Chapter 17: Duplex Ultrasound Imaging of the Lower Extremity Venous System Flashcards
Newly formed clotted blood within a vein, generally less than 14 days old
acute thrombus
residual material present within a vein for a period of several weeks or months; also called chronic change, scarring
chronic post-thrombotic changes
a vein that is the companion vessel to an artery and travels deep to the muscular fascia and lies within the deep muscular compartments of the leg
deep vein
a small vein that connects the deep and superficial venous systems
perforating vein
a vein that is superficial to the muscular fascia and the muscular compartments of the leg; travels within superficial fascial compartments; has no corresponding companion artery
superficial vein
an inward projection of the intimal layer of a vein wall producing two semilunar leaflets, which present the retrograde movement of blood flow
valve
Well’s criteria high probabality of DVT
more than 3 points
Well’s criteria intermediate probability of DVT
1-2 points
Well’s criteria low probability of DVT
0 points
thrombus poorly attached to vein wall; may be free floating
acute thrombus
Spectral and color Doppler signals complete thrombus
none
thrombus fully attached to vein wall
chronic post-thrombotic changes
veins will partially compress but not able to completely coapt walls
partial nonocclusive thrombus
Venous ultrasound used to assess three main things:
presence of absence of thrombus
appearance of thrombus
competence of contained valves
3 main categories of veins that can be imaged:
deep veins
superficial veins
perforating veins
main conduit for blood returning to the heart
deep veins
travel close to skin, superficial to muscle
superficial veins
What is the purpose of superficial veins?
get blood near skin to help regulate body temperature
small veins that connect deep veins with superficial veins
perforating veins
move blood from superficial veins to deep veins where blood can be pumped back to heart by muscular contractions
perforating veins
Leading cause of preventable death
venous thromboembolism
most common mechanisms for the formation of venous thrombosis
Virchow Triad
Virchow Triad
venous stasis
vessel wall injury
hypercoaguability
allows for increased exposure of clotting factor occurs in immobility
venous stasis
affect body’s normal thrombolytic system
cather related
trauma
vessel wall injury
associated with: cancer, birth control pills, hormone replacement therapy
hypercoaguability
very commonly begin in soleal sinus veins in calf or around small valve cusps in calfs because areas of slower flow may cause areas of stagnation
deep venous thrombus
Signs and symptoms are caused by:
venous obstruction
vascular and perivascular inflammation
embolization of thrombi
breakdown product of fibrin, which will be elevated in presence of DVT
D-dimer
What position works best for sonographic examination?
reversed Trendelenburg
What is the reversed Trendelenburg position?
patient lie flat on back, knees slightly bent, hips slightely externally rotated, head 20 degrees
Transducer that best images femoral, popliteal, most of calf, subclavian, and larger arms
linear array 5- 10 MHZ transducer
Transducer that best images superficial veins and most of arm veins; used in detailed reflux mapping and mapping
10-18 MHz linear array transducer with small footprint
transducer that best images IVC and iliac veins as well as deeper lying veins in bigger patients
curved linear array 2-5 MHz
A sonographer should compress a vein every __-__ cm throughout leg.
2-3
Where is the EIV located?
at the level of the inguinal ligament
Where is the CFV/GSV located?
medial direction in groin crease
large and longest superficial vein in the body
greater saphenous vein
The GSV terminates into the CFV at the _______ junction
saphenofemoral
The CFV is formed by the junction of the ___ and ____.
FV
DFV
The FV is more ____ than the DFV.
superficial
main venous outflow of the calf
Femoral vein
mainly drains thigh
DFV
located distal to the adductor canal
popliteal vein
main drainage for blood leaving the calf
popliteal vein
terminates into popliteal vein in mid to upper regions of popliteal fossa
anterior tibial vein
Why are thrombi rare in the anterior tibial veins?
