Ribs (PA view)

Last revised by Andrew Murphy on 23 Mar 2023

The ribs PA view is a specific projection employed in the assessment of the anterior ribs. Unlike a standard chest radiograph, this projection applies a lower kV higher mAs technique to highlight bony structures.

The PA view specifically focuses on the anterior ribs. The rib series is often considered to be an unnecessary, unjustified projection in many radiology departments. Indeed the Royal College of Radiologists (UK) iRefer guidelines state "Demonstration of a simple rib fracture does not usually alter management but if a complication such as pneumothorax or infection is suspected, chest radiograph would be appropriate" 2. Thus if the projection might change the patient management it may still be considered pertinent and worthy of discussion. 

  • the patient is erect facing the upright image receptor, the superior aspect of the receptor is 5 cm above the shoulder joints
  • the chin is raised as to be out of the image field 
  • shoulders are rotated anteriorly to allow the scapulae to move laterally off the lung fields, and this can be achieved by either:
    • hands placed on the posterior aspect of the hips, elbows partially flexed rolling anterior or
    • hands are placed around the image receptor in a hugging motion with a focus on the lateral movement of the scapulae
  • shoulders are depressed to move the clavicles below the lung apices
  • posteroanterior projection
  • suspended inspiration
  • centering point
  • collimation
    • superiorly 5 cm above the shoulder joint to allow proper visualization of the upper airways
    • inferior to the inferior border of the 12th rib 
    • lateral to the level of the acromioclavicular joints
  • orientation  
    • portrait or landscape 
  • detector size
    • 35 cm x 43 cm or 43 cm x 35 cm
  • exposure
    • 60 - 70 kVp
    • 30 - 40  mAs
  • SID
    • 100 cm
  • grid
    • yes

The entire rib cage should be visible from the 1st to the 12th. 

  • the chin should not be superimposing any structures
  • minimal to no superimposition of the scapulae borders on the lung fields
  • sternoclavicular joints are equal distant apart
  • the clavicle is in the same horizontal plane
  • a minimum of ten posterior ribs is visualized above the diaphragm
  • the ribs and thoracic cage are seen only faintly over the heart
  • clear vascular markings of the lungs should be visible

The isolated referral of a rib series in the assessment of rib trauma is controversial 1 however, still widely used. Ensure the projection is not performed under a chest examination AEC setting, this will not achieve the correct exposure to adequately present the bony structures of the thoracic cage.

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