Vascular Ultrasound and ABI Interpretation for Peripheral Arterial Disease

A patient has an ABI of 0.42. Which interpretation is best?

The PDF lists ABI

A patient has an ABI of 0.76. Which category does this fall into?

The PDF lists 0.5-0.9 as claudication/mild-to-moderate disease.

An ABI is 1.34 with an ankle pressure of 210 mmHg. What is the major concern?

ABI >1.30 is associated with medial calcification/noncompressibility.

Which brachial pressure should be used when calculating ABI?

Use the highest of the two brachial pressures.

A patient has ankle pressure of 72 mmHg. What concern is specifically associated with this value?

Ankle pressures

A serial ABI falls from 0.88 to 0.70. What does this change indicate?

A reduction >0.15 on serial exams indicates disease progression.

Which patient is the best candidate for TBI evaluation?

A patient with incompressible leg arteries from calcification.

A toe pressure is 24 mmHg. What does this indicate according to the PDF?

Toe pressure

A TBI is 0.15. Which symptom category is associated with this value?

TBI

A TBI is 0.35. Which category is listed?

TBI 0.2-0.5 is associated with claudication.

Which is the most common segmental pressure technique?

The 4-cuff method is the most common.

What is the key advantage of the 3-cuff technique?

It uses a larger thigh cuff and gives more accurate mid-thigh pressure.

What is a limitation of the 3-cuff method?

It cannot differentiate from popliteal disease.

A cuff is too wide during segmental pressure testing. What happens?

A cuff that is too wide causes pressure to be underestimated.

A cuff is too narrow during segmental pressure testing. What happens?

A cuff that is too narrow causes pressure to be overestimated.

Before segmental pressures, how long should the patient be supine?

10-15 minutes.

Why should the patient be kept warm during segmental pressures?

To prevent vasoconstriction.

Which pressure is obtained first in the sequence listed in the PDF?

Brachial pressure.

Which arteries are used for ankle pressure?

PTA and DPA.

What pressure difference between adjacent levels in the same leg is considered normal?

What pressure difference between the same level in both legs is considered normal?

Bilateral thigh pressures are below the highest brachial pressure. What disease is suspected?

Aorto-iliac disease.

An ankle pressure is 44 mmHg in a patient with nighttime burning foot pain. Which finding fits the PDF?

Rest pain is associated with ankle pressure

A patient develops predictable calf pain while walking that resolves with rest. What is this most consistent with?

Claudication.

A patient has buttock claudication. Which disease location is most consistent?

Aortoiliac disease.

A patient has thigh claudication. Which distribution is listed?

Iliac/femoral occlusive disease.

A patient has calf claudication. Which distribution is listed?

Femoro-popliteal disease.

A patient reports leg pain but the ABI increases or does not change after treadmill exercise. What does this suggest?

Pseudoclaudication.

What treadmill speed is listed for exercise testing?

1.5-2 mph.

A patient has true claudication during treadmill testing. What happens to ankle pressure?

It drops.

After exercise, a normal patient's pressure should return toward normal within approximately:

5 minutes.

After exercise, pressure/ABI recovery takes 8 minutes. What pattern is this associated with?

Multilevel obstruction; recovery is listed as 6-12 minutes.

What ankle pressure drop during reactive hyperemia indicates single-level disease?

35-50%.

What ankle pressure drop during reactive hyperemia indicates multilevel disease?

>50%.

What flow-velocity response is normal after the cuff is released during hyperemia testing?

>100% increase from resting velocity.

A patient has PVR waveforms with low amplitude and damping. What does this suggest?

Severe disease.

A PVR waveform loses reflection but maintains a sharp peak. What does this suggest?

Mild disease.

Why is PVR useful when arterial calcification is present?

PVR is not affected by calcified vessels.

What can PVR determine?

The level of obstruction but not its exact location.

Which is a PVR limitation?

Room temperature.

What is the most common limitation of digit pressures listed?

Room temperature and improper technique.

Which finding is characteristic of acute arterial occlusion?

Pain, pallor, pulselessness, paresthesia, paralysis, and polar sensation.

What is the critical issue with acute arterial occlusion compared with chronic occlusion?

Lack of collateral formation.

What is the most common symptom of PAD?

Claudication.

A patient has one or two ischemic toes rather than the entire foot. Which process is more consistent?

Arterial gangrene.

