Pediatric elbow (lateral view)

The lateral elbow view for pediatrics is part of a two view elbow series, examining the distal humerus, proximal radius and ulna.

Indications

The projection is the orthogonal view of the AP elbow allowing for examination of the ulna-trochlear joint, coronoid process, and the olecranon process. Used to assess both the anterior humeral and the radiocapitellar line.

This view is useful in evaluating joint effusions, infections, suspected dislocations or fractures, and localizing foreign bodies in pediatric patients. 

Patient position

• patient is sitting next to the table
• at 90° elbow flexion, the medial border of the palm, forearm and arm are kept in contact with the tabletop
• rotate the hand so the thumb is pointing towards the ceiling, ensuring all aspects of the arm from the wrist to the humerus are in the same horizontal plane

Technical factors

• lateral projection
• centering point
  • lateral epicondyle of the humerus
• collimation
  • superior to distal third of the humerus 
  • inferior to include one-third of the proximal radius and ulna
  • anterior to include the skin margin
  • posterior to skin margin
• orientation  
  • landscape
• detector size
  • 18 cm x 24 cm
• exposure ¹
  • 50-57 kVp
  • 2-3 mAs
• SID
  • 110 cm
• grid
  • no

Image technical evaluation

• there is superimposition of the humeral epicondyles
• there is a superimposed, concentric relationship of the trochlear groove (smallest circle) and the medial lip of the trochlea with the capitellum
• olecranon process is visible in profile
• elbow joint is open; radial tuberosity is superimposed by radius and not demonstrated in profile
• anterior half of the radial head is superimposed over the coronoid process

Practical points

Preparing the room beforehand (setting up the detector, exposure and preparing lead gowns) is extremely beneficial for elbow imaging as young children may begin to cry the moment their affected arm is brought away from their body.

If immediately abducting the patient's arm on to an elevated tabletop is challenging, begin with the arm adducted and rested on a lowered tabletop. Then, slowly begin to raise the tabletop whilst encouraging the patient to abduct until all aspects of their arm are in the same horizontal plane.

To ensure the radial tuberosity is superimposed by the radius and not demonstrated in profile on a lateral image, get patients into a lateral wrist position by instructing them to give you a "thumbs up" gesture and pointing their thumb to the ceiling.

Immobilization techniques

To prevent malrotation/motion artifact in the radiograph, parental holding at the proximal half of the child’s arm and distal half of the forearm may be required.

• if the parent is accompanying the child, whilst the parent puts on a lead gown, it is the radiographer's responsibility to ensure the child does not fall off the chair
• other alternative methods such as distraction techniques may be ideal to avoid scattered radiation to parents and staff ²