Chest X-Ray Interpretation

This guide can be used to interpret a CXR film in a systematic manner

Introduction

We begin by confirming the patient’s details and introducing the CXR Film for presentation.

1. “This is a Chest Radiograph of …” 
2. Check Name and Age. 
3. When was it taken? 
4. What position is the patient in? 
   • Are they standing (erect), prone, supine etc.  

Note: X-Ray is the technique/radiation used during the procedure, not the resulting image. Therefore, you should refer to the resulting image as a Radiograph.

Image Quality – RIPE 

1. Is there Rotation? 
   • Are the clavicles aligned? Are they equally spaced from the spinous processes? 
2. Is there Inspiration? 
   • Are you able to see 5-6 anterior ribs, both costophrenic angles and the lateral rib edges?
3. What is the Projection? 
   • Is it AP or PA? – most are PA 
   • If there is no label, assume it is PA 
4. Is the film adequately Exposed? 
   • Is the left hemidiaphragm visible? 
   • Can you see the spine and vertebrae behind the heart?

Airway – ABCDE Approach 

1. Look for the Trachea 
   • Is it centred or deviated? 
     1. It is normally central or slightly to the right 
   • If it deviates, is it being pulled or pushed to the side? 
     1. Pushed from large pleural effusion/tension pneumothorax
     2. Pulled from consolidation with lobar collapse. 
   • Note: the trachea may appear deviated if the patient was rotated. 
2. Carina & Bronchi 
   • Can you see the carina and bronchi? 
   • Can be used to determine if an NG tube has been placed correctly (ie not in the oesophagus) 
3. Hilum: 
   • Can you see any lymph nodes? 
     • If so, these are enlarged and suggest infection 
   • Are the hilum sizes equal? 
     • Enlargement may be caused by underlying malignancy. 

Breathing – ABCDE Approach 

1. Look at the Lungs: 
   • Divide each into 3 zones (not correlating with lobes) 
   • Compare each zone together. Are there any changes? 
   • Do the lung markings occupy the entire space? 
     1. If there is a lack of markings, suspect pneumothorax. 
   • Is there any consolidation present? 
2. Inspect the Pleura: 
   • Not normally visible, unless thickened 
   • Ensure the lung markings extend all the way to the edges of the lung fields. 
   • If there is black air space outside lung fields, suggests pneumothorax. 
   • If there is increased opacity, it suggests fluid or blood (haemothorax) build-up. 

Cardiac – ABCDE Approach 

1. Assess heart size: 
   • Note: You can only assess heart size on a PA film, as AP films exaggerate heart size. 
   • A normal heart should not occupy more than 50% of thoracic width. 
2. Assess Heart Borders 
   • All borders should be well defined in healthy individuals. 
   • These may be hard to see when lung pathology blocks the view. 
   • Loss of Right border is associated with R Middle lobe consolidation 
   • Loss of Left border is associated with Lingular consolidation. 

Diaphragm – ABCDE Approach 

Note: The right hemi-diaphragm is higher than left in most patients. 

1. On an erect CXR, the diaphragm should be indistinguishable from underlying tissues. 
   • If there is free air in the abdomen, this may be seen 
   • You may be able to see gas within the colon as it passes near the diaphragm. 
2. Costophrenic Angles 
   • The area where the dome of the diaphragm meets the lateral chest walls. 
   • They should be clearly visible and a well-defined angle 
     • Loss of the angle suggests the presence of fluid or consolidation. 
     • A blunt angle can be secondary to lung hyperinflation (such as in COPD). 

Everything Else – ABCDE Approach 

Scan the entire CXR in an ordered approach, starting from the outside 

• Have a look at the bones. 
  • Are there any fractures/lesions? 
• Inspect the soft tissues 
  • Are there any abnormalities (such as haematomas)? 
• Are there any medical instruments? 
  • Can you see any lines (ECG probes, central line)? 
  • Can you see any tubes (an NG tube, is it correctly placed)? 
  • Does the patient have a pacemaker/defibrillator? 
  • Has the patient had any artificial valves inserted? 

Review 

• Ensure you have looked at all areas of the radiograph 

Summarise Core Features/Abnormalities