Compression ultrasound of the legs can detect deep vein thrombosis (DVT). Key sites to compress include the femoral vein in the groin, the femoral vein just above the knee, and the below knee veins which can be visualized from the front of the leg between the tibia and fibula. Compressing the veins and looking for non-compressibility is the gold standard for diagnosing DVT on ultrasound. Scanning multiple sites increases sensitivity but can be more irritating for patients.

1. DVT ultrasound
SAH & RNSH 2011
Critical Care Ultrasound Course
Thanks to Cindy Lucas… and yet again to
Daniel Lichtenstein
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2. DVT
! Anatomy
! Below knee DVT?
! Compression US:
! Technique
! Sites
! What the scan can tell you
! Pitfalls

3. Anatomy of the deep veins

4. Anatomy of the deep veins
Below the knee Above the knee
!Anterior tibial ! Popliteal Vein in popliteal
fossa
!Posterior tibial
! From confluence of 3 calf
!Peroneal veins
!Gastrocnemial ! To adductor canal
!Soleal
! (Superficial) Femoral
! Profunda Femoris joins
4cm below inguinal
!Variable ligament
!Paired ! Common Femoral
!Tricky! ! Long/ great saphenous
!Relevance of DVT?

5. Here’s the problem
It would be nice to scan But it’s hard!
the below knee veins ! Variable
!Incr sensitivity ! Paired
!Incr accuracy ! Tiny
! Tricky
!Variable ! And most of them don’t
ermbolize
!Paired
! (But some do…)
!Tricky!
!Relevance of DVT?

6. Previous top tip: just
look for above knee
Leave the calves to the
sonographers!
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7. But Lichtenstein came up with a solution
! Except for the anterior tibials, the below
knee veins travel all in a line, a couple cm
below the interosseous membrane
! together with their arteries: 2 veins for
each artery = 6 vessels, all lined up
! We can see them from the front of the leg!
! Probe between the tibia & fibula

8. Now we have 2
options
1. Just above knee: leave the
calves to the sonographers!
2. Below knee (anterior
approach)
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9. DVT scan:
Technique
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10. Probe & preset?
! Ideally linear probe / vein preset
! But curved probe / FAST preset works
too
! Don’t need Doppler

11. Compression US
! Probe in transverse position
! Just squash the vein!
! If it squashes easily & completely, there
is no DVT
! If it doesn’t, there’s a DVT

14. Normal veins
! Completely compressible
! Press hard enough to just indent the
artery

15. Features of DVT
! Gold standard sign: vein not completely
compressible
! You might see thrombus
! Vein might fail to augment on Doppler

16. Test
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17. DVT?

18. DVT?

19. DVT?

20. DVT?

21. DVT?

22. DVT?

23. DVT?

24. Compression US
! Pros Cons
! Easy ! Misses external iliac
DVT
! Rapid
! Misses small non-
! B mode only
occlusive DVT
! 98% sensitive

25. Which sites can I compress?
2
3

26. Which sites can I
compress?
! Internal Jugular V
! Subclavian V
! IVC
! Saphenofemoral confluence (up fem)
! Lower (superf) femoral near adductor hiatus
! Long saphenous V
! Short saphenous V
! Popliteal vein & trifurcation
! Beloe knee veins

27. Which sites should I
compress?
! Up to you
! The more veins you scan, the more sensitive
you are… eg UL veins add 4% in PE
! The fewer you scan, the less irritating it is
! 3-point scan is reasonable
1. Upper femoral (confluence)
2. Lower femoral (near adductor hiatus)
3. Popliteal (irritating if supine) …or …below knee
(weird at first)

28. 1: Groin
! Probe in transverse position
! Start just below inguinal ligament
! ‘Mickey Mouse’ sign
! Femoral A
! Saphenofemoral confluence
! Then compress

34. 2: insertion of LSV / GSV

35. 2: insertion of LSV / GSV

36. 3: fem V just above knee
! Adductor hiatus
! Medial to the bone
! Hand behind, presses forward

43. 4: popliteal fossa
! Lie patient on side, or lift leg
! Popliteal vein
! Superficial to popliteal artery
! visualise bone beneath
! follow it to the trifurcation

49. 5: below the knee
! Supine patient
! Probe transverse
! Between tibia & fibula

53. Handy Hints as you go
down the leg
1. Decrease greyscale (dynamic range)
2. Decrease frequency
3. Increase depth as you go
4. Obese: change to curved probe
5. Sit with legs over bed / stand up
6. Valsalva (humming works)
7. Doppler …

54. Pitfalls
! Duplicate venous systems (duplex
popliteal up to 35%)
! Non occlusive thrombus
! LSV, SSV
! Ant tibial veins
! However … ‘90% = 100%’

55. One more time: Handy Hints
! You don’t need Doppler
! You don’t need linear probe
! But you won’t be 100%
! Below-knee isn’t that hard
! Sitting up / standing
! Valsalva (humming works)

56. DVT US: Summary
! Compression US
! Groin
! Just above knee
! Below knee