Scan Lab Final 2025 Flashcards
What are the components / materials that make up an acute thrombus?
A mixture of fibrin and RBCs w/ platelets and acute inflammatory cells.
What are the components/materials that make up a chronic thrombus?
Mostly collagen
What characteristics of a DVT is not recommended to utilize for diagnosis and why?
Echogenicity because an acute thrombus varies in appearance.
(Can be hypoechoic, hyperechoic, anechoic, or echogenic.)
A thrombus is characterized as acute or chronic, although some facilities use a third catagory called ___________
Subacute
What is the biggest muscle in the neck?
Sternocleidomastoid
What is the most frequently, sonographically encountered pathology in the neck?
Enlarged lymph node.
The carotid and vertebral arteries feed the…
Brain
What happens when pieces of plaque travel to your brain due to a carotid artery stenosis?
Stroke
What is the most severe treatment option for a carotid stenosis?
Carotid endarterectomy
What part of the body do the carotid arteries supply blood to?
Head and neck
What protects the common carotid arteries from superficial injuries?
Sternocleidomastoid muscle
What structure has a blood supply connected to the branches of the external carotid artery?
Thyroid
What are the first sign(s) of a pulmonary embolism?
Shortness of breath and chest pain
DVT can often lead to a…
pulmonary embolism
Varicose veins are a major risk factor for…
Deep Vein Thrombosis (DVT)
How does a DVT disrupt varicose veins?
It causes increased blood pressure in the veins
What is atherosclerosis?
A buildup of plaque on the inner walls of the arteries.
List two ways to prevent diabetic neuropathy:
-Blood sugar management
-Keeping feet clean
What would the waveform look like if you were to suffer from severe PAD (Peripheral artery disease) ?
Monophasic
What are the two types of DVT?
Acute DVT and Chronic DVT
What is the biggest difference between the two types of DVT?
The duration of symptoms
What is Mrs Welch’s favorite and least favorite exam?
Favorite: LEVDOPP exam
Least-Favorite: Transvaginal pelvic exam
Which of the two types of DVT is anechoic or hypoechoic, poorly attached, has smooth borders, and appears in dilated veins?
Acute DVT
How long should reflux in a normal vein last?
< 0.5 sec
According to the American Vein and Lymphatic society (AVLS), what is the recommended patient position when performing a LE venous reflux study?
Standing
What area is key in evaluating reflux?
Saphenofemoral and saphenopopliteal junction
Where are ulcers more likely to develop on diabetic feet?
On the bottom of the foot (plantar)
What is the primary imaging modality for planning the treatment of peripheral artery disease (PAD)?
CE-Magnetic Resonance Angiography (MRA)
What is the most common presentation of PAD (peripheral artery disease)?
Claudification (Pain while walking/standing)
What is another name for a lower venous reflux exam?
Venous insufficiency ultrasound.
What is the best patient positioning for a lower extremity reflux exam?
Standing
In a lower venous reflux exam, how long must reflux persist to be considered abnormal in the superficial veins?
> 0.5 secs
What are the two most common upper extremity vessels that PICC lines are inserted through?
Basilic vein and cephalic vein
Which chamber of the heart is the PICC lines positioned next to?
Right atrium
What is one of the most common complications to occur due to a PICC line?
UE DVT
What is the primary purpose of vein harvesting in the arteriovenous fistula (AVF) creation?
To create a high flow connection between an artery and a vein for a dialysis access.
What is the key benefit of endoscopic vein harvesting (EVH) compared to open vein harvesting (OVH)?
Reduced risk of nerve damage and wound complications.
Which vein is most commonly used for vascular bypass procedures?
Greater saphenous
What does the term “venous reflux” describe?
Backward flow of blood in veins due to valve insufficiency
Which modality is preferred for diagnosing venous reflux?
Ultrasound
Which condition can mimic the symptoms of DVT but typically does not involve a blood clot?
Bakers cyst
What condition is most commonly mistaken for DVT due to similar symptoms such as swelling and pain?
Cellulitis
Which condition can mimic DVT but involves fluid buildup in the tissues rather than a blood clot?
