I85PREP
⌘ K
RVT study materials
RVT study resources

RVT practice questions

One question at a time. Build your RVT understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Cerebrovascular

Which acoustic window is used to insonate the middle cerebral artery?

  1. Submandibular
  2. Transtemporal Correct answer.
  3. Transforaminal
  4. Transorbital

Explanation

The middle cerebral artery is reached through the thin squama of the temporal bone above the zygomatic arch, at a depth of roughly 30 to 60 mm. Each window is chosen for the vessels it can reach anatomically.

Question 2Cerebrovascular

Through the transtemporal window, the middle cerebral artery is normally sampled at a depth of approximately:

  1. 30 to 60 mm Correct answer.
  2. 5 to 15 mm
  3. 70 to 90 mm
  4. 15 to 25 mm

Explanation

The MCA runs laterally from the carotid terminus, so it lies 30 to 60 mm from the temporal skin surface. Depth readings help confirm vessel identity when several signals appear in the same window.

Question 3Cerebrovascular

Which Doppler angle is recommended when recording carotid velocities for stenosis grading?

  1. 60 degrees Correct answer.
  2. 30 degrees
  3. 45 degrees
  4. 90 degrees

Explanation

Velocities are most reproducible when the beam-to-vessel angle is kept at or below 60 degrees, and 60 degrees is the standard used in validated criteria. A 90-degree angle yields no detectable shift at all.

Question 4Cerebrovascular

Which spectral waveform is expected from a normal internal carotid artery?

  1. Low resistance with continuous forward diastolic flow Correct answer.
  2. Triphasic with early diastolic reversal
  3. Biphasic with flow reaching zero at end diastole
  4. High resistance with absent diastolic flow

Explanation

The internal carotid artery supplies the low-resistance cerebral circulation, so forward flow continues throughout diastole. Loss of that diastolic flow suggests distal obstruction or a hemodynamic cause.

Question 5Cerebrovascular

Tapping the superficial temporal artery produces oscillatory artifacts in which cervical vessel?

  1. Internal carotid artery
  2. Vertebral artery
  3. Common carotid artery distal to the bifurcation
  4. External carotid artery Correct answer.

Explanation

The superficial temporal artery is a branch of the external carotid artery, so the mechanical tap is transmitted backward into the ECA spectrum. This maneuver helps separate ECA from ICA when the two vessels run close together.

Question 6Cerebrovascular

The basilar artery is insonated through the transforaminal window at a depth of approximately:

  1. 120 to 140 mm
  2. 80 to 110 mm Correct answer.
  3. 30 to 45 mm
  4. 50 to 65 mm

Explanation

From the foramen magnum, the basilar artery lies deep to the clivus and is typically found at 80 to 110 mm. Velocities increase as the probe is angled toward the proximal basilar trunk.

Question 7Cerebrovascular

The pulsatility index is calculated by dividing the peak-to-trough velocity difference by which value?

  1. End-diastolic velocity
  2. Resistive index
  3. Time-averaged mean velocity Correct answer.
  4. Peak systolic velocity

Explanation

Gosling defined the pulsatility index as (peak systolic minus end-diastolic velocity) divided by the time-averaged mean velocity. It rises with increasing distal resistance and falls when resistance drops.

Question 8Cerebrovascular

In a normal orbit, Doppler flow in the ophthalmic artery appears:

  1. Absent during diastole
  2. Bidirectional within each cardiac cycle
  3. Antegrade and toward the probe Correct answer.
  4. Retrograde and away from the probe

Explanation

The ophthalmic artery carries blood from the internal carotid toward the orbit, so its normal direction is toward the transorbital probe. Flow direction here is a useful marker of collateral flow when the ICA is diseased.

Question 9Cerebrovascular

The Lindegaard ratio compares MCA velocity with the velocity in the ipsilateral extracranial internal carotid artery. A value greater than which threshold favors vasospasm over hyperemia?

