duplex scanning and color flow imaging in venous evaluation

List the 5 reasons why a upper/lower venous exam is performed.

• R/O or identify thrombus

• Better accuracy than other noninvasive techniques in diagnosing calf lesions

• Documents the presence of nonvascular soft tissue masses (Baker’s Cyst)

• Aids in the diagnoses of venous incompetence

• Evaluate for evidence of collaterals

What does ‘R/O’ stand for?

Rule out

Performing a upper/lower venous exam can be done to rule out or identify a thrombus. It can be categorized as…

1. ________ vs. ________

2. _________ vs. ___________

1. Acute vs. Chronic

2. Occlusive vs. Non-occlusive

Describe venous incompetence. (2)

• Valves do not maintain unidirectional flow

• Retrograde flow is occurring

Define collateralization.

Other vessels have formed to bypass occluded vessel

If the sonographer is scanning behind the knee/popliteal area, what pathology is seen here?

Baker’s Cyst

1. What is seen at the question mark?

2. Explain your answer.

1. Occlusive thrombus

2. No blood flow going through

1. What is seen at the question mark?

2. Explain your answer.

1. Non-occlusive thrombus

2. Blood flow is going through

List the 5 reasons why an US exam is useful when assessing the abdominal and pelvis veins.

• Documents the presence of elevated venous pressure

• Identify venous thrombus

• Distinguishes extrinsic from intrinsic compression

• Assessing shunts

• Evaluates liver disease by assessing the portal venous system

What is another term for elevated venous pressure in the MPV?

Portal hypertension

What is a disease process that can cause portal hypertension?

Cirrhosis

1. What structure is seen here?

2. What pathology is seen within it?

1. MPV

2. Thrombus

1. What structure is seen here?

2. What pathology is seen within it?

1. MPV

2. Thrombus

List the 3 limitations for a venous exam.

• Edema

• Recent surgery

• Obesity

What is the gold standard for venous imaging?

Venogram

List the 4 sources of false positive studies for a venous exam.

• Extrinsic compression

• Peripheral arterial disease

• COPD

• Improper doppler angle or probe pressure

List the 2 sources of false negative studies for a venous exam.

• Technically limited

• Proximal obstruction

List a structure for a lower venous exam that can have proximal obstruction.

Iliacs

Based on this image, what did the patient just have?

Surgery

When performing a venous exam, the sonographer should ensure that the vein is identified by the appropriate landmarks such as the…

Accompanying artery

When performing a venous exam, the sonographer will find that the vein lies _______ to the artery.

Medial

In what plane should the vein be visualized to ensure complete compressibility?

Transverse

What is the number 1 way to determine if there’s a thrombus on US?

Compression

Velocity signals should be obtained in the (1)_________ view to maximize the (2)_________________.

1. Sagittal

2. Doppler shift

If the sonographer wants to maximize color fill and flow patterns, what 5 settings should be adjusted?

• Decreasing scale

• Decrease wall filter

• Increase color gain

• Steer color box in the appropriate direction

• Heel toe transducer to optimize angle of insonation

Decreasing scale will help to detect what?

Slow flow

What is another term for ‘heel toeing’ the probe?

Rocking

When the sonographer wants color fill in the vessel, how should the vessel not be on the screen to obtain this?

Straight across

Color box steering is done to change what?

The angle of insonation

1. Is this color box steered in the right or wrong direction?

2. Explain your answer. (2)

1. Right

2. • Small angle

   • Good image

1. Is this color box steered in the right or wrong direction?

2. Explain your answer. (2)

1. Wrong

2. • Moderate angle

   • Flow is not optimal

1. Is this color box steered in the right or wrong direction?

2. Explain your answer. (2)

1. Wrong

2. • Large angle

   • Unusable image

If the sonographer is seeing crazy aliasing and bleed out, what can be done to fix this?

Increase scale

Color flow is not seen here.

The screen reads that velocity scale is at 69 cm/s.

What should be done to correct this issue?

Decrease scale

Color flow is seen well here.

The screen reads that velocity scale is at 30 cm/s.

What should be done to correct this issue?

Nothing, color fills fine

Color aliasing is seen in the portal vein and its branches.

The screen reads that velocity scale is at 2 cm/s.

What should be done to correct this issue?

