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Duplex Imaging-Arterial LE
By
Laurie Bentson MHA, RVT, RDMS
Learning Objective
• Review etiology and mechanism of LE arterial disease
• Discuss anatomy
• Discuss duplex imaging technique
• Review diagnostic criteria
• Discuss normal ultrasound findings
• Discuss abnormal ultrasound findings
• Discuss common pathological conditions encountered in LE arterial
duplex imaging
• Apply knowledge-case studies
Duplex Imaging- Arterial LE
Etiology for arterial disease: Atherosclerosis-most
common at 90%
• Process involving accumulation of fatty
substances in regions of intima in medium
and large arteries
• Disease can be focal or diffuse at any
level or multiple levels of the arterial
system
• Occurs primarily in regions where the
endothelial cells are dysfunctional due
to shear stress exposure on wall of
artery
• Outer wall of bifurcations
• Inner wall of curves arteries
• Origin or ostia
• Distal SFA
• Popliteal can calf arteries
Duplex Imaging-Arterial LE
Mechanism of Disease
Atherosclerosis
• Most common arterial disease (ALL
arteries!)
• Forms in the arterial wall and decreases
flow with lumen narrowing (stenosis) or
completely obstructs flow (occlusion)
• Significant obstruction changing flow
dynamics is considered
hemodynamically significant –
Typically 50% diameter reduction
and >60% stenosis per velocities
• Chronic progressive disease
• Occurs at bifurcation points
• Ultrasound imaging characterizes plaque
Duplex Imaging-Arterial LE
Mechanism of Disease
Emboli: Typically, a piece of plaque
or thrombus that moves from a
proximal point and travels distally
through larger arteries that become
smaller. Eventually embolus
obstructs vessel as artery becomes
smaller and embolus is larger than
vessel
• Emboli causes infarction or a
sudden reduction of flow to tissue
• Tissue ischemia occurs
Duplex Imaging-LE Arterial
Risk Factors
• Age
• Coronary artery disease (CAD)
• History of cerebral vascular disease
• Diabetes
• Hyperlipidemia
• Hypertension
• Obesity
• Smoking
• Sedentary lifestyle
Duplex Imaging-LE Arterial
Symptoms-Chronic Disease
Etiology: Atherosclerosis
Intermittent claudication
• Pain in large muscle groups caused by activity
• Pain may be described as fatigue, cramping, aching, or tiredness
• Usually occurs in calf, thigh, or buttocks
• Pain relieved with rest
Below: Conditions that mimic intermittent claudication-testing ordered to exclude or confirm arterial disease. Obtaining
accurate patient history so important!
Duplex Imaging-LE Arterial
Symptoms-Chronic Disease
Etiology: Atherosclerosis
• Rest pain
• Pain in foot while patient is lying
down
• Represents increasing severity of
disease
• Relieved by dangling extremity off
edge of bed-allow gravity to
improve perfusion
• Advanced peripheral arterial disease
(PAD)
• Thickening of toenails and loss of
toe hair
• Skin discoloration and scaliness
• Elevation pallor/dependent rubor
• Ulcers at pressure points
• Gangrene
Duplex Imaging-Arterial LE
Symptoms-Acute Disease
Etiology: Embolic
• ‘5 Ps’ (see left)
• Excruciating pain
• Pain not relieved with rest or gravity
• Pallor
• Cyanosis
• Cold leg
• Fixed mottling
Duplex Imaging-LE Arterial LE
Indications for Exam
• Claudication
• Rest Pain
• Cold leg
• Acute leg pain
• Gangrene-arterial ulcer
• Digit (toes) cyanosis
• Decrease or absent pulses
• Pre & post op revascularization
procedures
• Trauma
Duplex Imaging-Arterial LE
Testing:
• Lower extremity duplex ultrasound
exam should begin at groin
• Vessels to be examined include
• Common femoral artery (CFA)
• Superficial femoral artery (SFA)
• Profunda femoris artery (PFA)
• Popliteal artery
• Posterior tibial artery (PTA)
• Anterior tibial artery (ATA)
• Peroneal artery
Duplex Testing- Arterial LE
Testing:
• Aorto-iliac
• Challenging due to depth of vessels,
bowel gas, and obesity.
• Femoro-popliteal segment
• This area location of majority of PAD
in the legs
• Tibial arteries
• Visualized medial and anterior/lateral
below knee portion of leg
• Small, running parallel to skin surface,
must heel-toe to create appropriate
angle
• Difficult to image when diseased, as
they’re very small with low flow, often
calcified
Duplex Imaging-Arterial LE
Testing:
• Most common position is supine with
knee slightly flexed and thigh
abduction
• Lateral decubitus position may be
used to evaluate popliteal artery,
tibioperoneal trunk, and peroneal
artery
Duplex Imaging-Arterial LE
Testing:
• Curvilinear 5-2 MHz and/or phased
array 3-2 MHz transducers useful for
aortoiliac scanning and deeper lower
extremity vessels in heavier limbs
• Linear 7-4 MHz transducer useful for
the majority of lower extremity
vessels
• High resolution linear 15-7 MHz
transducer may allow better
visualization of more superficial
vessels, especially near ankle and foot
• Heel-toe to create angles for good
color fill and < 60-degree angle for PW Duplex Testing- Arterial LE Testing: Determine • Document gray scale image, color flow image, and spectral waveform in all vessels • Record for every major arterial segment • Gray scale images should include both transverse and sagittal planes • Spectral Doppler used as primary tool to categorize disease • Consider waveforms-should be multiphasic with sharp upstroke • PSV record in all major vessels • When disease is present (stenosis), velocities and waveforms should be recorded proximal to the stenosis, in the stenosis, and distal to the stenosis • Velocity ratios can be used to help classify disease severity Duplex Testing- Arterial LE Testing: Normal ( absent hemodynamically significant stenosis) • Doppler waveforms: Normal LE arterial waveforms multiphasic with sharp upstroke in systole, followed by flow reversal in late systole or early diastole (below baseline), finally forward flow component • General grayscale and color characteristics: • artery free of intraluminal echoes. • Possible plaque visible on wall however we use velocities to determine if hemodynamically significant • Color fill lumen wall-to-wall Duplex Testing- Arterial LE Testing: Abnormal Plaque Characteristics and Descriptions • Diffuse Plaque-long segment of artery lined with plaque, common in SFA • Stenotic-lumen narrowed by plaque or embolus • Hemodynamically significant stenosis-lumen narrowed by plaque or embolus to point that velocities increase->50% narrowing or greater
• Calcific-highly reflective plaque
• Occluded-complete occlusion of vessel determined by spectral
analysis
• Moving/Mobile-debris within lumen poorly adhered to vessel wall
Note: Not all plaque indicates >50% stenosis. Must see an increase in
focal velocity with post-stenotic turbulence and waveform change to
monophasic downstream
Duplex Testing- Arterial LE
Testing: Abnormal Stenosis > 50%
• Hemodynamically significant
lesion (>50%)
• Narrowing of lumen to > 50% by
intraluminal plaque
• Focal velocity increase (at least
double velocity in previous segment)
• Change in spectral waveform from
multiphasic to tardus parvus
(monophasic with delayed upstroke)
• Post-stenotic turbulence
Waveform changes proximal to, at stenosis
and distal to stenosis
Duplex Imaging-Arterial LE
•
•
•
•
•
Important to pause and discuss monophasic
waveforms as associated with LE arterial disease
LE arteries typically demonstrate high resistant,
multiphasic flow and monophasic said to be
abnormal
We must consider physiological influence on blood
flow! Waveform can be monophasic and normal.