  1. 3.0 Correct answer.
  2. 2.0
  3. 1.5
  4. 5.0

Explanation

A ratio above 3 supports vasospasm, because a global increase in flow raises velocities in both the intracranial and extracranial segments while spasm raises only the intracranial value. Ratios below 3 point toward hyperemia.

Question 10Cerebrovascular

In aneurysmal subarachnoid hemorrhage, TCD surveillance for vasospasm is most productive during which interval?

  1. The first 6 hours after the hemorrhage
  2. Weeks 4 to 6 after the hemorrhage
  3. Beginning 3 months after the hemorrhage
  4. Days 3 to 14 after the hemorrhage Correct answer.

Explanation

Vasospasm usually begins after the third day, peaks around days 7 to 10, and resolves by about day 14. Surveillance protocols therefore concentrate daily or alternate-day studies in that window.

Question 11Cerebrovascular

Reversed flow in the ophthalmic artery most suggests:

  1. Aneurysm arising at the basilar artery apex
  2. A distal vertebral artery stenosis at the V4 segment
  3. Ipsilateral severe ICA stenosis or occlusion Correct answer.
  4. Diffuse elevation of intracranial pressure alone

Explanation

When the internal carotid cannot supply the orbit, blood enters through external carotid collaterals and flows backward through the ophthalmic artery. The direction change is therefore a sign of hemodynamically significant ipsilateral ICA disease.

Question 12Cerebrovascular

In subclavian steal syndrome, the ipsilateral vertebral artery typically shows:

  1. High-velocity forward flow with marked spectral broadening
  2. Retrograde flow, at first only in diastole Correct answer.
  3. Absent diastolic flow with a sharp systolic peak
  4. Normal continuous forward flow throughout

Explanation

A proximal subclavian stenosis lowers pressure distal to the lesion, so the vertebral artery acts as a conduit feeding the arm. Reversal begins in diastole and becomes continuous as the pressure gradient grows.

Question 13Cerebrovascular

A young woman has alternating narrowing and dilatation along the mid-cervical internal carotid artery, with sparing of the bulb. This appearance is characteristic of:

  1. Atherosclerotic plaque at the bulb
  2. Radiation-induced arteriopathy
  3. Fibromuscular dysplasia Correct answer.
  4. Carotid body tumor

Explanation

Fibromuscular dysplasia produces the classic string-of-beads pattern in the mid and distal cervical ICA while the bulb is spared. Atherosclerosis, by contrast, favors the proximal bulb and bifurcation.

Question 14Cerebrovascular

A tapered flame-shaped narrowing that begins about 2 cm above the carotid bulb, accompanied by an echogenic intramural hematoma, is most consistent with:

  1. Takayasu arteritis
  2. Atherosclerotic plaque rupture
  3. Vasospasm of the cervical ICA
  4. Internal carotid artery dissection Correct answer.

Explanation

Dissection typically begins several centimeters above the bulb and tapers smoothly as blood tracks within the vessel wall. The intramural hematoma is the defining finding and helps separate dissection from atheroma.

Question 15Cerebrovascular

Which Doppler measurement serves as the primary criterion for grading internal carotid artery stenosis?

  1. Internal carotid end-diastolic velocity alone
  2. Common carotid end-diastolic velocity
  3. Internal carotid peak systolic velocity Correct answer.
  4. Ratio of ICA to ECA peak systolic velocity

Explanation

Internal carotid peak systolic velocity is the primary parameter in validated duplex criteria, with end-diastolic velocity and ICA-to-common-carotid ratio as supporting measures. Secondary parameters are used to confirm or adjust the category.

Question 16Cerebrovascular

Microembolic signals detected by transcranial Doppler are best described as:

  1. Continuous broad-band signal replacing the normal waveform
  2. Low-intensity bidirectional signals lasting several seconds
  3. Brief, unidirectional high-intensity signals occurring at random Correct answer.
  4. Symmetric signals appearing only at end diastole

Explanation

Embolic signals are short, unidirectional, intensity-increasing events that appear at random within an otherwise normal spectrum. They are distinguished from artifact, which is usually bidirectional and extends beyond the spectral window.

