Comprehensive Vascular Ultrasound Registry Review – Vocabulary Flashcards

A curated set of key vocabulary terms and concise definitions covering arterial and venous anatomy, hemodynamics, pathologies, diagnostic testing, treatment, cerebrovascular concepts, physics, and quality assurance essential for the Vascular Ultrasound Registry Review.

Innominate (Brachiocephalic) Artery

First major branch off the aortic arch that bifurcates into the right subclavian and right common carotid arteries.

Subclavian Artery

Artery that terminates at the outer border of the first rib to become the axillary artery.

Axillary Artery

Continuation of the subclavian; gives off eight branches before becoming the brachial artery.

Brachial Artery

Upper-arm artery that bifurcates into the radial and ulnar arteries at the antecubital fossa.

Radial Artery

Forearm artery that terminates at the deep palmar arch.

Ulnar Artery

Forearm artery that terminates at the superficial palmar arch.

Celiac Trunk

First visceral branch of the abdominal aorta; gives rise to the common hepatic, left gastric, and splenic arteries.

Superior Mesenteric Artery (SMA)

Second main branch of abdominal aorta supplying mid-gut; high-resistance fasting, low-resistance post-prandial.

Renal Arteries

Paired branches approximately 2 cm distal to the SMA; supply the kidneys.

Common Iliac Artery (CIA)

Terminal branches of the aorta that divide into internal and external iliac arteries.

External Iliac Artery (EIA)

Supplies lower extremity; becomes common femoral artery at the inguinal ligament.

Common Femoral Artery (CFA)

Formed by the EIA; bifurcates into the superficial femoral and deep femoral arteries.

Superficial Femoral Artery (SFA)

Travels through Hunter’s (adductor) canal to become the popliteal artery.

Popliteal Artery

Continuation of the SFA that branches into the anterior tibial artery and tibioperoneal trunk.

Tibioperoneal Trunk

Short segment that bifurcates into the posterior tibial and peroneal arteries.

Anterior Tibial Artery (ATA)

Runs anterolaterally down the leg to the dorsalis pedis artery.

Posterior Tibial Artery (PTA)

Courses medially in the calf; palpable posterior to the medial malleolus.

Peroneal Artery

Posterolateral calf artery running adjacent to the fibula.

Arterioles

Smallest arteries; primary vessels of resistance in circulation.

Capillaries

One-cell-layer vessels where nutrient and gas exchange occur; most vital part of the system.

Intima

Thin innermost vessel layer lined by endothelium.

Media

Thick muscular middle layer of an artery composed of smooth muscle and connective tissue.

Adventitia (Externa)

Outer vessel layer containing fibrous connective tissue and vasa vasorum.

Pressure Gradient

Difference in pressure between two points that drives blood flow.

Resistance

Opposition to flow determined mainly by vessel radius, length, and blood viscosity.

Poiseuille’s Law

Defines relationship between flow, pressure gradient, viscosity, length, and radius (flow ∝ r⁴).

Bernoulli Effect

Inverse relationship between pressure and velocity within a narrowing; higher velocity, lower pressure.

Laminar Flow

Normal concentric layers of flow with a clear spectral window.

Parabolic Flow

Most common laminar profile with highest velocity in the center of the vessel.

Plug Flow

Flow in which all layers travel at the same velocity, typically at vessel origins.

Turbulent Flow

Disorganized flow with spectral broadening and eddies; occurs distal to significant stenosis.

Reynolds Number

Dimensionless value predicting turbulence; >2000 indicates likely turbulent flow.

Tardus Parvus Waveform

Monophasic, low-velocity waveform with delayed upstroke indicating proximal obstruction.

Stroke Volume

Amount of blood ejected by the left ventricle during systole.

High-Resistance Waveform

Little or reversed diastolic flow (e.g., ECA, fasting SMA, peripheral arteries).

Low-Resistance Waveform

Forward diastolic flow throughout the cycle (e.g., ICA, renal, celiac arteries).

Atherosclerosis

Thickening and hardening of arterial walls with plaque formation; most common arterial disease.

Claudication

Exercise-induced pain relieved by rest; indicates moderate PAD distal to pain location.

Rest Pain

Foot pain at night relieved by dependency; signifies severe ischemia.

Dependent Rubor

Red discoloration of foot when dependent, pale when elevated; severe arterial disease sign.

Acute Arterial Occlusion

Sudden obstruction from thrombus or embolus producing the classic six Ps.

Primary Raynaud’s

Functional vasospasm in young women causing bilateral color change without fixed disease.

Secondary Raynaud’s

Cold-induced ischemia superimposed on fixed arterial disease; often unilateral.

Takayasu Arteritis

Large-vessel arteritis in young Asian women; nicknamed ‘pulseless disease.’

Buerger’s Disease

Thromboangiitis obliterans affecting distal arteries of young male smokers.

True Aneurysm

Dilatation involving all three vessel layers; fusiform is the most common type.

Pseudoaneurysm

Blood collection communicating with artery through a neck after wall puncture.

Coarctation

Congenital narrowing of the aortic arch causing upper-extremity hypertension in youths.

Popliteal Entrapment Syndrome

Compression of the popliteal artery by the gastrocnemius leading to exercise calf pain.

Thoracic Outlet Syndrome

Neurovascular compression at shoulder region causing positional arm symptoms.

