lower extremity venous duplex (normal) Flashcards
what types of duplex testing are there?
2D and Deoppler
what are the capabilities of duplex testing?
Identify venous thrombosis
Differentiate acute vs chronic disease
Distinguish extrinsic compression from intrinsic obstruction
Evaluate non-occluding thrombus
Evaluate soft tissue masses
Detect venous incompetence
Map superficial veins
what type of equipment is used in duplex?
Duplex equipment
Linear array transducer, 5-7 MHz
Color
PW Doppler
what is the LE venous protocol?
Low dynamic range/compression (high contrast image)
Lower Doppler scale (PRF) for color and spectral
Lower filter for color and spectral
position for duplex exams
pants off
reverse Trendelenburg
aka semi-Fowlers
Head bed 25-45 degrees higher than feet
Do not allow patient to bed at waist due to risk of compression of proximal veins
semi-frogleg
sitting up on edge of bed for calf veins
possibly prone for popliteal
imaging technique
Begin superior to the saphenofemoral junction
Small movements inferiorly with compressions – about thickness of the transducer face
Begin on anterior surface, moving medially as you go inferior. Popliteal imaged from posterior
Calf imaged from medial side
protocol
Trans compression at:
Common femoral proximal to SFJ
saphenofemoral junction – Mickey Mouse
CFV head
GS and CFA are the ears
Bifurcation of CF to see compression of profunda and femoral
Femoral
Proximal
Mid
Distal
Popliteal
Optional Greater Saphenous mid thigh
Doppler at same locations as compression
color
Spectral to show: Spontaneous flow, Cessation of flow with proximal compression or valsalva and Optional: augmentation of flow with distal compression
Color with distal augmentation to fill vessels at mid calf. Demonstrate: Posterior tibial, Peroneal
what can you say about the vein in relation to the artery?
is this normal?
how should you hold the Td to complete this exam? Why?
Vein slightly larger than artery
Complete collapse of vein with transducer compression
Do in transverse (not long, could fall off vein)
Don’t compress hard enough to collapse artery – that’s too hard
is this normal doppler? how can you tell?
Color should fill vessel. Flow toward head
Helps demonstrate partial thrombus
Helps identify vessel
Doppler instrumentations: 60 degree angle or less
Low scale – artery will likely demonstrate aliasing, that’s okay. Low filter. Gain up high enough
Color Doppler Energy (Power) may help
what test is widely used to visualize vein compression and do doppler? why is this test performed?
what test is more obsolete
duplex. to evaluate patency and competency.
CW, bi-directional doppler w/ strip chart – can use for smaller vessels in calf that duplex may not visualize esp if edema.
what 5 things need to be present for a normal spectral appearance?
spontaneity
Phasity
Cessation with proximal compression or valsalva
Augmentation with distal compression
Non-pulsatile
spontaneous
venous signal automatically at all levels except calf
what does phasity flow vary with?
what does deep inspiration do?
what does expiration do?
what does lack of phasity indicate?
respiration
deep inspiration stops flow
expiration augments
lack of phasity indicates obstruction proximal or systemic venous HTN, collateralization, “windstorm effect”
what is distal compression increases flow
what does it indicate?
what if it isn’t present?
augmentation
patency of veins at and above compression site
lack of augmentation - thrombus of calf, at site or above
false negative - partial thrombus, collaterals, calf thrombosis in only one
what does it mean if flow stops with Proximal compression or valsalva
veins are competent
normal valves with close and flow will stop
incompetent valves with have reversed flow
do normal veins pulse?
NO. they are non-pulsatile
pulsatility with venous HTN, CHF, excessive fluid, AV fistula
be sure you are not sampling over an artery
what variant is diplayes in this image?
what venous variant can be partial or complete and has a prevalance of ~ 20%
duplicated SFV (also below). notice proximal 1 SFV then divides into 2 SFV’s and distally rejoins into 1 SFV.
Why can’t it (image below) be a CFV bifurcating into SFV and profunda?there are 2 superiorly and 2 inferiorly
duplicated (bifid) SFV and popliteal veins
GSV or LSV may also be duplicated
what is the variant that follows through popliteal and moves to mid calf due to an absenc eof the tibioperoneal trunk?
trifurcation of calf veins.
What is the prevalence of the variant LSV termination at GSV, Vein of Giacomini or SFV (rather than pop)
~30%
*does not use the LS to evaluate when clinical question thrombus
is this duplex normal or abnormal?
normal – 5 phases
routine LE venous exam
Room warm if possible
5-6 MHz Linear Array Transducer
Venous Exam preset
Position machine and bed in an ergonomically correct way.
LE Venous protocol
Compression images are the most important part of the exam.
Try to keep the compression images grouped together during the exam as much as possible.
Different sonographers will use different techniques and imaging order. Listen to their ideas.
Different labs will have different protocols, this one exam of a common protocol.
what is this?
trans CFV proximal to GS junction
what is this?
trans CFV and GS junction *mickey mouse
what is this?
trans SFV proximal at birfurcation
what do you need to do to get the SFV mid
keep Td medial and push against the femus
from medial window are vessels deep or superficial?
very deep
what can you find from the anterior window doing a SFV distally?
Find femur, vessels are medial and even with the posterior boarder of the femur
what do you need to remember to do when getting a trans of the popliteal?
turn patient and be sure to follow it distally to bifurcation
what is this?
color of popliteal. notice differnce between spectral popliteal (below)
how should you image the CFV and GS junction in color?
in long if possible
what is this?
spectral at CFV
what is this?
color SFV proximal at bifurcation
what is this?
spectral SFV mid
what approach was used here? how can you tell?
medial (color SFV distal)
spectral from medial approach of SFV distal is below
what approach was used to get this image of the SFV distal?
anterior
what do you think you are looking at in this image?
how do you attemp to see these?
color of calf veins. attempt to see PT and peroneal in long (below) otherwise trans (front) is ok