Chronic venous insufficiency
When smoking cigarettes, what is the main cause for blood vessels to constrict and become narrow?
Nicotine
What is a common cause of CAS, PAD, and stroke?
Atherosclerosis
What is the preferred method of imaging for CAD (coronary artery disease)?
CCTA (coronary computed tomography angiography)
While scanning a LEVDOPP on a male with a history of high blood pressure, what is a likely pathology that you will find?
Thrombus
What is the most common cause of CVAs (Cerebrovascular accident / stroke) ?
Atherosclerosis
What is the first step in diagnosing a TIA (Transient Ischemic Attack “mini stroke”)?
Medical history and physical exam
If a patients mapped veins are determined to be unsuitable for surgical use due to factors such as poor size, stenosis, or insufficient quality, what are the common alternatives or approaches to ensure the success of the surgical procedure?
Use of a different vein in the same limb, or use of a synthetic/artificial graft such as a Dacron or ePTFE
When evaluating veins in the lower extremities for surgical use, which veins are prioritized for mapping?
Femoral vein, great saphenous vein, and popliteal vein.
When evaluating veins in the lower extremities for surgical use, how do factors like diameter, wall thickness, and valve integrity influence the selection of veins for vascular surgery?
Veins with…
-A diameter greater than 3mm,
-Thick walls
-Good valve function
What 3 specific veins are typically assessed when mapping veins in the upper extremities for surgical use?
Cephalic vein,
basilic vein,
median antebrachial vein
What are the key characteristics that determine whether the patients veins are suitable for procedures such as bypass grafting?
Veins must…
-Have a minimum diameter of 2mm,
-Be free from thrombosis,
-Have no significant valve incompetence.
How do you calculate ABI?
Highest systolic pressure at the ankle divided by the systolic pressure at the arm
How often are ABI values accurate?
95% of the time
accuracy for ABI values increases with…
Exercise
Why is exercise important in ABI testing?
It increases the sensitivity by 25%
What two imaging modalities are affected by patient movement?
MRA and U/S
What modality is most successful in predicting which plaque is most vulnerable to embolization?
Angiography
What metal is used in the contrast for an MRA?
Gadolinium
39-year-old male presents to the emergency room with tingling pain in both of his hands and a history of chewing tobacco. While scanning, you notice an occlusion in his right radial artery and a corkscrew collateral vessel branching off. What is the most likely diagnosis?
Buerger’s Disease
While performing an UEADopp on a 62-year-old male with a history of CKD, you notice the walls of his left brachial artery are echogenic and you can’t get color flow through the vessel. What is the most likely diagnosis?
Monckeberg’s Arteriosclerosis
You are performing a BUEADopp on a 23-year-old woman with a history of numbness and tingling in her fingers. While you are scanning her right subclavian artery, you notice the tips of her fingers have turned white. What is the most likely diagnosis?
Reynauds Disease
What is an immediate effect of smoking on the vascular system?
Vasoconstriction and increased blood pressure
Long term smoking increases the risk of abdominal aortic aneurysm primarily by:
Weakening the aortic wall through inflammation and tissue breakdown
A patient with a 30-year smoking history complains of leg pain when walking, which subsides at rest. Which physiological process best explains this symptom?
Chronic atherosclerosis seen in PAD limits blood flow to the limbs, causing claudication
What is the key difference between a cerebrovascular accident (CVA) and a transient ischemic attack (TIA)?
A CVA involves a permanent blockage of blood flow, while a TIA is a temporary reduction in blood flow
List some common factors which contribute to the occurrence of cerebrovascular accidents (CVAs), or strokes, by affecting the brains blood vessels?
Aneurysms,
arteriovenous malformations (AVMS),
atherosclerosis,
hemorrhagic events,
traumatic brain injury (TBI)
(All of these can all lead to a stroke risk)
What is another term for CVA?
Stroke
(Cardiovascular accident)
What is another term for TIA
Mini Stroke
(Transient ischemic attack)
How do the effects of a CVA differ from a TIA ?
-CVA causes permeant damage with long-lasting effects,
-TIA is temporary with no lasting damage.