How do we know when monophasic waveform
normal versus abnormal?
• Study the upstroke (red arrow, waveform on
left)
• If upstroke is sharp, with good pulsatility,
waveform is normal even if monophasic.
What can influence this change in waveform?
• Fever
• Open wound
• Exercise
• Inflammation of tissues (cellulites)
Duplex Testing- Arterial LE
Testing: Abnormal Occlusion
• No color flow
• No blood flow detected by spectral
Doppler
• Staccato waveform often indicates
downstream occlusion
• Must confirm by walking sample gate
through area of suspected occlusion
• Measure length of occlusion
• Collateral flow usually identified
proximal to and distal to occlusion
• Use flow in adjacent vein as a guide to
identify an occluded artery
Duplex Testing- Arterial LE
Testing Abnormal: Aneurysm
• Weakening of arterial wall
resulting in all three layers
expanding at point of weakness
• Can be bilateral and multilevel
• Aneurysm is present if the
diameter of a vessel is 1.5 times
greater than the adjacent, more
proximal segment
• Presence or absence of
thrombus should be
documented (embolic risk)
• Measure AP and Width
diameter with length
‘Rule of Thumb’ Aneurysm
measurement
• Measure residual flow
Measurements
• Also measure AP and Width
≥ 3 cm – Abdominal aorta
diameter of proximal segment
≥ 2 cm – Iliac artery
≥ 1 cm – Popliteal artery
Duplex Testing- Arterial LE
Testing Abnormal:
Pseudoaneurysm
• Known complication of
endovascular procedures
• Pulsating encapsulated
hematoma that
communicated with adjacent
artery
• Occurs with leakage of blood
after an injury to arterial wall
and surrounding soft tissue• Common cause is large
bore catheters
• CFA common location
Duplex Testing- Arterial LE
Testing Abnormal: Pseudoaneurysm
Treatment
• Ultrasound used to guide fine needle into PA
to inject thrombin.
• Thrombin will cause thrombosis of PA
• Neck length necessary to ensure no risk of
embolism from formed thrombus in
treatment of PA
• Document PTA/ATA waveforms pre and post
procedure to exclude embolic event
• Evaluate PA post procedure with sensitive
color and PW settings to confirm occlusion
• Patient will f/u within 72 hours to confirm PA
still occluded
Duplex Testing- Arterial LE
Testing Abnormal: AV Fistula
• Communication between artery and vein
• Traumatic or iatrogenic
• If iatrogenic, usually secondary to
endovascular procedure and the large bore
catheters used to gain access to arterial
system
• Clinical presentation is bruit and/or palpable
thrill, hematoma
• Ultrasound ordered to evaluate for PA. PA
protocol includes waveforms of CFA/CFV &
CFV/FV to exclude AV Fistulae. These limited
arterial exams evaluate for both AV Fistulae
and PA
• Color used to visualize focal aliasing
• PW used to confirm connection
Duplex Testing- Arterial LE
Testing Abnormal: AV Fistula
• Arterial limited exam to area of concern ordered
• Evaluate for both PA and AVF
• Waveforms obtained in all areas identified by
• Use color & PW to identify connection with
significant aliasing, high velocities and turbulent
flow
• If positive for AVF
• Venous flow at level of AVF will
demonstrate high velocities, turbulent flow
and arterialized
• Arterial flow proximal to AVF will
demonstrate high ED flow as indicated by
diagram
Duplex Testing- Arterial LE
Application of knowledge #1
• Patient s/p cardiac cath w/ RT groin
access.
• Patient c/o palpable pulsatile mass and
bruit RT groin
• This image obtained.
• What is finding?
• What waveforms will you obtain?
• What will you measure?
• What is another possible diagnosis
considering clinical presentation?
• If struggling with imaging, what can you
do to optimize?
Duplex Imaging-Arterial LE
Application of knowledge #2
• Consider location of stenosis and
ultrasound image with velocity
measurement
• With this diagnosis, what will the
RT CFA waveform look like? LT CFA?
• With this finding, with the
segmental BPs, 4 cuff method, will
the high thigh pressures be > than
brachial pressures or less?
• Will the ABI on right be lower than
on left? Or same low ABI
bilaterally?
Duplex Imaging-Arterial LE
Application of knowledge #3
• Pt has hx of AAA, HTN. C/O Blue
Toes LT foot
• LLE Arterial Duplex ordered
• This is one of your images popliteal
fossa.
