1. Reading Chest Radiographs

2. Basics Anterior-Posterior vs. Posterior-Anterior
AP exaggerates cardiac size
PA requires pt to stand
Look at the whole radiograph
Learn a system - do it the same EVERY time

3. System A-B-C-D-E-F A - Airway/lung fields B - Bones/soft tissue
C - Cardiac/mediastinum
D - Diaphragm
E - Examine Technique
F - Foreign bodies
It doesn’t matter what system you use as long as you do the same thing all the time.

4. Lung Parenchyma Classify disease into 3 categories
Airspace: alveolar filling
fluffy, opacities, air-bronchograms
Interstitial: lines and small dots
reticulonodular, reticular, nodular
Nodule: single or multiple, vary in size, w/ or w/o cavitation/calcification, smooth or irregular

5. Consolidation Filling or loss of air spaces Pus - Pneumonia
Fluid - Pulmonary edema
Blood - infarct, hemorrhage
Foreign body - aspiration
Tumor - bronchoalveolar carcinoma
Volume loss - atelectasis

6. RML atelectasis, lateral shows it well; DDX: PNA, aspiration

7. Consolidation Radiographic signs
Opacity, air bronchograms, silhouetting
Silhouette sign: intrathoracic lesion touching border of heart, aorta, diaphragm obliterating that border
Helps to identify location of consolidation

8. Left Heart
Silhouette sign
Lingular PNA

9. Consolidation Silhouette sign: What structure is silhouetted on PA?
R heart = RML
L heart = lingula
Aorta, diaphragm = Lower lobe
Lateral view: which diaphragm is silhouetted?
Fissure sign: abrupt margin
Increased density of vert. just above diaphragm on lateral

10. Collapse Atelectasis - volume loss
Extrinsic compression (effusion, tumor, etc)
Airway obstruction
Extraluminal - tumor, LAD
Intraluminal - tumor, foreign body
Lobar collapse: mediatstinal shift to affected side, displacement of hilum/fissures, fewer vessels on affected side

11. L lung collapse w/ mediastinal shift; gas under diaphragm

12. CT cut from L lung collapse w/ mediastinal shift

13. L hydroPTx w/ left lung collapse

14. Interstitial Pattern Acute process: Pneumonia - viral, fungal, Tb, PCP
Edema - CHF, Renal failure w/ overload
Drug/Transfusion reaction
Chronic: many etiologies
Normal/low lung volumes

17. Interstitial Pattern Upper lobe predominant
Tb, pneumoconioses, fibrosis from ankylosing spondylitis
Mid lung predominant
sarcoid, berylliosis, allergic alveolitis, eosinophilic granulomatosis
Lower lung predominant
IPF, lymphangitic tumor spread, CVD fibrosis, chronic edema, drug rxn

18. Interstitial Pattern Large Lung volumes: indicates air trapping
Cystic fibrosis
Eosinophilic granulomatosis
Lymhangioleiomyomatosis
Tuberous sclerosis

19. Pulmonary Nodule(s) Solitary Nodule: many etiologies
Primary lung tumor, mets, granuloma, septic emboli, pulmonary AVM, hamartoma, Wegener’s vasculitis, bronchiectasis, fungal infection, etc
Important features
Change over time: growing is worrisome
Calcification: eccentric is worrisome
Size: > 3cm more worrisome

20. Pulmonary Nodule(s) Multiple Nodules Metastatic until proven otherwise
septic/bland emboli
vasculitides, CVD
pneumoconioses
Eosinophilic granulomatosis
Fungi, viral, Tb PNA
Wegener’s
Lymphoma

21. mult. pulmonary nodules

22. mult. pulmonary nodules

23. Cardiac Anatomy Frontal view Right atrium SVC Aortic knob
Left atrial appendage
Left ventricle
Lateral view
Right atrium/Ventricle
Left ventricle
Left atrium
Aortic arch
Main Pulm. Artery
Descending Thoracic Aorta

24. Cardiac Anatomy
On frontal CXR - 45% or less than largest diameter from inner aspect of rib to rib laterally
Right heart border - mostly RA
Left Border - Aortic arch, MPA, LAA, LV

25. cardiomegaly

26. Atrial/Ventricular Hypertropy
Right Atrium - Right border >4cm from center of spine
Right Ventricle - fills retrosternal space >1/3 distance between diaphragm & sternomanubrial joint
Left Atrium - subcarinal angle >90 degrees, posterior deviation of left main stem bronchus
Left Ventricle - LV reaches spine prior to diaphragm

27. Pulmonary Vasculature
Many potential patterns to help narrow differential for cardiac disease
3 you need to know
Normal - lower lobe vessels larger due to gravity, taper smoothly to periphery, interlobar arterial size (11-16mm M, 9- 14mm F)

28. Pulmonary Vasculature
Pulmonary venous hypertension: upper lobe vessels larger “cephalization” result of hypoxic vasoconstriction; dependent edema
LV failure (ASCHD, valvular), atrial myxoma, PVOD
Pulmonary arterial hypertension: “pruning” or rapid tapering of peripheral vessels from large central arteries
Chronic venous HTN, COPD, Chronic PE, vasculitides, Primary PHTN, L-to-R shunt

29. Kerley A line
edema w/ Kerley A lines, perihilar fullness, relative sparing of periphery

30. Mediastinum Several compartments
Anterior: ant. = sternum, post. = pericardium
Middle: ant. = pericardium, post. = trachea
Posterior: ant. = trachea, post. = ribs
Don’t miss a widened mediastinum = could be an aortic aneurysm

31. Mediastinum Masses by compartment Anterior: “4T’s” Teratoma Thymoma
Terrible tumor (lymphoma, mets)
Thyroid - goiter
Middle:
Aortic aneurysm

32. Mediastinum Lymph nodes - Lymphoma/Mets Pericardial/bronchogenic cyst
Posterior:
Aneurysm
Lymph nodes
Neurogenic tumors - ganglion tumor
Spine - osteophyte
Esophagus - paraesophageal hernia
Substernal Thyroid

33. Post. mediastinal mass

34. anterior displacement of trachea

35. Pleural Abnormalities
Effusions: fluid
cc to blunt CP angle on frontal
150cc posterior to blunt CP angle on lateral
Free flowing or not?: obtain bilateral decubital films
Subpulmonic: lateral peaking of diaphragm, loss lung parenchyma below diaphragm

36. Pleural Abnormalities
Pneumothorax: air in pleural space
Apical or “deep sulcus”
Tension: flattened ipsilateral lung on mediastinum
Masses
Angle w/ chest wall is obtuse
Center of Mass
Well defined margin only on 1 side

37. L hydroPTx w/ left lung collapse

38. small bilateral pl. effusion

39. Pleural Abnormalities
Thickening
Focal: unilateral
usually from infection/hemorrhage
Plaque from asbestosis - near
diaphragms
Diffuse: unilateral
Smooth: Old Tb, empyem, hemothorax,
mesothelioma, mets, lymphoma
Nodular: same except Tb