What is cardiac dysfunction?
The hearts inability to pump blood effectively
Describe the appearance of a normal arteriole waveform?
Sharp systolic upstroke,
Briefly reversal of flow in early diastole,
Forward flow in late diastole
What pathology is commonly seen with continuous venous flow?
Right heart failure / DVT
What does a patient who is presenting with symptoms of a DVT commonly look like?
-Swelling
-Unilateral edema
-Warm feet
-Discoloration
If a patient is presenting with very cold feet, should they have an order for an arterial exam, or a venous exam?
Arterial
What is the fist thing you should ask a patient when you get them for their exam?
Confirm patients name and DOB
What vessels pass through the spine and are located posterior to the carotid arteries?
Vertebral arteries
What is a key ultrasound finding that suggests the presence of restenosis following a carotid endarterectomy?
Increased flow velocity with post-stenotic turbulence
What is the most common type of graft used in carotid artery bypass surgery?
Saphenous vein graft
What are the main vessels used in the upper extremity for vein mapping?
Cephalic and Basilic
What is the main goal of preoperative vein mapping?
To determine the best available veins for grafting
What 2 methods are used for harvesting veins?
Open vein harvesting and Endoscopic vein harvesting.
What type of waveform seen in a lower extremity arterial ultrasound is most likely to indicate severe stenosis or occlusion of a proximal artery (such as the iliac or common femoral artery)?
Tardus parvus waveform
What type of waveform seen in an upper extremity arterial ultrasound is typically indicative of normal, healthy, arterial flow?
Triphasic waveform
A monophasic waveform observed in the common femoral artery during a lower extremity arterial ultrasound is most likely indicative of:
Proximal stenosis
or
Occlusion / Atherosclerotic disease
What else may you find while performing a LE venous study?
Baker’s cyst,
lymphadenopathy,
cellulitis,
superficial thrombophlebitis,
varicosities,
hematomas.
What else may you find while performing a UE venous study?
PICC lines,
Catheter-associated thrombus,
Paget-Schroetter syndrome,
Thoracic outlet compression,
Masses compressing veins.
What are the signs/symptoms of a DVT?
Swelling,
pain,
redness,
warmth,
Homan’s sign,
and sometimes fever or positive D-dimer.
What other condition(s) may mimic a DVT?
Cellulitis,
Baker’s cyst,
lymphedema,
hematoma,
muscle tear,
venous insufficiency.
What are the causes of an upper and lower extremity DVT and are they different?
What makes you more predisposed to form a thrombus?
—Causes follow Virchow’s triad: venous stasis, endothelial damage, hypercoagulability.
—UE DVTs often catheter-related;
—LE DVTs linked to immobility/surgery.
—Risk factors: cancer, trauma, hormones, obesity, smoking.
How can you tell the difference between an acute and chronic DVT?
Acute: hypoechoic, vein distension, non-compressible.
Chronic: echogenic, small, with collaterals.
How what are the treatment options for an acute DVT vs a chronic DVT?
anticoagulants (acute),
compression and monitoring (chronic).
What is an upper extremity PICC line used for?
For long-term IV access.
How do you evaluate an upper extremity PICC line placement and patency?
Use ultrasound to…
-confirm location,
-evaluate for thrombosis,
-ensure vein patency and flow around the catheter.
What are the treatment options for an arterial stenosis/occlusion in the upper and lower extremities?
Lifestyle modification, antiplatelets, angioplasty, stenting, or surgical bypass.
What are the signs/symptoms of peripheral vascular disease and how do they differ from venous pathologies?
PVD: claudication, cold limbs, rest pain, non-healing ulcers.
Venous disease: swelling, aching, heaviness, discoloration, relieved by elevation.
What are three upper extremity arterial pathologies/disorders (other than stenosis/occlusion/TOS).
Aneurysms,
Vasculitis,
Embolism/Thrombosis,
Raynaud’s phenomenon.
What are the different types of UE fistulas/grafts, how do they work, and what are they used for?
Types: radiocephalic, brachiocephalic, brachiobasilic.
Used for dialysis access.