• What is your probe orientation?
• Which vessel is this?
• What is finding?
• Next imaging steps?
Duplex Imaging-Arterial LE
Application of knowledge #4
• Pt presents with abnormal RLE ABI, HTN,
Smoking and CAD
• Arterial Duplex ordered. You obtain this
image mid thigh.
• What is your probe orientation?
• Which vessel is this?
• What is your finding?
• Next steps?
• ABI abnormal. What does this say about
this finding in your image?
• Considering patient history, is ABI
reliable?
Indirect Testing
Lower Extremity Arterial System
Laurie Bentson MHA, RVT, RDMS
Indirect Testing-LE Arterial
Objective
• Discuss arterial lower extremity (LE) acute and chronic disease
process
• Symptoms of LE arterial disease
• Definition of indirect testing
• Testing technique
• Diagnostic Criteria
Indirect Testing
• Indirect testing involves the assessment of the arteries and veins
without direct visualization the vessel with ultrasound system.
• We can assess perfusion to extremity by evaluating waveforms, blood
pressures and changes in pressure poste exercise by using the indirect
testing method
• For the purpose of this presentation, indirect testing involves the use
of CW Doppler to assess waveforms, blood pressure cuffs to evaluate
the blood pressures of extremities and diameter circumferential
changes with arterial inflow-even in the digits!
Indirect Testing-LE Arterial
Etiology for arterial disease:Atherosclerosismost common at 90%
• Process involving accumulation of fatty
substances in regions of intima in medium
and large arteries
• Disease can be focal or diffuse at any
level or multiple levels of the arterial
system
• Occurs primarily in regions where the
endothelial cells are dysfunctional
due to shear stress exposure on wall
of artery
• Outer wall of bifurcations
• Inner wall of curves arteries
• Origin or ostia
• Distal SFA
• Popliteal can calf arteries
Indirect Testing-LE Arterial
Mechanism of Disease
Atherosclerosis
• Most common arterial disease (ALL arteries!)
• Forms in the arterial wall and decreases flow
with lumen narrowing (stenosis) or
completely obstructs flow (occlusion)
• Significant obstruction changing flow dynamics is
considered hemodynamically significant –Typically
50% diameter reduction and >60% stenosis per
velocities
• Chronic progressive disease
• Occurs at bifurcation points
• Ultrasound imaging characterizes plaque
Indirect Testing-LE Arterial
Mechanism of Disease
Emboli: Typically, a piece of plaque or
thrombus that moves from a proximal
point and travels distally through
larger arteries that become smaller.
Eventually embolus obstructs vessel
as artery becomes smaller and
embolus is larger than vessel
• Emboli causes infarction or a
sudden reduction of flow to tissue
• Tissue ischemia occurs
Indirect Testing-LE Arterial
Risk Factors
• Age
• Coronary artery disease (CAD)
• History of cerebral vascular disease
• Diabetes
• Hyperlipidemia
• Hypertension
• Obesity
• Smoking
• Sedentary lifestyle
Indirect Testing-LE Arterial
Symptoms-Chronic Disease
Etiology: Atherosclerosis
Intermittent claudication
• Pain in large muscle groups caused by activity
• Pain may be described as fatigue, cramping, aching, or tiredness
• Usually occurs in calf, thigh, or buttocks
• Pain relieved with rest
Below: Conditions that mimic intermittent claudication-testing ordered to exclude or confirm arterial disease. Obtaining
accurate patient history so important!
Indirect Testing-LE Arterial
Symptoms-Chronic Disease
Etiology: Atherosclerosis
• Rest pain
• Pain in foot while patient is lying
down
• Represents increasing severity of
disease
• Relieved by dangling extremity off
edge of bed-allow gravity to
improve perfusion
• Advanced peripheral arterial disease
(PAD)
• Thickening of toenails and loss of
toe hair
• Skin discoloration and scaliness
• Elevation pallor/dependent rubor
• Ulcers at pressure points
• Gangrene
Indirect Testing-LE Arterial
Symptoms-Acute Disease
Etiology: Embolic
• ‘5 Ps’ (see left)
• Excruciating pain
• Pain not relieved with rest or gravity
• Pallor
• Cyanosis
• Cold leg
• Fixed mottling
Indirect Testing-LE Arterial
Indications for Exam
• Claudication
• Rest Pain
• Gangrene-arterial ulcer
• Digit (toes) cyanosis
• Decrease or absent pulses
• Pre & post op revascularization procedures
• Trauma
Note: Acute symptoms not listed. Indirect testing not usually
ordered or used to evaluate acute arterial occlusion. Usually
order ultrasound imaging or contrast enhanced imaging. No
time for indirect testing and then imaging to confirm
findings because of potential for limb ischemia
Indirect Testing-LE Arterial
Patient History
• Symptoms
• Intermittent claudication (chronic)
• Rest pain (chronic)
• 5 ‘Ps’ (acute)
• Extremity cyanosis and/or cold (acute)
• Must ask about onset of symptoms-’How long have you
had this pain?’
• Must ask ‘What makes your pain feel better or go away?
• Important questions to determine if complaints
acute or chronic
• Ask about Risk Factors
• HTN
• DM
• Hyperlipidemia
• CAD
• CVA
Risk factors important because this history indicates
increased risk for PAD!
Indirect Testing-LE Arterial
Patient positioning
• Patient should be supine with head
raised slightly
• Patients usually cannot lie flat-makes
us dizzy as we get older!
• Supine-consider affects of
hydrostatic pressure
• Legs should be externally rotated with
knees flexed depending on vessels being
interrogated
• Allow time for patient to rest in supine
position prior to taking pressures
• Why? Often, we walk patient back
to exam room and recall,
exercises changes the dynamics
of flow-arterioles dilate to allow
more oxygenated blood to
exercising muscles
Indirect Testing-LE Arterial
Technical Considerations
• Cuff size is important
• Width should be 20% wider than the diameter
of underlying limb
• Cuff too narrow = falsely elevated pressure
• Cuff too wide = falsely lower pressure
• The proper fit of the cuff is what makes this exam
somewhat challenging
• Our legs are cone shaped therefore difficult to
wrap cuffs appropriately as the size of leg
tapers.