Increase scale

Adjusting color wall filter will adjust the filter setting displayed on (1)_______ scale ((2)____________ arrow))

1. Color

2. Horizontal

If we are talking about color wall filter, explain why the vessel appears this way. (2)

• Wall filter is too high

• Removing low flow

If we are talking about color wall filter, explain why the vessel appears this way. (2)

• Wall filter is reduced

• Displaying low flow

Color gain is set at 44% and this was seen on US.

Is this an adequate image to have or what should be done to correct it?

No, increase color gain

Color gain is set at 65% and this was seen on US.

Is this an adequate image to have or what should be done to correct it?

Yes, adequate image

Color gain is set at 100% and this was seen on US.

Is this an adequate image to have or what should be done to correct it?

No, decrease color gain

Color gain should eb set as high as possible with the exception of not displaying…

Random color speckles

To facilitate venous filling in the evaluation of a DVT, how should the patient be positioned?

Reverse Trendelenburg

Describe the reverse Trendelenburg position.

When the feet are lower than the head and heart

Why does the sonographer set the patient in a reverse Trendelenburg position for a venous exam?

Allows the legs to fill with more blood

To evaluate for venous reflux, describe how the patient will be positioned? (3)

• Standing

• Extremity evaluated should be in non-weight bearing state

• All weight should be on the contralateral extremity

1. When performing a venous exam, what plane is scanned in first?

2. Explain your answer.

1. Transverse

2. To assess complete compressibility of the vein walls

In the sagittal view of a venous exam, Doppler signals are evaluated for what 3 factors?

• Spontaneity

• Phasicity

• Augmentation with distal compression and proximal release

Proximal release can also be done in the form of what ‘maneuver’?

Valsalva

1. What patient positioning is seen here?

2. The patient in this position is used to evaluate for what pathology?

1. Reverse Trendelenburg

2. DVT

1. Why is this patient standing during the exam?

2. Will the extremity scanned be in a weight bearing or non-weight bearing state?

1. To evaluate for venous reflux

2. Non-weight bearing state

What is the name of the area where the GSV and CFV join together?

Saphenofemoral junction (SFJ)

List the 2 vessels involved in the SFJ.

• GSV

• CFV

Why is the SFJ evaluated carefully?

Because thrombus in a superficial system near the deep system requires more aggressive treatment

Which requires more aggressive treatment?

1. Thrombus in the superficial system near the deep system

2. Thrombus in the superficial system

1. Thrombus in the superficial system near the deep system

At some point, it is difficult to image the femoral vein.

1. Explain why.

2. Explain how this can be maneuvered to improve visualization.

1. Dives deep distally

2. Scanning at the posterior thigh, near the popliteal fossa

1. Where is the sonographer scanning in this image?

2. Will a thrombus here be a cause for concern?

3. If yes, why is that?

1. SFJ

2. Yes

3. Because it’s near the deep system, which can require more aggressive treatment

1. Where is the sonographer scanning in this image?

2. Will a thrombus here be a cause for concern?

3. If yes, why is that?

1. SFV and DFV (Profunda Femoris)

2. Yes

3. Thrombus would be in the deep system

Is the superficial femoral vein apart of the superficial or deep venous system?

Deep venous system

Where does the popliteal vein become the femoral vein?

Adductor Canal/Hunter’s Canal

The femoral vein will become the popliteal vein at what area?

Adductor Canal/Hunter’s Canal

What does the popliteal vein become at the Adductor Canal/Hunter’s Canal?

Femoral vein

List the 2 veins that form the popliteal vein in the calf area?

• ATV

• Tibio-Peroneal Trunk

The ATVs an Tibio-Peroneal trunk come together to form what vessel?

Popliteal vein

What pathology should the sonographer be on the look out for when scanning the popliteal vein? (2)

• Cystic structures

• Masses (Baker’s Cyst)

When we move the probe distally from the popliteal vein, what 2 other veins can we see around the popliteal area?

• Gastrocnemius veins

• Small saphenous vein (SSV)

When scanning in the popliteal area, what should the sonographer carefully evaluate for? (Aside from cystic structures and masses, BE SPECIFIC)

Thrombus where the SSV joins the popliteal vein

The sonographer scans behind the knee and carefully evaluates when the SSV joins the popliteal vein for a thrombus.

Why is that connection important to monitor for thrombus?

Because that’s where the superficial system joins with the deep system

In what area are we scanning to see these vessels?