Question 17Cerebrovascular

In a patient with occlusion of one internal carotid artery, flow in the ipsilateral anterior cerebral artery is reversed. This indicates collateral supply through the:

  1. Anterior communicating artery Correct answer.
  2. Posterior communicating artery
  3. Ophthalmic artery
  4. Ipsilateral external carotid branches

Explanation

Blood crosses from the patent side through the anterior communicating artery and fills the ipsilateral ACA in retrograde fashion. Reversal of ACA direction is therefore a sign of effective anterior collateralization.

Question 18Cerebrovascular

Markedly raised intracranial pressure produces which middle cerebral artery waveform pattern on TCD?

  1. Continuous venous-like flow without pulsatility
  2. High resistance with reduced or reversed diastolic flow Correct answer.
  3. Low resistance with increased diastolic velocity
  4. Normal waveform with a doubled systolic velocity

Explanation

As intracranial pressure rises, the diastolic pressure gradient across the cerebral bed falls, so diastolic flow diminishes and may reverse. The waveform becomes progressively more pulsatile as perfusion pressure drops.

Question 19Cerebrovascular

Carotid endarterectomy confers the greatest absolute benefit in which group?

  1. Symptomatic patients with 30% stenosis
  2. Asymptomatic patients with 80% stenosis
  3. Symptomatic patients with 70% or greater stenosis Correct answer.
  4. Asymptomatic patients with 50% stenosis

Explanation

Benefit rises steeply with stenosis severity in symptomatic patients, and the greatest reduction in stroke risk is seen at 70% or greater narrowing. Below 50% in symptomatic patients, medical therapy is preferred.

Question 20Cerebrovascular

The distal cervical internal carotid artery near the skull base is best approached with which window?

  1. Transtemporal
  2. Transforaminal
  3. Transorbital
  4. Submandibular Correct answer.

Explanation

Angling the probe medially under the mandible brings the high cervical ICA into view before it enters the carotid canal. The standard anterior cervical approach often cannot reach this segment because of the mandible.

Question 21Cerebrovascular

A highly vascular mass splays the internal and external carotid arteries apart at the bifurcation. The most likely diagnosis is:

  1. Carotid body tumor Correct answer.
  2. Carotid dissection with pseudoaneurysm
  3. Atherosclerotic plaque with neovascularization
  4. Subclavian steal syndrome

Explanation

Carotid body tumors are paragangliomas that arise in the bifurcation and widen the angle between the ICA and ECA. They are hypervascular with low-resistance arterial flow and are not atherosclerotic in origin.

Question 22Cerebrovascular

Duplex shows a markedly narrowed ICA lumen containing a thin string of flow, with a peak systolic velocity of only 85 cm/s. The best interpretation is:

  1. Complete occlusion of the ICA
  2. Near-occlusion with reduced flow beyond a critical stenosis Correct answer.
  3. Normal variant caused by low cardiac output
  4. No hemodynamically significant stenosis

Explanation

At near-occlusion, flow is so limited that velocities fall despite extreme anatomic narrowing, so a low velocity must not be read as mild disease. The visible string of flow confirms the artery is patent but critically narrowed.

Question 23Cerebrovascular

Which TCD finding supports a diagnosis of brain death?

  1. Small systolic spikes and absent diastolic flow intracranially Correct answer.
  2. High MCA velocity with a Lindegaard ratio above 3
  3. Increased diastolic flow with an overall low pulsatility index
  4. A normal waveform with mean velocity reduced by half

Explanation

When cerebral perfusion pressure falls below intracranial pressure, flow stops in diastole and only brief systolic spikes remain. The pattern must be bilateral and found in all intracranial vessels to be supportive.

Question 24Cerebrovascular

A breath-holding index below 0.69 %/s during TCD testing indicates:

  1. A positive right-to-left shunt study
  2. Normal cerebrovascular reserve
  3. Impaired cerebrovascular reserve Correct answer.
  4. Artifact from a poor acoustic window

Explanation

The index expresses the percentage rise in MCA mean velocity per second of breath holding, so a blunted response means the vessels cannot dilate further. This implies the cerebral circulation is already maximally vasodilated.