Indirect Testing-LE Arterial
Technical Considerations
• Manufacturers recommend either a 10 or 12 cm cuff for the arms and
ankles based on patient size-larger cuff for larger extremity
• Consider the bones of leg, need to place cuff below level of knee
otherwise excessively high pressures
• The air bladder of cuff should also be placed appropriately around the
muscle and not the bones of lower leg
• Don’t allow patient to lift leg to help you while placing cuffs
• Why? As soon as they relax their muscles, the cuff becomes loose
Review
• Signs and symptoms of PAD
• Risk factors
• Mechanism of disease
• Technical considerations with cuff
placement
• What is indirect testing?
Indirect Testing-LE Arterial
Testing: Ankle Brachial Index (ABI)
• Diagnostic test (meaning with criteria
to diagnose disease) to assess overall
perfusion of LEs
• ABI is calculated by dividing highest
systolic ankle pressure by the higher of
the two brachial systolic pressures
• How to? Obtain pressures in
bilateral brachial arteries, bilateral
PTA and bilateral DPA
Indirect Testing-LE Arterial
Testing: ABI
• Doppler signal is obtained distal to the
cuff
• Care must be taken not to compress
these vessels
• Once Doppler signal is obtained, cuff is
inflated to register systolic pressure-turn
up volume!
• Cuff should be inflated 20 mm Hg
above point where signal disappears
• Cuff should be deflated at a rate of
about 3 mm Hg/s
Indirect Testing-LE Arterial
Testing: Limitations
• Calcified arterial walls
• Chronic disease process in which the arterial wall
calcifies with progressive atherosclerotic disease
• Arterial wall hardens with deposits of calcium and no
longer compliant
• Difficult to compress when taking blood pressures
and if pressure obtained, not reliable secondary to
calcifications-common term used is noncompressible
arteries
• Patients with history of DM, renal dialysis and chronic
steroid therapy are known to have this complication
• Patients with ABI > 1.30 (can vary across
departments) is considered falsely elevated and
inaccurate-noncompressible arteries
Indirect Testing-LE Arterial
ABI Diagnostic Criteria
Indirect Testing-LE Arterial
• In next few slides we will discuss plethysmography and segmental blood
pressure testing followed by pre and post exercise pressures with
assessment of the digits
• The ABI can be used with ultrasound imaging or independently to
determine perfusion.
• The ABI is the number one test to assess overall perfusion and extremely
commonly used at bedside, trauma room, ER, doctor offices, etc.
• The ABI involves ankle-brachial pressures
• Segmental pressures and plethysmography involve cuff placement with
pressures entire leg
Indirect Testing-LE Arterial
• Note we can use a 3-cuff
method or a 4-cuff method
• Note size in cuffs
• The 3-cuff method uses a large
thigh cuff that fits the shape of
thigh very well
• Difficult to wrap the 12 cm cuff
around the proximal thigh for
appropriate fit
• Note the air hoses-we take all
BPs at ankle using strongest
signal (either PTA or DPA) and
cycle through the other
locations on leg one cuff at a
time starting with ankle
Indirect Testing-LE Arterial
Testing: Plethysmography
• Other names include air
plethysmography, pulse volume
recording (PVR) or volume pulse
recording (VPR). We will refer to this
testing type as PVR
• Cuff used to measure volume changes
in extremity under the cuff
• Changes occur secondary to arterial
inflow
• These volume changes are converted to
a waveform for qualitative analysis
meaning there is no data for diagnosis
only subjective evaluation to determine
if normal or abnormal
Indirect Testing-Arterial LE
Testing: PVR
• Three or four cuff method used
• Each cuff inflated to 55 to 65 mmHG to restrict
venous outflow-this allows cuff to detect
changes in volume that can only be related to
arterial flow if venous flow restricted
• Volume changes occurring under cuff from
arterial inflow
• Volume changes are converted to waveform
• Assess waveform and this is qualitative
assessment
• This waveform considered normal with sharp
upstroke and presence of reflect wave (blue
arrow) which is known as dicrotic notch
• Important to keep settings the same from leg
to leg. We compare waveforms in our
assessment and changes in settings can
appear pathological when normal
Indirect Testing-LE Arterial
Indirect Testing-LE Arterial
Testing: Segmental Blood
Pressures
• Segmental blood pressures can
determine site of disease with
diagnostic criteria
• Pressures are taken at the 3 or 4
sites of leg depending on which
method used
• Pressure differences noted
between levels and if significant
differences, disease can be
localized
Indirect Testing-LE Arterial
Testing: Segmental Blood Pressures
• Pressure drop > 30 mm Hg between levels
indicates presence of proximal obstruction
• Pressure changes between brachial
pressures of > 20 mmHG indicates disease
• Note width of thigh cuff changes
interpretation
• Single large thigh cuff results in thigh
pressure equal to brachial pressure
• Use of narrower high thigh cuff results
in pressures 30 mmHG above brachial
pressure
• **Width of thigh cuff changes
interpretation**
Indirect Testing-LE Arterial
Review report page to right
• Note cuff method-is it 3 or 4?
• Considering method, is the high
thigh pressures normal?
• What about brachial pressures,
normal?
• Any concerning areas that
indicate disease per pressures?
• Is ABI normal?
Indirect Testing-LE Arterial
Testing: CW Waveforms
• Continuous wave Doppler
(CW) transducer used to
obtain waveforms at CFA,
SFA, Popliteal, PTA and
DPA
• Qualitative assessment
• Necessary to adjust angle
of probe when obtaining
ABI and waveforms
• Angle to pitch
• Higher the pitch, the
better the waveform
Indirect Testing-LE Arterial
• Consider report page to left
• CW Doppler Waveforms
• Which locations are they
obtaining waveforms?