Behind the knee/Popliteal fossa

The sonographer is scanning behind the knee during a venous exam and stumbles upon this anechoic finding.

What can be assumed here?

Baker’s Cyst

Label the other vessels seen in this image.

1. SSV (small saphenous vein)

2. Lateral Gastrocnemius Vein

3. Medial Gastrocnemius Vein

What is the medial malleolus?

Bone on the medial side of the ankle and achilles tendon

Where should the probe be placed to locate the PTVs?

Between the medial malleolus and achilles tendon

Where can the peroneal veins be located?

A few centimeters up the calf

Which appears ‘deeper’ on US?

1. Peroneal Veins

2. PTVs

1. Peroneal Veins

Label the vessels crossed out on the image.

1. PTVs

2. Peroneal veins

1. Where can we locate the peroneal veins?

2. Which appears more ‘posterior’ on US? PTVs or Peros?

1. Few centimeters up the calf

2. Peroneal Vein

What position is used for examining chronic venous insufficiency?

Standing

List the 2 types of techniques used for a chronic venous insufficiency exam.

• Manual

• Automatic cuff inflator

When performing a chronic venous insufficiency exam, it is important that the leg examined has no…

Weight bearing

During a chronic venous insufficiency exam, while the vein of interest is being imaged and evaluated with spectral analysis, what movement is the patient asked to perform to determine the presence/absence of venous reflux?

Valsalva

On a pulse wave doppler, when a patient performs the Valsalva maneuver, how should the waveform appear?

Halted

1. During a chronic venous insufficiency exam, after the sonographer has had the patient Valsalva, when is then done?

2. What does this observe for?

1. Distal compressions

2. Presence/Absence of reflux with augmentation

List the 2 manual techniques that occurs during a chronic venous insufficiency exam.

With the techniques, explain what is looked for when this technique is performed?

• Valsalva - Presence/Absence of venous reflux

• Distal compression - Presence/absence of reflux with augmentation

The sonographer is performing a chronic venous insufficiency exam. When the sonographer applies distal compressions, this waveform was seen.

1. Describe the appearance of this waveform.

2. This waveform can indicate the presence/absence of…

1. Augmented

2. Reflux

The sonographer is performing a chronic venous insufficiency exam. When the sonographer tells the patient to valsalva, this waveform was seen.

1. Describe the appearance of this waveform.

2. This waveform can indicate the presence/absence of…

1. Halted

2. Venous reflux

For the chronic venous insufficiency exam, the sonographer is using an automatic cuff inflator.

1. What kind of cuff is used?

2. Where is it placed when evaluating the CFV?

1. 12×40 cm

2. High-thigh level

For a chronic venous insufficiency exam, where is the automatic cuff inflator placed to evaluate the popliteal vein and GSV?

Calf level

For a chronic venous insufficiency exam, where is the automatic cuff inflator placed to evaluate the PTVs?

Trans-Metatarsal level

For the chronic venous insufficiency exam using an automatic cuff inflator, the duplex system is used to obtain what 2 things?

• Image

• Waveform

Where should the transducer be placed when using an automatic cuff inflator?

Proximal to the cuff

Because our transducer is placed proximal to the automatic cuff inflator, what other maneuver is it essentially mimicking?

Distal compressions OR Augmentation

For the chronic venous insufficiency exam using automatic cuff inflators, when optimal doppler signals are obtained, what is then done? (2)

• The cuff is inflated to 80 mmHg

• Maintained for 1-2 seconds

For the chronic venous insufficiency exam using automatic cuff inflators, after the cuff has been inflated, it will then deflate by the (1)_________/_______ or manually.

2. What should the sonographer note for after cuff deflation?

1. Auto-inflator/deflator

2. Reversal of venous flow

For the chronic venous insufficiency exam using automatic cuff inflators, after inflation and deflation, if the sonographer notes reversal of venous reflux (flow reversal), what 2 things are measured?

• PSV

• Duration of flow reversal

For the chronic venous insufficiency exam using automatic cuff inflators, when noting the duration of flow reversal, what units will it be recorded in?

Seconds

What exam is being performed here?

Chronic venous insufficiency

How much is the automatic cuff inflator inflated to when evaluating the CFV?

80 mmHg

How much is the automatic cuff inflator inflated to when evaluating the popliteal vein and GSV?

100 mmHg