Chapter 12: Duplex Ultrasound of Lower Extremity Arteries Flashcards
A localized dilation of an artery involving all three layers of the arterial wall
aneurysm
A radiologic imaging technique performed using ionizing radiation and intravascular contrast material to provide detailed arterial system configuration and pathology information
contrast arteriography
ultrasound imaging of the arterial system performed to identify atherosclerotic disease and other arterial pathology and establish a detailed map of the arterial system evaluated
duplex arteriography
the deposit of fatty material within the vessel walls, which is characteristic of atherosclerosis
plaque
Normal lower extremity arterial finding
walls smooth and uniform
no focal areas of increased PSV
slight change in PSV across segments of arterial tree
multiphasic waveform with reverse flow component
uniform color filling
Stenotic lower extremity arterial finding
wall thickening
calcification
plaque encroaching into vessel lumen
focal increase in PSV
Poststenotic turbulence
Vr > or equal to 2.0
Monophasic waveform distally with no reverse flow and continuous flow in diastole
focal area of aliasing
turbulence distally
Aneurysm lower extremity arterial finding
increased diameter 1.5 times larger than adjacent more proximal segments
turbulence within dilated area
no color filling
gold standard imaging tool to evaluate peripheral arterial system; associated with systemic and local complications
contrast arteriography
indications of acute arterial ischemia
pallor
pulselessness
paralysis
parasthesia
intense pain
pulsatile mass detected in femoral or popliteal regions
peripheral arterial aneurysms
Primary pathologies suspected for arteriography
atherosclerotic
aneurysmal diseases
The SFA passes through the ______ and then becomes the popliteal artery.
adductor canal (Hunter’s canal)
The anterior tibial artery branches off the _____ artery.
popliteal
slightly smaller in diameter than the popliteal artery
3-5 cm longer
tibioperoneal trunk
The tibioperoneal trunk bifurcates into the _____ and _____.
peroneal artery
posterior tibial artery
Primary tool to categorize disease
velocity spectra
Velocity ratio calculation
PSV at stenosis divided by PSV just proximal to stenosis
used to estimate degree of stenosis
velocity spectra
______ can detect flows as low as ____.
2 cm/s
Most common problem with duplex arteriography
arterial wall calcification
Calcifications produce ______.
acoustic shadowing
Most plaque will appear ______.
heterogeneous
Irregulary surfaced plaques may represent _____ lesions.
ulcerative
A vessel is diagnosed as aneurysmal if the diameter is ____ times greater than the adjacent more proximal segment.
1.5
What will color flow imaging look like in areas of disease?
color aliasing
color flow channel within lumen reduced
color bruit may be present in surrounding tissue
primary measurement for severity of stenosis
PSV
A PSV Vr of ____ indicates a stenosis 50% or greater.
2-2.5
A PSV Vr of _____ indicates a stenosis 70% or greater.
3-3.5
normal or mildly diseased
> 50%
moderately diseased
50-69%
severely diseased
70-99%
high resistance, multiphasic waveform; sharp upstroke to peak systole maintained
normal peripheral arterial bed
vessel distal to disease will display a low-resistance signal with antegrade flow through diastole; delayed rise time to peak systole
significant arterial disease or occlusion
waveforms can display very high resistance pattern with only an antegrade flow component during systole and no flow during diastole
vessels proximal to occlusion or near occlusion
Used when DA not able to provide adequate imaging
standard percutaneous preoperative CA
_____ can identify arterial segments, while ___ cannot.
duplex arteriography
contrast arteriography
________ can be efficiently used for evaluation of the lower extremity arteries and is particularly helpful in patients being evaluated for lower extremity revasculartization.
Duplex ultrasound
What is the main technical limitation in the routine use of duplex ultrasound instead of contrast angiography to visualize arteries of the lower extremities due to?
most plaque will be calcified
On a posterior approach of the popliteal fossa, what is the branch identified on the anterior aspect of the image in relation to the popliteal artery?
gastrocneumius artery
Which artery is best visualized by a posterolateral approach at the level of the calf?
a. the posterior tibial artery
b. the peroneal artery
c. the popliteal artery
d. the tibioperoneal trunk
b
Which method represents good practice to thoroughly evaluate arterial disease in the lower extremities when using B-mode to view the vessel?
a. viewing in sagittal only
b. viewing in transverse only
c. moving from medial to lateral
d. using both transverse and longitudinal planes
d
What is the primary tool to evaluate disease of the lower extremity arteries using duplex ultrasound (with the exception of aneurysm)?
peak systolic velocity
How is the velocity ratio calculated?
PSV at stenosis divided by PSV proximal to stenosis