• Knowing resistance is high in
lower extremity and waveforms
therefore triphasic or biphasic,
where is location of suspected
disease using this qualitative
assessment?
Indirect Testing-LE Arterial
Testing: Exercise Testing
• Obtain ABI post exercise
• Usually used with all normal or near
ABIs and Segmental BPs exams
• Recall the pressure drops across
stenosis when volume of flow
increases across stenosis. Exercise will
increase volume of flow to legs and
unmask stenosis
• Exercise using treadmill or toe lifts. If
treadmill
• 12% incline
• 2 mph (or pace at which patient walks)
• Maximum 5 minutes walking time (okay
to stop early if necessary)
Indirect Testing-LE Arterial
Indirect Testing-LE Arterial
• Refer to report page to left
• At time of exercise, we have already completed ABIs and possibly segmental BPs.
We leave the cuffs on ankles and arms to expedite obtaining post exercise
pressures
• Patient exercises, you stay in room, checking in with patient constantly asking
about symptoms, asking if they are okay to continue.
• Patient completes exam and you assist them to table
• You immediately connect air hoses and start taking pressures, cycling through
both ankles and arms
• Then repeat
• Lowest value of post activity ABI categorizes functional severity of limb
• The initial pressure followed by the second pressure usually most important. It
indicates the drop of pressures post exercise when compressed to pre- exercise
pressures. We move quickly to capture this drop-prior to recovery.
• Some referring physicians want to see how long it takes to recover (indicated in
graph)
• ABI that recovers to preexercise level between 5-10 minutes associated
with single level disease
• If > 10 minutes associated with multilevel disease
Indirect Testing-LE Arterial
Testing: Digits Pressures and
Waveforms
• Standard to use with ABI in patients
with DM because of known possibility
of calcified arteries causing falsely
elevated pressures
• Also used to determine location of
healing in pre-operative assessment
for amputation or post-operative
evaluation to determine if tissue will
heal
• Small digital cuff great toe and
photoplethysmography (PPG) sensor
positioned distally on the toe
Indirect Testing-LE Arterial
Testing: Digital Pressures and
Waveforms
• No audible signal
• Low intensity infrared light used to
detect blood volume changes in the
microvascular bed of tissue
• Light emitted from PPG sensor
travels through biological tissues
and absorbed by blood more than
surrounding tissues – changes in
blood volume detected by the
same PPG sensor
• Energy converted to waveform
Indirect Testing-LE Arterial
•
•
•
•
•
•
Used in addition to ABI or Segmental blood pressure
Sonographer places cuff around great toe and sensor distal portion of toe. Clip or double-sided tape works well
Tracing obtained demonstrating volume changes of blood in great toe underneath PPG sensor
Cuff inflated until no waveform and then slowly bleed air
Systolic toe pressure is the first consistent pulse
Careful with toe movement, tremor and associated artifacts
Indirect Testing-LE Arterial
• Testing: Digit Pressures &
Waveforms
• Calculate toe-brachial index
• Normal >.8
• Toe pressure of 50 mmHg
indicates adequate pressure for
tissue healing
• Toe pressure < 30 mmHg considered critical ischemia Indirect Testing- LE Arterial Diagnostic Criteria Indirect Testing LE Arterial Exam Indirect Testing-LE Arterial Review What is ABI? Explain difference between ABI and Segmental BP exam? What is TBI and when will we use it? Why is exercising patient important? When will we exercise? Indirect Testing- LE Arterial Application of knowledge: Patient presents with c/o LLE pain after walking two blocks. Segmental blood pressure exam ordered, and you obtain the information on this report? Answer following questions: 1. Is this a 4-cuff or 3-cuff method? 2. What additional question should you ask patient about their history? 3. Considering method, is the high thigh pressures normal bilateral? 4. Where is disease? 5. Is ABI normal? 6. What will happen to pressures if you exercise patient? 7. Patient has history of DM. Does this matter? Why or why not? 8. What additional test should you perform for accurate information? Indirect Testing- LE Arterial Application of knowledge: • Patient presents with 6-month history of bilateral lower extremity calf pain after running 2 miles. Pain relieved with massage. Pt has hx of DM, HTN and smoking x 35 years. • Segmental blood pressure exam ordered, and you obtain this information on report. • Is exam normal? • Are the ankle pressures considered reliable? • What two additional exams should you perform to provide a thorough exam? Duplex Imaging-Arterial UE By Laurie Bentson Duplex Imaging-Arterial UE Objective • Discuss mechanism of disease upper extremity arterial system • Discuss symptoms of arterial disease • Discuss indications for ultrasound duplex examination • Discuss ultrasound imaging protocol and techniques • Discuss normal and abnormal image interpretation Duplex Imaging-Arterial UE • The use of a combination of real time B-mode ultrasound with pulse wave and color flow Doppler to evaluate the arteries of upper extremity (UE) Duplex Imaging-Arterial UE Mechanism of Disease • Atherosclerosis-rare in UE arterial system • Emboli-Plaque or thrombus that moves from a proximal point and travels distally through larger arteries that become smaller eventually obstructing the smaller arteries when embolus no longer travels through • Vasospasm-temporary constriction of the arteries (typically digital arteries)that may cause significant discomfort to the patient or be a sign of a more serious underlying disease • Extrinsic compression-typically musculoskeletal configuration causing stenosis or occlusion of subclavian artery and vein compromising blood flow to extremity • Mechanical compression Duplex Imaging-UE Arterial Risk Factors • Age • Coronary artery disease (CAD) • Diabetes • Hyperlipidemia • Hypertension • Obesity • Smoking • Female • Cold climates • Immunology and connective tissue disorder • Repetivie UE motion • Anatomical variation of ribs • Large pectoral muscles Indirect