Compartment Syndrome

Increased pressure within fascial compartment compressing vessels, often anterior tibial area.

Continuous-Wave (CW) Doppler

Non-imaging Doppler using two crystals; no depth resolution but high velocity detection.

Spectral Analysis

Graphical display of individual frequency shifts versus time in PW Doppler.

Pulsatility Index (PI)

(PSV-EDV)/Mean velocity; assesses downstream resistance.

Acceleration Time

Time from systolic onset to peak; >133 ms suggests proximal inflow disease.

Ankle-Brachial Index (ABI)

Ankle systolic pressure divided by highest brachial pressure; normal ≥1.0, severe <0.5.

Reactive Hyperemia Test

Post-occlusive pressure test for patients unable to exercise; evaluates multi-level disease.

Pulse Volume Recording (PVR)

Pneumatic plethysmography recording limb volume changes as waveforms.

Photoplethysmography (PPG)

Infrared sensor detecting capillary flow; used for digit pressures and venous studies.

Venous Refill Time (VRT)

Time for PPG signal to return after exercise; <20 s indicates venous insufficiency.

Allen Test

Radial-ulnar compression test assessing palmar arch patency before radial graft harvest.

Hemodialysis Access Graft

Surgical AV communication (fistula or synthetic) to provide high-flow dialysis access.

Steal Syndrome

Distal arterial flow reversal due to high-flow AV graft or fistula.

Bypass Graft

Artery-to-artery conduit circumventing occlusive disease; may be synthetic or vein.

In-Situ Vein Graft

GSV left in place, branches ligated, valves lyzed; risk of AV fistula from missed branches.

Renal-Aortic Ratio (RAR)

PSV renal artery / PSV aorta; ≥3.5 indicates ≥60 % renal artery stenosis.

End-Diastolic Ratio (EDR)

EDV/PSV in kidney arteries; <0.2 suggests increased resistance.

Mesenteric Ischemia

Post-prandial abdominal pain with weight loss due to ≥2 visceral artery stenoses.

Celiac Band Syndrome

Respiratory-dependent compression of celiac artery by median arcuate ligament.

Transjugular Intrahepatic Portosystemic Shunt (TIPS)

Stent between portal and hepatic veins to decompress portal hypertension.

Circle of Willis

Intracranial arterial ring providing cerebral collateral pathways.

Transient Ischemic Attack (TIA)

Neurologic deficit resolving within 24 hours; usually embolic.

Reversible Ischemic Neurologic Deficit (RIND)

Neurologic deficit resolving within 72 hours.

Cerebrovascular Accident (CVA)

Permanent neurologic deficit commonly called a stroke.

Vertebrobasilar Insufficiency (VBI)

Posterior circulation ischemia producing non-lateralizing symptoms like vertigo and ataxia.

Amaurosis Fugax

Transient monocular blindness from ipsilateral ICA/ophthalmic emboli.

Homonymous Hemianopia

Loss of same visual field halves in both eyes from cortical stroke.

Ulcerative Plaque

Crater-like erosion in fibrous cap; high embolic risk.

Intraplaque Hemorrhage

Sonolucent area within plaque representing fresh bleed; unstable lesion.

Fibromuscular Dysplasia (FMD)

Medial overgrowth causing ‘string-of-beads’ appearance, usually mid-distal ICA.

Subclavian Steal

Proximal subclavian obstruction causing ipsilateral vertebral flow reversal.

Temporal Arteritis

Inflammation of superficial temporal artery showing ‘halo sign’ on duplex.

Transcranial Doppler (TCD)

2 MHz PW Doppler through cranial windows to assess intracranial flow.

Anterior Communicating Artery Collateral

Flow crossing from contralateral ACA to supply ipsilateral ACA/MCA during ICA occlusion.

Posterior Communicating Artery Collateral

Flow from vertebrobasilar system to anterior circulation via PCoA.

Hollenhorst Plaque

Cholesterol embolus in retinal artery seen on ophthalmic exam.

Paget-Schroetter Syndrome

Effort thrombosis of axillary/subclavian vein in athletes.

May-Thurner Syndrome

Compression of left common iliac vein by right common iliac artery.

Nutcracker Syndrome

Compression of left renal vein between SMA and aorta.

Phlegmasia Alba Dolens

Severe iliofemoral DVT causing painful white leg from arterial spasm.

Phlegmasia Cerulea Dolens

Massive DVT producing painful blue leg and reduced arterial inflow.

Virchow’s Triad

Risk factors for DVT: trauma, venous stasis, hypercoagulability.

Venous Valves

Bicuspid intimal folds preventing retrograde flow; numerous in calf veins.

Transmural Pressure

Difference between intraluminal and interstitial pressures determining vein shape.

Calf Muscle Pump

‘Venous heart’ that ejects blood upon contraction; relies on competent valves.

Brawny Discoloration

Brown skin pigmentation from hemosiderin deposits in chronic venous hypertension.

Lipodermatosclerosis

Hardening and tapering of lower leg skin due to chronic venous disease.

Venous Air Plethysmography

Calf cuff volume test measuring ejection fraction and reflux quantification.

Ejection Fraction (Venous)

Percent venous volume expelled after one toe-rise; normal >60%.

Augmentation Maneuver

Distal compression or proximal release to transiently increase venous flow on Doppler.