Upper extremity DVT is less common than lower extremity DVT but clinically important — particularly in patients with central venous catheters, PICC lines, port-a-caths, or those with malignancy. The anatomy is more complex than the legs and the compression technique is different in many areas. Here's a systematic approach.

Indications

Swelling, pain, or redness of the arm
PICC line or central venous catheter in situ (surveillance or symptom evaluation)
Port-a-cath or implanted device with concern for thrombus
Malignancy with hypercoagulable state
Paget-Schroetter syndrome (effort thrombosis — young athletes, repetitive overhead activity)
Pulmonary embolism workup when leg veins are negative

Anatomy Review

Upper extremity veins are more variable than lower extremity. Know these:

Deep veins (followed proximally to distally):

Subclavian vein → axillary vein → brachial veins (paired, run with brachial artery) → radial and ulnar veins

Superficial veins (clinically important):

Cephalic vein (lateral arm, runs to axillary or shoulder level)
Basilic vein (medial arm, joins brachial veins at mid-arm to form axillary)

Central veins (often beyond compression evaluation):

Subclavian → brachiocephalic (innominate) → SVC
These can't be compressed due to overlying bone (clavicle, sternum)

Equipment and Setup

Probe: 5–12 MHz linear transducer. Use the highest frequency that provides adequate depth.

Patient position: Supine with arm slightly abducted, externally rotated, elbow slightly flexed. This puts the vessels in a more accessible position. Turning the head slightly away from the side being scanned opens up the neck/shoulder junction.

Gel: Use enough gel — the vein surface is often superficial and too little gel causes pressure artifact.

Systematic Scanning Approach

1. Internal Jugular Vein

Start here. The IJV may seem outside the "upper extremity," but central catheter thrombus often begins at the IJV insertion.

Transverse plane, high on the neck
Compress: the IJV should collapse completely with light pressure
Assess for intraluminal echogenicity, wall thickening
Document color flow in sagittal plane

2. Subclavian Vein

The subclavian vein runs behind the clavicle and cannot be directly compressed. Use color and spectral Doppler instead.

Infraclavicular approach: probe below the clavicle, angled superiorly
Look for: spontaneous respiratory phasicity (vein gets bigger on inspiration if normal), augmentation with distal compression
Loss of phasicity = upstream obstruction or downstream compression
Evaluate for intraluminal thrombus, catheter artifact

3. Axillary Vein

This is where compression becomes reliable again.

Probe in the axilla, pointing toward the shoulder
Compress in transverse — the vein should fully collapse
The axillary artery is the companion artery — it will not compress (helps you distinguish them)
Color Doppler to confirm patency

4. Brachial Veins

The brachial veins are paired (two veins for one artery) and run the full length of the upper arm medially.

Follow from axilla to antecubital fossa in transverse
Compress every 1–2 cm systematically
The brachial artery will be your landmark (pulsatile, doesn't compress)
Both brachial veins must be evaluated — a thrombus can be in just one

5. Basilic and Cephalic Veins (Superficial)

These are most important in PICC-line patients (PICCs are usually placed in basilic or cephalic veins).

Basilic: Medial surface of the upper arm, becomes deep at mid-arm
Cephalic: Lateral arm, runs to the deltopectoral groove
Follow the catheter from the insertion site proximally — look for surrounding hyperechoic thrombus
If the catheter lumen is visible, assess for mural thrombus along catheter walls

6. Antecubital Veins and Forearm

Extend to the antecubital fossa if the clinical question involves distal clot, PICC insertion site, or peripheral IV.

Basilic and cephalic veins converge in the antecubital fossa
Median cubital vein connects them — often the site of IV blood draws
Follow both veins distally into the forearm if indicated

Compression Technique Notes

Upper extremity compression differs from lower extremity:

Light pressure only — veins are more superficial and the vessels collapse much more easily than leg veins. Heavy pressure collapses the artery before the vein and can compress a DVT, giving a false negative.
Veins that don't compress fully with light pressure = thrombus
Document in transverse: A cine clip of compression is ideal. Still images should show the vein pre- and post-compression.

Color Doppler Evaluation

For areas that can't be compressed (subclavian):

Phasic respiratory variation: normal veins show cyclical enlargement with inspiration
Augmentation: compress distally (squeeze the forearm) and watch for flow augmentation proximally
Absent or dampened phasicity = obstruction between sample site and central circulation
Intraluminal thrombus may partially or completely fill the vessel on color Doppler

PICC Line and Catheter Evaluation

PICC-related thrombosis is a growing problem as central lines become more common.

What to document:

Location of PICC tip (if visible) — ideally at the SVC/right atrial junction
Thrombus: mural vs occlusive, length, echogenicity (acute = hypoechoic, chronic = hyperechoic)
Vein compressibility adjacent to catheter
Surrounding inflammatory changes (perivenous edema)

PICC tip location: You may be able to visualize the catheter tip by scanning from the right supraclavicular window into the IJV/brachiocephalic junction. Not always possible.

Reporting Template

Document for each segment:

Compressibility (fully compressible / partially compressible / non-compressible)
Color flow (present / absent / filling defect)
Spectral waveform (normal phasicity / dampened / absent)
Echogenicity of lumen (anechoic / hypoechoic intraluminal material / hyperechoic)

Report conclusion language:

"No sonographic evidence of DVT in the right upper extremity deep venous system from the subclavian to the brachial veins."
"Occlusive DVT involving the right brachial vein, extending from the axilla to the antecubital fossa. Right cephalic vein patent."
"Non-occlusive mural thrombus along the PICC catheter in the right basilic vein proximally. Distal basilic vein and brachial veins are patent."

Common Pitfalls

Missing the second brachial vein: The brachial veins are paired — always document both.

Compression pressure too heavy: You may compress a DVT into the vessel wall, giving a false negative. Use the minimum pressure that collapses a normal vein.

Confusing the cephalic and basilic veins: Cephalic = lateral arm. Basilic = medial arm. Basilic becomes deep at mid-arm to join the brachial veins.

Not documenting subclavian phasicity: The subclavian can't be compressed, so your only Doppler finding is spectral phasicity and color flow. Don't skip this step.

SonoBuddy's Protocols section includes full step-by-step protocols for venous duplex studies — with key images to capture and report checklist items.

Upper Extremity DVT Ultrasound Protocol: Step-by-Step Guide