1. Leg DVT Ultrasound
Caitlin Gardiner

2. The Role of Ultrasound
 To exclude deep vein thrombosis as a cause for pain and swelling in the lower limb
Screening tool in post operative surgery
Known pulmonary embolus, (?location of their embolus) (1)

3. The Principal of DVT US Non compressibility
Filling defects with colour Doppler
Focal tenderness (acute thrombus will be hypoechoic and difficult to see on B-mode without increasing gain)
Hyperechoic lesion within lumen of the vein

4. Probe and Pre-set selection
Mid frequency linear probe (5-8MHZ)
Have access to curvi-linear probe
Low PRF (velocity) colour / power / Doppler settings with low wall filter when assessing veins with low velocity flow (2)
Select the appropriate vascular setting on the US machine

5. Patient Set Up
Supine, erect or seated in a reclined position to allow access to the groin.
Venous distension is useful for assessing calf veins
The patient must remove their pants as scanning commences at the groin (2)
Important to be conservative and profession. A gown or blanket may be helpful
Be conscious that a large amount of the patients are older, post surgery or have limited mobility

6. Anatomy
All images extracted from

7. Common Femoral & (Superficial) Femoral Veins
Patient supine with slight external rotation of affected leg
In transverse, high in the groin crease, locate the CFA & CFV at the sapheno-femoral junction. Compress the vein.
Continue to follow the vein sequentially compressing down to the distal thigh (3)

10. Popliteal vein
Seat the patient on the side of the bed to help dilate the veins for easier visualisation.
Place the probe transversely at the knee crease in the popliteal fossa. Compress the popliteal vein throughout the popliteal fossa (3)

12. Calf Veins Patient still seated on bed
Transversely, with the toe of the probe on the medial edge of the mid tibia, locate the paired posterior tibial and peroneal veins
Assess their compressibility along their length. Alternatively, in longitudinal, use colour Doppler to confirm their patency (3)

14. Basic Hard Copy Images
A leg DVT series should include the following minimum images:
CFV: pre/post compression
Proffunda femoris
SFV proximal TS: pre/post compression
SFV proximal LS: with colour Doppler
SFV distal TS: pre/post compression
SFV distal LS: with colour Doppler
POPV TS: pre/post compression
POPV LS: with colour Doppler
Posterior tibial veins LS colour Doppler
Peroneal veins LS colour Doppler
Sapheno-femoral-junction (1)

15. Differential Diagnosis
Common differential diagnoses identifiable on ultrasound are:
Bakers cyst (semi-membranosis-gastrocnemial bursa) in the medial popliteal fossa.
Superficial venous thrombosis of varices and the long/short saphenous veins.
Calf muscle tears (2,3)

16. Limitations Obese patients, or those with severe oedema
Patients with open wounds/sutures/bandages
Patients with a low pain threshold (2)

17. Thank you

18. References (1) ASUM, 2007. Short Syllabus, DVT. www.asum.com.au
(2) Rumack C, Wilson R, Charboneau W and Levine D, Diagnostic Ultrasound 2-Volume Set, 4th Edition. Mosby.
(3) Thrush A and Hartshorne T, Vascular Ultrasound: How, Why and When, 3e. Churchhill Livingstone.
(4) Weinberg I, DVT Ultrasound Protocol. Vascular Medicine.