Pediatric wrist (PA view)

The posteroanterior wrist view for pediatrics is one of three views in order to examine the carpal bones, distal radioulnar joint and metacarpals. 

Indications

This projection demonstrates the wrist joint in its natural anatomical position allowing for evaluation of the distal radius, ulna and carpal bones.

It is useful in diagnosing fractures and localizing foreign bodies in pediatric patients.

Patient position

• patient is either seated alongside the table or supine with arm outstretched
• the affected wrist is placed with palm on the image receptor
• the wrist and elbow should ideally be at shoulder height to demonstrate the radius and ulna correctly

Technical factors

• posteroanterior projection
• centering point
  • midcarpal region
• collimation
  • laterally to the skin margins
  • include the metacarpals superiorly
  • include the distal third of the radius and ulna inferiorly
• orientation
  • portrait
• detector size
  • 18 cm x 24 cm
• exposure ¹
  • 40-52 kVp
  • 2-3 mAs
• SID
  • 100 cm
• grid
  • no

Image technical evaluation

There is only minor superimposition of the metacarpal bases. The articulation between the distal radius and the ulna is open or has little superimposition. The concavity of the metacarpal shafts is equal ². 

Practical points

Preparing the room beforehand (setting up the detector, exposure and preparing lead gowns) is important as pediatric patients may not remain still when their affected wrist is moved onto the detector. 

Immobilization techniques

It is important for the radiograph to be free from motion artifact and rotation to avoid repeated x-rays.

• it may be necessary for the parent or radiographer to hold the patient in position
• ideally the parent should be in the child's direct line of sight
• techniques will vary based on the department
• distraction techniques can be utilized to avoid scattered radiation to parents and staff ³