Clinical Prep quiz 3

Which spectral Doppler parameter represents the highest velocity reached during systole?

C. PSV

A hemodynamically significant stenosis is best defined as:

C. A narrowing where increased velocity can no longer maintain distal pressure and flow volume

Approximately what diameter reduction in a carotid artery may begin producing distal pressure and flow volume changes?

C. 50%

A 70% diameter reduction in a large vessel such as the aorta corresponds to approximately:

D. 90% area reduction

Distal to a hemodynamically significant stenosis, which combination is expected?

C. Decreased RI and decreased PI

Which waveform characteristic is most consistent with a tardus-parvus pattern?

B. Delayed acceleration and dampened systolic peak

Which vessel normally demonstrates the lowest resistance waveform?

C. ICA

Which vessel normally demonstrates the highest resistance waveform?

C. ECA

According to the modified IAC 2021 carotid criteria, a normal ICA PSV is:

C. <180 cm/sec

Which combination suggests ≥70% ICA stenosis?

B. PSV 240 cm/sec, ratio 4.5, EDV 110 cm/sec

An ICA/CCA PSV ratio greater than what value supports ≥70% ICA stenosis?

C. 4.0

Which additional parameter supports ≥70% ICA stenosis?

D. EDV >100 cm/sec

The angle of insonation is defined as the angle between:

B. Flow jet and Doppler beam

The most accurate velocity measurement occurs when the Doppler beam is:

D. Parallel to flow

Increasing the Doppler angle without correction will:

B. Decrease measured velocity

Which action helps reduce velocity overestimation?

C. Use smaller Doppler angle correction

A normal peripheral arterial waveform is:

C. Multiphasic and highly pulsatile

Loss of multiphasic flow in a lower extremity artery most commonly suggests:

B. Proximal or distal arterial disease

Which Doppler finding suggests inflow disease?

B. Tardus-parvus waveform

A vessel distal to a severe stenosis is expected to demonstrate:

C. Dampened waveform morphology

What effect do arterial stents have on vessel compliance?

C. Reduce compliance

Why can velocities appear elevated in a normal stent?

A. Compliance is reduced

Which carotid vessel should normally demonstrate the greatest amount of diastolic flow?

C. ICA

Well-maintained antegrade diastolic flow is normally seen in the:

A. ICA and vertebral arteries

Central upper extremity venous flow should normally be:

B. Pulsatile, spontaneous, and phasic

Normal lower extremity venous flow should be:

B. Phasic with respiration

Distal compression during venous Doppler should produce:

C. Augmentation of flow

Normal renal artery PSV should be:

C. ≤200 cm/sec

A normal renal artery-to-aortic ratio (RAR) is:

C. ≤3.5

Which acceleration time suggests a normal renal artery waveform?

D. 60 ms

Normal hilar acceleration time should be:

B. ≤70 ms

Normal hilar acceleration index should be:

C. ≥300 cm/s²

A renal artery waveform with prolonged acceleration time and decreased acceleration index suggests:

C. Proximal renal artery stenosis

Normal renal RI should be:

D. ≤0.8

A renal AVF most commonly occurs as a complication of:

C. Renal biopsy

Which Doppler finding is classic for a renal AVF?

B. Very high PSV and EDV

Which waveform feature is most characteristic of an AV fistula?

B. Continuous high-volume low-resistance flow

Patent foramen ovale occurs in approximately what percentage of people?

D. 25%

During a TCD bubble study, which artery is commonly monitored?

C. Right MCA

The standard agitated saline mixture used for PFO testing consists of:

C. 9 mL saline and 1 mL air

A carotid waveform demonstrates PSV 260 cm/sec, EDV 85 cm/sec, and ICA/CCA ratio of 4.6. Which parameter prevents classification as ≥70% stenosis using modified criteria?

C. EDV

Which vessel would be expected to have the lowest pulsatility index under normal conditions?

C. ICA

A decrease in RI distal to a stenosis primarily occurs because:

B. Pulsatile energy is dampened

What primarily causes a decrease in RI distal to a stenosis?

B. Pulsatile energy is dampened

Which waveform change is most suggestive of severe proximal disease?

C. Tardus-parvus morphology

What should be suspected if a vessel demonstrates preserved PSV but markedly reduced PI?

A. Distal vasodilation or significant proximal disease

Which factor contributes to the backward component of an arterial pressure wave?

B. Capillary bed resistance

Which arterial system normally generates the most prominent reversal component?

C. Lower extremity muscular circulation

What does a vertebral artery with continuous antegrade flow and excellent diastolic flow indicate?

A. Normal

Which waveform finding would most strongly suggest distal arterial occlusion?

A. Increased diastolic flow proximal to lesion

Why does flow velocity increase through a stenosis?

B. Continuity principle

What is the greatest concern when using a Doppler angle of 75°?

B. Significant velocity error from minor angle changes

Which Doppler angle should generally be avoided due to large velocity inaccuracies?

D. >70°

Which parameter is more specific and less likely to produce false-positive carotid stenosis diagnoses?

C. EDV

What is the most likely stenosis category for a carotid lesion with PSV 250 cm/sec and EDV 45 cm/sec?

C. 50-69%

Which finding most strongly suggests near occlusion?

C. Variable or undetectable velocities despite visible lumen narrowing

What waveform characteristic is expected immediately distal to a severe stenosis?

C. Delayed systolic acceleration

What does an acceleration time of 140 ms suggest in renal Doppler evaluation?

C. Proximal renal artery stenosis

Which renal measurement is abnormal?

D. AI 250 cm/s²

What is the most accurate finding for a renal artery with PSV 220 cm/sec and RAR 2.8?

B. Findings are borderline and require correlation

Which finding is most suggestive of renal vein thrombosis?

B. High-resistance arterial waveform with reduced diastolic flow

Which vessel normally has the highest amount of antegrade diastolic flow?

C. ICA

What does a lower extremity artery with monophasic flow throughout the leg most likely indicate?

B. Severe inflow disease

What is the most likely explanation for a stented artery with mildly elevated velocities but normal morphology?

B. Reduced vessel compliance from the stent

Which finding is most concerning for in-stent restenosis?

B. Focal velocity acceleration within the stent

What should normal central venous flow be like?

B. Pulsatile and respiratory phasic

What does loss of respiratory phasicity in a common femoral vein most strongly suggest?

B. Proximal venous obstruction

Which venous maneuver should create augmentation?

B. Distal compression

What does equal augmentation at both common femoral veins help exclude?

B. Iliac obstruction

Why is a dialysis access fistula intentionally created?

B. Create steady high-volume flow for dialysis

Which vessel serves as inflow in a typical radiocephalic AVF?

B. Radial artery

What should a functioning AVF generally produce?

B. Low-resistance arterial inflow

Which pathology produces some of the highest Doppler velocities in vascular ultrasound?

B. Renal AVF

When is a PFO study considered positive?

B. HITS are detected in the MCA after injection

Why is Valsalva performed during a PFO study?

B. Promote transient right-to-left shunting

Which statement regarding PFO is TRUE?

B. Occurs in approximately 25% of people

What does a waveform becoming less pulsatile but maintaining forward flow most likely indicate?

A. Reduced downstream resistance

Which measurement is most affected by poor angle correction?

B. PSV

Which spectral parameter requires PSV, EDV, and TAP for calculation?

C. PI

Which index most directly reflects downstream vascular resistance?

C. RI

What should a high-resistance vascular bed normally demonstrate?

B. Significant pulsatility and possible reversal component

What is the most likely stenosis category for a patient with ICA PSV 245 cm/sec, EDV 115 cm/sec, and ICA/CCA ratio of 4.8?

C. ≥70%

What is the most appropriate interpretation for a patient with ICA PSV 260 cm/sec and ICA/CCA ratio 5.0?

B. Findings favor 50-69% stenosis and require correlation

What is the most likely diagnosis for a lower extremity arterial waveform demonstrating delayed systolic acceleration, rounded systolic peak, and loss of pulsatility?

B. Severe proximal inflow disease

Where is the most likely lesion if a common femoral artery waveform is monophasic and popliteal and tibial arteries are also monophasic?

C. Iliac inflow segment

Why does a waveform proximal to an arterial occlusion demonstrate increased diastolic flow and reduced resistance?

A. Blood is diverted into collateral pathways

What is most likely indicated by a hilar acceleration time of 145 ms and acceleration index of 180 cm/s² during renal Doppler interrogation?

C. Proximal renal artery stenosis

What diagnosis is most likely for a renal artery PSV of 230 cm/sec, RAR of 4.2, and prolonged hilar AT?

B. Significant renal artery stenosis

What is the most likely explanation for a patient with difficult-to-control hypertension and PSV 350 cm/sec in the proximal renal artery?

A. Renal artery stenosis

What is the most likely diagnosis for a renal Doppler exam demonstrating very high PSV and EDV with marked color bruit in the renal parenchyma after a biopsy?

C. Renal AVF

What is the most likely explanation for a dramatic increase in PSV when changing the angle correction from 60° to 75° during carotid imaging?

C. Velocity overestimation due to angle error

What is the most appropriate interpretation for a vertebral artery demonstrating antegrade flow with abundant diastolic flow?

B. Normal vertebral artery

What should be suspected if a vertebral artery demonstrates a high-resistance waveform with markedly reduced diastolic flow?

A. Distal vertebral obstruction

What should be suspected if a patient demonstrates monophasic venous flow in the common femoral vein with loss of respiratory phasicity?

B. Iliac vein obstruction

What is the most likely explanation for absent distal augmentation in the femoral vein?

B. Distal obstruction or thrombus

What is the correct interpretation for a functioning dialysis fistula with low-resistance flow and elevated diastolic velocities in the inflow artery?

A. Normal functioning access

What is most likely indicated by a focal PSV increase from 150 cm/sec proximally to 600 cm/sec at one location in a dialysis graft?

B. Graft stenosis

What is the most likely stenosis category for a patient with ICA PSV 160 cm/sec, EDV 35 cm/sec, and ICA/CCA ratio 1.8?

A. Normal or <50%

What is the most likely stenosis category for a carotid lesion demonstrating PSV 220 cm/sec, EDV 95 cm/sec, and ratio 3.8?

B. 50-69%

What is the most likely stenosis category for a carotid lesion demonstrating PSV 240 cm/sec, EDV 120 cm/sec, and ratio 4.5?

C. ≥70%