Duplex Ultrasound of Lower Extremity Arteries - Ch. 12

A radiologic imaging technique performed using ionizing radiation to provide detailed arterial system configuration and pathology information.

contrast arteriography

A localized dilation of an artery involving all three layers of the arterial wall.

aneurysm

Ultrasound imaging of the arterial system performed to identify atherosclerotic disease and other arterial pathology, providing a detailed map of the arterial system evaluated.

duplex arteriography

The deposit of fatty material within the vessels walls, which is characteristic of atherosclerosis.

plaque

What is the main technical limitation in the routine use of duplex ultrasound instead of contrast angiography to visualize the arteries of the lower extremities due to?

a. Most plaque will be calcified

b. Most equipment does not have that imaging capacity.

c. Most sonographers are not trained to obtain diagnostic data.

d. Most physicians are not trained to interpret data.

a. 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?

a. the anterior tibial artery

b. a geniculate artery

c. a gastrocnemius artery

d. the tibioperoneal trunk

c. a gastrocnemius 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. the peroneal artery

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. Using both transverse and longitudinal planes

What is the primary tool to evaluate disease of the lower extremity arteries using duplex ultrasound (at the exception of aneurysm)?

a. aliasing on color Doppler

b. B-mode imaging

c. color display with power Doppler

d. peak systolic velocity

d. peak systolic velocity

How is the velocity ratio (Vr) calculated?

a. PSV at stenosis divided by PSV proximal to stenosis

b. PSV proximal to stenosis divided by PSV at stenosis

c. PSV at stenosis divided by PSV distal to stenosis

d. PSV distal to stenosis divided by PSV at stenosis

a. PSV at stenosis divided by PSV proximal to stenosis

Which of the following is NOT a consideration when assessing for the possibility of treatment of an arterial lesion by angioplasty or stenting (or both)?

a. size of the artery

b. position of the branches

c. length of the stenosis

d. location of the stenosis

b. position of the branches

Why does duplex ultrasound have an advantage over contrast angiography for the examination of vessel walls?

a. The plaque thickness can be measured.

b. The plaque characteristics can be determined.

c. The wall thickness can be measured.

d. The remaining lumen can be measured.

c. The wall thickness can be measured.

Which of the following is a main pitfall of duplex ultrasound (in general) in examining arterial disease?

a. flow at velocities less than 20 cm/s

b. flow at velocities over 400 cm/s

c. length of occluded segment

d. collateral vessels

a. flow at velocities less than 20 cm/s

When using duplex ultrasound to record slow flow (<20 cm/s) in an arterial segment, which of the following adjustments would NOT be useful?

a. Decrease the PRF

b. Use a low wall filter

c. Increase the persistence of color

d. Decrease the Doppler gain

d. Decrease the Doppler gain

When assessing the appearance of plaque on a grayscale image, what might an irregular plaque surface indicate?

a. stable plaque unlikely to rupture

b. an area of necrosis

c. an area of ulceration

d. thrombus formation on top of the plaque

c. an area of ulceration

Why is reporting the presence of a partial thrombus in an aneurysm important?

a. Partial thrombus may not be visible on contrast angiography.

b. Pieces of thrombus can embolize.

c. The lumen may not be enlarged.

d. It will likely proceed to an acute occlusion.

b. Pieces of thrombus can embolize.

When can a greater than 70% stenosis in any arteries of the lower extremities be safely inferred?

a. The PSV is half distal to the stenosis.

b. The PSV is doubled at the stenosis.

c. The Vr is equal to or greater than 2.

d. The Vr is equal to or greater than 3.

d. The Vr is equal to or greater than 3.

