Faroes Lectures 2019

1. World Federation for Ultrasound
in Medicine & Biology

2. A NEW TECHNIQUE?
 1967 – Series plus animal studies
 63 suspected Pulmonary Emboli, 35 normal, 85
other
 51/55 Confirmed (NMed, autopsy, surgery,
angiogram)

3. DEVELOPMENTS IN THE
LAST 52 YRS
 Ultrasound is routinely used to diagnose pleural
effusions and guide pleural drainage
 Thoracic Ultrasound is not mentioned in the ACR
Appropriateness criteria for
 Acute Respiratory Illness,
 Chronic Dyspnoea,
 Congestive Heart Failure, or
 Dyspnoea- Suspected Cardiac Origin

4. WHY DID WE STOP?
 Assumption that lungs were full of air therefore
ultrasound artifacts will prevent any diagnostic
information
BUT
 Recognition that most diseases extend to the pleural
surface (in some form)
 Artifacts can be diagnostic

5. ARTEFACTS IN LUNG
A Lines
 Horizontal reverberation artefacts
 More prominent in pneumothorax

6. ARTEFACTS IN LUNG

7. ARTEFACTS IN LUNG
B LINES (previously “lung rockets”)
 Vertical short path reverberation artifacts
 From the pleural surfact to the edge of the screen
 Obliterate horizontal reverberation artifacts
 Move with lung sliding
 A few may be normal at the bases
 Can become confluent
 Arise from thickened interlobular septae
 Fluid, fibrosis, etc.

8. ARTEFACTS IN LUNG

9. WHAT TO LOOK AT
 SLIDING
 “LUNG PULSE”
 B LINES
 PLEURAL SURFACE
 PLEURAL EFFUSIONS

10. PNEUMOTHORAX
 Now well established in critical care
 More accurate than supine Xray
 Lung sliding & lung pulse EXCLUDES PTx
 Lung point confirms PTx
 Ref: Blaivis 2008, Kirkpatrick 2004, Dulchavsky 2001

11. PNEUMOTHORAX

12. ALVEOLAR
INTERSTITIAL
SYNDROME
 Defined as > 3 lung B lines (rockets) per area
examined
 Occur in pulmonary oedema, ARDS (ALI), diffuse
parenchymal lung diseases, pulmonary contusion
 Correspond to interstitial thickening (7mm apart) or
ground glass (<3mm apart) on CT from alveolar fluid

13. PULMONARY OEDEMA

14. PULMONARY OEDEMA
 Multiple lung B lines
 Smooth pleural surface
 Normal lung sliding (usually)
 Distribution follows gravity
 B Lines shown to reduce with dialysis in CRF
patients

15. PULMONARY FIBROSIS

16. INTERSTITIAL
PNEUMONITIS

17. INTERSTITIAL
PNEUMONITIS

18. ARDS
 Irregular thickened pleural surface
 Reduced sliding
 Patchy distribution (normal / “spared”areas between)
 Anterior subpleural consolidation
 Shows progression from normal to multiple rockets to
coalescent rockets to consolidation

20. PULMONARY FIBROSIS &
INTERSTITIAL
PNEUMONITIS
 Irregular, fragmented pleural surface
 Reduced sliding
 Distribution depends on cause

21. INTERPRETING THE
ROCKETS IN AIS
 Distinguishing the cause is based upon:
 Pleural surface – smooth or irregular
 Sliding – normal or reduced
 Distribution – gravity or otherwise
 Clinical correlation still important

22. PNEUMONIA
 Dense consolidation
 Hepatization
 Air bronchograms
 Fluid bronchograms (post stenotic pneumonia)
 Reduction or loss of sliding

23. PNEUMONIA

24. PNEUMONIA

25. PNEUMONIA
 Signs with less dense consolidation:
 Irregular pleural line
 Hypoechoic area with irregular edges
 Usually contains bronchograms (air or fluid)
 Reduced lung sliding
 Often surrounded by B lines (“rockets”)
 Pleural fluid or pleural effusion

26. PNEUMONIA

27. PNEUMONIA
 Multiple studies and Meta-analysis
 Usually ED or ICU setting
 Sensitivity 91-100%, Specificity 78-100%
 Positive (+) LR = 11.05, Negative (-) LR = 0.08
 Compared to CXR:
 Sensitivity 38-68%, Specificity 89-95%
 Adults, paediatric and Neonatal studies

28. LUNG ABSCESS

29. LUNG ABSCESS

30. PULMONARY EMBOLUS
 Multiple hypoechoic triangular or round defects
 Well demarcated from surrounding (normal) lung
 unlike infection
 Normal lung movement
 Absence of colour flow from vessels

31. PULMONARY EMBOLUS

32. PULMONARY EMBOLUS
 Prospective study of 352 pts
 Confirmed (2+ lesions),
 Probable (1 lesion & effusion)
 Possible (1 small lesion or effusion)
 Normal
 CTPA gold standard
 Sensitivity 74%, Specificity 95%
 Confirmed + Probable
 For Confirmed: sensitivity = 43%, spec 99%

33. COPD & ASTHMA
 No distinct lung ultrasound signs
 Sliding may be difficult to detect with hyperinflation
or bullae
 Ultrasound Dx is based upon lack of other findings

34. Pleural Effusion
 Fluid in pleural space
 Usually anechoic
 May have echogenic ‘debris’ (protein, fibrin or cells)
 May have septations

35. Pleural Effusion

36. Pleural Mass

37. LEVEL OF EFFICACY
 TEST ATTRIBUTES
 Technical efficacy
 Diagnostic accuracy efficacy
 DECISION MAKING
 Diagnostic thinking efficacy
 Therapeutic efficacy
 HEALTH OUTCOMES
 Patient Outcomes efficacy
 Societal efficacy

38. IMPACT ON DECISION
MAKING AND
THERAPEUTIC EFFECT
 ICU setting
 Increased diagnostic accuracy
 Reduced CT scans
 Lichtenstein and Meziere, Silva et al, Bataille et al
 ED setting
 Earlier Diagnosis
 More accurate diagnosis
 Change management
 Goffi et al, Laursen et al, Zanobetti et al

39. IMPACT ON OUTCOMES
 ED SETTING
 NO Improvement
 Mortality
 Length of stay
 Reduction in other tests

40. LIMITATIONS
 Subcutaneous emphysema prevents evaluation
 PTx can hide pathology beneath (e.g. pulmonary
contusions)
 Overlap of findings in interstitial syndrome
 Utility in mixed disease?

41. CONCLUSION
 Lung Ultrasound can differentiate between different
groups of lung pathologies.
 Lung Ultrasound cannot necessarily give a definite
diagnosis, and interpretation in the clinical setting is
still required.
 The benefits of Ultrasound (portability, rapidity,
repeatability) make it an ideal modality for the
critically unwell, including for diagnosis of lung
disease.
 Evidence of the accuracy and utility is accumulating
 Watch this space