do not communicate with primary source of thrombi in leg- soleal sinus veins
primary source of thombi in leg
soleal sinus veins
drain gastrocnemius muscles
gastrocnemius veins
superficial vein; terminates into popliteal vein at about same level as gastrocneumius veins
small saphenous viens
terminus of the SSV into popliteal vein
saphenopopliteal junction
when SSV bypasses popliteal vein and continues up to posterior thigh of GSV in thigh
cranial extension of SSV
merge together to form fibioperoneal trunk
common posterial tibial and common peroneal vein
Paired PTVS unite to form:
common posterior tibial trunk
paired peroneals unite to form:
common peroneal trunk
paired and positioned alongside posterior tibial artery
posterior tibial veins
lie adjacent to fibula; parallel to the PTVs through most of the calf
Peroneal veins
major storage areas for blood in calf
soleal sinus veins
common site for thrombi to form
soleal sinus veins
Normal venous walls
thin and smooth
slight dilatations in vein wall
valve sinuses
thin white structures within sinus freely moving in bloodstream
valve leaflets
Spectral Doppler should show _____ signals within all normal major vessels
spontaneous
The waveform of a normal vein should be ____ with respiration.
phasic
Signals should _____ with proximal compression or Valsalva maneuver
cease
composed of a mixture of fibrin and red blood cells with platelets and acute inflammatory cells; heterogeneous echoes
acute thrombus
may demonstrate a tip or tail that appears to be free-floating
acute thrombus
strands of material within vein lumen; scarring; wall-thickening
chronic post-thrombotic changes
volume of thrombus shrinking
thrombus contraction or relaxation
surface characteristics of chronic post-thrombotic changes
irregular
thin strands with a weblike appearance in vein lumen
synechaie
important descriptors for thrombus
size of vein
surface characteristics
compressability and deformability
free-floating or firmly attached
flow that lacks respiratory phasicity and does not cease with proximal compression or Valsalva
continuous
flow in lower extremity veins both antegrade and retrograde
venous reflux/ venous insufficiency
Which category of veins are the main conduit for blood, are surrounded by muscle, and have an accompanying artery?
deep veins
What is the main function of the superficial venous system under normal conditions?
to help regulate body temperature
In which way do valves in perforating veins ensure that blood moves, under normal conditions?
from the superficial to the deep system
From epidemiologic studies, what percentage of patients develop postthrombotic symptoms?
30%
Which limb of Virchow’s triad is demonstrated by a venous thrombus that starts at a valve cusp?
stasis
A patient presents to the vascular lab for lower extremity venous evaluation. The patient has known Factor V Leiden genetic factor. Under what risk factor of Virchow’s triad does this patient fall?
hypercoaguability
Many patients with venous thrombosis are asymptomatic; however, when symptoms occur, what are some of the most common?
extremity pain, tenderness, and swelling
What would a high probability for DVT correspond to on Well’s score?
> 3 points
When can a false-negative D-dimer be seen in the presence of a DVT?
assay cannot detect low levels of fibrins
For routine operation of a vascular lab, the use of a high-frequency linear transducer ( 10-18 MHz) is recommended for the evaluation of which of the following?
a. superficial vein reflux
b. perforators
c. distal femoral vein
d. iliac veins
a
Why will using a reverse Trendelenburg position to examine the lower extremity venous system make the exam more difficult?
veins without thrombus will be harder to compress
What is the primary method used to determine the presence of thrombus in the extremity veins?
transducer compression of the veins
Which of the following is NOT a normal qualitative Doppler feature evaluated in the lower extremity venous system?
a. continuity of signal
b. spontaneity of signal
c. phasicity of signal
d. augmentation of signals
a
Which of the following large deep veins are commonly bifid?
a. the profunda and popliteal veins
b. the femoral and popliteal veins
c. the external iliac and femoral veins
d. the common femoral and popliteal veins
d
Which vessels are NOT routinely evaluated in a lower extremity venous duplex examination?
A. Femoral vein
B. Great saphenous vein
C. Anterior tibial veins
D. Small saphenous vein
C
Which veins are one of the major blood located in the calf?
A. The tibial veins
B. The small saphenous vein
C. The soleal sinus vein
D. The popliteal vein
C
What do intraluminal echoes that are rigid, well attached to the vein wall, and have an irregular surface suggest?
Chronic postthrombotic changes
In what case will indirect assessment of the iliac veins and IVC using Doppler at the common femoral veins suggest evidence of obstruction?
A. The Doppler spectrum exhibits phasicity
B. The Doppler spectrum exhibits pulsatility
C. The Doppler spectrum exhibits continuity
D. The Doppler spectrum ceases with Valsalva
C
During a lower extremity venous duplex examination, a thin, white structure is noticed moving freely in the lumen of the vein. What does this most likely represent?
Valve leaflet
Which veins are one of the major blood reservoirs located in the calf?