Describe the ultrasound protocol used to evaluate the functionality of UE fistulas/grafts
Evaluate inflow artery, anastomosis, outflow vein, flow volume, and check for stenosis or thrombosis.
What test(s) can a patient have done to diagnose lower extremity pain (other than ultrasound of veins/arteries)?
ABI (functional),
CTA/MRA (anatomical),
angiography (gold standard).
Describe how ABI, CTA/MRA, and Angiography differ from each other:
ABI (functional) is fast and noninvasive
CTA/MRA (anatomical) show structural issues
Angiography (gold standard) is invasive but most detailed.
Describe the lower extremity complications a diabetic may encounter.
Neuropathy,
arterial insufficiency,
poor wound healing,
ulcers,
infections,
increased risk of gangrene or amputation.
What does retrograde flow in the vertebral artery look like on spectral Doppler and what is the significance of this finding?
Appears below baseline, indicating reversed flow—sign of subclavian steal syndrome.
What velocity measurements are indicative of significant disease?
PSV >125 cm/s =
50% stenosis or greater
(Peak systolic velocity greater than 125 cm/s is indicative of disease)
What % stenosis is considered problematic, operable, and non-operable?
(<50% Stenosis: Typically not problematic, managed medically (PSV < 125 cm/s))
50–69% Stenosis: Moderate disease; operability depends on symptoms and other risk factors (PSV 125-230 cm/s)
≥70% Stenosis: Severe; usually considered still operable with endarterectomy or stenting (PSV > 230 cm/s)
Near Occlusion: Still potentially operable, though technically challenging
Total Occlusion: Non-operable by standard surgery; managed conservatively or via collateral assessment
What is a normal PSV?
Normal peak systolic velocity greater is <125 cm/s
What is indicative of a normal amount of stenosis ?
0% — <50%
0% stenosis is most normal, but velocities UNDER 125 cm/s with minimal plaque will typically fall under the <50% range and still be considered normal.
What % Stenosis would be considered a near occlusion?
> 95%
Not completely occluded — still a trickle of flow
Still technically operable.
What is the expected PSV for a near occlusion?
Highly variable (trick question)
It can be…
- Very high due to a tight jet through the narrowed lumen
- Very low due to severely reduced flow
- show a classic “string sign” (narrow trickle of flow in color Doppler)
What is the % stenosis and PSV measurement expected from a total occlusion?
100% Stenosis
0 cm/s PSV — no measureable flow.
(Non operable)
What else may you find while performing a carotid ultrasound (outside the carotid system)?
-Thyroid nodules
-Lymph nodes
-Parotid masses
-Neck soft tissue abnormalities.
What is the difference between a CVA and a TIA and how are they treated?
CVA = stroke, permanent
TIA = temporary (<24 hrs).
Treatments: meds, risk modification, surgery.
What treatment options does a patient have with operable stenosis?
Endarterectomy or stenting.
Post-op ultrasound checks for restenosis, thrombosis, dissection, or intimal flap.
What postoperative complications does ultrasound evaluate for following surgical treatment of an operable stenosis?
Following an endarterectomy or stenting procedure, post-op ultrasound checks for…
restenosis,
thrombosis,
dissection,
or intimal flap.
What would the carotid system look like sonographically on a post-op endarterectomy patient?
Endarterectomy:
irregular vessel wall
What would the carotid system look like sonographically on a post-op stent-placement patient?
stent:
echogenic with shadowing
What would the carotid system look like sonographically on a post-op bypass graft patient?
Bypass:
visible anastomosis and graft segment.
What three imaging modalities are used to evaluate the carotid system?
Describe their limitations, contraindications, and how the information they give differs from one another and ultrasound.
- Ultrasound: real-time, noninvasive.
- CTA/MRA: detailed anatomy but requires contrast/radiation.
- Angiography: invasive, highest resolution.
Upper and lower extremity vein mappings may be preoperative for which vascular bypass procedures?
Describe how the vein is harvested and used for those procedures.
CABG or peripheral bypass.
The vein is harvested, reversed, or left in-situ, and then used to bypass occluded arteries.