Testing-UE Arterial Symptoms • Numbness • Tingling • Claudication • Bruit • Limb pain at rest • Digital cyanosis Indirect Testing-UE Arterial Indications for Exam • Thoracic outlet syndrome (TOS) • Cold sensitivity • Raynaud’s • Pulselessness • Cold extremity • Positional pain • Gangrene • Pulselessness • Decrease in blood pressures from arm to arm • Extremity tingling • Subclavian Steal Syndrome Duplex Imaging-Arterial UE Location of Disease • Focal or diffuse • Affect multiple levels of single level of anatomy • At origin of vessel • Subclavian or axillary artery (more common)-actually left subclavian artery most common location-disease often a continuation of disease within aortic arch • Palmar arch or digital arteries Duplex Imaging-Arterial UE Patient History • Important to seek specific information in those patients presenting with suspected TOS and cold sensitivity • In patients with suspected TOS, must ask about the position that causes patient to experience the symptoms • For those suffering with possible cold sensitivity, important to ask about the color changes associated with Primary Raynaud’s • Smoking and digital ischemia indicate Buerger's Disease Duplex Imaging-Arterial UE Testing • Obtain bilateral brachial blood pressures • Arteries to be examined include • Subclavian • Axillary • Brachial • Radial Prox • Radial Distal (at wrist) • Ulnar Prox • Ulnar Distal at wrist Duplex Imaging-Arterial UE Testing: • Right subclavian easier to visualize at origin secondary to brachiocephalic artery • Subclavian artery little more challenging with position of clavicle • Short artery • We can visualize segments of subclavian artery • Axillary artery identified from anterior approach deep to pectoralis major and minor muscles • Followed through axilla, deep to axillary fat pad • Brachial artery begins as artery crosses teres major muscle • Courses more superficial in medial arm between biceps and triceps muscles • Obtain view of proximal, mid, and distal brachial, radial, and ulnar arteries • Evaluate for and document areas of stenosis, occlusion, or aneurysmal enlargement Duplex Imaging-Arterial UE Interpretation: Normal upper extremity waveform • Triphasic/multiphasic • Sharp systolic peak • Brief period of diastolic flow reversal • Minimal continued forward flow in diastole • Normal PSV varies from 80 to 120 cm/s in subclavian; 40 to 60 cm/s in brachial, radial, and ulnar arteries Duplex Imaging-Arterial UE • Interpretation: • Determine • Plaque location, plaque characteristics • Peak systolic velocities • Changes in spectral waveform analysis • Velocity ratios comparing normal inflow arterial velocities to highest velocity within stenosis Duplex Imaging-Arterial UE Interpretation: Abnormal findings-Stenosis • Elevated PSV • Post stenotic turbulence • Dampened distal waveforms with loss of end-systolic flow reversaltardus parvus • General guidelines suggest velocity ratio ≥2 is consistent with >50%
stenosis
• Waveform changes and brachial
blood pressures can help determine
stenosis significance
Duplex Imaging-Arterial UE
Interpretation: Abnormal Findings
Occlusion
• Absence of flow within lumen with
color Doppler
• Absence of flow within lumen
confirmed with spectral Doppler
• Intraluminal echogenic material visible
• Use vein as anatomic landmark
Duplex Imaging-Arterial UE
Interpretation: Diagnostic Criteria-Velociteis
Duplex Imaging-Arterial UE
Interpretation Abnormal: Aneurysm
• Permanent localized dilation resulting
in 50% increase in diameter of an
artery compared to adjacent normal
artery
• Document width, AP and length
• Evaluate for thrombus within
aneurysm
Duplex Imaging-Arterial UE
Interpretation Abnormal: TOS
• Impingement of the neurovascular bundle
at the thoracic outlet
• Compression may be secondary to
cervical ribs, hypertrophy of the
scalene muscles and bony lesions
• Patients experience pain, numbness,
tingling and weakness
• 95% of cases is a nerve compression
Duplex Imaging-Arterial UE
Interpretation Abnormal: TOS
• In 5% of cases, vessels involved
• Results in compression and
damage to subclavian vessels
• Repeated trauma can cause
aneurysm, stenosis, ulceration,
or occlusion of subclavian artery
and/or vein
• Duplex ultrasound can be used to
document these abnormalities
• Most important position when
evaluating patients is the symptomatic
arm position
Duplex Imaging-Arterial UE
Interpretation Abnormal:
Thromboangiitis Obliterans Disease
• Primarily involves small and medium
size vessels of hands and feet
• Non-atherosclerotic, inflammatory
segmental occlusive disease
characterized by thrombosis and
recanalization of affected vessels
• Duplex ultrasound used to evaluate
for proximal occlusive disease
secondary to atherosclerosis that can
further complicate Buerger’s Disease
Duplex Imaging-Arterial UE
Interpretation Abnormal: Takayasu
Arteritis
• Autoimmune disorder that affects the
arteries of the aortic arch and
abdominal aorta
• Most common in women 20-30 age
groups
• Acute: associated with fever, malaise
• Results in long segment occlusion or
stenosis of affected arteries
Duplex Imaging-Arterial UE
Application of Knowledge Exercise
• Pt presents with pain and
numbness left arm in specific
positions
• What is potential diagnosis?
• What is most important question
to ask when obtaining patient
history?
• Dual imaging used and you take
this image on symptomatic side.
What does it indicate?
• Which position is most important
for evaluation?
Duplex Imaging-Arterial UE
Application of knowledge
• 45 y/o man presents with digit
ischemia. Hx smoking
• LE duplex ordered and you
obtain this image in area of
PTA.
• What disease does this indicate?
What is disease process creating
appearance of artery?
Duplex Imaging-Arterial UE
Application of knowledge
• Patient presents with decreased
pulses RUE and vertigo.
• Duplex ultrasound ordered and these
two images obtain of subclavian
artery. What does velocity indicate?
What about waveform distal? Is this
normal or abnormal?
• Angiogram ordered to confirm your
ultrasound findings. Do you see
narrowed vessel?
• Considering these findings and
complaint of vertigo, what else should
we consider?