Question 25Cerebrovascular

During a contrast TCD study for right-to-left shunt, a positive result is indicated by:

  1. Microembolic signals in the MCA shortly after injection Correct answer.
  2. A sudden fall in MCA velocity to zero
  3. Loss of the diastolic component of the MCA waveform
  4. Reversal of flow in the basilar artery

Explanation

Agitated saline crosses a shunt and appears in the cerebral circulation as countable high-intensity signals. The number and timing of signals relative to the injection grade the shunt magnitude.

Question 26Cerebrovascular

On transcranial Doppler, the mean flow velocity in a normal adult middle cerebral artery most typically falls within which range?

  1. 20 to 30 cm/s
  2. 180 to 200 cm/s
  3. 55 to 65 cm/s Correct answer.
  4. 120 to 140 cm/s

Explanation

Normal middle cerebral artery mean velocities in adults are roughly 55 to 65 cm/s, with an accepted normal band of about 40 to 80 cm/s. Values below this band raise concern for a proximal flow-limiting lesion or a poor acoustic window, while values well above it raise concern for stenosis, vasospasm, or hyperemia. The middle cerebral artery is the most reproducible intracranial vessel for serial velocity comparison.

Question 27Cerebrovascular

Which spectral Doppler feature distinguishes the internal carotid artery from the external carotid artery at the bifurcation?

  1. Continuous forward flow throughout diastole Correct answer.
  2. A sharp upstroke with no diastolic flow at all
  3. Prominent early diastolic flow reversal
  4. A monophasic waveform resembling venous flow

Explanation

The internal carotid artery perfuses the low-resistance cerebral circulation, so it shows broad spectral broadening and continuous forward flow throughout diastole. The external carotid artery supplies the higher-resistance facial and scalp beds, giving a sharper upstroke, a narrower spectral window, and low or briefly reversed diastolic flow. Temporal tapping maneuvers can be used when the waveform alone is ambiguous.

Question 28Cerebrovascular

When performing carotid duplex, which angle of insonation should be maintained?

  1. Exactly 45 degrees in every case
  2. 0 degrees
  3. 60 degrees or less Correct answer.
  4. 90 degrees

Explanation

The Doppler shift is proportional to the cosine of the angle between the beam and the direction of flow. At 60 degrees the cosine is 0.5 and small angle errors cause only modest velocity error, but as the angle approaches 90 degrees the cosine falls steeply and the measured shift collapses toward zero. Standard practice therefore keeps the angle at 60 degrees or less and steers the cursor to parallel the vessel wall.

Question 29Cerebrovascular

Where is the transtemporal acoustic window for transcranial Doppler located?

  1. At the angle of the mandible
  2. Just above the orbital rim
  3. Above the zygomatic arch, anterior to the ear Correct answer.
  4. At the occipital midline just below the inion

Explanation

The transtemporal window uses the thin squamosal portion of the temporal bone above the zygomatic arch and slightly anterior to the ear. It provides access to the terminal internal carotid artery, middle cerebral artery, anterior cerebral artery, posterior cerebral artery, and the anterior communicating region. Failure to find the window may reflect thickening of the temporal bone rather than absence of flow.

Question 30Cerebrovascular

An older adult with new temporal headache and jaw claudication undergoes a superficial temporal artery ultrasound. A hypoechoic wall thickening encircles the vessel and the lumen compresses when pressure is applied with the probe. This finding is termed:

  1. The double-line sign
  2. The yin-yang sign
  3. The sparkle sign
  4. The halo sign Correct answer.

Explanation

Concentric hypoechoic mural thickening of a temporal artery branch is the halo sign of giant cell arteritis, representing mural edema. A compressible lumen under probe pressure (the compression sign) adds specificity for active arteritis. Prompt recognition matters because treatment is started on clinical and sonographic grounds before biopsy results return.

