Ultrasound Teaching Atlas
Draft — not yet peer-reviewedcoreVascular / Lower extremityDVT

DVT — Common Femoral Vein (Compression)

Two-point compression ultrasound: a vein that does not fully collapse harbors thrombus.

This module is a content/teaching-structure draft. Images shown are illustrative schematics — real, de-identified, license-verified ultrasound clips replace them before peer review.

Learning objectives

  • Identify the common femoral vein and artery at the saphenofemoral junction ('Mickey Mouse' sign).
  • Apply graded compression and recognize complete vs. incomplete vein collapse.
  • Understand the 2-point versus 3-point compression protocol.

Maps to

  • Resident: ACEP Emergency Ultrasound — DVT: Image Acquisition
  • Resident: ACEP Emergency Ultrasound — DVT: Compressibility assessment
  • Tech: ARDMS Vascular Technology (VT) — lower-extremity venous

Acquisition — getting the view

Probe
linear
Patient position
Supine, mild reverse Trendelenburg, leg externally rotated and slightly bent ('frog-leg').
Orientation convention
radiology
Probe placement
Groin, just below the inguinal ligament (common femoral vein)
Marker direction
Indicator to patient's right (transverse / short axis)

Probe placement (3D)

Groin, just below the inguinal ligament (common femoral vein)

Structures in the imaging plane (near → far): Skin / subcutaneous tissue · Common femoral vein (medial) · Common femoral artery (lateral) · Saphenofemoral junction

Step by step

  1. Place the linear probe transverse over the groin to find the common femoral vein and artery side by side.
    Why: At the saphenofemoral junction the vessels form the 'Mickey Mouse' sign.
  2. Compress straight down until the artery just begins to deform. A normal vein collapses completely.
    Why: Incomplete collapse is the key sign of thrombus.
  3. Repeat compression every 1–2 cm down to the femoral vein, then at the popliteal vein (2-point) or add the mid-thigh femoral vein (3-point).
    Why: Tests all the proximal segments where DVT commonly forms.

Troubleshooting

Cannot distinguish vein from artery.
The artery is pulsatile, thicker-walled, and non-compressible; the vein compresses and is usually medial.
Vein is hard to compress in a large leg.
Use two hands (counter-pressure beneath the thigh) or switch to a curvilinear probe for depth.

Findings: normal

Fully compressible vein

With gentle pressure the vein walls coapt completely — no residual lumen — indicating no thrombus.

Schematic of a fully compressible femoral vein
Schematic: vein collapses fully with compression (normal).
Original schematic, dedicated to the public domain (CC0).

Findings: pathology

Deep vein thrombosis

The vein does not compress — the walls fail to coapt. Echogenic intraluminal material may be visible, but acute clot can be anechoic, so rely on non-compressibility.

Signs: Non-compressible vein; Possible echogenic intraluminal thrombus

Schematic of a non-compressible femoral vein with thrombus
Schematic: vein fails to compress — DVT.
Original schematic, dedicated to the public domain (CC0).

Interpretation practice

With firm probe pressure the artery deforms but the adjacent vein walls do not coapt. What does this indicate?

Femoral vein failing to compress under pressure
Vein does not collapse with compression — interpret.
Original schematic, dedicated to the public domain (CC0).

Check your understanding

What is the single most important sign of DVT on compression ultrasound?

Where are the two points assessed in a 2-point compression protocol?

References

Related modules

← All modules