Duplex Imaging-Arterial UE
Application of knowledge
• Patient presents with acute
onset of hand pain and coldness
• Ultrasound arterial duplex
ordered UE and you take this
image radial artery. Note
intraluminal echogenic material
Duplex Imaging-Arterial UE
Continued:
• You obtain Doppler waveform
proximal to area with
intraluminal echoes
• Is this normal?
• What does it indicate?
Duplex Imaging-Arterial UE
Continued:
• You take this image distal to area
of suspicion
• Is waveform normal?
• What additional images are
necessary to complete this
exam?
• What is diagnosis?
Indirect Testing UE Arterial
Laurie Bentson MHA, RVT, RDMS
Indirect Testing-UE Arterial
• Discuss anatomy UE arterial system
• Define mechanism of disease UE arterial system
• Discuss patient symptoms and clinical indications for testing
• Discuss types of testing
• Diagnostic criteria
Indirect Testing-UE Arterial
Mechanism of Disease
• Arterial disease secondary
to atherosclerosis creating
obstructions in the upper
extremity is RARE
encountered in or equal to .9
Indirect Testing-UE Arterial
• Testing: Primary Raynaud’s ONLY
• Ice submission used to confirm
diagnosis of Primary Raynaud’s
• PPG waveform analysis of digits pre
ice submersion
• Hands placed in ice water bath for
30-40 seconds
• PPG waveform analysis during or
immediately after ice submersion
• PPG digital waveforms obtained
approximately 2.5 minutes post ice
submersion and then again 10
minutes post immersion (times can
vary based on department protocol)
Indirect Testing-UE Arterial
Should return to normal within 10 minutes
Indirect Testing-UE Arterial
Treatment: Raynaud’s
• Cessation of smoking
• Cold avoidance
• Calcium channel blockers (vasodilators)
• Treat of associated disease
• Relocate to warm climate
• Micro-revascularization
Indirect Testing-UE Arterial
Testing: Thromboangiitis Obliterans (aka Buerger’s Disease)
• Inflammatory process that causes thrombosis of the digital arteries
• Acute inflammation and thrombosis of arteries affecting hands and feet
• Obstructive Disease
• Typical patient is a young male (20-40 years), heavy smoker
• Most common is Orient, Southeast Asia, India
Indirect Testing-UE Arterial
Testing: Thromboangiitis Obliterans
Symptoms
• Claudication of hands and feet
• Rest pain hands and feet
• Pain very intense
• Tingling, numbness
• Pallor with cold
• Digital ischemia
• Gangrene
Indirect Testing-UE Arterial
Testing: Buerger’s Disease
• UE Segmental Blood Pressures
• PVRs
• CW Doppler waveforms
• Digital Pressures
• May need to warm hands if
No ICE! Recall patient symptoms can include pallor with cold. We must consider
history-heavy smoking, pain with use of hands, gender and ischemia/gangrene
indicate obstructive disease rather than vasospastic disease.
Indirect Testing-UE Arterial
Review
What is difference between
vasospastic disorders and obstructive
disorders?
What is difference between Primary
and Secondary Raynaud’s?
What is difference in testing
between Primary and Secondary
Raynaud’s?
Indirect Testing-UE Arterial
Summary
• Arterial physiological testing valuable tool for indirect assessment of arterial
disorders ranging from stenosis to vasospastic disorders
• Provides ability to diagnose disease
• Cannot determine exact location
• Technical considerations important for quality testing
• Waveform morphology somewhat subjective however pressures quantitative.
Duplex Imaging-Arterial UE
By
Laurie Bentson
Duplex Imaging-Arterial UE
Objective
• Discuss mechanism of disease upper extremity arterial system
• Discuss symptoms of arterial disease
• Discuss indications for ultrasound duplex examination
• Discuss ultrasound imaging protocol and techniques
• Discuss normal and abnormal image interpretation
Duplex Imaging-Arterial UE
• The use of a combination of real
time B-mode ultrasound with pulse
wave and color flow Doppler to
evaluate the arteries of upper
extremity (UE)
Duplex Imaging-Arterial UE
Mechanism of Disease
• Atherosclerosis-rare in UE arterial system
• Emboli-Plaque or thrombus that moves from a proximal point and travels distally through
larger arteries that become smaller eventually obstructing the smaller arteries when
embolus no longer travels through
• Vasospasm-temporary constriction of the arteries (typically digital arteries)that may
cause significant discomfort to the patient or be a sign of a more serious underlying
disease
• Extrinsic compression-typically musculoskeletal configuration causing stenosis or
occlusion of subclavian artery and vein compromising blood flow to extremity
• Mechanical compression
Duplex Imaging-UE Arterial
Risk Factors
• Age
• Coronary artery disease (CAD)
• Diabetes
• Hyperlipidemia
• Hypertension
• Obesity
• Smoking
• Female
• Cold climates
• Immunology and connective tissue disorder
• Repetivie UE motion
• Anatomical variation of ribs
• Large pectoral muscles
Indirect Testing-UE Arterial
Symptoms
• Numbness
• Tingling
• Claudication
• Bruit
• Limb pain at rest
• Digital cyanosis
Indirect Testing-UE Arterial
Indications for Exam
• Thoracic outlet syndrome (TOS)
• Cold sensitivity
• Raynaud’s
• Pulselessness
• Cold extremity
• Positional pain
• Gangrene
• Pulselessness
• Decrease in blood pressures from arm to arm
• Extremity tingling
• Subclavian Steal Syndrome
Duplex Imaging-Arterial UE
Location of Disease
• Focal or diffuse
• Affect multiple levels of single level of anatomy
• At origin of vessel
• Subclavian or axillary artery (more common)-actually left subclavian
artery most common location-disease often a continuation of disease
within aortic arch
• Palmar arch or digital arteries
Duplex Imaging-Arterial UE
Patient History
• Important to seek specific information in those patients presenting
with suspected TOS and cold sensitivity
• In patients with suspected TOS, must ask about the position that
