technique of detecting DVT with ultrasound

1. DEEP VEIN
THROMBOSIS

2. • 30/gentleman
• Hx of tib/fib #
• c/o: pain & slight discharge
fr pin site
• O/E: edema and tenderness
with serosanginous
discharge fr single pin site

3. Differential
• Cellulitis
• OM
• Dependant edema
• Infected hematoma
• Wound complication

4. DVT

5. • Thrombosis in the lower limb
• Frequently diagnosis in ED -frequently missed
• Can cause PE-increased mortality & morbidity
• Ambiguous clinical signs & symptoms-non
sensitive & non specific

6. USG compression technique
• Primary diagnostic modality + clinical
probability + D-dimer
• Non invasive, can be repeated
• Portable
• Lack of complication

7. PROBES
• Linear probe
• B mode image
• Adequate gel
• Adjust TGC and depth

8. USG compression technique
Gold standard:
venogram/contrast venography
Disadvantage:
• Invasive
• Anaphylaxis, contrast
extravasation
• Not available 24H
Other method: ct
venography/MR venography
• Expensive
• Tunnel of death
• Not available 24H

9. USG compression technique
2 point compression test
• Scan only at groin & popliteal fossa
• Easy to perform
Extended compression
• Fr groin till popliteal fossa
• Easy to perform
Complete compression
• Whole LL fr groin till calf
• Time consuming & difficult to identify

10. Evidence : compressing
every inch vs segmental
• Risk of missing segmental DVT (thrombus limited
to one section of the deep vein)
• Studies have shown the sensitivity of abbreviated
approach equal to complete exhaustive
approach, both reaching 100 % for proximal DVT
Birdwell BG; annals of internal medicine 128:1-7, 1998
Poppiti R;JVasc Surg 22:553-557, 1995
Lund F;Angiology 20:155-176, 1996
Heijboer H; N Engl J Med 329:1365-1369, 1993

11. Anatomy

13. Patient position
• Supine
• Hip externally rotated &
slight flexion
• Slight knee flexion

14. Anatomy-popliteal

15. • Leg slightly flexed at
knee
• Place transducer at post
fossa
• Transverse orientation

16. Method 2 PC
• Adequate gel
• Start at CFV at inguinal
region
• At junction CFV,SFV &
DFV aooly gentle & firm
pressure
• Then proceed at popliteal
fossa, locate PV & PA-
gentle pressure
• If you see a clot, trace it
proximally to see the
extent

17. Sonoanatomy
Vein
• Compressible
• Anechoiec
• Thinner wall
• Non pulsatile

18. DVT femoral

19. DVT femoral

20. DVT femoral

21. Popliteal fossa

22. Popliteal fossa

23. Popliteal fossa

24. Common pitfalls
• Challenging subjects
• Confusion on vessel anatomy
• Calf vein dvt
• Pelvic vein dvt
• Mistaking lymph nodes for dvt
• Chronic dvt

25. Upper limb DVT

26. Less common than lower limb
> common in pt with IV lines and malignancy
• Presence of CVL 72%
• Infection 28%
• Extra thoracic malignancy 22%
• Thoracic malignancy 21%
• Renal failure 21%
• Prior LL DVT 18%

27. Clinical features:
• Predisposing factors: IV lines, malignancy
• Arm swelling, pain, heaviness
• Dilated subcutaneous veins
• Upper limbs cyanosis
• asymptomatic

28. Upper limb venous

29. Technique
• Patient is paced supine and place the arm on
bed
• Linear transducer
• Starts at elbow and then upper arm and then
axilla
• Compression scan from basilic and brachial
veins to axillary veins
• Colour Doppler to assess the subclavian and
IJV

30. Normal study

31. u/s is not sensitive for DVT involving SCV –need
other modalities

32. Pulmonary
Embolism

33. • Incidence: 23-69 : 100 000 (in USA)
• CTPA is the method of choice for diagnosis
Disadvantage:
• Not available in some centre
• Unstable hemodynamically to trasnport

34. Criteria
• Normal lung u/s + DVT
• 81% sensitive & 99% specific

35. BLUE protocol

36. DVT

37. THANK YOU