How is low-resistance blood flow characterized on a Doppler spectrum?

a. antegrade flow throughout diastole

b. antegrade flow in systole only

c. retrograde flow in systole

d. sharp downstroke in early diastole

a. antegrade flow throughout diastole

Which of the following is NOT a potential pathologic finding when the Doppler spectrum of an artery of the lower extremity displays low-resistance characteristics?

a. arteriovenous fistula

b. postreactive hyperemia

c. cellulitis

d. trauma

b. postreactive hyperemia

Doppler spectra with a characteristic low-resistance outline may be seen distal to a hemodynamically significant stenosis. What will the Doppler spectra also display?

a. delay on the downstroke in systole

b. delay on the upstroke in systole

c. retrograde flow in diastole

d. retrograde flow in systole

b. delay on the upstroke in systole

What characteristic outline will Doppler spectra in an arterial segment proximal to a hemodynamically significant stenosis or an occlusion have?

a. no flow in diastole

b. no flow in systole

c. retrograde flow in diastole

d. retrograde flow in systole

a. no flow in diastole

Which of the following is NOT a factor typically associated with the need to perform contrast angiography after a limited duplex ultrasound of the arterial system?

a. high infrapopliteal vessel calcification

b. limb-threatening ischemia

c. female gender

d. older age

c. female gender

Why is the use of contrast angiography in diabetic patients particularly worrisome?

a. ionizing radiation

b. nephrotoxic agents

c. poor visualization of calcified segments

d. poor visualization of low flow

b. nephrotoxic agents

What aspects of duplex ultrasound assessment of the lower extremity arteries allow better estimation of the true hemodynamic significance of an arterial lesion, when compared to contrast angiography?

a. Doppler spectrum analysis and color Doppler

b. Doppler spectrum analysis only

c. power and color Doppler

d. flow velocities and velocity ratios

a. Doppler spectrum analysis and color Doppler

Conditions and risk factors for which patients are referred for duplex ultrasound of the lower extremity arteries are ____________________ as those for indirect physiologic testing.

the same/similar

The below-knee segment of the popliteal artery is best examined through a ___________________ approach.

posterior

Most arteries of the lower extremity can be examined by duplex ultrasound using a ____________________ approach.

medial

The two arteries or arterial segments, which cannot be well examined with duplex ultrasound via a medial approach, are the popliteal artery and _______________________________.

the anterior tibial artery

The superficial femoral artery typically changes name to become the popliteal artery as the vessel exits the __________________________________.

adductor or Hunters canal

On a posterior approach of the upper calf, the artery branching off the popliteal artery deep to the popliteal artery is most likely the ______________________________.

anterior tibial artery

In general, color and power Doppler's primary advantages is for _____________________ and tracking of the vessels.

localization

When an occlusion is discovered during duplex assessment of the lower extremity arteries, documentation of where the vessel is ________________________ by collateral flow is useful to the vascular surgeon.

reconstituted

To evaluate the dorsalis pedis and distal posterior tibial arteries adequately, a sonographer should be particularly careful with the ___________________ from the transducer.

pressure

Duplex ultrasound is superior to contrast angiography in determining a suitable site for the distal anastomosis of a graft because it can detect the _____________ area of the vessel wall.

softest

Using a lower frequency transducer to view the SFA at the adductor canal or the tibioperoneal trunk at the upper calf will reduce ______________________.

resolution

Determining/characterizing the "nature" of a plaque or wall thickening is important information a sonographer can convey to a surgeon because ______________ through a calcified plaque is almost impossible.

suturing

Although the peak systolic velocity (PSV) is the primary measurement obtained, stenosis are classified based on _______________________.

Vr (velocity ratio)

Using duplex ultrasound instead of contrast angiography in patients with severe-to-critical limb ischemia is recommended because the examination with duplex is more ______________________________.

expeditious

A vessel is considered aneurysmal if the diameter is _______________ times greater than the more proximal segment.

1.5

Very low flow, particularly to assess the patency of possible outflow vessels, is more easily achieved with duplex ultrasound than with contrast angiography with the use of _________________________.

power Doppler

When assessing the lower extremity arterial system with a duplex ultrasound, only the first few centimeters of the _____________________________ artery are evaluated.

profunda femoris

Distal to a hemodynamically significant stenosis, the Doppler waveform demonstrates poststenotic __________________.

turbulence

At a measured diameter of 1.1 cm, a common femoral artery would be considered ____________, whereas a popliteal artery that measures 1.1 cm would be considered ______________________.

normal

dilated/aneurysmal

As compared to contrast arteriography, duplex ultrasound allows direct visualization of the entire artery and not just the ________________.

lumen