causes patient to experience the symptoms
• For those suffering with possible cold sensitivity, important to ask
about the color changes associated with Primary Raynaud’s
• Smoking and digital ischemia indicate Buerger’s Disease
Duplex Imaging-Arterial UE
Testing
• Obtain bilateral brachial blood pressures
• Arteries to be examined include
• Subclavian
• Axillary
• Brachial
• Radial Prox
• Radial Distal (at wrist)
• Ulnar Prox
• Ulnar Distal at wrist
Duplex Imaging-Arterial UE
Testing:
• Right subclavian easier to visualize at origin secondary
to brachiocephalic artery
• Subclavian artery little more challenging with
position of clavicle
• Short artery
• We can visualize segments of subclavian artery
• Axillary artery identified from anterior approach deep
to pectoralis major and minor muscles
• Followed through axilla, deep to axillary fat pad
• Brachial artery begins as artery crosses teres major
muscle
• Courses more superficial in medial arm between
biceps and triceps muscles
• Obtain view of proximal, mid, and distal brachial,
radial, and ulnar arteries
• Evaluate for and document areas of stenosis,
occlusion, or aneurysmal enlargement
Duplex Imaging-Arterial UE
Interpretation: Normal upper extremity
waveform
• Triphasic/multiphasic
• Sharp systolic peak
• Brief period of diastolic flow
reversal
• Minimal continued forward flow in
diastole
• Normal PSV varies from 80 to 120
cm/s in subclavian; 40 to 60 cm/s in
brachial, radial, and ulnar arteries
Duplex Imaging-Arterial UE
• Interpretation:
• Determine
• Plaque location, plaque
characteristics
• Peak systolic velocities
• Changes in spectral waveform
analysis
• Velocity ratios comparing
normal inflow arterial
velocities to highest velocity
within stenosis
Duplex Imaging-Arterial UE
Interpretation: Abnormal findings-Stenosis
• Elevated PSV
• Post stenotic turbulence
• Dampened distal waveforms with
loss of end-systolic flow reversaltardus parvus
• General guidelines suggest velocity
ratio ≥2 is consistent with >50%
stenosis
• Waveform changes and brachial
blood pressures can help determine
stenosis significance
Duplex Imaging-Arterial UE
Interpretation: Abnormal Findings
Occlusion
• Absence of flow within lumen with
color Doppler
• Absence of flow within lumen
confirmed with spectral Doppler
• Intraluminal echogenic material visible
• Use vein as anatomic landmark
Duplex Imaging-Arterial UE
Interpretation: Diagnostic Criteria-Velociteis
Duplex Imaging-Arterial UE
Interpretation Abnormal: Aneurysm
• Permanent localized dilation resulting
in 50% increase in diameter of an
artery compared to adjacent normal
artery
• Document width, AP and length
• Evaluate for thrombus within
aneurysm
Duplex Imaging-Arterial UE
Interpretation Abnormal: TOS
• Impingement of the neurovascular bundle
at the thoracic outlet
• Compression may be secondary to
cervical ribs, hypertrophy of the
scalene muscles and bony lesions
• Patients experience pain, numbness,
tingling and weakness
• 95% of cases is a nerve compression
Duplex Imaging-Arterial UE
Interpretation Abnormal: TOS
• In 5% of cases, vessels involved
• Results in compression and
damage to subclavian vessels
• Repeated trauma can cause
aneurysm, stenosis, ulceration,
or occlusion of subclavian artery
and/or vein
• Duplex ultrasound can be used to
document these abnormalities
• Most important position when
evaluating patients is the symptomatic
arm position
Duplex Imaging-Arterial UE
Interpretation Abnormal:
Thromboangiitis Obliterans Disease
• Primarily involves small and medium
size vessels of hands and feet
• Non-atherosclerotic, inflammatory
segmental occlusive disease
characterized by thrombosis and
recanalization of affected vessels
• Duplex ultrasound used to evaluate
for proximal occlusive disease
secondary to atherosclerosis that can
further complicate Buerger’s Disease
Duplex Imaging-Arterial UE
Interpretation Abnormal: Takayasu
Arteritis
• Autoimmune disorder that affects the
arteries of the aortic arch and
abdominal aorta
• Most common in women 20-30 age
groups
• Acute: associated with fever, malaise
• Results in long segment occlusion or
stenosis of affected arteries
Duplex Imaging-Arterial UE
Application of Knowledge Exercise
• Pt presents with pain and
numbness left arm in specific
positions
• What is potential diagnosis?
• What is most important question
to ask when obtaining patient
history?
• Dual imaging used and you take
this image on symptomatic side.
What does it indicate?
• Which position is most important
for evaluation?
Duplex Imaging-Arterial UE
Application of knowledge
• 45 y/o man presents with digit
ischemia. Hx smoking
• LE duplex ordered and you
obtain this image in area of
PTA.
• What disease does this indicate?
What is disease process creating
appearance of artery?
Duplex Imaging-Arterial UE
Application of knowledge
• Patient presents with decreased
pulses RUE and vertigo.
• Duplex ultrasound ordered and these
two images obtain of subclavian
artery. What does velocity indicate?
What about waveform distal? Is this
normal or abnormal?
• Angiogram ordered to confirm your
ultrasound findings. Do you see
narrowed vessel?
• Considering these findings and
complaint of vertigo, what else should
we consider?
Duplex Imaging-Arterial UE
Application of knowledge
• Patient presents with acute
onset of hand pain and coldness
• Ultrasound arterial duplex
ordered UE and you take this
image radial artery. Note
intraluminal echogenic material
Duplex Imaging-Arterial UE
Continued:
• You obtain Doppler waveform
proximal to area with
intraluminal echoes
• Is this normal?
• What does it indicate?
Duplex Imaging-Arterial UE
Continued:
• You take this image distal to area
of suspicion
• Is waveform normal?
• What additional images are
necessary to complete this
exam?
• What is diagnosis?

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