chest radiograph assessment using ABCDEFGHI
ABCDEFGHI can be used to guide a systematic interpretation of chest x-rays.
Assessment of quality / Airway
The quality of the image can be assessed using the mnemonic PIER:
- position: is this a supine AP file? PA? Lateral?
- inspiration: count the posterior ribs. You should see 10 to 11 ribs with a good inspiratory effect
- exposure: well-exposed films have good lung detail and an outline of the spinal column
- rotation: the space between the medial clavicle and the margin of the adjacent vertebrae should be roughly equal to each other; look for indwelling lines or objects
Bones and soft tissues
Scan the bones for symmetry, fractures, osteoporosis, and lesions. Evaluate the soft tissues for foreign bodies, swelling, and subcutaneous air.
Cardiac
Evaluate the heart size: the heart should be <50% of the chest diameter on PA films and <60% on AP films. Check for the heart shape, calcifications, and prosthetic valves.
Diaphragm
Check the hemidiaphragms for position (the right is commonly slightly higher than the left due to the liver) and shape (may be flattened bilaterally in chronic asthma or emphysema, or unilaterally in case of tension pneumothorax or foreign body aspiration). Look below the diaphragm for free gas.
Effusions / Extrathoracic soft tissue
Pleural effusions may be large and obvious or small and subtle. Always check the costophrenic angles for sharpness (blunted angles may indicate small effusions). Check the lateral film for small posterior effusions (more sensitive for small effusions).
Fields, fissures and foreign bodies
Check lungs for infiltrates (interstitial vs. alveolar), masses, consolidation (+/- air bronchograms), pneumothoraces, and vascular markings. Vessels should taper and should be almost invisible at the lung periphery.
Evaluate the major and minor fissures for thickening, fluid or change in position.
Check the position of foreign bodies e.g. ETT, NGT, pacemaker leads, central venous lines etc. Comment on previous surgery e.g. cholecystectomy clips, sternotomy wires.
Great vessels / gastric bubble
Check aortic size and shape and the outlines of pulmonary vessels. The aortic knob should be clearly seen. The gastric bubble should be seen clearly and not displaced.
Hila and mediastinum
Evaluate the hila for lymphadenopathy, calcifications, and masses. The left hilum is normally higher than the right. Check for widening of the mediastinum (which may indicate aortic dissection in the appropriate clinical setting) and tracheal deviation (which may indicate a mass effect, e.g. from large goiter, or tension pneumothorax). In children, be careful not to mistake the thymus for a mass!
Impression
In most cases, an impression is worthwhile as it not only forces you to synthesize all the findings together but acts as a double check.
Related Radiopaedia articles
Chest
- imaging techniques
- chest x-ray
- approach
- adult
- frontal projection
- lateral projection
- lateral decubitus
- congenital heart disease
- medical devices in the thorax
- common lines and tubes
- nasogastric tubes
- endotracheal tubes
- central venous catheters
- pleural catheters
- cardiac conduction devices
- prosthetic heart valve
- review areas
- pediatric
- neonatal
- adult
- airspace opacification
- differential diagnoses of airspace opacification
- lobar consolidation
- atelectasis
- mechanism-based
- morphology-based
- lobar lung collapse
- chest x-ray in the exam setting
- adult chest x-ray in the exam setting
- pediatric chest x-ray in the exam setting
- neonatal chest x-ray in the exam setting
- cardiomediastinal contour
- chest radiograph zones
- tracheal air column
- fissures
- normal chest x-ray appearance of the diaphragm
- nipple shadow
- lines and stripes