What veins are usually mapped in the upper and lower extremities?
A: UE: cephalic, basilic.
LE: GSV, SSV
For vein mapping procedures, what characteristics does the vein need to have to be considered “useable” by the surgeon?
What is done if there is not a “useable” vessel?
Vein must be…
≥2.5 mm,
compressible,
patent,
thrombus-free.
What is done if the patients vein does NOT meet the criteria for vein mapping?
A synthetic graft or alternate vein is used
What problems, signs, or symptoms may occur postoperatively at the donation site?
Which patients’ may be more inclined to have complications postoperatively?
Problems include edema, hematoma, & infection.
Higher risk in diabetics, obese, and immunocompromised patients.
What is the patient positioning and maneuvers used for a lower venous reflux exam?
Positioning: Standing or reverse Trendelenburg.
Maneuvers: Augmentation or Valsalva.
What vessels are evaluated during a lower extremity reflux study?
GSV, SSV, perforators, femoral, & popliteal veins.
Describe what venous reflux is and what causes it.
Venous Reflux is retrograde flow that is >0.5 sec from valve failure.
Describe the normal lower extremity venous waveform and how it differs from that found in a vein with reflux.
Normal waveform = phasic, respiratory.
Reflux waveform = shows reversed flow post-augmentation.
What are the treatment options for venous reflux, how are they performed, and are they permanent?
Compression therapy - not permanent
Thermal ablation - Usually permanent (85-95%)
Sclerotherapy - Can be permanent, better for small veins (80-90%)
Ligation - Most invasive, can be permanent (80-90%).
Some are long-lasting but may require maintenance.
How does cardiac dysfunction affect the vascular system?
It reduces cardiac output, causing a decrease in arterial flow
This can cause dampened arterial waveforms and venous pulsatility,
(especially in the upper extremities.)
What alterations to the waveforms will be seen on venous vs. arterial spectral Doppler exams in cardiac dysfunction?
Venous Doppler: Increased pulsatility (especially in central and upper extremity veins)
Arterial Doppler: Dampened, monophasic waveforms due to decreased forward flow from low cardiac output
What type of effects does long term smoking have on the vascular system?
Vasoconstriction,
endothelial damage
atherosclerosis
arterial stiffening
What information is needed when gathering a complete patient history prior to performing an arterial study versus a venous study?
Arterial: claudication, smoking, diabetes
Venous: swelling, recent surgery, blood pressure medication
What are pulse volume recordings (PVR) and how are they used?
-PVRs are non-invasive and measure volume changes in a limb with each heartbeat using air-filled cuffs to assess flow.
-Used to localize arterial disease, (especially when Doppler signals are difficult to interpret)
When is photoplethysmography (PPG) used and what information does it give?
-Photoplethysmography (PPG) is used to evaluate superficial blood flow, especially in toes or digits.
-Helpful when vessels are non-compressible
-Often used for toe pressures or venous reflux testing.
-Measures capillary perfusion
What does a normal vs. an abnormal PVR waveform look like?
Normal PVR waveform is triphasic or sharp with a dicrotic notch
Abnormal PVR waveform will be dampened or rounded, indicating obstruction.
What are the normal/abnormal ABI values?
Are they always correct?
Normal: 0.90–1.30.
Abnormal: Less than <0.90 - Peripheral artery disease (PAD).
ABI may be falsely elevated with calcified vessels
Why do we do “exercise testing” when performing an ABI?
exercise will make increase the accuracy of the exam and will reveal any masked ischemia
Describe the normal and abnormal waveforms found in the upper and lower extremities?
Normal = triphasic;
Abnormal = monophasic or dampened (indicating disease).
Describe the segmental pressures protocol for the upper and lower extremities, how to interpret the information, and the goal of “exercising” the patient.
Measure pressures at multiple levels (brachial, thigh, calf, ankle).
Greater than >20 mmHg drop between segments = disease.
Exercise identifies functional limitations.
Are there any patient limitations/contraindications you need to be aware of or may encounter when performing a segmental pressures exam?
Yes:
-DVT
-Wounds
-Recent surgery
-Pain
-Inability to exercise.