What is blue toe syndrome?

Embolic material lodging in a digital artery.

Which waveform change is most concerning for a proximal lower-extremity stenosis?

Triphasic to monophasic change in adjacent segments.

A lower-extremity PSV doubles compared with the pre-stenosis velocity. What degree of stenosis is listed?

50% stenosis.

A lower-extremity PSV increases fourfold compared with pre-stenosis. What degree is listed?

75% stenosis.

What happens to PI distal to a significant stenosis?

PI decreases.

What happens to acceleration time distal to stenosis?

Acceleration time increases.

What AT indicates inflow disease?

AT >140 ms.

CFA AT is >140 ms bilaterally. What is suspected?

Aortic disease.

CFA AT is >140 ms on one side. What is suspected?

Iliac disease.

What causes spectral broadening distal to a stenosis?

Turbulence.

What is the normal CCA PSV listed?

What is normal ICA EDV listed?

What is the normal ECA PSV listed?

Which waveform is normally low resistance?

ICA.

Which waveform is normally high resistance with minimal diastolic flow?

ECA.

What is the purpose of a temporal tap?

To differentiate the ECA from the ICA.

A patient has critical ICA stenosis. Which color Doppler finding is expected?

String flow sign.

Is a bruit expected with critical carotid stenosis?

Usually not; flow is greatly reduced.

Which finding confirms carotid occlusion most directly?

Absent distal ICA flow.

Which Doppler mode is preferred to confirm carotid occlusion?

Power Doppler.

What can the ipsilateral MCA show with ICA occlusion?

Decreased, blunted flow.

What indirect ECA finding can accompany ICA occlusion?

Decreased resistance with increased diastolic flow.

What is the most common site of vertebral artery stenosis?

Vertebral artery origin.

What vertebral PSV suggests stenosis?

PSV >100 cm/s.

What velocity ratio suggests vertebral stenosis?

Pre/post-stenotic ratio >2.0.

Loss of vertebral diastolic flow suggests what?

Distal occlusion.

What waveform is an early sign of subclavian stenosis?

Pre-steal/systolic deceleration.

When subclavian steal is suspected, what additional measurement should be obtained?

Bilateral brachial pressures.

What percentage of subclavian steal involves the left vertebral artery in the PDF?

85%.

What is the strongest stroke risk factor listed?

Hypertension.

What is the most common type of stroke listed?

Ischemic.

What percentage of strokes are listed as caused by ischemia?

85%.

Which carotid lesion presents the highest risk of TIA/stroke?

ICA stenosis.

TIA symptoms last:

A patient has neurologic symptoms lasting longer than 24 hours. Which term is used in the PDF?

CVA.

Right ICA stenosis would most likely produce which hemispheric motor finding?

Left-sided paresis/paresthesia.

Left ICA stenosis would most likely produce:

Right-sided paresis.

What is amaurosis fugax?

Temporary partial or total monocular blindness.

Which aphasia is expressive?

Broca aphasia.

Which aphasia is receptive?

Wernicke aphasia.

Which artery is associated with Wernicke aphasia and severe contralateral face/arm hemiparesis?

MCA.

Which artery is associated with severe contralateral leg hemiparesis and incontinence?

ACA.

Which artery is associated with dyslexia and coma?

PCA.

Which system is associated with vertigo, ataxia, diplopia, drop attacks, and dysphagia?

Vertebrobasilar system.

What is a drop attack?

Falling without loss of consciousness.

Which carotid plaque has the greatest embolization risk in the PDF?

Soft plaque.

What is intraplaque hemorrhage described as on ultrasound?

A sonolucent area within plaque.

What is the classic appearance of fibromuscular dysplasia?

String of pearls.

Where is FMD most commonly seen according to the PDF?

Renal arteries.

Where does carotid FMD typically occur compared with atherosclerosis?

Mid/distal ICA; atherosclerosis is in the proximal ICA.

What is the ultrasound appearance of an adventitial cyst of the popliteal artery?

Scimitar sign.

Which artery is most commonly affected by adventitial cystic disease?

Popliteal artery.

Which patient profile is most typical for adventitial cysts?

Young-to-middle-aged man.

What is the sonographic sign of carotid dissection?

Linear echogenic flap separating true and false lumens.

What can color Doppler demonstrate in a dissection?

Flow in two lumens with turbulence and bidirectional false-lumen flow.