CV Pathology Flashcards
What are the stages of plaque development
Intimal cell mass
Insudation of LDL into intimal cell mass
Damaged endothelium allows platelets to adhere to exposed subendothelial collagen stimulating fibrous plaque growth
Angiogenesis of vaso vasorum
Plaque surface ulcerates and thrombus forms on luminal surface
what is are these images demonstrating?
what are the risk factors?
atherosclerotic plaque early stage (Traditionally sonographically we don’t see any changes until step 3, fibrous plaque. Studies have shown intima- medial thickness measurements can “predict” further plaque development. With changes in life style and medication to slow process)
LDL levels
Intimal injury – HTN, smoking, DM
Platelet aggregation – low dose anticoag meds
identify what type of plaque
what are their characteristics?
all Heterogeneous - mixed echoic pattern. Homogeneous is- uniform plaque texture
what are teh 5 carotid plaque types, characteristics and risk of symptoms?
what type of plaqe is shown here?
smooth plaque
what type of plaque is this
irregular, complex. older, has been there longer b/c hyperechoic
what types of ulcerative plaque are there?
what is it a concern for?
Ulceration:
heterogeneous
sharp, irregular borders
≥ 2mm defect
Intraplaque hemorrhage (IPH) from vaso vasorum:
sonolucent region
eggshell pattern
embolism
what are the goals for identifying plaque?
1) identify presence of plaque
2) characterize the plaque (echogenicity, ulcerations)
3) determine percent of stenosis
if stenosis is <60% there are __ ______ changes
what method of imaging do we use?
no hemodynamic
2D or B-mode
If stenois is ___ % the hemodynamic changes are better; provided there is not ___ (3)
what do you compare your mapping of stenosis to?
60%
Proximal stenosis
Distal occlusion
Heart disease
*Compare to “gold standard” angiogram - complex (maps out vascular tree incl circle of willis for surgeon)
if < ___ %, no hemodynamic changes
the velocity will still look pretty normal but will have to use 2D to get the %.
what did they use to base % of stenosis on before they used 2D or B-mode?
how reliable is spectral broadening grading?
0-49% based on presence of spectral broadening
(Original carotid frequency criteria developed before
B-mode quality was improved)
unreliable
what are the Causes for spectral broadening unrelated to stenosis (4)?
Gate placement near wall or outside vessel
Wide gate
Excessive Doppler gain
Poor Doppler angle (>70 degrees)
what does the 2D bulb method grade?
what else is is used to base the % of stenosis w/ this method?
0-49% stenosis
B-Mode image and
cross-sectional diameter calculation
what is the equation used to calculate stenosis usign 2D/Bulb method?
Percent stenosis based on residual lumen and true lumen at the same location
what does the Bluth Criteria or Bulb Method Angio demonstrate?
Percent stenosis based on residual lumen and true lumen at the same location
*anytime we are talking about % stenosis, the info is compared to a gold standard. meaning the exam we use is the “closest to truth”. in vasc, angiography is still considered the gold standard.
*stenosis is estimated by the % of remaining lumen
what are teh differences b/t angio and US in the bulb method?
what 2 methods are used for angio?
US - u can see vessel wall, angio you can’t. so they can underestimate in angio b/c they cannot see how wide the bessel is supposed to be as they can only see flow not vessel walls.
NASCET
ACAS
UIHC was part of study at ___ which helped to determine ___.
biggest risk of endarterectomy?
NASCET
at what % stenoss the risk of endarterectomy outweighs the benefits.
stroke
NASCET determined what?
ACAS determined what?
at what point a Pt goes to surgery . in 1998 - 50-69% and 1991 said >70%
cca reduced stroke by 5.8% over 5 yrs in asymptomatic pt w/ >or = to 60% ICA stenosis
what are teh problems w/ NASCET - ACAS measurements
Assuming a bulb diameter of 9 mm and distal ICA D of 5 mm
Comparison of angiogram measure methods
what does NASCET compare to ?
distal ICA
what did NASCET/ACAS do for sonography?
US lab QA analysis
Angio NASCET method may underestimate stenosis compared to US 2D method (b/c bulb is bigger than distal ICA)
These issues relate to 2D/Bulb method used with <50% stenosis
Angio NASCET method used to measure ____ stenosis
Since Doppler inaccurate for subcategorizing ___ subcategories for minor degrees of stenosis not be used
Stenosis must be categorized into at least:
percent
<50%,
Normal (no plaque seen)
<50%
50-69%
>70%
Near occlusion
Occlusion
what is doppler used to method?
