1. Interpretation of Chest Radiographs
UNC Emergency Medicine
Medical Student Lecture Series

2. Objectives The Basics Pattern Recognition Practice!
Approach to interpretation
Anatomy
Interstital disease
Alveolar disease
Pattern Recognition
Practice!

3. Interpretation Use a systematic approach
Use or develop one you like
Use the same approach every time
Describe what you see
Form a differential based on patient presentation and appearance of x-ray
If you find an abnormality, don’t stop there
Finish your systematic reading
The second lesion is often missed

4. Systematic Approach ABCDE Airway (trachea)
Midline v. deviated or rotated, FB in trachea, ET tube position
Bones (clavices, ribs, humeri, etc)
Cardiomediastinal silhoutte
Diaphragms (and the costophrenic angles)
Everything Else (lung fields, soft tissues, tubes, lines, wires, devices, etc)

5. Normal Chest Radiograph

6. Anatomy Trachea Right atrium Left ventricle Aortic knob
Right main stem bronchus
Left main
stem bronchus
Pulmonary
artery
Pulmonary
artery
Right atrium
Left ventricle

7. Anatomy Upper lobes Lingula Right costophrenic angle Stomach
Middle lobe
Lingula
Right costophrenic
angle
Stomach
Left hemidiaphragm
Lower Lobes

8. Upper lobes
Right
middle lobe
Lower lobes
Lingula

9. Common Views PA/Lateral CXR Portable CXR PA Right anterior oblique
Left Lateral AP
Right lateral decubitus
AP supine
Portable CXR

10. These are from the Same Patient
Explain the difference…..

11. PA AP Always get a PA film to avoid cardiac magnification
Exceptions: trauma, active cardiac chest pain,
unstable, unable to cooperate with procedure

12. Silhouette Sign
Two substances of the same density, in direct contact, cannot be differentiated from each other on x-ray
Common locations
Lower lobes-diaphragms
Right heart border – RML
Left heart border – Lingula
Left diaphragm – Heart (on lateral view)

13. Air Bronchogram Sign
Visualization of air in the intrapulmonary bronchi
Abnormal
Denotes a pulmonary lesion/consolidation (excludes a pleural or mediastinal lesion)
Seen in pneumonia, pulmonary edema or pulmonary infarct
Silhouette
sign
An air bronchogram within the heart shadow suggests LLL consolidation

14. Interstitial Lung Disease
The vessels (lung markings) appear more prominent
Alveoli are still aerated
DDx: Pulmonary edema, inflammation, tumor, fibrosis

15. Alveolar Disease Vessels are less visible in the area of disease
Lung is not aerated
May have air bronchograms or silhouette sign
DDx: Bacterial pneumonia, pulmonary edema

16. Let’s Practice What type of film Describe what you see
Consolidation, infiltrate, nodular, diffuse, streaky, opacification
Look for Silhouette sign and air bronchograms
Is it an interstitial or alveolar pattern?
Other findings…
Give differential or diagnosis

17. 75 yo F with hx of MI now presenting with SOB, hypoxia

18. Pulmonary edema

20. Opacification of right hemithorax, obscured left hemidiaphram
DDx: Massive pleural effusion, right pneumonectomy

22. Multiple R sided rib fractures – flail chest

24. Opacification of left hemithorax, air-fluid level in
Air-fluid (cavitary)
lesion
Opacification of left hemithorax, air-fluid level in
left upper lobe, left clavicular fracture
Diagnosis: Left empyema after trauma

25. Same patient
Lateral view
Air-fluid level

26. 48 yo M with hx of PUD presenting with abdominal pain

27. pneumoperitoneum

28. 67 yo smoker with one week of cough, sob, fevers

29. Left lower lobe pneumonia

30. “Spine Sign”

32. Dx: Subcutaneous air in neck and shoulder and pneumomediastinum (left heart border)

34. Is it a tension pneumothorax? Lack of lung markings on
right, collapsed lung
Dx: Complete right
pneumothorax
Is it a tension
pneumothorax?
Collapsed lung

35. NO! Tension Pneumothorax
Mediastinum is shifted to opposite site of pneumothorax
Look at trachea and bronchi
Look at heart
Your patient is unstable or in distress
Absent breath sounds
Respiratory difficulty, hypoxia
Hypotension
Trachea shifted

36. Deep sulcus sign

37. Thank You!
Any Questions?