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Lesions in apices of Lungs

Common diseases

• Tuberculosis
• Pancoast tumor

Components of Pancoast tumor

• Apical shadow
• Destruction of posterior first and second rib
• Horner's syndrome
• Brachial plexus involvement

In the CXR you cannot recognize Horner's and brachial plexus involvement (sometimes shoulder sags on that side).

You should always take a very close look at ribs for destruction.  If it is present, most likely it is cancer.

LUL atelectasis

• Opacification in left upper lung field
• Signs of loss of lung volume

• Tracheal shift to left
• Left hilum pulled up
• Forward movement of oblique fissure in lateral view (Bowing sign)
• Diaphragm higher
• Proportion of left lung less than usual (45%)
• Smaller hemithorax

Absorptive atelectasis: When there is obstruction to airways (Bronchogenic carcinoma/Bronchoscopy), ventilation to lobe stops, air gets absorbed gradually and the lung becomes atelectatic

 

Pneumothorax

• Air in pleural space/no vascular markings
• Edge of atelectatic lung visible
• Hemithorax larger on right

Relaxation atelectasis: With Pneumothorax the negative pressure in pleural space is lost. Hence there is nothing to hold lung to chest wall. Lung relaxes to atelectatic position. Chest wall relaxes to its resting TLC position, hence larger than opposite side.

Radiological sign for tension

Tracheal shift
Diaphragm being pushed down

Remember you should judge tension primarily by the hemodynamic consequence.

Silouhette sign. Remember the reason we are able to see the Heart margin clearly is because of contrast with air filled lung. Once the lung is atelectatic it becomes a liquid density and the contrast is lost.

 

Multiple diffuse nodules

Granulomatous diseases:

• Miliary TB
• Sarcoidosis
• Histoplasmosis
• Silicosis
• Eosinophilic granuloma

Metastasis from Thyroid

Alveolar cell carcinoma

 

Multiple mass lesions

Whenever you see multiple mass lesions considerations are either the disease process is at the end of vessel or bronchus, as both of them branch and reach lung tissue.

• Vascular
  • Tumor emboli/Metastasis
  • Septic emboli
  • Vasculitis/Wegners granuloma
• Bronchial
  • Aspiration

Tumor emboli are in the interstitum and there is no inflammation, hence the margins of the mass lesions are sharp.

Lung abscess

Any time you see a fluid level in a cavity, the most likely diagnosis is Lung abscess. I am not even going to give you other uncommon causes.

Common segments where aspiration lung abscess occurs

• Axillary subsegment of anterior and posterior RUL segments
• Superior segment of RLL
• Superior segment of LLL

These three segments will account for 85-90% of all aspirated  lung abscesses. This is determined by patients position at the time of aspiration. Gravity determines which segment, the aspirate will end up in. Check out the lesson on Lung abscess. You need to have knowledge of three dimensional view of the bronchial tree to understand why these segments are the site for aspiration Lung abscess.

Lung abscess in an atypical location

Consider the etiology for Lung abscess

• Endobronchial lesion
• Deglutition problem
• Esophageal disease

Diffuse alveolar infiltrates

Radiological Characteristics

• Soft fluffy lesions
• Coalescing lesions
• Air bronchogram
• Butterfly/Medullary distribution
• Cortical distribution
• Alveologram
• Segmental/Lobar density

Etiology of Chronic alveolar infiltrates.

• Alveolar proteinosis
• Alveolar form of Sarcoidosis
• Alveolar form of TB
• Alveolar form of Lymphoma
• Psudolymphoma
• Alveolar cell carcinoma
• Mineral oil aspiration
• Alveolar pattern of metastases
• Desquamative interstitial pneumonia
• Fungal infections

Normal

You should know what a normal CXR looks like and know the variations.
Should be aware of changes due to techniques and development of film.

Bullous Emphysema

Radiological characteristics

• Bullae are harder to recognize and are missed most often.
• Look for avascular regions, hyperlucent areas.
• Lines that do not correspond to known fissures could be walls of blebs.
• Bullae become evident when there is Pneumothorax, look carefully along the pleural surface of atelectatic lung.

Etiology

• In  Emphysema (COPD)
• Bullous emphysema (No airway obstruction)

Mediastinal Lymphadenopathy

Radiological characteristics

• Widening of mediastinum
• Polycyclic margin
• Clear space between heart and the nodal density with Hilar nodes
• Extrapleural sign with Mediastinal nodes
• Obliteration of Silouhette based on location
• Widening of Carina with subcarinal nodes

Common etiology

• Cancer Lung
• Lymphoma
• Granulomatous diseases
  • TB
  • Sarcoidosis
  • Histoplasmosis
  • Silicosis

 Solitary pulmonary nodule

Radiological criteria

• Liquid density
• Distinct margin
• Between 2-5 CMS in diameter
• Oval or round
• no other lesions

 Common lesions that can give you the Solitary pulmonary nodule

• Cancer
• Benign tumor
• Granulomas
• Round Pneumonia
• Rare but with characteristic features
• AV fistula
• Round atelectasis
• Hydatid cyst
• Rheumatoid nodule

Loculated Empyema

• Homogenous density

• Often mistaken for consolidation or Pleural effusion

• Criteria for lobar consolidation or Pleural effusion not met

• Lines not corresponding to fissures

• lateral view most helpful

Inlet to outlet sign:

Structures traversing from inlet to outlet of Thorax

• Aorta on left
• Esophagus on right
• Thoracic duct (but it is never large enough to be radiologically visible)

Radiological Characteristics

• Inlet to outlet shadow
• Widening of mediastinum
• Inhomogeneity of cardiac density

Etiology

• Left side
  • Dissecting Aneurysm of Aorta (The wavy margins is suggestive of dissection of Aorta)
• Right side
  • Right sided Aortic arch
  • Achalasia of Esophagus