- anterior junction line
- posterior junction line
- right paratracheal stripe
- left paratracheal stripe
- posterior tracheal stripe/tracheo-esophageal stripe
- posterior wall of bronchus intermedius
- right paraspinal line
- left paraspinal line
- aortic-pulmonary stripe
- aortopulmonary window
- azygo-esophageal recess
- spaces
- signs
- air bronchogram
- big rib sign
- Chang sign
- Chen sign
- coin lesion
- continuous diaphragm sign
- dense hilum sign
- double contour sign
- egg-on-a-string sign
- extrapleural sign
- finger in glove sign
- flat waist sign
- Fleischner sign
- ginkgo leaf sign
- Golden S sign
- Hampton hump
- haystack sign
- hilum convergence sign
- hilum overlay sign
- Hoffman-Rigler sign
- holly leaf sign
- incomplete border sign
- juxtaphrenic peak sign
- Kirklin sign
- medial stripe sign
- melting ice cube sign
- more black sign
- Naclerio V sign
- Palla sign
- pericardial fat tag sign
- Shmoo sign
- silhouette sign
- snowman sign
- spinnaker sign
- steeple sign
- straight left heart border sign
- third mogul sign
- tram-track sign
- walking man sign
- water bottle sign
- wave sign
- Westermark sign
- approach
- HRCT
- chest x-ray
- airways
- bronchitis
- small airways disease
- bronchiectasis
- broncho-arterial ratio
- related conditions
- differentials by distribution
- narrowing
- tracheal stenosis
- diffuse tracheal narrowing (differential)
- bronchial stenosis
- diffuse airway narrowing (differential)
- tracheal stenosis
- diverticula
- pulmonary edema
- interstitial lung disease (ILD)
- drug-induced interstitial lung disease
- hypersensitivity pneumonitis
- acute hypersensitivity pneumonitis
- subacute hypersensitivity pneumonitis
- chronic hypersensitivity pneumonitis
- etiology
- bird fancier's lung: pigeon fancier's lung
- farmer's lung
- cheese workers' lung
- bagassosis
- mushroom worker’s lung
- malt worker’s lung
- maple bark disease
- hot tub lung
- wine maker’s lung
- woodsman’s disease
- thatched roof lung
- tobacco grower’s lung
- potato riddler’s lung
- summer-type pneumonitis
- dry rot lung
- machine operator’s lung
- humidifier lung
- shower curtain disease
- furrier’s lung
- miller’s lung
- lycoperdonosis
- saxophone lung
- idiopathic interstitial pneumonia (mnemonic)
- acute interstitial pneumonia (AIP)
- cryptogenic organizing pneumonia (COP)
- desquamative interstitial pneumonia (DIP)
- non-specific interstitial pneumonia (NSIP)
- idiopathic pleuroparenchymal fibroelastosis
- lymphoid interstitial pneumonia (LIP)
- respiratory bronchiolitis–associated interstitial lung disease (RB-ILD)
- usual interstitial pneumonia / idiopathic pulmonary fibrosis (UIP/IPF)
- pneumoconioses
- fibrotic
- non-fibrotic
- lung cancer
- non-small-cell lung cancer
- adenocarcinoma
- pre-invasive tumors
- minimally invasive tumors
- invasive tumors
- variants of invasive carcinoma
- described imaging features
- adenosquamous carcinoma
- large cell carcinoma
- primary sarcomatoid carcinoma of the lung
- squamous cell carcinoma
- salivary gland-type tumors
- adenocarcinoma
- pulmonary neuroendocrine tumors
- preinvasive lesions
- lung cancer invasion patterns
- tumor spread through air spaces (STAS)
- presence of non-lepidic patterns such as acinar, papillary, solid, or micropapillary
- myofibroblastic stroma associated with invasive tumor cells
- pleural invasion
- vascular invasion
- tumors by location
- benign neoplasms
- pulmonary metastases
- lung cancer screening
- lung cancer staging
- lung cancer staging
- IASLC (International Association for the Study of Lung Cancer) 8th edition (current)
- IASLC (International Association for the Study of Lung Cancer) 7th edition (superseeded)
- 1996 AJCC-UICC Regional Lymph Node Classification for Lung Cancer Staging
- non-small-cell lung cancer