Question 31Cerebrovascular

In the STOP protocol for children with sickle cell disease, which transcranial Doppler measurement identifies the group at highest stroke risk?

  1. Resistive index above 0.8
  2. Time-averaged mean of 200 cm/s or more Correct answer.
  3. Mean velocity below 70 cm/s
  4. Peak systolic velocity of 120 cm/s

Explanation

The STOP trial stratified stroke risk by the time-averaged mean of the maximum velocity in the middle cerebral artery or terminal internal carotid artery. A value of 200 cm/s or greater defined the high-risk group in whom regular transfusion produced a large reduction in stroke. Intermediate values of roughly 170 to 199 cm/s were designated conditional and followed with repeat studies.

Question 32Cerebrovascular

Two patients have carotid stenoses of equal angiographic severity. One plaque is uniformly echolucent and the other densely calcified with strong acoustic shadowing. Which statement best reflects the recognized clinical implication?

  1. The calcified plaque is more prone to rupture because it is brittle
  2. Plaque echogenicity has no relationship to symptoms
  3. Both plaques carry identical risk because the degree of stenosis is the same
  4. The echolucent plaque has a higher rupture risk Correct answer.

Explanation

Plaque composition influences risk independently of stenosis severity. Echolucent plaques are typically lipid-rich or contain hemorrhage with a thin fibrous cap, features associated with instability, rupture, and ipsilateral ischemic symptoms. Densely calcified plaques are generally more stable and less frequently the embolic source.

Question 33Cerebrovascular

During transcranial Doppler monitoring after subarachnoid hemorrhage, which mean middle cerebral artery velocity is conventionally used as the threshold suggesting vasospasm?

  1. 70 cm/s
  2. 90 cm/s
  3. 120 cm/s Correct answer.
  4. 40 cm/s

Explanation

A mean middle cerebral artery velocity of about 120 cm/s or greater is the conventional transcranial Doppler threshold for suspected vasospasm. Velocities above this value prompt closer correlation with the clinical examination and with the extracranial internal carotid velocity to separate spasm from hyperemia. Serial trends are more informative than a single measurement.

Question 34Cerebrovascular

Duplex of the common carotid artery shows a delayed systolic upstroke, a rounded systolic peak, and reduced overall amplitude. A severe stenosis is present in the ipsilateral brachiocephalic trunk. This waveform pattern is called:

  1. Tardus parvus Correct answer.
  2. Spectral broadening
  3. Pulsus bisferiens
  4. Dicrotic notch reversal

Explanation

A dampened, delayed systolic upstroke with loss of the sharp peak downstream of a hemodynamically significant proximal obstruction is the tardus parvus waveform. It reflects reduced pulse pressure reaching the distal vessel and should direct attention to the more proximal inflow vessels rather than to the segment being sampled. Recognizing it prevents misattributing the abnormality to the vessel under the probe.

Question 35Cerebrovascular

A patient has a documented occlusion of the left internal carotid artery. Duplex of the right internal carotid artery shows a peak systolic velocity of 130 cm/s with no visible plaque and a normal-appearing lumen. The most likely explanation is:

  1. Reduced cardiac output producing turbulence
  2. A false elevation caused by an incorrect Doppler angle
  3. Compensatory increased flow through the patent artery Correct answer.
  4. Interval development of a new atherosclerotic stenosis

Explanation

When one internal carotid artery occludes, the contralateral artery must supply both hemispheres and its volume flow rises. Velocities therefore increase without any atherosclerotic narrowing, and the spectrum keeps a normal low-resistance shape without post-stenotic disturbance. Velocity criteria for stenosis must always be interpreted with the contralateral status in mind.

Question 36Cerebrovascular

Through the temporal window, a sample at 62 mm depth shows flow directed toward the transducer, and a sample at 75 mm with slight angulation shows flow directed away. These signals most likely represent:

  1. Middle cerebral artery superficially and anterior cerebral artery deeper Correct answer.
  2. Posterior cerebral artery superficially and middle cerebral artery deeper
  3. Anterior cerebral artery at both depths
  4. Middle cerebral artery at both depths

Explanation

At the transtemporal window the middle cerebral artery is normally found at roughly 40 to 65 mm with flow toward the probe. Deeper and slightly anterior, the A1 segment of the anterior cerebral artery shows flow away from the probe. Depth plus direction together allow reliable vessel identification.

Question 37Cerebrovascular

A vertebral artery measures 2 mm in diameter along its entire cervical course while the contralateral vertebral artery measures 4.5 mm; velocities in the small vessel are normal to mildly elevated. This appearance is most consistent with:

  1. Subclavian steal
  2. Fibromuscular dysplasia
  3. Vertebral artery dissection
  4. Congenital vertebral artery hypoplasia Correct answer.

Explanation

A uniformly small-caliber vertebral artery with a smooth wall and preserved, sometimes mildly elevated, velocities throughout its course represents congenital hypoplasia. It is a common normal variant and is distinguished from acquired disease by its long-segment uniformity and absence of mural abnormality. The contralateral vessel is typically dominant and supplies most of the basilar flow.

Question 38Cerebrovascular

Transcranial Doppler insonation of a feeding artery to a cerebral arteriovenous malformation typically shows:

  1. Absent diastolic flow
  2. High velocity with low pulsatility Correct answer.
  3. Reciprocal systolic flow reversal
  4. Low velocity with high pulsatility

Explanation

Arteriovenous malformations shunt blood directly from artery to vein, bypassing the high-resistance capillary bed. Feeding arteries therefore carry high-volume, low-resistance flow with elevated velocities and continuous high diastolic flow, so pulsatility is reduced. These features help distinguish a feeding artery from normal parenchymal vessels.

Question 39Cerebrovascular

After microbubble contrast administration, fine mobile echoes are seen moving within the body of a soft carotid plaque. This finding most likely represents:

  1. Intraplaque hemorrhage with clot retraction
  2. Artifact from adjacent calcific shadowing
  3. Neovascularization within the plaque Correct answer.
  4. Surface ulceration of the plaque

Explanation

Contrast ultrasound can depict microbubbles within the fragile capillary network that grows into a thickened plaque. Visible intraplaque contrast enhancement indicates neovascularization, a marker of plaque vulnerability and prior or future ischemic symptoms. The enhancement occurs within the plaque substance rather than at its surface.

Question 40Cerebrovascular

A young patient with recurrent transient ischemic attacks has stenotic terminal internal carotid arteries with a hazy basal network of small collateral vessels. Corresponding transcranial Doppler findings would most likely include:

  1. Reversed flow in the basilar artery
  2. Uniformly increased velocities in all intracranial arteries
  3. Absent flow signals in all intracranial vessels
  4. High-velocity low-resistance flow in basal collateral vessels Correct answer.

Explanation

In moyamoya disease, progressive stenosis of the distal internal carotid arteries is accompanied by lenticulostriate and thalamoperforating collaterals that supply the ischemic territory. These small collateral channels carry increased volume flow at low resistance, so transcranial Doppler shows high-velocity, low-pulsatility signals near the skull base alongside stenotic velocities in the terminal carotid. This combination of proximal stenosis with collateral flow is the characteristic pattern.

Question 41Peripheral Arterial

A normal resting ankle-brachial index in a healthy adult falls within which range?

  1. 0.50 to 0.89
  2. 1.50 to 2.00
  3. Below 0.50
  4. 0.90 to 1.40 Correct answer.

Explanation

Normal ABI is generally 0.90 to 1.40. Lower values suggest obstructive peripheral arterial disease, while markedly elevated values suggest noncompressible calcified arteries.

Question 42Peripheral Arterial

Which spectral Doppler feature is characteristic of a normal triphasic lower extremity arterial waveform?

  1. Absent diastolic flow and rounded upstroke
  2. Broad spectral broadening in systole
  3. Continuous forward flow throughout diastole
  4. Sharp upstroke with early diastolic reversal Correct answer.