Map the stenosis: Proximal, Max velocity in, Post stenotic turbulence
Measure - Peak systole, Peak end diastole
what are soem tips for mapping?
Work the Doppler sample volume through the stenotic region: think 3 dimensions!, take 2 or 3 samples (have to get the highest velocity), LISTEN for the highest jet
what are these examples of?
Peak systole will increase
Peak end diastole will begin to increase
Spectral broadening
As approach occlusion: Trickle flow, Velocities decrease
doppler changes w/ stenosis
Look at the waveforms
increasing peak systole
increasing end diastole
spectral broadening
Disregard velocities and
percent stenosis
what vessel?
what % stenosis?
ECA
80-99% stenosed (vel 354/167)
why do we put color on?
to provide a location of stenosis. we set our color gain to just alias.
Significant velocity acceleration occurs at stenosis of ____ diameter or greater
Velocities do not appreciably increase over stenosis less than ___ D
60%
50%
Most stenoses of > 60% cause significant _______.
A focal velocity acceleration over the plaque, followed by _____ is an essential finding for a 50-60% or greater stenosis
post-stenotic turbulence
turbulence
atient 3 has a rt distal CCA stenosis. you are unable to image the stenosis at the bulb in the tranverse due to shadowing from calcified plaque. the Rt ICA also shows clear aliasing and reversal of flow.
rt mid CCA PSV is 69 and EDV is 21. distal CCA PSV 49 EDV 13. in stenosis PSV 354 EDV 175 (spectral broadening) post-stenosis there is significant spectral broadening demonstrating turbulence. distal RT ICA there is still significant spectral broadening. the Rt ECA has a PSV of 97 (compensating w/ collateral flow. so may be stenosis in ICA if this is PSV is 97 here and 67 more distal)
What can be said about htis case? ICA/CCA ratio?
Unable to estimate diameter reduction from image due to calcified plaque.
Velocity decreases just before stenosis, then accelerates.
ICA/CCA ratio = 5.1
PSV 354 cm/s EDV = 175 cm/s
Severe post-stenotic turbulence which persists in the distal ICA
> 70% stenosis by NASCET method
> 80% stenosis by traditional criteria
what steps do you take to map a stenosis?
Identify plaque
Characterize
Map lesion – prox, jet, distal
PSV, EDV – look on the chart
Compare CCA to ICA
Compare to other side
If the ICA stenosis is less than 50%, what is the best method to determine percent stenosis?
spectral Doppler
B-mode
color Doppler
power Doppler
b-mode
Which of the following criteria must be present to indicate a greater than 50% stenosis?
peak systolic velocity of < 150 cm/s in the cerebrovascular system
plaque visualized on B-mode
peak systolic velocity of >150 cm/s in the cerebrovascular system
end diastolic velocity of > 60 cm/s in the cerebrovascular system
plaque visualization on b-mode
Using the Society of Radiologists in Ultrasound criteria table, given the following information, what is the percent stenosis?
\* focal area of plaque at the proximal ICA \* CCA peak systolic velocity of 80 cm/s \* Proximal ICA peak systolic velocity of 200 cm/s at focal area of vessel narrowing \* Proximal ICA end diastolic velocity of 65 cm/s at focal area of vessel narrowing \* Post stenotic turbulence in the ICA
<50%
50-69%
>70%
near occlusion
50-69%
Using the revised SRU criteria table, given the following information, what is the ICA/CCA peak systolic velocity ratio?
\* focal area of plaque at the proximal ICA \* CCA peak systolic velocity of 80 cm/s \* Proximal ICA peak systolic velocity of 200 cm/s at focal area of vessel narrowing \* Proximal ICA end diastolic velocity of 80 cm/s at focal area of vessel narrowing \* Post stenotic turbulence in the ICA
1
<2.0
- 5
- 0
2.5
Which of the following is a true statement about carotid duplex exam velocity criteria?
it should be used to categorize disease
it should be used to determine normalcy
velocity increases result only from focal vessel narrowing
velocity decreases only occur in post stenotic vessel widening
it should be sued to categorize dx
The vessel identified by the arrow is part of what circulation?
vertebrobasilar
anterior cerebrovascular
external carotid
posterior cerebrovascular
ant cerebrovascular
What vessel is identified by the arrow?
Basilar
ICA
CCA
Vertebral
vertebral
Where would the arterial obstruction be based on the direction of flow in these vessels?
right CCA
left CCA
left vertebral
left subclavian
lt subclavian
Where would the arterial obstruction be based on the direction of flow in these vessels?
left ECA
left subclavian
right subclavian
left CCA
lt CCA