A. The tibial veins
B. The small saphenous vein
C. The soleal sinus vein
D. The popliteal vein
C
What do intraluminal echoes that are rigid, well attached to the vein wall, and have an irregular surface suggest?
Chronic postthrombotic changes
In what case will indirect assessment of the iliac veins and IVC using Doppler at the common femoral veins suggest evidence of obstruction?
The Doppler spectrum exhibits continuity
During a lower extremity venous duplex examination, a thin, white structure is noticed moving freely in the lumen of the vein. What does this most likely represent?
Valve leaflet
Which of the following is a normal response to venous flow with a valsalva maneuver?
A. Augmented flow
B. Phasicity of flow
C. Continuous flow
D. Cessation of flow
D
A patient presents to the vascular lab with sudden onset of left lower extremity pain and swelling. Upon duplex examination, poorly attached Echogenic material is noted within a dilated femoral vein, and the femoral vein does not compress with applied transducer pressure? What do these findings suggest?
Acute deep venous thrombosis
When a patient presents with right heart failure, what impact is often observed in the spectral Doppler waveform in the lower extremities?
Increased pulsatility
A patient presents to the emergency department with a massively swollen right lower extremity which is extremely painful and bluish in color. What do these findings suggest?
Phlegmasia cerulea dolens
Which treatment option is typically reserved for emergent situations in larger veins of the iliofemoral region?
A. Heparin
B. Coumadin
C. Elastic stockings
D. Thrombolysis
D
What is the primary treatment of acute lower extremity deep venous thrombosis?
Anticoagulation
Duplex ultrasound for the evaluation of the deep and superficial venous system has largely replaced _______ for the detection of DVT.
Radio graphic contrast venography
Duplex ultrasound has the capability to diagnose, localize, and determine the relative age of _____.
Thrombus
The primary mechanism for the formation of venous thrombosis which includes venous stasis, vessel wall injury, and a hypercoaguable state is known as _____.
Virchow triad
The fact that DVT is often undiagnosed or undiagnosed is likely because DVT is frequently _____.
Asymptomatic
The development of venous thrombosis is determined by a balance between clotting factors and _______.
Coagulation inhibitors fibrinolytic system
Tachypnea, tachycardia, and chest pain are often signs of _______.
Pulmonary embolism
A palpable cord along the medial aspect of the lower extremity would be a clinical sign for ______.
Superficial venous thrombosis
A patient with localized tenderness with limb swelling and a recent history of major surgery would score _____ points based on Wells criteria.
> 3
The clinical diagnosis of DVT has _____ sensitivity and specificity
Poor
Appropriate positioning of the patient for a lower extremity venous evaluation includes having the patient lie on their back with their knee slightly bent and hip ______ rotated.
Externally
The evaluation of the IVC and iliac veins in most adult patients would require the use of a ______ transducer.
Curvilinear
The position described as the tilting of the exam table during a venous examination so that the legs are approximately 20 degrees lower than the upper body is called ______.
Reverse trendelenburg
Transducer compression of the extremity veins should NOT be performed in a _______ plane as it is easy to roll off the veins from this approach.
Longitudinal
The junction of the great saphenous vein within the common femoral vein usually occurs ______ to the bifurcation of the superficial and deep femoral arteries.
Proximal
The main venous outflow for the calf is the _____.
Femoral vein
The extension of the small saphenous vein above the popliteal fossa is referred to as the _____ extension of the small saphenous vein.
Cranial
It is not unusual for the ________ vein to share a common trunk with the gastrocnemius vein.
Small saphenous
The posterior tibial and peroneal veins typically communicate with the _______ veins.
Soleal sinus
The only way to adequately image the content of the venous lumen to exclude DVT when performing compression is to view the vessel in ______
Transverse
The process of a thrombus continuing to shrink and fill less of the vein can be known as ______.
Recanalization
When using Doppler, if there is a thrombosis between the level of the transducer and the site of distal compression, the result will be _________ with the compression.
No augmentation
Unilateral pulsatile venous flow can be associated with _______.
Arteriovenous fistulae
Compression of the left common iliac by the right common iliac artery can result in _______ syndrome.
May Thurner
A no vascular, anechoic, well-defined, oval mass found incidentally during a lower extremity venous duplex evaluation most likely represents a(n)
Cyst
Computed tomography venography and magnetic resonance venography are often used to evaluate the status of the _____ veins.
Iliac