Explanation

A normal triphasic waveform has a steep systolic acceleration, a narrow spectral band, early diastolic flow reversal, and a small late diastolic forward component. Loss of these features suggests proximal obstruction or distal vasodilation.

Question 43Peripheral Arterial

Which cuff size is most appropriate for measuring systolic pressure at the ankle?

  1. A forearm cuff wrapped around the calf
  2. A digital cuff placed on the great toe
  3. A cuff matched to ankle circumference Correct answer.
  4. A thigh cuff placed above the knee

Explanation

Cuff width should be matched to limb circumference to avoid falsely high or low pressure readings. An ankle cuff selected for the patient's ankle size gives the most reliable segmental pressure.

Question 44Peripheral Arterial

The dorsalis pedis artery is the distal continuation of which artery?

  1. Posterior tibial artery
  2. Anterior tibial artery Correct answer.
  3. Popliteal artery
  4. Peroneal artery

Explanation

The anterior tibial artery crosses the interosseous membrane and continues onto the dorsum of the foot as the dorsalis pedis artery. The posterior tibial artery continues as the plantar arteries.

Question 45Peripheral Arterial

An ankle-brachial index of 0.80 in a symptomatic patient most likely indicates which condition?

  1. Normal arterial function
  2. Acute compartment syndrome
  3. Peripheral arterial disease Correct answer.
  4. Venous insufficiency

Explanation

An ABI below 0.90 is abnormal and supports a diagnosis of peripheral arterial disease. Values from 0.50 to 0.89 generally correspond to mild to moderate disease.

Question 46Peripheral Arterial

Why is the toe-brachial index often used when ankle pressures may be falsely elevated?

  1. Toe vessels are more prone to vasospasm
  2. Toe cuffs are larger than ankle cuffs
  3. Digital arteries are less often calcified Correct answer.
  4. Toe pressures directly measure iliac stenosis

Explanation

Medial calcinosis can make tibial arteries noncompressible and falsely elevate ankle pressures. Digital arteries are less commonly affected by calcification, so toe pressures may better reflect true perfusion.

Question 47Peripheral Arterial

Which artery is commonly used as the proximal reference for lower extremity Doppler waveforms at the groin?

  1. Profunda femoris artery
  2. Superficial femoral artery
  3. Popliteal artery
  4. Common femoral artery Correct answer.

Explanation

The common femoral artery is the standard proximal sampling site because it reflects inflow from the iliac system and is readily accessible at the groin. Waveform changes there help distinguish inflow from outflow disease.

Question 48Peripheral Arterial

A monophasic Doppler waveform in the dorsalis pedis artery most suggests which finding?

  1. Venous obstruction
  2. Compensatory high flow
  3. A proximal stenosis Correct answer.
  4. Normal resting flow

Explanation

A monophasic waveform with loss of the normal multiphasic pattern indicates damping from a proximal stenosis or occlusion. The more proximal the obstruction, the more blunted the distal waveform becomes.

Question 49Peripheral Arterial

An older patient with diabetes has an ankle-brachial index of 1.55 and nonhealing foot ulcers. What is the most likely explanation?

  1. Exercise-induced vasodilation
  2. Severe iliac stenosis limiting inflow
  3. Medial calcinosis of tibial arteries Correct answer.
  4. Improper cuff placement on the thigh

Explanation

An ABI above 1.40 often reflects medial calcinosis, especially in patients with diabetes or renal disease, making tibial arteries noncompressible. In this setting, toe pressures or waveform analysis are more reliable.

Question 50Peripheral Arterial

During lower extremity segmental pressure testing, a systolic pressure drop of how much between adjacent cuffs is considered hemodynamically significant?

  1. 5 mm Hg
  2. 20 mm Hg Correct answer.
  3. 60 mm Hg
  4. 40 mm Hg

Explanation

A drop of 20 mm Hg or more between adjacent segmental cuffs suggests a significant stenosis or occlusion in the intervening arterial segment. Smaller differences may fall within normal measurement variability.