and internal carotid
What is TIA and what is the long term outcomes?
Transient Ischemic Attack
Symptoms resolve within 24 hrs (pg 33)
What is a characteristic of a subclavian steal?
- more common on left side
- prox subclavian stenosis can cause ipsilateral vert flow to reverse to supply blood to arm. controlateral vert flow increases to provide flow to arm
- usually does not cause neurological symptoms
- with severe carotid disease, flow in basilar may reverse causing neurologic symptoms, subclavian steal syndrome
- retrograde flow in rt vert and prox subclavian usually indicates innominate obstruction.
when you put the doppler sample in a vessel it should be parallel to what?
the vessel wall
What is the most valuable tool for us when determining a stenosis?
color and spectral doppler (pgs 49 & 51)
duplex imaging
The North American Symptomatic Carotid Endarterectomy Trial
(NASCET)
Published in 1991 showed benefit from endartectomy vs medical treatment in patients with > 70 % stenosis. Used a new standardized method of measuring stenosis on carotid angiograms. Residual lumen at max stenosis was measured with calipers and compared to the diameter of the distal lumen of the ICA. (pg 70)
What kind of flow pattern is the ICA?
low resistance (pg 53)
ICA waveform
ECA waveform
