Chest radiograph

Dr Craig Hacking and Dr Jeremy Jones et al.

The chest radiograph (also known as the chest x-ray or CXR) is the most ubiquitous radiological investigation.

For pediatric chest radiograph see: Chest radiograph (pediatric)

The chest radiograph is performed for a broad content of indications, including but not limited to 1-4:

  • PA view
    • is performed standing and in full inspiration
    • it examines the lungs, bony thoracic cavity, mediastinum and great vessels
    • disadvantages: must be able to stand erect
    • advantages: better visualization of the mediastinum and lungs
  • lateral view
    • performed erect left lateral, labeled with the side closest to the cassette
    • ideal for localization of suspected lung lesions when taken in conjunction with the PA view
    • examines the retrosternal and retrocardiac spaces
    • used to confirm the presence & location of opacities on frontal X-rays
    • salient points
      • gastric bubble is under the left hemidiaphragm; left hemidiaphragm is less distinct due to the cardiac silhouette
      • right hemidiaphragm appears higher and more complete (as the right is closer to the beam)

Other forms of the chest radiographs are performed in a variety of clinical scenarios, usually if the patient is unable to tolerate a standing PA radiograph:

  • AP erect
    • sitting up on the bed; can be performed outside the radiology department, by a mobile x-ray unit
    • disadvantages: mediastinal structures may appear magnified, poorly inspired, rotated; poor inspiration causes crowding of the vessels
    • advantages: better for intubated, sick patients
  • supine
    •  usually for trauma and critical care patients
  • lateral decubitus
    • the patient is laying either left lateral or right lateral on a trolley on top of a radiolucent sponge.
    • the detector is placed landscape posterior to the patient running parallel with the long axis of the thorax.
    • the patient’s hands should be raised to avoid superimposing on the region of interest, legs may be flexed for balance.
    • problem-solving film, used to differentiate pneumothorax vs. pleural effusion; pneumothorax vs. pneumomediastinum.
    • air trapping due to inhaled foreign bodies, and showing and quantifying pleural effusions
  • expiration view
    •  for pneumothorax and air trapping due to inhaled foreign bodies
  • lordotic view
    • demonstrates areas of the lung apices that appear obscured on the PA/AP chest radiographic views
  • right anterior oblique (RAO)/left anterior oblique (LAO) view
    •  for rib fractures and intrathoracic lesions (RAO also used routinely used in barium esophagography)
  • ribs AP view
    • for suspected posterior rib fractures 
  • ribs PA view
    • for suspected anterior rib fractures 
  • sternum lateral view 
    • a lateral projection often used to query fractures or infection
  • sternum oblique view 
    • an RAO projection that is orthogonal to the lateral sternum view 
  • rotation of the frontal projection can markedly affect the appearance of the CXR
    • apparent mediastinal widening
    • tracheal deviation
    • apparent increased thickness of the paratracheal stripes
    • asymmetric lung density
  • supine positioning of the patient will alter the appearance of the CXR
    • enlarge the heart (cardiothoracic ratio)
    • alter the appearance of fluid or gas in the pleural space
      • pneumothorax
      • pleural effusion
    • alter the appearance of fluid in the lung air spaces
      • upper lobe vascular redistribution
      • alveolar fluid distribution

The patient should be asked to remove all clothing and jewelry from the waist up and dress in a hospital gown. Long hair should be worn up.

Chest x-ray
Radiographic views
Share article

Article information

rID: 14511
System: Chest
Section: Radiography
Synonyms or Alternate Spellings:
  • Chest film
  • Chest radiogram
  • Chest roentgenogram
  • CXR
  • Frontal chest radiograph
  • Chest x ray
  • Lateral chest radiograph
  • PA CXR
  • AP CXR
  • Chest x-ray
  • Chest radiographs
  • Chest x-rays
  • Chest Tele-Roentgenogram

Support Radiopaedia and see fewer ads

Cases and figures

  • Case 1: normal PA chest
    Drag here to reorder.
  • Case 2: annotated PA
    Drag here to reorder.
  • Case 3: PA inspiratory
    Drag here to reorder.
  • Case 4: PA expiratory
    Drag here to reorder.
  • PA and lateral ch...
    Case 5: lateral chest
    Drag here to reorder.
  • Case 6: supine
    Drag here to reorder.
  • Case 7: lateral decubitus
    Drag here to reorder.
  • Case 8: normal AP chest radiograph
    Drag here to reorder.
  • Case 9: effect of expiration on the superior mediastinum
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.