Assessment of lungs, pleura and airways on chest x-ray (approach)

Described below are points onis one approach to the systematic assessment of airways, lung parenchyma,lungs and pleura on chest radiographsx-ray. Start by assessing the tracheal air column, followed by the lungs and finally the pleural spaces. 

Tracheobronchial tree

• assess position, should be central and deviation can be due to
  • pneumothorax: visceralpositive mass effect, e.g. mediastinal mass, pleural line parallel to the thoracic cavityeffusion, the absence oftenion pneumothorax
  • negative mass effect, e.g. atelectasis, volume loss

Lungs

• assess lung markings (vessels)volume
  • views to exaggerate pneumothoraxincreased: erect CXR in full expiration, lateral decubitus with the suspect side upemphysema
  • on supine filmdecreased: deep sulcus signatelectasis, sharply outlined diaphragm, hyperlucent upper abdomen
  pulmonary fibrosis
  • imposters: scapula margin, clothes, wrinkles, lines/tubing, bullous disease
  • management: < 2cm - observe, > 2cm - aspirate.
• haemo-pneumothorax: air-fluid level, no meniscus visible
• tension pneumothorax: ipsilateral diaphragm depressed, mediastinal contents pushed contralaterally
• pleural effusion: look for the meniscus sign. Collects in the costophrenic angles. If supine - veiling opacity. Empyema can organize into loculations
• apical pleural thickening: focal area of thickening over the apex, can be heavily calcified
• pleural plaques: similar to the density of bone. Common posteriorly & laterally & inferior 1/3 of the thorax. Metastasis - less dense than bone
• assess each lung collapse: opacity with no air bronchograms, negative mass effect (displacement of fissure, hilum, mediastinum, elevation of hemidiaphragm, the decrease in spacing between the ribs)

Pathology:

• central bronchogenic carcinoma and lobar collapse: "golden sign of S"

2. Lung parenchyma

• lobar collapse: opacity with no air bronchogram, negative mass effect with shift of a lung fissure, hilum, hemidiaphragm
• lung collapse: opacity with whiteout, negative mass effect with mediastinal shiftzone individually as well as comparing to the contralateral side
• increased interstitial marking vs. airspace opacification
• consolidation: alveolar pathology ("cloud-like/cotton-candy" shadowing); no volume lossassess for pulmonary nodule/mass, air bronchogram, homogeneous airspace opacity. Clears and/or reticular opacity
  • pulmonary nodules can be mimicked by 6 weeks, if not suspect malignancynipple shadows
• assess pulmonary oedemavasculature
  • enlarged: increased interstitial markings ("too many squiggly lines"); airspace opacificationcongestive heart failure, pulmonary hypertension
  • emphysemadecreased: 1. pulmonary hyperinflationWestermark sign

Pleura

• lung edge sign of pneumothorax
  • if hydropneumothorax an air-fluid level will be present
• abnormal pleural opacification, 2e.g. narrowed mediastinum, 3. prominant pulmonary vessels, 4. Reduced peripheral pulmonary vessels, 5. distance to hila/base
  • pleural effusion: meniscus sign
  • pleural plaque (can be calcified)
  • pleural mass

Pathology: